# Knurled Tool



## oskar (May 8, 2018)

Looking for suggestions on a knurled tool for my Taig mini lathe with a tool holder capacity 1/4” to 3/8”. Would like to make some knobs for small screws.

Searching I noticed they also come with several wheels with different patterns which will be nice


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## FLguy (May 8, 2018)

Look at Sherline they have a small knurling tool that ought to work well for you. I have one on my Sherline 4400 lathe am happy with it.


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## oskar (May 8, 2018)

Found it at Sherline, looks pretty good, thanks


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## mikey (May 9, 2018)

I own the Sherline knurler and it works. However, it is nowhere near as good as a scissors knurler. The problem is that nobody makes a good scissors knurler for the Sherline/Taig sized lathes so I made my own by looking at a single blurry picture of a knurler made by Chris Heapy of the UK. Maybe these pics will be enough to get your thinking going:






All mild steel, aluminum spacers, aluminum mounting block. Knurls are from FormRol, pins are drill blanks. There is zero play between the plates and arms but the arms move freely; it is extremely rigid. Capacity is 1/8" to 2-1/4" OD. It will knurl everything we commonly work with, from plastics to brass to steel to stainless steel. It mounts solidly to the Sherline cross slide with two T-nuts.

I do not have plans for it but can give you details if you have questions. I will tell you that there is no comparison between this knurler and the Sherline tool.


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## British Steel (May 9, 2018)

Agree with Mikey, scissor knurlers are way better, particularly on small lathes - the "bump" knurlers that just run in from the cross-slide put a lot of force back into the toolpost and don't engage as positively - you can get scissor knurlers to fit in the toolpost slots though, or you may be able to remove the bar and replace it with a piece of suitable key stock to clamp in the TP?

Dave H. (the other one)


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## oskar (May 9, 2018)

Thanks Mike for your time and definitely it’s a project I would like to do. I found the FormRol site which is very good with tons of information plus I found a .PDF document about Knurls which I will read to educate myself.

No need for plans but I have these questions:

What is the approx. overall size of the main block?
What is the size of the main bolt? Are the threads coarse or fine?
What is the size of the knurls you have?

Much appreciated
Nicolas


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## FLguy (May 9, 2018)

Mikey that knurler looks very similar to the one Hemingway Kits from the UK sells. I made a larger sized one on that design for my big lathe. It's a joy to use.


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## Ken from ontario (May 9, 2018)

I don't know what happened to my post here.


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## Ken from ontario (May 9, 2018)

Dave ,Mikey, thank you both for your replies, I read them in my yahoo mailbox (that's where I usually receive notifications for all my my threads/post) but they disappeared from this thread after the quick upgrade this afternoon.  
Mikey, now that you explained how the knuckles are secured,I can see the grooves clearly.neat idea bytheway ,the whole project looks very well machined and precise. the one I'm working on is quite sloppy compared to yours but after all it is inspired by my other Chinese knurling tool which (surprisingly) works exceptionally well.


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## oskar (May 9, 2018)

There are some post missing here, can this be corrected?


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## mikey (May 10, 2018)

Yeah, can this be corrected? If not, I'll re-do my responses if I can remember what I said ...


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## HMF (May 10, 2018)

That likely occurred during the migration from the old to new server. Sorry about that.


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## mikey (May 10, 2018)

Nelson said:


> That likely occurred during the migration from the old to new server. Sorry about that.



Okay, no problem, Nelson. We'll just respond again. Thanks for looking into it.

Mike


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## mikey (May 10, 2018)

oskar said:


> Thanks Mike for your time and definitely it’s a project I would like to do. I found the FormRol site which is very good with tons of information plus I found a .PDF document about Knurls which I will read to educate myself.
> 
> No need for plans but I have these questions:
> 
> ...



I'm gonna' try to remember what I said the first time but if I miss something, ask, okay?

The mounting block is 6061-T6; 2-1/4" front to back, 1-1/2" high, 1-1/4" thick. The mounting block places the centerline of the knurler on the centerline of the lathe behind the work piece. The bottom of the knurler plate registers on the edge of the cross slide and when the screws are locked down into the T-nuts in the cross slide, the entire knurling tool is solidly held and cannot turn or move unless you want it to. Some users feel that a slight angle of the knurls toward the headstock is desirable; I have not found this to be necessary.

Contrast this to the Sherline tool, which is intended to be mounted loose so the base of the tool can move. Presumably, this is to allow the knurls to track better. My results suggest that a solidly mounted knurler with tight tolerances will form a more precise knurl with very little chance of mistracking if everything is done right.

The main tension screw is 12L14. The threads were 1/4-28 on top with a class 3 fit into the top nut. The bottom thread inserts into the half-moon insert with a 1/4-20 thread, Loc-tited in. 12L14 is more than adequate for this application because there is not an excessive amount of tension on the stud. Over the years, it has performed flawlessly with no sign of wear.

Knurls are from FormRol, 1/2" OD X 1/4" thick X 3/16" ID hole. These knurls are from the EQ series (1/4" wide) instead of the EP series (3/16" wide EPR/EPL 230) that Sherline uses. The knurls I used were the straight EQ 230 pair (fine pitch to reduce mistracking), EQR/EQL 225 and EQR/EQL 230. I had them custom grind a bevel on both sides to allow for axial running and they work well for that. 

All knurls above are Circular Pitch knurls. I do not use Diametric Pitch knurls and do not calculate diameters; I just crank down to achieve about a 90% pattern depth and run the knurl. Note that FormRol considers anything deeper than a 90% pattern to be over-knurling that can damage your knurls.  These are HSS knurls but I've done a fair number of knurls in stainless steel and have noted no significant wear. If I were to do a lot of it in SS though, I would use cobalt knurls and maybe switch to carbide pins.

Unasked for info:

Side plates are 1/4" thick mild steel.
Arms are 5/8" mild steel, milled square to 1/2" X 1/2" X 3" long.
Top nut is 12L14 steel.
Delrin washer underneath top nut
Half-moon inserts are 1/2" OD, O-1 tool steel left in annealed state. No point in hardening them when they run in mild steel with very little movement.
Aluminum spacers are ~3/8" OD.
Hope this helps, Nicolas.


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## mikey (May 10, 2018)

@Ken from ontario wrote:
_Mikey, I got a question for you, the pins that hold the knurls, how are they secured so they don't become loose and slide off? I'm working on modifying a bump type knurling tool and for the pins I used SH cap screws with lock nuts ,I like your approach better, it looks cleaner , I have lots of drill rod to use but as I said I'm worried in case the knurls would slide off during the operation unless they are slip fit.
Oskar, I'm sorry for posting this question in your thread but it is something you may encounter yourself if you decide to build the tool from scratch. _

Then Dave (@British Steel) nailed it:
_Hi Ken,

I may be wrong (Mikey won't be!) but the 2 SHCS visible on the scissor arms look like they have washers under their heads, and those could fit in a groove in the pins, locking them in place?

Dave H. (the other one) _

I will respond again for the benefit of those who come later and expect an answer.

The pins are 3/16" drill blanks, not drill rod. They have a shallow slot cut on one end. A stainless washer has a flat ground on one side that fits into this slot. A 6-32 SCHC locks the washer in place. This holds the pin solidly but allows for very quick disassembly for cleaning. I got this idea from one of Guy Lautard's bedside readers and it works well. Drill blanks are hardened and the slots were cut with a Dremel abrasive wheel.


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## ddickey (May 10, 2018)

That's pretty much exactly how I did mine. I also lapped the pin in the hole for the knurl.


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## oskar (May 10, 2018)

Thanks Mike for your time and the detailed description. BTW your knurled tool looks more like a piece of art than a tool, its amazing!

I will never achieve such a workmanship with my limited skills however I will try to make a workable tool.

Nicolas


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## mikey (May 10, 2018)

oskar said:


> Thanks Mike for your time and the detailed description. BTW your knurled tool looks more like a piece of art than a tool, its amazing!
> 
> I will never achieve such a workmanship with my limited skills however I will try to make a workable tool.
> 
> Nicolas



Thanks, Nicolas, but its just a tool, done with care. You CAN do this. If you like, PM me and we can work on it together.


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## oskar (May 10, 2018)

mikey said:


> Thanks, Nicolas, but its just a tool, done with care. You CAN do this. If you like, PM me and we can work on it together.



Much appreciated Mike, finishing now a QCTP and when this is done I will start the knurl tool. Have to order some material and I will contact you when needed.

BTW trying to order the the drill blanks from KBC tools but they dont show the length and when I called the guy said its "Jobbers length" but did not know the actual length. Anyone knows what length is "jobbers length"?

Since I'm in Canada I try to order locally and the knurls available are as per attached picture. I choose the 25TPI/50T. Is this acceptable or another choice will be better? I only work with aluminum
http://www.kbctools.ca/customer/kbtoin/customerpages/digitalcatalogs/cmaster.htm#book/281

Nicolas


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## ddickey (May 10, 2018)

Did you ordered the knurl pins also.


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## oskar (May 10, 2018)

Just realised I didn’t include the picture in my last post, its attached here

No I didn’t order the knurl pins yet because KBC provides steel pins for $3.25 or Carbide pins for $19.10 and the drill blanks are $2.95.


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## mikey (May 10, 2018)

Big knurls, Nicolas. You might consider a 1/2" OD knurl instead. 

Re the pins, how do you envision securing them to the arms? That will determine which material to use.


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## oskar (May 10, 2018)

They only have 3/4" OD, I will call and find out if they can get me 1/2" OD

I was thinking to secure the knurls to the arm like you did but my arm will be made with 1/2" thick aluminum. I prefer not to use steel since I only do hobby work and aluminum is much easier to mill. 
Nicolas


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## mikey (May 11, 2018)

I would use mild steel if I were you but its your call. Knurling involves pretty high forces, though, so maybe think about it. Mild steel is not difficult to mill and it will hold up better over time. Also bear in mind that the modulus of elasticity of steel is three times that of aluminum.


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## oskar (May 11, 2018)

mikey said:


> I would use mild steel if I were you but its your call. Knurling involves pretty high forces, though, so maybe think about it. Mild steel is not difficult to mill and it will hold up better over time. Also bear in mind that the modulus of elasticity of steel is three times that of aluminum.


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## oskar (May 11, 2018)

Hi Mike

I understand your concern about the mild steel but it’s only about a month I have my mini lathe and never used a lathe before so I’m hesitant to use steel right now. If all goes well later on I can replace the aluminum knurl tool with one made out of steel. I only have a hobby shop which is equipped for woodwork and I cut aluminum to size using a Miter saw and Skill saw with a 50 tooth carbide blades. These blades work well on aluminum but are not good for mild steel.

The knurls I want to make are to replace some 8-32 and 10-32 SHCS on my mini lathe and I will make them out of brass or aluminum with a diamond pattern. Which pattern do you like better between the ones you bought (EQR/EQI 225 or 230) and do they produce a diamond pattern?


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## mikey (May 11, 2018)

Both are good. The 230 is a finer pattern than the 225. I don't have a lot of pics of knurls so I keep showing the same ones. 

Here is one in aluminum with the 225 knurls:




Here is what is called a square knurl, done with a pair of 230 straight knurls and a pointed HSS tool ground to the same angle as the knurl's teeth. You cut the straight knurl, measure the distance between the peaks, then cut perpendicular lines to the same depth and pattern with the HSS tool. Makes for an interesting pattern. Not my idea; this came from Geo. H. Thomas.




The 225 is just slightly coarser than the 230 but the difference is noticeable. If I had to pick one, I would choose the 225.


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## oskar (May 11, 2018)

Thanks for the pictures Mike, those knurls look pretty sleek

I got in touch with Form Roll Die and they can ship to Canada. They gave me a price of $13.35 for each of EQR 225 & EQL 225 and I plan to order them on Monday. I will also ask them if they can custom grind a bevel on both sides on each knurl like you did and if not too expensive I will take it.

I will also order 2 drill blanks 3/16” from KBC in Canada. Do you know if FormRoll can also supply these drill blanks? If yes I might as well get the set from them.

Nicolas


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## mikey (May 11, 2018)

I decided to take a look to see if anybody made a knurler that would work on the Taig without you going through the trouble of making one and I found this: http://www.cartertools.com/lmsk.html

Here is the knurler: https://littlemachineshop.com/products/product_view.php?ProductID=1911

Cost is not too dear and it would get you up and running quickly. Rather than making a knurler from aluminum, I would consider the one from LMS instead. Later, when you are more confident of working with steel, we can re-visit making a knurler if you like.


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## oskar (May 11, 2018)

Mike you are amazing and thanks for your time again

It’s funny because I visited cartertools site many time before but I missed that page. It’s also interesting because a similar tool (picture attached) is selling in a town close to mine.

In any case I apologise if I sound stubborn but I prefer to make my own and the main reason is to gain the experience using my lathe. If the results are not good, then I will buy either the one you mentioned or the one close to my town.


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## WarrenP (May 11, 2018)

mikey said:


> Here is the knurler: https://littlemachineshop.com/products/product_view.php?ProductID=1911
> 
> Cost is not too dear and it would get you up and running quickly. Rather than making a knurler from aluminum, I would consider the one from LMS instead. Later, when you are more confident of working with steel, we can re-visit making a knurler if you like.



I have that knurler, so far I have to say it works very well..


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## Silverbullet (May 12, 2018)

With an old Kant twist clamp building one is much easier.


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## ddickey (May 12, 2018)

Why not just order a kit? 
http://www.hemingwaykits.com/acatalog/Knurling_Tool.html


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## oskar (May 12, 2018)

Thats very interesting. I sent email asking some details. It could be a good alternative


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## mikey (May 12, 2018)

Nicolas, if you go with that Hemmingway kit, please do a review if you can. I am curious to see how much actual machining is required to assemble this knurler. Hopefully, most of it is done for you because their price is pretty high for some small bits of steel. If it can be done without the use of a milling machine then I think this is a really good option.


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## oskar (May 12, 2018)

Good point Mike

I already sent an email to ask for the shipping cost but I will send another one now to ask what work is involved plus to include a set of knurls since I don’t know their size.

Regarding the cost of the unit I think it will be less expensive than the one we talked yesterday because the cost of 23.90 Pound includes 20% VAT tax which I don’t have to pay.


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## oskar (May 14, 2018)

Looks like no one is at the Hemingwaykits site. Sent 2 emails last Saturday and as of now I have no response. Most likely I will give up on them


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## ddickey (May 14, 2018)

Have you checked your junk folder?


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## oskar (May 14, 2018)

I don’t have junk folder but I have trash folder and nothing is there. In any case I never set any antispam rules in my email program and never had any problem before or missing emails.

Perhaps is something common in England? Last month I sent email to another British company from eBay and never got a reply. I went ahead and ordered the items I wanted and on the eBay invoice I had to ask the vendor to reduce the sipping cost since I was buying a few items from the same place. The guy came the next day and all went fine, but never answered my email!


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## Aaron_W (May 17, 2018)

This is awesome, I've been thinking about knurling after making a few small things that would be nicer knurled. I was getting ready to ask about the Sherline knurling tool and this thread popped up in the featured thread box. Another project to add to the list. 




oskar said:


> Hi Mike
> 
> I understand your concern about the mild steel but it’s only about a month I have my mini lathe and never used a lathe before so I’m hesitant to use steel right now.




If you use 12L14 it isn't bad at all. I was also reluctant to using steel on my Sherline, particularly after working with some cold rolled steel that was not so easy to work with. 

I'm using 12L14 for the crank shaft on a little wobbler steam engine and other than taking smaller cuts, I'm not finding it any more difficult to work with than brass or aluminum.


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## cascao (May 17, 2018)

If you gonna make one, this one is a good sugestion.


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## oskar (May 17, 2018)

I like that design and its simpler


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## Cadillac STS (May 17, 2018)

mikey said:


> I own the Sherline knurler and it works. However, it is nowhere near as good as a scissors knurler. The problem is that nobody makes a good scissors knurler for the Sherline/Taig sized lathes so I made my own by looking at a single blurry picture of a knurler made by Chris Heapy of the UK. Maybe these pics will be enough to get your thinking going:
> 
> View attachment 267095
> View attachment 267094
> ...



Would you consider taking this all apart, setting the parts altogether with a scale in the picture?  A few different angles of the setup also.  This way it would be easier for someone to see and replicate it. 

As is sometimes said a picture (with a scale in the background) is worth 1000 words. 

Current readers may not need it but years of future searchers would appreciate that.  And this thread is good enough already to show up searching.


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## oskar (May 17, 2018)

I found this knurl tool on youtube by Curt Filipowski






I consider making this one after I get my knurl wheels from Formtol. Mike’s is the best I have seen so far but kind too difficult for my limited experience.


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## ddickey (May 17, 2018)

Toms Techniques makes a nice looking one also.


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## mikey (May 17, 2018)

Cadillac STS said:


> Would you consider taking this all apart, setting the parts altogether with a scale in the picture?  A few different angles of the setup also.  This way it would be easier for someone to see and replicate it.



Yeah, breakdown pics would be useful. I'll try to do it as soon as I can.


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## mikey (May 17, 2018)

@Cadillac STS, here you go. Not sure how the picture quality will be. First pic shows all the parts in relative position. You can see that the arms hinge on a stainless steel bushing through which a 10-32 SHCS passes. The bushing is sized to just fit a reamed hole in the outer side plate and the end of the arm. Also visible are the aluminum spacers that are exactly the same width as the arms. You can also see some draw-file marks on the inside of the plate; since the spacers and arms are the same width, to allow the arms to move you must draw file just enough clearance on the side plates. This gives you movement but no discernible play. The screws that pass through the spacers simply thread into the aluminum mounting block that mounts to the cross slide of the lathe.

Disassembled:




Arms: Here you can see that the holes for the half-moon pivoting inserts are round on one side of the arm and slotted on the other side to clear the threaded shaft. The half-moon is O-1 steel. The threaded shaft is 12L14, screw cut to 1/4-28 on top and 1/4-20 on the bottom and Loc-Tited into the lower half-moon insert. Note also that the half-moon cutout in the arms is about 1/8" forward of the center of the arms to provide a bit more leverage; you can crank down with just hand pressure to produce full depth knurls because of this. The plates constrain the arms laterally so this tool is much more rigid than other designs.




How they fit: You can see that there is a reduced diameter below the hex head of the tensioning knob. That diameter just passes between the plates to allow sufficient travel when knurling smaller diameters. Note also that the front of the plates is rounded to allow clearance for larger diameter work pieces.




Not too complicated. Dimensions are not critical in terms of size but you must work with care. By that, I mean all holes are reamed carefully, bushings and spacers are turned accurately, all parts are squared. None of this is difficult and it is a good opportunity to do work with precision.

The nice thing for me was that everything other than the knurls was already in my shop so I paid only for the knurls. This thing took the better part of a week to design and machine but it has served me well for over a decade. It has not mistracked or produced a single bad knurl so I'm satisfied with it.

Hope this clarifies things for you guys.

EDIT: I forgot to re-emphasize a really important lesson I learned. *In order for any feature to be in the exact same location on two or more separate work pieces, you must clamp the pieces together and machine the feature in one operation.* For example, if you want the holes at the ends of the arms in the exact same place you have to clamp the arms side by side and square to each other, then drill, then ream. OR, if you want the half-moon holes to be at the same point on the arms, you must clamp them together and drill between those arms. This is the only way to get things exactly the same, and I've already paid for the lesson.


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## oskar (May 17, 2018)

Very nice work Mike, thanks


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## mikey (May 17, 2018)

oskar said:


> Very nice work Mike, thanks



Thanks, oskar.


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## oskar (May 21, 2018)

mikey said:


> Nicolas, if you go with that Hemmingway kit, please do a review if you can. I am curious to see how much actual machining is required to assemble this knurler. Hopefully, most of it is done for you because their price is pretty high for some small bits of steel. If it can be done without the use of a milling machine then I think this is a really good option.



Just had a reply from the Hemingway Kits (Kirk Burwell) and he confirmed that all kits provided needs machining. So yes his price is very high


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## DHarris (May 21, 2018)

Oskar, I had one of the Hemingway kits and the machining is not too extensive - mostly drilling holes and some general shaping on the knurl arms (helps to have a mill).  BUT - I, like Mikey, have a Sherline lathe and mill and this knurler is, in my opinion, wayyyyy to big for my little Sherline!  So, I made one like Mikey made and it works great like he said - my only change to his design was to make it for a QCTP.  I'm not familiar with the Taig lathe - so don't know if it would be too big for that lathe, but check out the specs on the Hemingway site to be sure - - I'd send you the kit I bought, but i've already given it away to another guy.


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## oskar (May 21, 2018)

Glad to hear your experience Dave, thanks

I have decided against Hemingway Kits because as Mike said it’s too expensive when you include the shipping cost and I agree.

I considered making the Knurl tool for my QCTP but I think it will be more stable if I do it as Mike’s however my cross slide on my mini lathe is only 3.75” long so I have to change some dimensions. I made a model in MDF and I’m working now to find the optimal dimensions.

Nicolas


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## ddickey (May 21, 2018)

What was shipping to CAN?
$12 to the states.


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## oskar (May 21, 2018)

He said when I click to place the order I will see the total cost (excluding the VAT tax) and including the shipping cost and I have the option to cancel the order before I click ok but to get there I have to input my VISA numbers and I don't want that. I would say $12 sound right


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## ddickey (May 21, 2018)

Yeah. With the CAN dollar it would be a little pricey. With shipping and buying knurls it would be ~$100 I bet.


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