Knurling Tool for medium (Harrison M300) size lathe

[Lee Jones 6Participant @leejones6]

Currently in the market for a knurling tool.

I understand that the scissor/c-clamp style puts less pressure on the spindle than the push-in style, but that's about the limit of my knowledge presently.

When are c-clamp style tools not the best option?

Does anyone have any product (bought rather than made [maybe further down the line if this doesn't work out]) recommendations that have served them well?

What does a 6 wheel model offer? Are they just 3 different patterns located on the same tool?

[Lee Jones 6Participant @leejones6]

[Tony Pratt 1Participant @tonypratt1]

Well logic dictates that a ‘clamp type’ knurling tool puts less side load on the headstock bearings but many were used in industry for years with I suppose little damage to lathes & as you have a decent sized machine I can’t see a problem?

I personally have a cheapo copy of a Jones & Shipman clamp type knurling tool purchased from Chronos, it’s pretty loose in its construction but actually gives good results, and the 6 wheel type normally can produce 3 different patterns, typically fine, medium & coarse.

Tony

[HollowpointParticipant @hollowpoint]

Keep an eye out for a Marlco knurling tool. Not cheap but the best IMO.

[Former MemberParticipant @formermember32069]

[This posting has been removed]

[KWILParticipant @kwil]

It also depends upon the size (diameter) of the item you are knurling. I have M300 and Myford S7 and use a clamp type for preferance.

[Lee Jones 6Participant @leejones6]

With regards to conventional style knurling tools, what the the benefits to single or double wheeled tools?

[KWILParticipant @kwil]

2 wheel will help to prevent the item riding up if applied at the correct level, ie deflection is only horizontal.

[CirclipParticipant @circlip]

Also worth considering, Knurl cutting tool.

Regards Ian.

[Clive FosterParticipant @clivefoster55965]

+1 for what Hollowpoint says about the Marlco tool. I have one. Excellent device. The Hemingway kit is essentially same design but, I think, a little smaller.

Nice (new) sharp knurls make a huge difference to how well the job goes. I have my doubts about the quality of standard fit knurls on the low end tools. I'd budget for a new set anyway if picking up a used tool. Only takes one bad go on stainless steel to rip the sharp edge right off. Or worse. Got two nicely D shaped ones on my Marlco that way. But I suspect the previous owners had bought on price not performance.

The new ones I got from Zoro seem good despite a more affordable (not cheap tho' price compared to some other pro suppliers.

A potential disadvantage of push tools is that the work needs to be stiff enough to stand the strain without bending.

The hand held nutcracker type are quite easily made and surprisingly effective on normal jobs. Not for stainless tho'.

This is mine, a proper commercial product.

The design has been replicated for a Model Engineer article published 29 th January 1999.

American Magazine Popular Science for October 1941 has brief DIY details for a very similar one **LINK** or Google for Nutcracker Knurling Tool.

Also one in May 1965 edition of the American Practical Mechanics magazine **LINK**. Somewhat larger I think.

Clive

Edited By Clive Foster on 11/05/2020 13:28:10

[Lee Jones 6Participant @leejones6]

Went for a large 2 wheel push-in forming type; with fine, medium and course wheels provided ans a package.

A nutcracker type knurling tool has also been placed on the 'to-make in the future' list.

Thanks for all your help and advice.

[not done it yetParticipant @notdoneityet]

I suspect the only time scissor knurlers would not be the preferred type is if the workpiece diameter were too big!

With our machines tending to be smaller than industrial/commercial units, the scissor type must be the recommended type for the majority of hobbyists. Their only other down-side is that ‘prickly aspect’ of extra initial cost.

[Nigel McBurney 1Participant @nigelmcburney1]

The tool holder central securing bolt must be really tight,as the pressure from the knurling can cause the toolhoider to rotate and the knurl holder comes away from the work. Some of the larger type Dickson holders had a locating pin to keep the main block of the toolholder from rotating away from the work.

[Lee Jones 6Participant @leejones6]

Right, the size limitation was one reason I decided against the scissor/clamp style.

I read about the toolpost rotation issue in a previous thread.

My toolpost is the T1 T63 type. I need to check if it has the anti-rotation pin fitted.

[John Paton 1Participant @johnpaton1]

Scissor type can also operate on slender components which would otherwise flex under lateral pressure

Also handy are the 'multi knurl head' type tool where you simply spin the head round to select the knurl pattern you require (saves time changing the wheels over) but these are the plunge type rather than scissor so better suited to heavier work.

[thaiguzziParticipant @thaiguzzi]

Posted by Lee Jones 6 on 12/05/2020 08:53:03:

Went for a large 2 wheel push-in forming type; with fine, medium and course wheels provided ans a package.

A nutcracker type knurling tool has also been placed on the 'to-make in the future' list.

Thanks for all your help and advice.

If you are going to make one in the future, i cannot highly recommend Hemingway's Marlco copy enough.

Marvelous tool.

[Clive FosterParticipant @clivefoster55965]

+1 to what thaiguzzi says about the Marlco style.

But probably 3/4 of my knurling is of a size and style where the nutcracker is fine and far faster. Say up to 3/4" or a bit more diameter in alloy or an ordinary steel.

Grab, maybe adjust, squeeze. Job done.

The Marlco usually lives in its own Dickson holder but its still way slow for onesie / twosie / just want something to grip jobs.

Clive

[Gary WoodingParticipant @garywooding25363]

I designed and made this one about 16 years ago. There's a write-up in MEW.

If you're interested I can let you have a copy (of the write-up).

[KWILParticipant @kwil]

+1 for Gary's design, made one then and it still works!!

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