Making Tube Rollers

[Smudgemo]

If a guy wanted to make some rollers to replace/augment the crummy ones that come with the Harbor Freight tube roller, how would he go about it on a lathe? I want to roll 1.125" tubes to start, but will make more dies if this works.
I'm thinking 1018 (as opposed to cast iron) in a 4" rod skimmed and bored (easy part), but how would you go about making the groove? I somewhere saw someone using a ball-turning attachment, but don't have one and don't really want to make one if I don't have to. Maybe something like the buttons in Ivan Law's gear book? Most of the job seems fairly straight-forward, but I'd rather ask for some guidance before attempting this on an expensive steel rod. I also already know SWAG Offroad sells great dies, but you know how it is.

Liberated photo courtesy of HF:

Thanks for any input.
-Ryan

 

[DMS]

A form tool that large is going to be nearly impossible unless you have a really (really) supper (exceptionally) beefy lathe. Ball turner would probably be best. There is also a method I have heard others on here extol (though I haven't tried myself). Basically you cut a bunch of steps to approximate a circle, then smooth things out with a file to finish.

 

[pineyfolks]

When I made mine I used a parting tool to relieve the center as much as possible then I ground a left and right hand radius tools to do the sides. This cut chatter down to near nothing. If your not rolling a tight radius you can get by with a vee cut in the rollers just to keep things going straight, and you don't have to make a set for different size tubes.

 

[Smudgemo]

Thanks. I should have mentioned this is for thin-wall (.028 or .035) 4130 for bicycle frames. The imperfections on the stock rollers mar the tube finish, and a V roller would deform the tube's profile.

 

[richl]

You are building more trational bike frames? I dabble with customcruiser and chopper designs.
I'll be interested in hearing more about this also, I plan to make some custom roller dies for my tubing roller and jd2 bender.

rich

 

[Tom Griffin]

Ryan,

Do you have a mill? If so, you can use a boring head to generate the radius. Hold the roll in a dividing head and rotate it against the boring head set to the proper radius. You'll probably need to do it in a few steps, or rough most of the material out on the lathe first. I would also suggest doing yourself a favor by using something easier to machine than 1018 since you have so much machining to do on them. 12L14 would be my choice.

Tom

 

[CNC Dude]

Wasn't there somebody on this forum using a small 9x20 lathe converted into CNC to make, precisely, tube roller dies? I kind of remember seeing something like that a few days ago, but couldn't find the post after a quick search. Those dies looked pretty insanely cool!

 

[lrsglory]

Ryan,

Do you have a mill? If so, you can use a boring head to generate the radius. Hold the roll in a dividing head and rotate it against the boring head set to the proper radius. You'll probably need to do it in a few steps, or rough most of the material out on the lathe first. I would also suggest doing yourself a favor by using something easier to machine than 1018 since you have so much machining to do on them. 12L14 would be my choice.

Tom

Wow ! Slicker than Snot. Possible improvement. Use a end mill the diameter of the radius , if available. Could take the material out a lot faster. X in while rotating the part, 1/2 the diameter of the endmill. Whatcha think ?

 

[Smudgemo]

I have a small mill, but no boring head or rotary table (yet.) The 12L14 would be nicer, but then it's getting a lot closer to as expensive as buying them finished. I think they're around $170 or so.

I finally found the photo I was looking for(in this thread at MTBR), and this wouldn't be very difficult to make:


But then I keep thinking about whether I'd rather make a bike or tooling.

 

[Bill C.]

Thanks. I should have mentioned this is for thin-wall (.028 or .035) 4130 for bicycle frames. The imperfections on the stock rollers mar the tube finish, and a V roller would deform the tube's profile.

I agree with the others treat the rollers as if you are cutting a pulley. Mark off the center then use a parting tool to plunge cut the smallest diameter then start cutting steps on both sides of the center cut leaving stock on all cuts until you are ready to finish the radius. A smaller lathe should cut it if you take your time and light cuts. Good luck