Steel pipe roller design

[Davemorl]

Hi,

I am considering making a pipe roller and I'm planning on having the three roller setup with the middle moving up and down on a screw and the bottom two being driven either by gears or chain and sprockets from a 3 phase motor with a 100:1 right angle worm gearbox so should be around 14rpm. Is this two fast or slow in your opinion.

I have a few other decisions to make. What would be better for the driven wheels? Larger diameter or smaller? I would assume the larger the better as there will be more surface area in contact with the pipe so it will less likely slip? Does the diameter really matter for the middle moving die?

Also I'm thinking of engineering plastics for the dies?! Is this wise? I know they are very good under compression loads?! Or should I stick to steel?

Thank you in advance!

Dave!

[LKeithR]

What size pipe? What wall thickness? How tight a radius do you intend to roll? All of these factors determine
how much force is applied to the rolls. Unless you're only rolling very light material at relatively large radiii I
don't think plastic is going to stand up very well...

[Davemorl]

Let's say 60mm and 3mm wall max. I'd say the smallest radius at this will be very large into the 10's of metres. It would probably be used to make a hand wheel of less than a metre with flat bar or round stock of less than 5mm as well.

The only reason I'm considering plastic is they use plastic wheels on say a 2.5 ton trolley and they seem to manage perfectly fine.

[chipmaker4130]

I recently finished making a custom roller for work. All three rollers are powered by hydraulic motors (one motor for the two bottom rollers and one for the center), and are 4" OD. The shafts project out both sides so we can mount two different sets of rollers. The max speed is 90 rpm, continuously adjusted down to 0. It weighs about 250lbs. As an initial test, I rolled a length of 1/2" sch 40 steel pipe into about a 9" dia circle. With rollers that big, the CTC distance on the lower rollers is 8", which on the small pipe leaves a 3" straight on both ends. The dies made so far are simple 90deg V grooves, and they didn't cause any visible deformation of the test pipe.

It will mostly be used for 3/4" solid stainless (304) rounds, and square/rectangular tubing.

[754]

I am not understand your radius expectations you listed..
A 1 metre ring would use .5 metre radius..

[Dedave]

I would recommend 8"-10" dies minimum, made of steel. Power all 3, and the setup should allow for the bottom two dies to get narrower as the radius is tighter.

Our shop used to roll brass railings, and they came out real nice. Some were for spiral stairs.

It was always a multi pass situation, so you may want some speed for the long parts, especially if you use tiny roller dies. 1 foot per second would be fast to me. 1 foot per minute would be slow. Do the math on diameter and gear reduction and motor speed. It's nice to have a foot pedal with variable speed too.

More info about how and what you are doing can help in generating ideas to make that machine just how you need it.