Clamp Type Knurling Tool

[PixMan]

Tom,

I've got a good amount of 1018 CRS holding down the shelves on my stock rack which was gifted to me. It's a 16x40 lathe with (nearly) a 5HP spindle. I've tried using my Dorian No.10 knurling tool holder to knurl a 25 pitch diamond knurl in Ø1-5/8" 303 stainless steel and I just couldn't get beyond a light knurl. It just kept pushing away and moved the stock back into the chuck.

What is the coarsest knurl you've done with your tool, what material was it and what diameter? I've used some very robust diametrally opposed knurling tools in my work and had great success with the rigidity of the all-steel construction. Knowing just how much force was needed to knurl the 25 pitch in stainless steel is why I lean toward making mine steel, and I may also "scale it up" to accommodate larger work and the "next size up" knurling wheels.

Do you think it's still overkill to use steel, or would you still go with aluminum?

[Mayhem]

I suggest you go ahead and make two Ken. One in aluminium and the other in steel. Then, if you decide there is no difference between the two, or in fact the steel one is more to your liking, the aluminium one can go in my suitcase and not be too heavy

[PixMan]

I like that idea and just may do that.

Weight of a piece like that doesn't matter to me a bit. As compared to lifting my 12" 4-jaw independent chuck with it's attached D1-6 adapter up onto my lathe, if a steel version of the knurling tool weighed 75 pounds (34Kg) it would still be less than 1/2 the weight of the chuck!

Good winter project.

[TomG]

(11-20-2014, 02:31 PM)PixMan Wrote: Tom,

I've got a good amount of 1018 CRS holding down the shelves on my stock rack which was gifted to me. It's a 16x40 lathe with (nearly) a 5HP spindle. I've tried using my Dorian No.10 knurling tool holder to knurl a 25 pitch diamond knurl in Ø1-5/8" 303 stainless steel and I just couldn't get beyond a light knurl. It just kept pushing away and moved the stock back into the chuck.

What is the coarsest knurl you've done with your tool, what material was it and what diameter? I've used some very robust diametrally opposed knurling tools in my work and had great success with the rigidity of the all-steel construction. Knowing just how much force was needed to knurl the 25 pitch in stainless steel is why I lean toward making mine steel, and I may also "scale it up" to accommodate larger work and the "next size up" knurling wheels.

Do you think it's still overkill to use steel, or would you still go with aluminum?

Yeah, steel is still overkill. I made some rolls for a grain mill (home brewing) and they were 1 1/4" diameter 1018 with a 12TPI knurl. That was pretty much the limit of this knurling tool but it's also not a knurl that I use every day. It would be plenty sturdy for a 24 pitch knurl even in stainless.

Tom

[TomG]

That Darren is always thinking.

[Dr Stan]

(11-20-2014, 11:51 AM)TomG Wrote:

(11-20-2014, 10:53 AM)Dr Stan Wrote: Tom,

Very nice design & drawings.     I especially like removing the stress from the cross slide.

What is the largest diameter it is designed to knurl?

One comment/suggestion.  I'd add the 10-32 bolt hole pattern on the back/bottom of the holder which would enable one to mount it 90 degrees from the existing design.  I think it would give the knurler more options for mounting and probably reduce tailstock extension making the set-up more rigid.  That would be especially advantageous to those with smaller (< 10") lathes.

Thanks,

Stan

Thanks Stan.

The largest diameter that can be knurled is 2".

I'm not sure what you mean by adding a bolt hole pattern to the bottom. Also what do you mean by "tailstock extension"? The tool is meant to mount in a quick change tool post.

Tom

Tom,

What I'm attempting to communicate is to allow mounting on the side of the QCTP rather than, as I take it, on the front.  It appears to me one would need to extend the tail stock a fair amount in order to clear the holder.  Moving it to the side should reduce the amount of tail stock extension.

BTW, thanks for the info on the capacity.

Stan

[Dr Stan]

(11-20-2014, 08:16 PM)PixMan Wrote: I like that idea and just may do that.

Weight of a piece like that doesn't matter to me a bit. As compared to lifting my 12" 4-jaw independent chuck with it's attached D1-6 adapter up onto my lathe, if a steel version of the knurling tool weighed 75 pounds (34Kg) it would still be less than 1/2 the weight of the chuck!

Good winter project.

I understand all too well.  I too have a 12" 4 jaw but with a D1-4 mount.  Still heavier than I like to lift these days.  Fortunately I also have a 1000 Kg capacity hydraulic lift table which gets it up to a workable height.  Using it in combination with the custom made chuck boards for the 4 jaw, 8" 6 jaw, 6" 4 jaw, and collett chuck makes it much easier on my poor back. 

[PixMan]

Another thing I'm thinking of doing with Tom's design is to make a second style of holder that has a 3/4" straight shank and be grabbed in my Jacobs 18N drill chuck, held in the tailstock. Then it could act as the Hardinge U-style knurling tools I used on smaller machines to just feed over the end of a part in the chuck or collet. No sideways torque on the toolpost!

[TomG]

Ken,

The commercial clamp knurling tool that I have has some additional framework and a 1/2" shaft so the tool can be mounted in the tailstock. I've actually never used it which is why I left it out of this design.

Tom

[dallen]

I made one of these some time back when Tom first posted a photo of it. The design that Tom has presented mounts on the front side of the tool post. It puts no load on the tool post or carriage other then what little force it takes to keep it from spinning. The original has a spud on the back so it can be held in the tail stock or in a turret. Only reason I can see for holding it there would be if you were making numerous parts that needed to be knurled.

I cast the plate for mine, by the time I made the pattern and did the machine work on it I could of used plate and been time ahead.

you will need .5 inch diameter knurls to use the full capacity of the center hole.

I used .5 inch brazed on lathe bits for the stock to make my knurl holders out of.

I made mine as shown in the MSC catalog, but could easily change to Toms Design without loosing any strength or rigidity.

DA