Hi Ian,

You could try individual tangential knurls separated by a grooving/parting/vee tool.

Good luck.

Well there are two problems, you need to follow the contour of the work and the knurls also need to be square on to the profile as well, [ assuming standard knurls]

Just an idea ! make a straight feed two wheel knurling tool that has the head articulated so it can follow the profile, thus the head and wheels swing left & right. As for the in feed to follow the contour then it's either by hand, eye & feel or make a profile follower similar to the ones where the taper turning attachment used.

Possibly an overkill for a one off ? Whether it will work I know not but my first thoughts – lets see what the team come up with

John

FWIW, to my eye the grooved version looks better!

The 'proper' way might be to mount the knurling tool on a long-radius turning fixture or a copying attachment so as to follow the curve. In all probability you'd have to make the gadget plus a template, so you've got the decision to make as to whether the knurled finish is worth that, the grooves being so hugely easier and functionally similar.

Edited By Mick B1 on 19/03/2023 11:27:57

Possibly done by pressing ? Noel

Thinking about my experience of using the hand held squeeze knurler device mentioned by Bizibilder it might be possible to keep sufficiently even pressure on the tool to create a good looking knurl by twisting the tool slightly so it runs from side to side. The technique works fine on a long(ish) parallel shaft.

Can't see any reason why it shouldn't follow moderate slopes and curves. Obviously if the slope is too steep or the curve too great it's going to dig in. Given an adequately shallow curve or slope it obvious issue is keeping the right level of pressure on the tool as it runs up and down the the cuve. I imagine it will take several strokes to form the knurl squeezing harder with successive runs. For ordinary small knurling you just squeeze until the knurl looks deep enough.

Here is a picture of the tool Bizibilder refers tor :-

Certainly hasn't been made for years and rare then. Found mine maybe 40 years ago in the "going to throw away" box at an experienced machine tool and tooling dealer who didn't realise what it was and how effective it could be. Having used one I knew better and gladly handed over an extra £1 for it on top of the price of the big Pollard drill I went to buy.

Minor correction to what Bizibilder said. The screw sets the squeeze depth not the clamping load. I'd think screw clamping could be dangerous if the tool gets away from you. Although the adjustments imply it can be set to handle work over 2 inches – 50 mm in diameter I find it starts getting cumbersome over an inch – 25 mm or so. But what it does do it does really well. Had to knurl some 6 mm pins to fill some no longer needed holes in a part being modified yesterday. Longest party of the job was finding some stock and mounting in the lathe. Squeeze and repeat 8 times gave me 8 pins 10 mm long ready to tap in.

Links to drawings and build instructions for that and couple of similar ones in the thread linked to by Bizibilder.

Clive

Edited By Clive Foster on 19/03/2023 15:52:05

Irbailey

Need to lean it a touch and push slightly sideways to make it move along. It's a feel thing really. Given the right mix of squeeze force with a modest push and gentle lean it walks sideways very controllably.

If you hold it dead square when you squeeze it stays in place. Just the ticket for doing knurled head screws.

Toolpost mount types you feed side to side using saddle feed. On lighter machines its probably better not to try and make a full knurl in one go.

Clive

I bought one of these knives from Brick Lane street market in London about 60 years ago. Ex military tools and hardware was sold at most markets and many specialist shops in those days, seldom see the stuff now! The handle on mine was ribbed, I've seen many more over the years but never one with a knurled handle. Interesting thread, knurling is tricky enough on straight sections, I'm intrigued to see how it turns out.

Daveb

Is the following a stupid idea?
I use a frame based knurl which is simple to set up and avoids pushing with the toolpost. Imagine such a system but with a longer length of threaded hole for the screws that adjust the knurl pressures and put a strong spring between those screws and the knurl heads. If that spring is long enough and of the right 'power' then the amount of deflection of the knurls to move over the curve of the workpiece wouldn't affect the knurl pressure change by much and give an even finish?

pgk

Just my two-cents woth on thiz. But it seems to me that even if one had the benefit of some sort of 'follower cam' to move the cross slide in and out to match the curve of the knife handle (using a push style knurler) one would still obtain a rather 'iffy' knurl as the constant change in handle diameter would have the knurl pattern (regarding number of even points around the circumference of the handle) changing over the length of the handle, varying from even numbers of points through to bands where one would have 'extra bits' and back into areas of even numbers of points. I imagine a visual going in- and out of phase sort of thing. Same sort of chowdering as that series of banded knurls on the example knife handles.. but more smoothly obtained.

Where's Sir John when We need Him?