Thanks for your detailed reply & clear pictures.
Sidebar question (sorry I was ogling your tool rack haha). Can you tell me about your knurling tool? Is it your own design or commercial unit? Looks like a standoff integrated to the shank... so you can approach a shoulder & keep the tool post back a bit, or?
Certainly. I first bought an inexpensive import scissors knurling tool from Enco:
https://www.mscdirect.com/product/details/78657012?rItem=78657012
This is not a quality tool, and would have required a lot of tuning, and fixing to make it into one. I didn't have the patience to do this:
So I decided to buy a higher quality knurling tool from Eagle Rock. That's what you see in the photo. Eagle Rock makes lots of different models, right, center, left offset, etc. They're entry level version I'm sure is great, but it's not designed to easily replace the knurling wheels. I bought this one
http://specialtytooling.eaglerockon...-scissor-type-knurling-tools/k1-44-21-0625r-e
from Ajax tools for $300
http://www.ajaxtoolsupply.com/earoknscclkn2.html
I based my decision largely on this review:
The Eagle Rock is made in the USA, and is a fine tool. I wouldn't put it in the category of a Swiss watch or as refined as what Stephan did in his upgrade of an import, but it suits my needs and I can recommend it. That specific tool comes with 20 TPI diamond wheels that are 3/4" diameter, 3/8" wide with a 1/4" bore for the axle.
I had not knurled before jumping immediately into the deep end of the pool, taking on a heavy deep knurling of 316 stainless steel with 12 TPI wheels. These are the wheels:
This is what I was making - thumb screws
for the sliding cover over the compound DRO scale:
That was challenging. And I'd put it at the limit of the 1340 lathe without moving to a solid tool post (eliminating the compound) which I intend to do soon. Jbolt has a thread that discusses the solid tool post mount here on H-M. as well as YouTube videos by Stefan
(
)
and Robin
(
).
The biggest problem I've found with knurling is that under heavy load, the tool post (Dorian in my case) will tend to drift clockwise - which really chowders-up the knurling. Tighten everything down, lock the cross slide, and use cutting oil.
More conventional diamond cutting 20 TPI is much easier on the machine. Here's a video of that operation - making the handles and knobs for the 1340 out of 316 Stainless:
https://www.flickr.com/photos/davidpbest/34162064130/in/album-72157672547607804/ The handles, took several passes at progressively deeper cuts, and it was important to get the OD on the part matched to the TPI of the knurling wheel to get good results.
I ended up making a spreadsheet for looking up the required OD for the TPI knurling wheels I have on hand (12, 20 and 21) and I'm attaching it here - look for the OD you are targeting, and to the right will be the precise OD that comes closest to the target that matches the TPI of the wheel.
Hope this helps.
