Kant-twist Knurling Tool

[MrWhoopee]

Yesterday I finally grew tired of the frustrations of bump knurling. I briefly considered buying a scissor type knurler. Briefly. I've had this idea rattling around in my head, a knurler built around a Kant-twist style clamp. I have these imitation Kant-twists, they were cheap enough I didn't mine cannibalizing one.

https://www.ebay.com/itm/38342699419...AAAOSwR1FeS-at

It had to be wider than the stock clamp to accommodate the 3/8 knurling rolls, so I took it completely apart and made new pivot, spacers, nut etc. to increase the width. I also made a shank to fit the toolholder on my lathe.

This is the unit mocked up, before I riveted everything back together.



After finishing some details, I riveted it all together.



This is my first attempt, 3/4 dia. aluminum



and this is steel.



After tweaking the alignment of the rolls, this is a piece of 1/2" black pipe, turned to cleanup before knurling.



Not perfect, but not bad.

[Stu]

That is slicker than snot, I like it.

[Bented]

I use clamp knurling mostly, works a charm
https://photos.smugmug.com/My-First-...5B1%5D-640.mp4

However one may exert enough pressure to explode a knurling wheel or 2.

[BCRider]

That is slicker than snot, I like it.

Agreed!

I think you might have just come up with a new "Standard" that will sweep all others to the side! It's a super strong design, It has a WIDE range of diameters it would swallow between the knurls and the adjustment screw is aimed back away from the work area where if a wrench or socket is dropped it's not going to fall into the spinny stuff. This is just a winner of a design in every way I can think of.

Tell me the pins for the knurls are easy to remove and trap back into position for fast knurl changes... Then it'll be totally perfect.

[MrWhoopee]

Tell me the pins for the knurls are easy to remove and trap back into position for fast knurl changes... Then it'll be totally perfect.

Yep, they're socket head screws,

[alanganes]

This is one of those things that seems obvious, but only after someone smarter than me thinks of it. Very nice! I have a scissor style like Bented shows in his video though mine is a "made in India" one I bought from Enco ages ago. It actually works OK. I don't knurl stuff very often so I'm a bit hit and miss on getting the thing tightened just right. I really like your version, thanks for posting.

[Lew Hartswick]

LIKE it. :-) With all the KantTwist copies I've made, about 15 or so, I hadn't thought of that. IF I ever get access to a shop again that will be one of my first projects. The side plates will have to be a bit thicker and the mounting bar will have to be designed to fit. Unless I get back to the high school I'll have to make the other fixtures to do it. Hummmm; What do you think I could sell one of those for ?? It would give me something to do (If I get access to a shop again) :-)
...lew...

[MrWhoopee]

LIKE it. :-) With all the KantTwist copies I've made, about 15 or so, I hadn't thought of that. IF I ever get access to a shop again that will be one of my first projects. The side plates will have to be a bit thicker and the mounting bar will have to be designed to fit. Unless I get back to the high school I'll have to make the other fixtures to do it. Hummmm; What do you think I could sell one of those for ?? It would give me something to do (If I get access to a shop again) :-)
...lew...

Yes, I think if I was making the side plates they would be at least 3/16". Some of my difficulties where caused by the side plates getting slightly bent during disassembly. The mounting bar is a very close slip fit over the center pivot, which I made 1/2" dia. The clearance between the side plates and mounting bar should be held to less than .005". Seriously considering making one from scratch now that I know it works. Will probably make it bolt together instead of riveted.

[Bob Engelhardt]

... I have these imitation Kant-twists, they were cheap enough I didn't mine cannibalizing one.

https://www.ebay.com/itm/38342699419...AAAOSwR1FeS-at

[snip]

$27 for 4 versus $17 apiece - that's tempting. Are they "OK", or is it a case of you get what you pay for?

Not perfect, but not bad.

Yeah, if I didn't already have a scissors knurler I'd make one.

[Lew Hartswick]

Yes, I think if I was making the side plates they would be at least 3/16". Some of my difficulties where caused by the side plates getting slightly bent during disassembly. The mounting bar is a very close slip fit over the center pivot, which I made 1/2" dia. The clearance between the side plates and mounting bar should be held to less than .005". Seriously considering making one from scratch now that I know it works. Will probably make it bolt together instead of riveted.

The ones I made I found a slick way to rivet the large ones but the 2" ones I used a screw into the spacer as an easier way to make the spacers. The mounting/pivot is the area of design I'd have to give some thought to.
...lew...

[BCRider]

Yes, I think if I was making the side plates they would be at least 3/16". Some of my difficulties where caused by the side plates getting slightly bent during disassembly. The mounting bar is a very close slip fit over the center pivot, which I made 1/2" dia. The clearance between the side plates and mounting bar should be held to less than .005". Seriously considering making one from scratch now that I know it works. Will probably make it bolt together instead of riveted.

Plus it would be good if the plate used for them were a higher yield point "tool steel" or one of the other more durable steel alloys. There's a lot of pressure in the contact pivot holes at all points and the last thing we'd want is to see those holes be wallowed out by the metal moving. And with the steel picked for avoiding that aspect I'm thinking that we'd also have taken care of any bending due to side loads on the plates. With that in mind how thick are the Kant clone's side plates? And the pin diameters in the pivot points?

Of course in the end the Kant Twist style design is still a scissors style mechanism. I really like how it changes the direction of the tensioner screw and how it wraps around the part being knurled to produce such a wide range of size options. But mostly using a Kant clone as a parts donor is about saving time for making a scissors style knurling tool. Which in the end is still a rocking great idea.

[jmm03]

on a scissor type tool how do you determine the depth of the knurl? scrap first, successive passes? Jim

[MrWhoopee]

$27 for 4 versus $17 apiece - that's tempting. Are they "OK", or is it a case of you get what you pay for?

They are surprisingly good . 👍 The side plates are thicker than the genuine 2-1/2 I have. Waiting for them to make larger ones.
I

[MrWhoopee]

on a scissor type tool how do you determine the depth of the knurl? scrap first, successive passes? Jim

I'm still learning. Successive passes so far.

[MrWhoopee]

Thanks for all the kind words. I fully expected to be told it had already been done.