# Knurling advice



## Maplehead

i am trying to knurl a 1/4" wide brass rod. Have tried on 34" aluminum as well. I set up on my Grizxly micro lathe but I leave the lathe off and instead hand turn the chuck. I am using the littlemachineshop clamp knurling tool. I am using the light knurls. (I prefer the coarse knurls but they won't work at all.) my method is to place the knurls over the widest part of the rod, clamp down tight enough to grip, turn one rotation and then continue to tighten and turn. Two things keep happening: the tool angles of perpendicular of the rod and the pattern is messy and never that deep.
Any advice on how to do this better is greatly appreciated.


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## catsparadise

If the knurler is like the Large Capacity 1911 one on the LMS site then it's similar to the one I have for my mini-lathe which I get good results with.
My method is as follows. Turn the circumference of the work to close to an integral number of knurler tooth pitches (mine has an 0.8mm pitch, so a 14mm diameter is approx 55 pitches and works well). Fit the knurler in the toolpost and make sure the wheels are perpendicular to the lathe axis and the toolpost and tool fixings are tight. Bring the two wheels into contact with the work so they're diametrically opposite one another. Tighten the nut until the wheels touch the work, then give it another 1/2 turn tighter. Oil the wheels/work liberally. Turn on the lathe at a slow speed and move the carriage along the work to produce the length of knurl required. At this point I tend to give the knurler another 1/4 turn tighter and feed back to where I started from. Stop the lathe, loosen the knurler and admire your handiwork! Works OK in EN8 steel for me, so should be good in Al / brass.

Hope this helps.
Rob


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## Alan H.

Yeap, be sure you are considering the knurl pitch and the diameter of the piece.  

There are many calculators out there.  Take a look at this google search.


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## Maplehead

Hi Rob
Thanks for the reply.
Technically I do not need to move the carriage as I am only knurling a 1/8" portion of the brass rod. The rest of the rod on either side of the knurl gets turned down to .112". The knurled portion is for finger gripping to turn what eventually is essentially a "screw".
I'm assuming the numbers you are running up there is to make sure the knurl lines don't get too messy. I'm not even at that stage of detail or quality yet. I can't get the teeth to cut in enough to really feel the knurl.
And yes, I have the same knurler as you.


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## Maplehead

Running these numbers is for making a quality knurl? One that doesn't have overlapping?
Is that what that's all about?


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## Alan H.

Yes, knurling displaces material therefore you need to track in the same grooves to get it to work.   Once you get a set of grooves started it helps the tracking/displacing process.   Otherwise it makes a mess.


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## chips&more

Welcome, I have been knurling for 50 years and have NEVER done any math calculations. I realize/understand the reasoning about using math but the knurl comes out beautiful without the math for me. I use the scissor type. I DO NOT start on top the project sight. I start off at one edge and guess on how much scissor to apply (can be tweaked latter). Then feed across with lubricant. Do not let the knurls ride too long in the same spot. Get the knurl done and get out. Flooding with coolant would be a good thing. The longer you knurl in one spot the worst it gets because chips with get embedded in your knurl...Good Luck


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## rgray

I have that knurler also from LMS. Mine was very low quality. The top nut stripped out, the arms became floppy loose.
So here is how I abused it...Put it on your stock and run the nut down till it contacts the work, then back the cross slide back and turn the nut down some more then advance it into the work with the cross slide with the lathe running. If the knurl is not deep enough repeat that process.
Have to be careful with small stock that can bend using this method, or support the end with a center.


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## Maplehead

Thanks chips&more
My knurling needs require knurl patterns that are narrower than the knurling wheel itself, so I don't carriage slide the knurler.
Given your thoughts above, should I be doing this knurl in only one rotation?
On another knurling question, since I am hand turning the chuck, lathe torque seems to not be of matter here.
I am assuming that the torque of the lathe is not what allows the depth of bite from the knurl but instead the ability to turn the rod under the biting knurl.
My other question here is can you get a good bite depth on these little clamp knurlers? 
Is it all about how much I turn that clamp wheel?


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## Maplehead

Hi rgray
Yeah, I'm not overly impressed with that tool. Mine has a lot of lateral play in it. Plus, those little C clips stink.


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## rgray

Maplehead said:


> I'm not overly impressed with that tool



I think it was a good tool that had it's production end up in china ruining it's quality.
Another thought I had....are you using 1/2 hard brass... I always took this for granted until I ran into some hard brass and wow is it different and would probably be impossible to knurl.


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## Maplehead

It's c360 brass


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## T Bredehoft

I go along with tightening the nut off the work then advancing the tool until just before top dead center. 
If the knurl is not neat/good, back off and tighten a bit more. With the lathe running slowly, it may take a number of repeats to get a good pattern. One rev might work for marshmallows, but not metal. I learned  yesterday that I can't knurl plastic. It simply won't take a pattern. 
Keep doing this until you get a good knurl.
If the work is too light to do this, knurl it before turning the smaller diameters.


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## Maplehead

Hi Tom
I'm definitely knurling first since after turning the diameter is only .112". The rod just deflects out of the chuck in that case, or breaks.
I thought the whole point of a clamp knurler is to relieve the side pressure?
I am not running the lathe while knurling as I don't have the torque to do so. I am hand cranking the chuck.
I guess I'll practice all the suggestions here tonight, but it just seems to me that I cannot get the knurls to bite enough into the rod. I'm not a weak person either so I can tighten that tool up pretty good. But one thing that happens when I do is either the knurler or the rod begins to go astray.I think if I had a chuck on the tail stock that spun then I would be able to accomplish a lot more.
Anyways, thanks for the reply.
If anybody can give me some love on my other post below, that'd be nice too.


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## wildo

Maplehead said:


> ...but it just seems to me that I cannot get the knurls to bite enough into the rod. I'm not a weak person either so I can tighten that tool up pretty good.



I'm no expert, in fact I've knurled exactly two times ever. However, this comment seems odd to me. Just eliminating some obvious stuff:

Are you sure your clamp-type knurl tool isn't bottomed out? That is, are you sure the clamp closes tighter than the diameter of your work?
Are you cleaning out the knurl wheels such that they are not full of chips? Like a file needs a file card to clean out the serrations, I think a knurl wheel can get filled with chips. Just recently I learned that Tapmatic #1 Gold is a very good lubricant for knurling on brass and keeping the knurl wheels clean.
https://www.amazon.com/gp/product/B00065VG0M/


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## chips&more

T Bredehoft said:


> I go along with tightening the nut off the work then advancing the tool until just before top dead center.
> If the knurl is not neat/good, back off and tighten a bit more. With the lathe running slowly, it may take a number of repeats to get a good pattern. One rev might work for marshmallows, but not metal. I learned  yesterday that I can't knurl plastic. It simply won't take a pattern.
> Keep doing this until you get a good knurl.
> If the work is too light to do this, knurl it before turning the smaller diameters.


I hear you on trying to knurl different types of material. And trying to get the definitive “sharp” pointed diamond pattern my not be possible or not wanted. I say not wanted because that sharp point pattern can hurt the fingers and that may not be desirable for the application. Using reverse pattern knurlers is a good option. Sometimes just a light knurling pass is good enough, doesn’t hurt the fingers and the material is still happy about taking the pattern.


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## Maplehead

I bet the knurls could use a good cleaning at this point.
I actually would rather not be diamond knurling but instead I'd rather be using the straight coarse knurl. However, I couldn't get any bite on that.


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## mikey

Maplehead said:


> Two things keep happening: _the tool angles of perpendicular of the rod_ and the pattern is messy and never that deep.
> Any advice on how to do this better is greatly appreciated.



I'm not sure what the comment on tool angles means. I am also not familiar with that knurler; I can tell you that if the arms of your knurler can move a lot side to side then that is part of the problem. Knurling creates a LOT of force and in this type of knurler, almost all of that force is born by the arm joints. If those arms are moving a lot then you cannot expect the knurler to produce a good pattern.

First issue is that you're knurling thin diameter stock; it can bend and move under the force of the knurlers. If the fit of the knurling wheels on one or both of the axles is really loose then the wheels can move forward or back of the centerline and this will cause the work piece to move as well. There goes your pattern. Try to be sure the knurls are perpendicular to the work or even a few degrees toward the chuck; they will track better and also not pull the work out of the chuck.

Its difficult to troubleshoot an issue like this. I'll tell you how I would do this and maybe that might give you some insight.

I would skim cut the stock to get any skin of of it. Quite often, the surface will be much harder than the underlying material due to compacting during the forming process. I don't bother with calculating diameters in most cases unless the knurls need to be a particular diameter. There are times when a knurl must be of a specific diameter to provide an adequate fit in a hole; then calculations matter. Any other time, I just knurl it as it lies.

I always chamfer the end of the work so my knurls have a ramp to access the work. My knurls have a chamfered edge to enable axial running (I can feed them down the work piece) and they like a ramp; some knurls have a convex shape to do the same thing.

I place 1/2 - 3/4 of the knurl on the end of the work and bring it into contact, then give it a 1/4 turn. This is enough to emboss a pattern that I can see. Then I rotate the work two turns to make sure the pattern tracks. Much of the time, it doesn't track. If so, I increase pressure until it does track. Once it tracks, I increase pressure to create the knurl pattern I want, either full or partial depth. Then I power feed it the length I need. Some materials, like brass, can be done in several passes if you wish. For materials that work harden, like stainless steel, it is best to create a full depth knurl in one pass. This is not something you can do by hand; you need to do it under power with the lathe turning and the power feed engaged.

If I have to put a knurl in the middle of the work piece then I just move the knurls into position and slowly increase pressure until I get the pattern I need and knurl normally from there.

Just about all materials will flake some if you dwell and brass is particularly notable for this. It is best to run it in and out under power and use either compressed air or a wire brush. I use lubricant for most things but not brass; it seems to just gum things up so I prefer compressed air to clear the flakes and it seems to work well for me.

Most of the problems with knurling are the result of insufficient pressure on the knurls. You are displacing material; you are not cutting it unless you're using a cut knurler. You need to apply enough pressure to get the pattern you need and it helps to look at the preliminary pattern under magnification to be sure the peaks are sharp (or not sharp if going for a partial pattern) before you do an axial run.

Once your knurl is done, use a wire brush and clear the flakes. If the pattern is too sharp, use a file and skim cut the points off. Air works to clear the debris. Then you can work the rest of the piece or dress the edges of the knurl or whatever.

Hope this helps. Maybe Darkzero will chime in here - he does beautiful work.


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## Wreck™Wreck

Knurl it under power, for .25 diameter 500 RPM's or so, run the tool to X .0 as fast as possible then feed axially at .006-012 IPR depending on material.
Use a coolant nozzle for each knurl.

I can not stress this enough, hit the part with the tool as fast as possible, this will reduce double tracking.

A test before running the 16 actual parts, 1/2" Dia. 304 stainless , 16 pitch knurls, 375 RPM's, .050 IPR in feed to 0 in X and .008 IPR feed for 3 inches worked a charm. One end held in soft jaws and the other with a live center using an Eagle Rock scissor tool. I have to knurl several times per month, I hate knurling only slightly less then tapered pipe threads.


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## rgray

I have a cut knurler that really takes the stress out of it. especially for little parts. 
it's from a Brown & Sharpe screw machine....will do up to 3/4 but only the end of a shaft and only for about 1/2" in length.
It can do up to 3/8" for any length you can hold as small sizes will pass through the body.


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## Maplehead

I think my little micro lathe just doesn't have the strength to knurl.
The motor stops on pressure and even the tool cross slide moved a bit when I hunkered down.
The pic shows about the best I can get.


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## francist

You might try reducing the diameter on either side of the area you want to knurl. I know you don't want to go full depth because of the increased flex potential, but reducing it just enough to get your knurling done might help. Then go back and turn it down to the 1/8" or so finished diameter like you were going to. More setups, I know, but it might get you your knurl.

-frank


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## mikey

Maplehead said:


> I think my little micro lathe just doesn't have the strength to knurl.
> The motor stops on pressure and even the tool cross slide moved a bit when I hunkered down.
> The pic shows about the best I can get.



Which lathe are you using?


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## darkzero

Try practicing on aluminum. It's soft & very forgiving & will also give you an idea if it really is your lathe that is not able to handle it. I did some knurling on my old 8x14 & it did ok.

I mainly knurl Ti 6-4, SS, & brass. If you don't calculate diameters for hard materials you will more than often than not get double tracking. I hate double tracking! I hate bump knurlers. I use an Eagle Rock K1-44 HD scissor knurl, cobalt convex wheels, carbide rolls pins, yada yada. I won't get get into all the details on how I knurl cause it won't apply here. I just wanted to say that I almost always calculate diameters when knurling, except on aluminum cause it's so soft you can get away with it.

With hard materials, I knurl so I complete the form in one pass only whether it be a full form or partial form knurl, otherwise you'll get flaking. I flood the knurling wheels with lube generously as well. Try knurling Ti without calculating diameters & it will almost be guaranteed to look like crap.

Here's my knurling on Ti 6-4


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## mikey

Show off!

Toldja' Will will impress ...


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## woodchucker

Nice Will. What kind of knurl is that 3rd pic with the spiral knurls.


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## darkzero

mikey said:


> Show off!
> 
> Toldja' Will will impress ...



Um, I wasn't trying to. 



woochucker said:


> Nice Will. What kind of knurl is that 3rd pic with the spiral knurls.



I hear some people call it spiral knurling (easier I guess) but I think the proper term is single diagonal knurling, at least that what I call it. For diamond knurling you use LH & RH knurling wheels. For the single diagonal knurling both knurling wheels will be the same direction, 2 LH or 2 RH, doesn't matter. Or if you're using a bump knurler you can just one wheel but again I don't like bump knurlers, well my lathe doesn't like them much either.


Here's a pic of when I was knurling that Ti spear. I had to use a follow rest when knurling it.






One of these blanks turned into this (I didn't make the light, just did the knurling for Fred)






Here's a Ti ice pick that I made for Matt at QMT (Precision Matthews)







Sorry for the thread hijack, back to knurling, lets help the OP get some good knurls!


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## darkzero

Here's the calculator that I used to use: http://littlemachineshop.com/reference/knurler.php

Well I still use it sort of, my lil brother made me an app for my phone with a bunch of calculators that I use often all put into one app.

Attached is the Excel spreadsheet version


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## Maplehead

I'm using a Grizzly G0745 4x6 micro lathe.
Will, those knurls are exceptionally good.
I'm still confused about the math approach. As you can see in my pic my knurls are just under 1/8" wide. The knurling wheels are wider. So guven that I have zero need to move the wheels axially. So what's the point of the math? As I see it, I only have two options, make only one rotation of the brass rod or multiple rotations. The knurling tool and rod stay put along the length(axially?).


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## darkzero

Maplehead said:


> I'm using a Grizzly G0745 4x6 micro lathe.
> Will, those knurls are exceptionally good.
> I'm still confused about the math approach. As you can see in my pic my knurls are just under 1/8" wide. The knurling wheels are wider. So guven that I have zero need to move the wheels axially. So what's the point of the math? As I see it, I only have two options, make only one rotation of the brass rod or multiple rotations. The knurling tool and rod stay put along the length(axially?).



Thanks.

Calculating diameters has nothing to do with traversing. It's for calculating the starting workpiece diameter to match the pitch (teeth per inch) of the knurling wheels so you get an even amount of "lines" cut in the circumference of the round stock. In other words to prevent double tracking.

With softer materials & form knurling, you can get away without calculating diameters cause you can just increase the feed of the knurling tool to eventually form the knurl until it gets proper tracking. With harder materials, a partial form knurl, or cut knurling you can't do that.

A 4x6 is not very rigid. It might not be able to handle a full form knurl (full pointed peaks) on a dense material like brass. Try with aluminum or delrin to see what happens. Looking at your pic, you should be able to do at least a partial profile knurl (flat peaks or just the diamond pattern) but you have to calculate to prevent double tracking.


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## woodchucker

It's math for the diameter. So you get nice crisp knurls


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## JohnnyTK

darkzero said:


> Um, I wasn't trying to.
> 
> 
> 
> I hear some people call it spiral knurling (easier I guess) but I think the proper term is single diagonal knurling, at least that what I call it. For diamond knurling you use LH & RH knurling wheels. For the single diagonal knurling both knurling wheels will be the same direction, 2 LH or 2 RH, doesn't matter. Or if you're using a bump knurler you can just one wheel but again I don't like bump knurlers, well my lathe doesn't like them much either.
> 
> 
> Here's a pic of when I was knurling that Ti spear. I had to use a follow rest when knurling it.
> 
> 
> 
> 
> 
> 
> 
> One of these blanks turned into this (I didn't make the light, just did the knurling for Fred)
> 
> 
> 
> 
> 
> 
> Here's a Ti ice pick that I made for Matt at QMT (Precision Matthews)
> 
> 
> 
> 
> 
> 
> 
> Sorry for the thread hijack, back to knurling, lets help the OP get some good knurls!



How did you do the bluing on the knurls?

Tks.


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## mikey

Took a look at the Grizzy Micro-lathe and it has a 1/5hp motor so now its clear why you can't use power to knurl with. You might have some success with a partial form straight knurl in aluminum; they require less pressure to form a pattern vs a diamond.

I don't know what your plans are but you might want to keep an eye out for a used Sherline lathe. The standard length bed is bigger than yours and it has the equivalent of a 1/2hp motor on it. It will knurl without any problems at all.


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## darkzero

JohnnyTK said:


> How did you do the bluing on the knurls?
> 
> Tks.



I anodized the titanium.


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## mikey

I looked at the Boston area CL and saw this for sale in Needham, MA: https://worcester.craigslist.org/tls/6046805625.html

I would be on this in a heartbeat, even if I didn't need it. Complete machine shop for 3K!


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## Maplehead

Mike, does it need to be under power?
When I do it I just turn the chuck by hand.
Speed isn't an issue is it?

I ran the calculator for a .375" brass rod using a 33 LPI knurl and I get .367. So as I am to understand this, I should turn the rod down to .367" and then the knurl pattern should fall into place upon a full rod rotation. This is assuming the clamp doesn't start wandering diagonally off as it does.


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## Maplehead

mikey said:


> I looked at the Boston area CL and saw this for sale in Needham, MA: https://worcester.craigslist.org/tls/6046805625.html
> 
> I would be on this in a heartbeat, even if I didn't need it. Complete machine shop for 3K!



If I only had the money. And that's not even the saddest part. I make guitars on the side and I just started getting into making the hardware for my guitars, hence the machining. Just a few years ago I could have had ten times or more that amount of high end machinery since my father-in-law, a very generous guy and somebody I was close with, bought and sold machinery. He sold into the hundreds of thousands every year and bought up little shops like this ad shows with his pocket change. He used to tell me, "anything you want". Sadly he's incapacitated in a nursing home now.
My guitars are unique in that the wood is joined on curves. Pictured is not inlays but maple and walnut joined on curves.


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## darkzero

Maplehead said:


> Mike, does it need to be under power?
> When I do it I just turn the chuck by hand.
> Speed isn't an issue is it?
> 
> I ran the calculator for a .375" brass rod using a 33 LPI knurl and I get .367. So as I am to understand this, I should turn the rod down to .367" and then the knurl pattern should fall into place upon a full rod rotation. This is assuming the clamp doesn't start wandering diagonally off as it does.


I pretty much always knurl under power. But if you just want a single band of partial profile knurl then turning the spindle by hand is ok.

For your dia & wheel pitch it is .3665". Don't have to hit that mark but if you still get double tracking shoot for a thou or 2 over for hard or dense materials. You'll run into inconsistencies depending on the quality of the knurling wheels & how much slop your mounting pins might have. You'll have to figure out how your tool & wheels perform if you do. Quality wheels matter. I personally won't even bother with the cheap stuff. I only use Accu-Trak wheels.


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## Maplehead

I doubt mine is quality. What I don't like about it is that it has lateral play and that play seems to get it to start diagonally drifting off the rod.


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## mikey

No, it doesn't have to be under power, and speed is not an issue in your case.

Ideally, a calculator should give you the OD you need so that a full pattern knurl will produce a knurled OD of a predictable size. It is the finished knurl size that matters, not whether the knurls will track and this is a point of confusion for a lot of folks. Typically, parts with knurls must fit into a hole of a specific size so that the knurl will resist the pulling forces the part is expected to experience. There are tolerances for these kinds of fit and the calculators are intended to help you figure out how to produce parts that fall within those tolerances. 

I've seen discussions about the math behind the calculators and spreadsheets and this is all theory, in my opinion. I tried many times to get it to work for me (so that my wheels track) and sometimes it works, sometimes it doesn't. Most often, it doesn't so I've learned to just increase pressure until the wheels track and they do. The only time I use a calculator is in the above situation, where I need a knurl of a specific size to fit in a specific hole to provide a specific fit; this is a rare thing in my little shop. 

So, to answer your question. If you turn the starting OD to 0.367" then theoretically, it might allow the wheels to track. 

Then again, it might not.


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## mikey

Maplehead said:


> If I only had the money. And that's not even the saddest part. I make guitars on the side and I just started getting into making the hardware for my guitars, hence the machining. Just a few years ago I could have had ten times or more that amount of high end machinery since my father-in-law, a very generous guy and somebody I was close with, bought and sold machinery. He sold into the hundreds of thousands every year and bought up little shops like this ad shows with his pocket change. He used to tell me, "anything you want". Sadly he's incapacitated in a nursing home now.
> My guitars are unique in that the wood is joined on curves. Pictured is not inlays but maple and walnut joined on curves.



Beautiful work! I admire guys who can create objects of beauty like that.

Sorry about your father in law. Hell of a place to be for a machine guy, I think. Personally, when its my time to go I hope I drop dead in front of my lathe.


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## Maplehead

Thanks, yeah his life is a living hell right now.
His old company use to turn the axles for the Trident submarines. Talk about a lathe.


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## mikey

Maplehead said:


> Thanks, yeah his life is a living hell right now.
> His old company use to turn the axles for the Trident submarines. Talk about a lathe.



Next time you see him, tell him someone on the forums wishes him well.


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## David S

Maplehead I have a small Atlas 618 lathe and I have the scissors style knurler.  It has a knob on it similar to yours but I wasn't able to get enough pressure on it.  So I drilled some radial holes in the knob so that I could use a tommy bar and really crank on it.  I make sure the knurls are dead top and bottom, then crank them down till they touch firmly and then give it another good crank  quarter to half turn with the tommy bars, and keep cranking down as I rotate the chuck.  I often do as you do with just hand turning the chuck.  In brass I needed much more force than I could muster up with just the knob alone.

David


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## Maplehead

Good to know David. Thanks.
Part of this as a beginner is learning how much something really needs. One of my issues is the tool not staying straight when I crank it down. Last night I made a t slot nut and block to sit aside my tool post on my cross slide to keep it from turning. It's reaction was to just turn the other way, away from the support block.


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## David S

Yes Maple head my scissors type is of poor quality.  I had to modify it.  But the big improvement was being able to really crank it down.

David


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## mikey

You can also use a hand knurler and this might be the best option for you. Eagle Rock makes some of the best knurling tools around and they also produce a hand knurler. Here is one on ebay for a not bad price: http://www.ebay.com/itm/EAGLE-ROCK-...261101?hash=item1c3eb6f1ad:g:vlEAAOSwcUBYUBy2


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## brino

mikey said:


> It is the finished knurl size that matters, not whether the knurls will track and this is a point of confusion for a lot of folks.



What?!?!
Mikey can you explain this a bit. I was following this thread right up to that statement.

I have NEVER cared about the finished size of a knurled section. For me they are only handles and if it's 10thou bigger or smaller, my hand will never notice. I ONLY care about the tracking. I hate the double track and consider that a scrapped piece.

I tend to agree with Will here:



darkzero said:


> It's for calculating the starting workpiece diameter to match the pitch (teeth per inch) of the knurling wheels so you get an even amount of "lines" cut in the circumference of the round stock. In other words to prevent double tracking.



Aren't you saying the opposite?

-brino


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## mikey

Let me come at your question this way. Way back when I started to knurl stuff, I used calculators because I thought it would tell me the OD I needed to get my wheels to track. The documentation of the calculator I used then said so, and since it was all based on math and tpi and helix angles I thought it had to be right. I calculated and turned, calculated and turned and still couldn't get my wheels to track. I even did as the documentation said; turn down a few thou and try again, and again and again and still had poor tracking. 

So, I called (back then, email wasn't common) Form-Rol, the guys who make the knurls I used at the time, and asked them how the heck do I figure out the OD needed to get the wheels to track. The response I got was surprise! The tech guy told me that the calculations are intended to give me the OD needed to bring the knurl to the expected size when a full pattern was formed so that my part would fit properly. I said I just wanted the wheels to track and I didn't care about the size of the knurl. He told me, "... just increase pressure." 

My experience since that time has led me to agree with tech guy. If I want the wheels to track, I crank down on the arms and the wheels track. So now the only time I calculate is if I need a specific fit. I turn the work to the calculated OD and then I crank in the pressure needed to produce a full pattern knurl and check for fit.

Don't take my word for it; try prepping a blank and increase pressure on the knurls. They will track. For materials that work harden you need to get it to full depth or whatever depth you need and cut it in a single pass. I do this for stainless all the time ... but I don't calculate.


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## brino

mikey said:


> Don't take my word for it; try prepping a blank and increase pressure on the knurls.



Oh I fully believe that! No question.

It's just that all the talk and all the calculators I have seen point to turning the OD to get a whole number of the knurl pattern around the work.

Thanks for the background.

-brino


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## darkzero

That's very interesting Mike, I've never heard that before. All the formulas & calculators I use & have seen are to prevent double tracking like how I mentioned earlier. They've always worked for me & that's how I was taught. 2 general formulas that I'm aware of, one for diametral pitch wheels & another for circular pitch wheels. 

I don't even know how to make a knurl for a spec'd size, I have an idea but it's just an idea & have no idea how it's actually done. I don't make production parts nor have I ever needed to make a knurl to a specific OD for a press fit so I really don't care. The main purpose for knurling is for grip but for me, cosmetic comes first, then functionality cause I'm anal like that, lol. Like Brino I don't care about the finished size.

When I knurl hard materials like SS & Ti that work harden easy, there's no way I can just continue feeding to make the knurl form & track properly. I don't even like to make a second pass on hard materials, I do it in one shot. I've tried & tried when I was learning, not once did it work for me. The materials are too hard to displace that much & will work harden before coming out right. I always calculate for diameters & I have a pretty high success rate even though I dread knurling every single time on those materials.

Lots of good info in this thread though, whatever works for someone is all that matters.

Accu-Trak has very good info on knurling. https://www.accu-trak.com/technicalinfo.html


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## mikey

I once had to replace a broken head stud that had rusted. This was a long time ago but I think the head gasket was blown and it allowed water to corrode the stud. Anyway, we had to pull the stud out and I opted to make a replacement stud rather than buy the set; they didn't sell just one. I had to learn how to bring that knurl to size and thread the other end ... all on a Sherline lathe, which is all I had at the time. I made the knurl slightly larger so it would bite in that hole and it worked. That engine is still running.

I'm with you guys most of the time - I knurl for decorative purposes 99.9% of the time. I don't do exotic stuff like Ti but I've done stainless enough to know that you have to know how to do it right the first time.

I'm not arguing that you shouldn't calculate. There are times when you need to do it, such as when you need a specific fit or like Will says, when you are working with stuff that is intolerant of error. For most common materials like brass, aluminum or mild steel, we can get away with not calculating if we choose to do so. There are a lot of guys like me who don't bother with calculators and have been doing so for years - give it a try and see if it works for you.


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## Silverbullet

I've done lots of knurling on lots of materials . The amount of pressure it takes to basically dent the material per line or crossed lines is much more then anyone thinks . One reason the small LATHES don't work with the direct pressure on the tool post is enough to saverely damage your machine , broken cross slides and compounds ,tool post at minimum . About fifty years ago I bought one which you set it on the work piece two wheels under one whell over adjustable with a pin , you then turned the lathe on and squeezed the handles with your grip to cut the knurls . Every once in awhile I see one on eBay but ill say one thing it hurts to put the amount of pressure it takes to knurl. Think I paid about twenty bucks in 1975 new from msc I even had an account with them .
That eagle brand model works great too.


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## mikey

@darkzero , which Eagle Rock knurler do you have? I've been thinking about this subject and I want to look into a new knurler. I have an Aloris AXA-19 and a shop-made knurler. Both work well but after seeing what you can do with that Eagle Rock, I'm having some thoughts. See what I mean about coveting and helping guys spend money?   

From what I can see, I would need the one for manual lathes and the 0 - 2-1/8" version comes with a 5/8" part that fits in a tool holder, right? If I'm not mistaken, I think ER also makes a "heavy duty" version but it isn't listed in their catalog. Any info on that?

My shop-made knurler actually works better than my Aloris one. I think its because the fit of my axles in the knurls is better - very little discernible play. I suspect the ER knurler will have a better fit as well. I also plan to get some Accu-trak knurls to go with it so I'm sorta serious about this. Well, after I recover from spending 60K on a home improvement project I have going right now.


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## darkzero

mikey said:


> @darkzero , which Eagle Rock knurler do you have? I've been thinking about this subject and I want to look into a new knurler. I have an Aloris AXA-19 and a shop-made knurler. Both work well but after seeing what you can do with that Eagle Rock, I'm having some thoughts. See what I mean about coveting and helping guys spend money?
> 
> From what I can see, I would need the one for manual lathes and the 0 - 2-1/8" version comes with a 5/8" part that fits in a tool holder, right? If I'm not mistaken, I think ER also makes a "heavy duty" version but it isn't listed in their catalog. Any info on that?
> 
> My shop-made knurler actually works better than my Aloris one. I think its because the fit of my axles in the knurls is better - very little discernible play. I suspect the ER knurler will have a better fit as well. I also plan to get some Accu-trak knurls to go with it so I'm sorta serious about this. Well, after I recover from spending 60K on a home improvement project I have going right now.



Haha! Sure happy to help!

Yes, that's exactly what I have, the Eagle Rock K1-44 heavy duty knurler, 0 - 2-1/8". Mine has a 3/4" shank & uses the standard knurls. There's a counterbored version also that allows to to knurl up to a shoulder but they're not as strong as the standard & they use special wheels. I'm also using solid carbide knurl pins & convex cobalt knurl wheels by Accu-Trak. I replaced the top nut with a nyloc nut.

I knew a guy on another forum who had the BXA-19. He said it didn't work well for him. But we were all on a quest to get perfect knurling on Ti 6-4.

Those K1-44s are not cheap though, over $300 new. They're less expensive K1-201 looks similar but doesn't perform the same on tough metals. Still a good knurler too though. Now here's that part where you might hate me...or more.  I got 3/4" shank cause I didn't have a choice. Years ago I found my K1-44 on ebay, looked like it was never used, not one set screw mark on the shank. It was listed simply as "Knurling Tool", no description. $80 shipped buy it now. Took one look at it & when I saw the stamp on the shank I clicked buy it now as fast as I could!

I've also got a little Dorian straddle knurler, you can see it sitting on the saddle. I've never tried it though & it has a really small shank. I only picked it up a while back cause Travers was clearing them out for $50.


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## darkzero

Just to clarify, The Aloris, K1-201, shoulder type K1-44, & other popular tools aren't bad knurling tools & are very capable. When I say they're not as as strong, I mean as in comparison to the standard K1-44. My main goal was to achieve full form diamond knurling on Ti 6-4. I had a time when the  knurling force so strong that no matter how tight I tightened down my Dorian tool post, it would just spin when traversing, even tried brown paper under it. I had to use the dowel pins under the Dorian to pin it to the T-nut.

Oh and Accu-Trak has a nice looking heavy duty scissor knurler tool, they call it a straddle knurler. But it's not cheap either. https://www.accu-trak.com/holders_straddle.html


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## mikey

darkzero said:


> Haha! Sure happy to help!
> 
> Now here's that part where you might hate me...or more.  I got 3/4" shank cause I didn't have a choice. Years ago I found my K1-44 on ebay, looked like it was never used, not one set screw mark on the shank. It was listed simply as "Knurling Tool", no description. *$80 shipped *buy it now. Took one look at it & when I saw the stamp on the shank I clicked buy it now as fast as I could!



Thanks, Will. That is exactly what I needed to see. Now that I know what I'm looking for, I'll watch ebay. As I told @EmilioG , the patienter I am, the luckier I get. The only reason I'm even thinking about it is that I want to make some stainless knurled rear set pegs for my son's bike. He doesn't know I'm going to make them so it will be a nice surprise. 

You've set a pretty high standard, Will, in both knurling and in your photographs - superb quality! 

Thank you for your help to me and the rest of the forum.

Mike


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## mikey

darkzero said:


> Just to clarify, The Aloris, K1-201, shoulder type K1-44, & other popular tools aren't bad knurling tools & are very capable. When I say they're not as as strong, I mean as in comparison to the standard K1-44. My main goal was to achieve full form diamond knurling on Ti 6-4. I had a time when the  knurling force so strong that no matter how tight I tightened down my Dorian tool post, it would just spin when traversing, even tried brown paper under it. I had to use the dowel pins under the Dorian to pin it to the T-nut.
> 
> Oh and Accu-Trak has a nice looking heavy duty scissor knurler tool, they call it a straddle knurler. But it's not cheap either. https://www.accu-trak.com/holders_straddle.html



You are not making this easier on me, Will. $359.00 for a knurler is pretty steep for a tool that will not earn its keep but it does look formidable. If I can't go to sleep tonight, it will be all your fault.


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## darkzero

Thanks Mike & thank you as well for sharing your knowledge here. You're a great & helpful member here as well as others. When someone needs help, you always seem to be there!

Yeah those knurling tools aren't cheap, I would have a hard time paying full price for one, especially for something that doesn't get used as often as say a tool post or chuck.

Although I don't need another I look for them too. I also look for cut knurlers. Cut knurlers are awesome & I've always wanted one. You should see how much those things go for! If I come across something I'll be sure to let you know.


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## darkzero

Custom SS knurled foot pegs would be cool! 

Unrealted, I was looking through some of my old knurling pics, did you guys know you could knurl delrin, like form knurl, not cut knurl. It was an experiment I did when someone asked on another forum.

First try was just a partial form. On the second band I tried full form but without any lube, it melted. Then with lube, it worked, not very clean crisp peaks but decent considering I did not think it would work at all.


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## mikey

darkzero said:


> If I come across something I'll be sure to let you know.



Thanks, Will. 

I don't know if I want you to let me know! You are already making me think about spending somewhere between $250 and $360.00 on a knurler! Remember in that thread where I said the most fun we have is getting other guys to spend money on tools? Remember that? This is you doing that!!!  Don't even think I don't know what you're up to.  

When I get those rear set pegs done, I'll post a pic if I remember. At my age, I need to be careful about making promises because while my integrity is intact, my remembery isn't what it used to be.


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## Maplehead

Wait a second Mike, Will is just trying to get you to buy a knurler. You were trying to get me to buy a complete machine shop, lol.
(BTW, I was just at a restaurant last night in that highlighted circle on the Craigslist ads map.)
What is form or cut knurler?
I'd like to clarify a couple things here I am sort of getting.
For hard materials you make one pass. Correct?
So you literally have the correct amount of knurler pressure cranked down before you begin to turn?
And then you only turn to one rotation on the workpiece and done?
Tracking is keeping the knurling teeth in the previously cut tracks?
Double tracking is when the teeth cross partially over into another track, causing a messed up pattern?
Lastly, I'm getting the impression that it takes a whole lot more force to create the raised pattern than what I am doing.
With my micro machining equipment, I have to figure out how to REALLY crank down on the knurling tool and work piece, while at the same time keeping the tool in line with the work piece, meaning perpendicular to it, and keeping it top-dead-center to the work piece as well, and then rotate the work piece only one rotation, assuming my OD is perfect for the knurling teeth amount and size, and no other factors come into play. Correct?


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## woodchucker

I picked up a Eagle Rock knock off a few years ago. It's excellent, probably not as good as an EAGLE ROCK, but it works great, is tight. I F'd up when trying to put different rollers in, I couldn't tell which side to push out the pins from... so in that respect probably a little inferior. But even with the damage I did, it was repairable and works great.  My knurls improved a bit.. BUT
After learning that my knurls were still not what I wanted, I started using a calculator, and they are now where I want them. Not as talented as Will, but way better than b4. My standard knurls are crisp, pointed (where I have to file them to lose the points), and precise.   

If you want better, calculate, and get a scissor knurler. If I buy rollers I can't see markings for (I go to farm shows, flea markets, and garage sales), what I do is put oil on the roller, and then roll it out on paper and count the lines per inch.  
And now that I know who's king of knurling, if I have a question... Will,  you the man!


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## mikey

Maplehead said:


> Wait a second Mike, Will is just trying to get you to buy a knurler. You were trying to get me to buy a complete machine shop, lol.
> (BTW, I was just at a restaurant last night in that highlighted circle on the Craigslist ads map.)
> What is form or cut knurler?
> I'd like to clarify a couple things here I am sort of getting.
> For hard materials you make one pass. Correct?
> So you literally have the correct amount of knurler pressure cranked down before you begin to turn?
> And then you only turn to one rotation on the workpiece and done?
> Tracking is keeping the knurling teeth in the previously cut tracks?
> Double tracking is when the teeth cross partially over into another track, causing a messed up pattern?
> Lastly, I'm getting the impression that it takes a whole lot more force to create the raised pattern than what I am doing.
> With my micro machining equipment, I have to figure out how to REALLY crank down on the knurling tool and work piece, while at the same time keeping the tool in line with the work piece, meaning perpendicular to it, and keeping it top-dead-center to the work piece as well, and then rotate the work piece only one rotation, assuming my OD is perfect for the knurling teeth amount and size, and no other factors come into play. Correct?



Gotta' watch Will ... sneaky guy! In my own defense, I was just trying to help!

See this for an explanation of a cut knurler: https://www.accu-trak.com/holders_cuttype.html
The difference between cut knurling and displacement knurling is that the former process actually cuts or mills the knurl, while the latter process forms or displaces material to produce the knurl.

Some materials like stainless, titanium and high carbon steels will work harden if you even look at them. When you make a knurling pass on these materials, meaning you engage your knurling wheels to get a pattern and then run them down the work piece under power, it work hardens the surface. If you then try to make another pass you are doing it on a very hard surface and you will not be able to displace that material so you cannot get to full depth. To get around this, you either increase the pressure on the end of the work to get the pattern you need and then make a full-depth pass or you set it up on a scrap piece to set the knurler at the right setting and then knurl it in one pass. The point is to avoid making more than one pass on these materials; it won't give you a second chance.

When we say you make "a pass", we are referring to feeding the knurler down the length of a work piece axially, from the tailstock end towards the chuck. Most knurls are made this way, and the length you feed the knurler depends on your needs. Of course, this is done under power, which your lathe cannot do.

Yup, you got it. When the knurls track properly, the teeth fall into the same pattern. Double tracking will result in the teeth criss-crossing.

Knurling is not cutting; it is displacing or forming of the material. The knurls are literally moving material into a pattern; to form a groove the adjacent material must be raised. It takes a lot of pressure to displace material like this so yes, you need a knurler than can apply a lot of pressure. The alignment of the knurls is perpendicular to the work or nearly so and the knurls are ideally kept centered over the axis of the work, or nearly so. You apply enough pressure to create the pattern you want - either full depth so you get sharp points or partial depth so you get flattened points - and then rotate the work piece until you get the pattern you want or run it down the work piece if you need a longer knurl.

Hope this clears it up. You main limiting factor right now is your lathe. It is small, light, underpowered and not rigid enough to really knurl most materials. You might get away knurling aluminum or delrin but brass or anything harder is going to be difficult and frustrating. If you want to stay with small machines then consider getting something more robust. A Sherline or Taig machine might be a better option.


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## Maplehead

Thanks Mike and All for the replies and advice.
Since I am not going to be making "passes", I think I will try using two vises to hold the workpiece and then see if this little scissors knurler is strong enough for me to tweak it down and displace some brass.


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## darkzero

mikey said:


> Thanks, Will.
> 
> I don't know if I want you to let me know! You are already making me think about spending somewhere between $250 and $360.00 on a knurler! Remember in that thread where I said the most fun we have is getting other guys to spend money on tools? Remember that? This is you doing that!!!  Don't even think I don't know what you're up to.
> 
> When I get those rear set pegs done, I'll post a pic if I remember. At my age, I need to be careful about making promises because while my integrity is intact, my remembery isn't what it used to be.



Huh, whaddaya talking about, I dun know noting! 

Hey, I can at least try right? Yeah, remeber those damn TECO sets! I thought I didn't need one but apparently I do!

Yes, please do if you remember, I love to see stuff that people make!




Maplehead said:


> Wait a second Mike, Will is just trying to get you to buy a knurler. You were trying to get me to buy a complete machine shop, lol.


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## darkzero

woochucker said:


> I picked up a Eagle Rock knock off a few years ago. It's excellent, probably not as good as an EAGLE ROCK, but it works great, is tight. I F'd up when trying to put different rollers in, I couldn't tell which side to push out the pins from... so in that respect probably a little inferior....
> 
> ...And now that I know who's king of knurling, if I have a question... Will,  you the man!



You bring up a good point that I forgot to mention. That's another difference between the Eagle Rock K1-201 & HD K1-44. The imports are clones of the K1-201. For the K1-201 the knurl pins are pressed in which is fine. The K1-44 uses set screws to hold the pin in, just loosen the set screw & the pins push right out. I like to change wheels often so that is another plus for me. But more importantly, when knurling hard materials you're better off using solid carbide pins. Trying to press in carbide pins on the K1-201 is not fun. It can cause a lot of frustration & carbide chips easily.

King, no not me, I'm not the king of anything. I'm just a hobby guy like many of you guess. I just get lucky!


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## ddickey

I bought one of these a year or so ago and it is junk. Super flimsy.
https://www.amazon.com/gp/product/B006UHAB2E/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1


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## darkzero

ddickey said:


> I bought one of these a year or so ago and it is junk. Super flimsy.
> https://www.amazon.com/gp/product/B006UHAB2E/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1



That's the difference between an import clone & the real Eagle Rock K1-201. Some clones are better than others though.

It can be improved though. Not sure how hard the arms are on the clones if at all. But you can bore and/or ream the pivot holes, then make a new pivot that fits tighter. Then harden the pivot. Add an additional nut on top of the adjuster for locking.

My K1-44 is hard hard hard, I tried milling down the shank with a HSS endmill when I first got it, it just laughed at the endmill. I ended up just getting an oversized holder for it.


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## gheumann

MA - everything you need to know has already been said, I think - but I do a fair bit of knurling too. The point of the math is this: Think of the knurling wheel(s) and the work just like gears, They have to mesh. The "teeth" on the work have to be in the same place on the second revolution as on the 1st. If the work diameter is not correct, the knurling wheel teeth will be in a totally different position on the metal when it comes around again. You can easily see this by BARELY engaging the knurler. Spin the chuck 1 turn (or a little less) and you will see the hoped-for pattern. Now spin it one more turn. If your work diameter is correct, the 2nd revolution will have placed its marks directly over the 1st set - it should look the same (maybe a little deeper.) If NOT, you'll see a fresh set of marks in between the 1st ones. IF the diameter is wrong and you knurl, you will get a pattern but it will be finer, shallower and uglier than when you do it right. 

I have the LMS scissor knurler and it works fine for me, but I bought it 10 or 15 years ago. At that time their calculator didn't work great, and if I remember correctly the stated pitch of the wheels was suspect. So I measured them myself. Easy. Hold one wheel of your knurler over a piece of paper and roll it along for a few inches. You will see a series of slashes. Measure how many there are in an inch. (Better yet, as they MIGHT be metric, measure for 3".) Now you now the number of lines per inch. I made an Excel sheet. If you know Excel - the formula to figure out the closest proper knurling diameter to the diameter you're starting with is =ROUND(INT(A1*B1*PI())/B1/PI(),3) where Column A is the original diameter and Column B is the LPI of the knurling wheel. 

Here is the chart I keep in my toolbox for 3 sets of knurling wheels with pitches of 33, 22 and 14 LPI. If you check your wheels and they match you can use this chart. 

Example - you want to knurl a piece of 0.500 stock with the 22 LPI wheel? Turn the stock to 0.492" first. 


P.S. It doesn't take a lot of torque to knurl - if your lathe won't turn something is wrong. 

I do mine at fairly low RPM. I barely engage the wheels (centered over the work), start the lathe (low RPM works for me but I've never tried higher speeds as someone suggested above), then tighten the clamping wheel - about as hard as I can with my fingers. (On aluminum, less than that. For steel? Might need more.) If I need to advance the carriage, I do so slowly. I've tried with lube and without - as long as I keep the wheels clean I haven't found it necessary (my experience is on Aluminum or brass).

Hope that helps.


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## mikey

Just in case Darkzero has been working on anyone else's mind, the K1-44 is available with a 5/8" shank to fit the AXA tool holders: http://specialtytooling.eaglerockon...-scissor-type-knurling-tools/k1-44-21-0625r-e

Note that they now come in LH, RH or center so order the right one for your needs.


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## Maplehead

Good info greg, thanks.
Does your LMS knurler have play in it? Mine does.
I tried with the correct diameter this morning but it still doubletracked.


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## bss1

I have a Aloris BXA knurler and try to knurl in a single pass. This seems to work most of the time. For those of you that make multiple passes, do you reverse the feed direction, or put the whole lathe in reverse when using power feed?  Most of the time I have good luck with a single pass, but there are times when i would like to take a second pass to deepen the pattern.


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## Maplehead

So I tried counting the lines on my fine/straight knurling wheel. The package says 33LPI so I used that in the formula. I got double tracking.
I tried the paper test and counted the lines within an inch and I counted 31LPI. I adjust my my formula and got more double tracking.
Tonight I am going to split the difference and input 32LPI.


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## mikey

bss1 said:


> I have a Aloris BXA knurler and try to knurl in a single pass. This seems to work most of the time. For those of you that make multiple passes, do you reverse the feed direction, or put the whole lathe in reverse when using power feed?  Most of the time I have good luck with a single pass, but there are times when i would like to take a second pass to deepen the pattern.



I disengage power feed, leave the lathe running and just [manually] feed out at about twice the speed that I used going in. It helps to use a wire brush and some compressed air to clear the flakes before you back out. The cleaner you get it, the crisper your pattern will be on the second pass.


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## Wreck™Wreck

mikey said:


> Just in case Darkzero has been working on anyone else's mind, the K1-44 is available with a 5/8" shank to fit the AXA tool holders: http://specialtytooling.eaglerockon...-scissor-type-knurling-tools/k1-44-21-0625r-e
> 
> Note that they now come in LH, RH or center so order the right one for your needs.


Curious, have never turned a particular diameter for knurling just what the Customer drawing demands, for instance 2.500 Diameter, 12 Pitch, 3" length. I do however do a recurring job, straight knurl on 1" Delrin rounds 5" long, this is more challenging then doing the same in 304 stainless.


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## mikey

Wreck, let me ask you - are you getting a clean knurl in Delrin? If so, how are you doing it? I get a fairly good pattern but its a bit smeared, if you know what I mean. I've tried fast, slow and medium speed. I've tried with coolant, compressed air to cool and clear flakes. I've even tried knurling with virgin knurls to be sure they're sharp. Every result is the same or nearly so. The only thing I haven't tried is to freeze it before quickly knurling it but I've been thinking about it.

Share your expertise if you will.


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## Maplehead

Hi All
So I tried all three setting, 31-33 LPI. Same results each time.
I turn the stock down to the required diamter based on the formula.
I put the knurling tool squarely over the rod at what looks like top dead center.
I tighten lightly and hand turn one revolution, (the chuck), and then tighten a little more and turn a revolution and repeat for about six turns.
Mult-tracking every time.
What am I doing wrong?
I am including a vid showing the play in my knurling tool. Is that it?
Plus a couple samples.


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## darkzero

mikey said:


> Wreck, let me ask you - are you getting a clean knurl in Delrin? If so, how are you doing it? I get a fairly good pattern but its a bit smeared, if you know what I mean. I've tried fast, slow and medium speed. I've tried with coolant, compressed air to cool and clear flakes. I've even tried knurling with virgin knurls to be sure they're sharp. Every result is the same or nearly so. The only thing I haven't tried is to freeze it before quickly knurling it but I've been thinking about it.
> 
> Share your expertise if you will.



I just used lube, might of used my cold air gun too, I forget. I got pretty good results, well IMO, as seen in the pic I posted earlier in this thread.


----------



## Maplehead

Thanks Will. I'll give it a try.
I calculated my .375" brass rod, using a 31 lines per inch (teeth) wheel to have me turn the diameter to .37"
Then I tried as if the teeth were 32 which gave me a diameter to turn to of .368"
33 LPI had me turn diameter to .367"
Nothing worked.
So I should try next at .372"?


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## mikey

Maplehead said:


> ... Mult-tracking every time.
> What am I doing wrong?



Have you tried just increasing pressure on the knurls? The play in the arms may or may not be a problem. I don't like it personally but I don't think that's the major issue. I think inadequate pressure is the issue.


----------



## darkzero

Maplehead said:


> Thanks Will. I'll give it a try.
> I calculated my .375" brass rod, using a 31 lines per inch (teeth) wheel to have me turn the diameter to .37"
> Then I tried as if the teeth were 32 which gave me a diameter to turn to of .368"
> 33 LPI had me turn diameter to .367"
> Nothing worked.
> So I should try next at .372"?



Sorry, I deleted my post after thinking about it. If it's just vertical play, it shouldn't matter as the play should be cancelled out when you tighten down on the stock. I can't view mov videos from my phone so I'll have to wait till I get to computer to view it. I also can't see very much detail in the pic you posted.

So after I view your video I'll see if I have any more ideas.

But don't go smaller in dia, that never worked for me, if anything try going slightly bigger than the calculated dia.


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## mikey

darkzero said:


> I just used lube, might of used my cold air gun too, I forget. I got pretty good results, well IMO, as seen in the pic I posted earlier in this thread.



I can get those results, too, Will but I wondered what else might be possible. I know there must be a way to get cleaner knurls in Delrin.


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## Maplehead

The play is lateral, maybe three or so degrees each side. No need to view detail. The quality stinks.
Mike, after every turn I tightened the knurls.
As I hold onto the rod the turns the chuck I can feel each tooth as the knurl turns. Boomp, boomp, boomp.


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## darkzero

mikey said:


> I can get those results, too, Will but I wondered what else might be possible. I know there must be a way to get cleaner knurls in Delrin.



Yes, there is a way, a cut knurler. Hint hint, just $aying.


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## mikey

Crank up the pressure until the wheels track. Brass is fairly easy to knurl - shouldn't take that much to do it. Try it on a new piece of material. Just skim cut the outer layer off, then put the knurling tool in place. Engage the knurls and then take a 1/4 turn. If it fails to track, take another 1/4 turn and it should track. Then increase pressure until you get a full pattern. Give it a try.


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## mikey

darkzero said:


> Yes, there is a way, a cut knurler. Hint hint, just $aying.



Punk!


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## Maplehead

Thanks, will try tomorrow. Burnt out for the night now.


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## darkzero

mikey said:


> Punk!


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## Doubleeboy

I have a no name Eagle Rock knock off from Enco,  to get good knurls I had to take the sloop out of the longitudinal axis by tightening the center screw and nut.  By doing that I was able to stop most double track issues.  That and making darn sure my rig was dead square to work and upper and lower arm were dead center vertically.   I have an acquaintance,  late 70s age, owned his own shop for most of his life, he never contemplates diameter he just knurls, either bump or scissors style, makes pretty good looking knurls, says if he has trouble double tracking he cleans the knurls, uses more force and does em again.    He just rolled his eyes when I tried to explain the calculations for proper starting diameter, saying something about why change what works for him.  I myself am not so lucky, but I had no argument so left it alone.


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## T Bredehoft

I don't do a lot of Knurling, but I find that I can made a good knurl on any diameter (within the range of the tool) by increasing the pressure and feeding in and out until it looks good. ( I use a home made scissor type knurling tool)   The two knurls are free to move vertically together, if the piece is running out.


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## 4GSR

I have a cut knurl type dad borrowed from work back in 1968 or was that 1969 and forgot to take back.  I was so spoiled to using it that when we got a bigger lathe, a 16" Axelson, ten years later.  We bought a Aloris CA tool post package that had one of those holders with the knurls on one end and a place for a facing tool on the other.  I could never get that thing to cut any kind of knurl on that Axelson.  And you know how rough you can on a Axelson!  Anyone know where to get knurls for this obsolete Swiss made knurling tool?  I can find just about any cut knurls, but either the ID is tool small or the OD is too big!  Ken


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## darkzero

4gsr said:


> I have a cut knurl type dad borrowed from work back in 1968 or was that 1969 and forgot to take back.  I was so spoiled to using it that when we got a bigger lathe, a 16" Axelson, ten years later.  We bought a Aloris CA tool post package that had one of those holders with the knurls on one end and a place for a facing tool on the other.  I could never get that thing to cut any kind of knurl on that Axelson.  And you know how rough you can on a Axelson!  Anyone know where to get knurls for this obsolete Swiss made knurling tool?  I can find just about any cut knurls, but either the ID is tool small or the OD is too big!  Ken



Accu-Trak has a few different sizes for cut knurls. https://www.accu-trak.com/knurls_cuttype.html

They can also make you custom wheels. Not sure how pricing is for that but I can vouch for their quality & customer service though. I only use their wheels & have been very happy with them.


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## ronboult

Mikey wrote in post #71 regarding Eagle Rock Knurlers  "Note that they now come in LH, RH or center so order the right one for your needs"
I think I know what he means but nowhere on the Eagle Rock site can I find an explanation. Can anyone confirm which side of the Knurling tool is left and right hand. Is it the same as parting tools etc.
I think the knurling wheels for left and rightknurlig tools  would need to be mirror images and would again be different from the Centre knurlers. Is the centre Knurler stronger being supported on both sides of the knurl?
Finally why do we need right and left hand knurlers? Is it to allow knurling up to a shoulder? Not sure how many times I would actually need to so that if at all.
Ron


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## darkzero

ronboult said:


> Mikey wrote in post #71 regarding Eagle Rock Knurlers  "Note that they now come in LH, RH or center so order the right one for your needs"
> I think I know what he means but nowhere on the Eagle Rock site can I find an explanation. Can anyone confirm which side of the Knurling tool is left and right hand. Is it the same as parting tools etc.
> I think the knurling wheels for left and rightknurlig tools  would need to be mirror images and would again be different from the Centre knurlers. Is the centre Knurler stronger being supported on both sides of the knurl?
> Finally why do we need right and left hand knurlers? Is it to allow knurling up to a shoulder? Not sure how many times I would actually need to so that if at all.
> Ron



The LH, RH, & Center designations are for the shank. RH would most commonly be used on a manual lathe. LH is for use on CNC machining centers like in a turret. Center positions the tool so center line sits lower than a cutting tool usually sits (cutting tools usually have the cutting surface inline with the top of the shank, but not always).

The standard version with the knurling wheels supported on both sides is stronger. The version they call Counterbored is only supported on one side so it can knurl closer to a shoulder. The knurling wheels for these aren't available everywhere though & is most likely proprietay to Eagle Rock.


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## ronboult

Thanks Will
Clear now. Was confusing RH Centre and LH with the pictures that show the knurling wheel in the centre or on the edge of the arms. Will keep look out for a bargain RH tool with centre mounted wheels
Cheers Ron


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## Maplehead

Update
Last night I tried the approach that one or more of you suggested.
After turning the rod to diameter I tightened down the knurls about a quarter turn and then moved the chuck back and forth, only knurling just about half of the rod. (A quarter each knurling wheel.)
I did this for a bit and continued to tighten. I had to use plyers to tighten as I was past hand tightening.
When I could see some depth I began to expand the range until I eventually was spinning the rod's circumference completely.
I had to apply a clamp to my knurling tool and the crosslide so that the tool would not go out-of-perpendicular to the rod.
All in all I would say it produced a better knurl but not a great one. I could still see a bit of double tracking.


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## 4GSR

darkzero said:


> Accu-Trak has a few different sizes for cut knurls. https://www.accu-trak.com/knurls_cuttype.html
> 
> They can also make you custom wheels. Not sure how pricing is for that but I can vouch for their quality & customer service though. I only use their wheels & have been very happy with them.


That was one of the websites I checked.  I'm afraid to get special one's quoted...yeiks!


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## mikey

Maplehead said:


> Update
> Last night I tried the approach that one or more of you suggested.
> After turning the rod to diameter I tightened down the knurls about a quarter turn and then moved the chuck back and forth, only knurling just about half of the rod. (A quarter each knurling wheel.)
> I did this for a bit and continued to tighten. I had to use plyers to tighten as I was past hand tightening.
> When I could see some depth I began to expand the range until I eventually was spinning the rod's circumference completely.
> I had to apply a clamp to my knurling tool and the crosslide so that the tool would not go out-of-perpendicular to the rod.
> All in all I would say it produced a better knurl but not a great one. I could still see a bit of double tracking.



Why not try the same thing on aluminum to see if it works better? You are working with a tool that is not very rigid in design and probably not structurally rigid, either. Therefore, the material you're knurling must be softer and aluminum might just work better for you.


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## RodJShaw

Is there a formula for calculating the feed rate needed by knurls with a 22 degree helix angle? Or does feed rate not matter? I'd have thought that it would be critical.


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## Maplehead

mikey said:


> Why not try the same thing on aluminum to see if it works better? You are working with a tool that is not very rigid in design and probably not structurally rigid, either. Therefore, the material you're knurling must be softer and aluminum might just work better for you.


Hi Mike

It needs to be brass. It's for a guitar bridge of my design and I prefer brass over aluminum for sound qualities.


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## mikey

Maplehead said:


> Hi Mike
> 
> It needs to be brass. It's for a guitar bridge of my design and I prefer brass over aluminum for sound qualities.



Okay, then the only other thing I can suggest is to buy new knurls and try again. For small knurls like you're using, Form-Rol makes some good ones. Check ebay and see if you can find a new pair and I bet your results will be much better. Look for knurls with the same OD, ID and pattern. HSS is fine.


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## Wreck™Wreck

mikey said:


> Wreck, let me ask you - are you getting a clean knurl in Delrin? If so, how are you doing it? I get a fairly good pattern but its a bit smeared, if you know what I mean. I've tried fast, slow and medium speed. I've tried with coolant, compressed air to cool and clear flakes. I've even tried knurling with virgin knurls to be sure they're sharp. Every result is the same or nearly so. The only thing I haven't tried is to freeze it before quickly knurling it but I've been thinking about it.
> 
> Share your expertise if you will.


Can't help you there, these parts are covered by some sort of expanded urethane foam when finished, the surface holds the finish process, I would not call it a clean knurl pattern by hobbyist standards yet suitable for the pharma industry in this application.

If you insist on knurling  this material and producing a visibly flawless pattern invest in a cut knurl tool you will be amazed by the results.
As seen here, one may produce excellent parts with nice visual appearances this way.

https://www.mscdirect.com/browse/tn..._id=64142912&gclid=CIC-kfX-i9MCFQ6Bswod73sEAg

As a side note I generally  test the set up and make 20 bad parts before making a good one, you may not have this option.


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## mikey

Okay, thanks for the information. Glad to know you have to experiment, too. 

Unless I run into a very good deal or decide to make one, a cut knurler is probably not in my future. @darkzero has been working on me but I'm gonna' resist!


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## darkzero

Just wait till I find the perfect deal! 

(Unfortunately ebay is not as great as it used to be for killer deals)


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