Making rollers for a ring bender

[Brass_Machine]

Ok... need some help here. I am designing a ring type tube roller to do some light and small tube rolling. One thing (among many) that I haven't done on a lathe yet is make a semi circular groove. I kinda have an idea on how it is done... but I am not 100% sure. What I want to make is this:



How do I make the groove that the tube rides in? I know I am going to have to get some round drill rod the same size as the tube groove I want. Gotta make a holder for the rod. How do I grind and then heat treat the drill rod? Any type of relief etc? What angle does the tool need to be set at? I heard perpendicular to the piece I am turning?

I am not quite lost... need some help getting back on the path.

Eric

[bogstandard]

OOOOh Eric, you do make life difficult for yourself.

I think you have an RT and a mill, try the way on the C-o-C

I did all the rollers on my tube bender this way. Only takes minutes for each size.

If you want to do it on the lathe, you are correct, any angle from perpendicular will give an eliptical shaped groove. You would only need a very shallow angle on top, say 3 or 4 degrees at most. But expect a bit of noise, as it is plunge cutting, very similar to parting off.
Bring your drill rod up to cherry red and hold at that for about 30 seconds, then quick quench. You should then temper it to straw colour for long life, but use as is if you are only doing a couple of rollers.

If you want to see a basic toolholder for it, let me know and another C-o-C will be posted.


John

[Brass_Machine]

Doh! That way is much much easier. My mind was set that I had to do that on a lathe! I have a RT... el cheapo that it is. Just gotta set it up now. Many thanks John!

Eric

[Bernd]

John,

Very interesting method of cutting a groove in a roll.

My question. What if the size is not of the cutter you have. Lets say I need a .600" dia. but only have a .500" dia cutter. How could I make the groove the size I need it to be?

One idea I had was to cut with the 1/2" cutter and then use a boring bar set to take out the rest of the stock. Would that be feasible?

But thinking as I'm typing. Would close enough work. Inother words use the next larger cutter and just make a larger groove?

Eric, what size tube are you bending? Just courious.

Bernd

[Brass_Machine]

Hey Bernd,

I am going to be bending .25 and .375 tubing... brass and aluminum.

Eric

[bogstandard]

I actually described the method I used to Ralph last week when he called, plus the fact that I put two grooves in each roller, to save on material costs and storage. I think Ralph had the same misunderstanding as Eric did about the grooves. Once I had explained it, all was clear.

It is the cutting of the grooves that put most people off making these sets of benders, just because it is not a normal machining method, and people think it is too difficult a process.

There are hundreds of different designs for tube benders, from dead easy to very complicated, but they all seem to do almost the same job, so why make it complicated.

It took me about half a day to make mine.

If anyone wants a couple of different sets of construction notes, send me an email.

John

[Brass_Machine]

...

If anyone wants a couple of different sets of construction notes, send me an email.

John

I am up for that!

Eric

[Divided he ad]

I actually described the method I used to Ralph last week when he called, plus the fact that I put two grooves in each roller, to save on material costs and storage. I think Ralph had the same misunderstanding as Eric did about the grooves. Once I had explained it, all was clear.

Yep that's the method alright! The bending tool that John has is brill'! does the job real well   

And I did have the "how the hell??" question about the rollers..... and this method of making the recesses works for me 


I have the plans printed and ready in my shop.... Got distracted before I made anything though!!  I'll sort it soon.

I have only the gap between the frame and the roller depths to adjust to allow for the twin recess version and the plans I have are great... They include metric as well as imperial!!



I'm interested in what your up to Eric??        



Ralph.

[Brass_Machine]

...
I'm interested in what your up to Eric??        



Ralph.

Hey Ralph... it will be used for a couple of different things. But mainly for some LED lamps I have in mind. I am almost done clearing out the bike bits, this way I can focus on other things. Stuff I want to anyway!

Eric

[SPiN Racing]

I just purchased a new "toy" this week... well.. late last week.
A tubing bender.

For rollcage tubing actually.

BUT its a vertical bender, and a really neat piece of kit.

I guess I better get some pics of it and post em in "tools".
May spur some ideas on things for you.

[Darren]

Yep, you better had, can't go teasing us like that and run away you know 

We want to see new toys,,,, so we can go "ooh, ahh" 

[Divided he ad]

Good to know that     is still contagious   

I can focus on other things. Stuff I want to anyway!

That's why you have a home 'shop Eric..... 


Got to see this stuff happening, you were saying about these a while ago...... You are more than aware of the rules.....  get photo's and post 'em!!!     




Ralph.