-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Knurling advice
- Thread starter Maplehead
- Start date
- Joined
- Sep 5, 2013
- Messages
- 3,861
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
-frank
- Joined
- Dec 20, 2012
- Messages
- 9,422
Which lathe are you using?
- Joined
- Nov 27, 2012
- Messages
- 7,933
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
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
- Joined
- Nov 25, 2015
- Messages
- 9,882
Nice Will. What kind of knurl is that 3rd pic with the spiral knurls.
- Joined
- Nov 27, 2012
- Messages
- 7,933
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!
- Joined
- Nov 27, 2012
- Messages
- 7,933
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
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
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?).
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?).
- Joined
- Nov 27, 2012
- Messages
- 7,933
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.
Similar threads
