Coffee In My Sugar: A Scissor Knurler / Lathe Question

[darkzero]

Not sure what benefit there is to scissors vs clamp style

Generally the scissor type can apply more pressure than the clamp style & is better for harder materials. Clamp style usually has a thumb nut & the scissor type has a nut to be used with a wrench. Also due to the design there's more leverage applied due to the nut placement on the arms.

I knew some one with a genuine Aloris clamp style knurler & he was not happy with it. Didn't perform well on harder materials & would flex/bend when tightening the thumb nut with pliers.

 

[mikey]

Is there a real difference between what you guys are calling the clamp style vs the typical scissors knurler? Both have two arms that close on the work in a scissors-like fashion to create the knurling force. I can see that there might be a mechanical advantage to the Eagle Rock type of tool over the style where the arms are pulled together by a screw/nut/handle but in terms of function, what is the difference? I've just lumped them all into the "scissors knurler" category until now.

I own an Eagle Rock K1-44, an Aloris AXA-19 and a shop made "clamp" knurler. All work well except that the Eagle Rock is maybe gooder on harder stuff. For regular shop materials I don't see a lot of difference.

 

[darkzero]

That's basically what it comes down to, different designs & how much pressure the different designs can apply.

I've always called the old Aloris #19 a clamp style. Not sure if Aloris is the actual designer of this style & not sure of the actual proper names of all the different styles. Like this below except this is a shop made one. They usually have a thumb wheel/nut in front of the pivot to adjust pressure. The pivots can only handle so much & will flex when too much force is applied. Some clamp styles have just one pivot instead of two.


Then there are straddle types. Below are the 2 different styles I have know as the straddle type. However I suppose the clamp style above can be considered a straddle type. The heavier duty version is much like a scissor type where the adjuster is behind the pivot. The smaller straddle type has a smaller adjuster that works much like the clamp style above.




Then there's yet another style called a straddle type. It's the style that Aloris currently offers. I believe Aloris no longer makes the #19 clamp style with a thumb nut. I have a small Dorian one in this style.



For the standard scissor type there is simply a bolt & nut that holds the 2 arms & shank together. The Eagle Rock heavy duty type also uses a bolt to hold the arms together but instead of a nut the bolt threads directly into the much beefier mount on the shank & is also secured with a set screw to adjust play/twist under pressure.

I don't oppose one style over the other. They all have their advantages & disadvantages. I'm certainly no expert on knurling (or anything related to this hobby), these were just my observations when I searched for knurling tools. There's yet even more styles for form knurlers like the 3 wheel style. Use whatever works for you is what I do, bump knurlers included. Still need to play with my cut knurlers that I bought like 2 yrs ago.

 

[middle.road]

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That's basically what it comes down to, different designs & how much pressure the different designs can apply.

I've always called the old Aloris #19 a clamp style. Not sure if Aloris is the actual designer of this style & not sure of the actual proper names of all the different styles. Like this below except this is a shop made one. They usually have a thumb wheel/nut in front of the pivot to adjust pressure. The pivots can only handle so much & will flex when too much force is applied. Some clamp styles have just one pivot instead of two.
View attachment 312755

Then there are straddle types. Below are the 2 different styles I have know as the straddle type. However I suppose the clamp style above can be considered a straddle type. The heavier duty version is much like a scissor type where the adjuster is behind the pivot. The smaller straddle type has a smaller adjuster that works much like the clamp style above.
View attachment 312756
View attachment 312757


Then there's yet another style called a straddle type. It's the style that Aloris currently offers. I believe Aloris no longer makes the #19 clamp style with a thumb nut. I have a small Dorian one in this style.
View attachment 312760


For the standard scissor type there is simply a bolt & nut that holds the 2 arms & shank together. The Eagle Rock heavy duty type also uses a bolt to hold the arms together but instead of a nut the bolt threads directly into the much beefier mount on the shank & is also secured with a set screw to adjust play/twist under pressure.

I don't oppose one style over the other. They all have their advantages & disadvantages. I'm certainly no expert on knurling (or anything related to this hobby), these were just my observations when I searched for knurling tools. There's yet even more styles for form knurlers like the 3 wheel style. Use whatever works for you is what I do, bump knurlers included. Still need to play with my cut knurlers that I bought like 2 yrs ago.

 

[mikey]

Thanks, Will. I agree. I own one of each type you showed and all of them work well. My favorite is my shop-made one; it isn't the most powerful of the three but it is the most precise and produces the nicest knurls.

Okay, we are way off topic.

 

[Aaron_W]

Generally the scissor type can apply more pressure than the clamp style & is better for harder materials. Clamp style usually has a thumb nut & the scissor type has a nut to be used with a wrench. Also due to the design there's more leverage applied due to the nut placement on the arms.

I knew some one with a genuine Aloris clamp style knurler & he was not happy with it. Didn't perform well on harder materials & would flex/bend when tightening the thumb nut with pliers.

Makes sense, I can see how the different designs could each offer certain benefits over the others.

 

[Titanium Knurler]

LooseNut, just for the sake of completeness I thought I would throw in some info on the three wheel type knurler that DarkZero mentioned. The advantage of this type of knurler is that you can apply a tremendous amount of force to the three knurl wheels without putting any lateral force on the spindle/spindle bearings or displacing your work. Because of this you can knurl very deeply in one pass and you can knurl thin(.085”) stock if ever needed. I am not sure if the scissor or clamp-style knurlers will work on real thin stuff.

I think this style would work well for your intended job since it would put a deep knurl pattern on your 6061 with a single pass and with minimal stress on your dream lathe. However, these knurlers are expensive and there is no used market for them; I looked for months and couldn’t find a single one on eBay or CL. I eventually broke down and purchased a new one from Dorian. Another disadvantage for you is that the tool post shank is large on these tools. To get a three wheel knurler to handle up to 1” stock the shaft is .75” and to do 1.5” stock the shaft is 1”. I had to modify my tool holder on my PM 1236-T to get the 1” shaft to fit and to align with my lathe center.

Anyway, here are a couple shots from the Dorian cotologue and some shots of a project I just finished where I put a deep diamond knurl pattern on a 1.25” piece of O1 tool steel in one pass. BTW, the PM 1236-T had no difficulty with this job. Knurnling does not seem to require a lot of HP so I don’t think that will be much of an issue for you and your new lathe.

Good luck with your project and keep us posted,
Mike

 

[mikey]

Very nice, very bank!

 

[Titanium Knurler]

Very nice, very bank!

Alright, what the hell does, “very bank” mean. I couldn’t even find it in my urban dictionary. It’s bad enough feeling uncool with my sons, now I am uncool on my escape Forum!

BTW, any idea what the project is?

 

[darkzero]

Broke da bank. Oh wait, I got confused with broke da mouth.

Ok, ok, ok.... expensive!