Cadflat Tube Bender Project.

[Oddbod]

Not sure how far I will get with this project idea, but what the heck, the start is obviously a good place to begin I guess.

Once again, I need something of a challenge to keep my mind in good shape.
I have recently become interested in tube and pipe benders.
I borrowed one several years ago to help me fabricate all my hot rod chassis internal cross members.
It was a hydraulic electric unit mounted on top of an old shopping cart.
It worked well but had its limits obviously.

In the meantime I have been studying units on YouTube and more recently saw an opportunity to acquire several components that I saw worth in that may go some way to becoming a tube/pipe bender machine I guess it could be called.
I am looking to base it more on the mandrel style of bending whereby the tube is drawn around a circular form.

My criteria for now is to be able to bend 32mm and 50mm outside diameter tube upto 3mm wall thickness.
If successful my buddy tells me he would be willing to help me take it to bending light exhaust tube up to 65mm diameter using a mandrel insert for bending stainless steel.
I guess the other obvious use is for making roll cages and similar accessories.

I've never done this before but am willing to have a go, so dont laugh it does not go as planned.

Stay tuned...

[RiverPatrol]

Oh goody, another project from Oddbod.

[r1lark]

Looking forward to the posts on this tube bender project!!

[Oddbod]

I am running with what I have, so the bender will be a mechanical driven unit and not hydraulic.

So far I have an electric motor with an attached reduction gearbox.
I have determined that while tis is a good start, the attached electric motor is a little under powered and the reduction it provides is still not low enough.

I have looked around and as luck would have it a guy was selling new long time stored electric motors, one of which came with a matching flange size and spacing to fit directly onto my reduction gearbox which was a good start.
Only problem was the shaft diameter was larger and has it held a gear in the box, I needed to pull the amateur out and machine it to the correct diameter and cut a new keyway.

I do not own all the fancy machining equipment so this took a little more time that usual.

In the meantime, I found an additional stand alone reduction gearbox that I plan to add in line with the one I already have to get my rpm down to where I see is required.

How did I work out what rpm is required, well, I sat in front of YouTube with a stop watch and watched several machines operating and figured that mine would be slightly less powerful and so I went conservative on the rpm timing and see my final drive being between 1 and 2 rpm of rotation in the bending stroke.

[Esteban]

You are a brave guy. Another project to follow. Congratulations.

[Oddbod]

Fingers crossed my friend.
It could all end up in the trash, who knows until I try...

[RiverPatrol]

I am running with what I have, so the bender will be a mechanical driven unit and not hydraulic.

So far I have an electric motor with an attached reduction gearbox.
I have determined that while tis is a good start, the attached electric motor is a little under powered and the reduction it provides is still not low enough.

I have looked around and as luck would have it a guy was selling new long time stored electric motors, one of which came with a matching flange size and spacing to fit directly onto my reduction gearbox which was a good start.
Only problem was the shaft diameter was larger and has it held a gear in the box, I needed to pull the amateur out and machine it to the correct diameter and cut a new keyway.

I do not own all the fancy machining equipment so this took a little more time that usual.

In the meantime, I found an additional stand alone reduction gearbox that I plan to add in line with the one I already have to get my rpm down to where I see is required.

How did I work out what rpm is required, well, I sat in front of YouTube with a stop watch and watched several machines operating and figured that mine would be slightly less powerful and so I went conservative on the rpm timing and see my final drive being between 1 and 2 rpm of rotation in the bending stroke.

See, this is what I love about Oddbod's posts.

[Oddbod]

Woops sorry, I some how missed attaching pic's of my secondary reduction gearbox.

This is some unit, call it heavy duty if you like.
If this wont bend tube nothing will...

It is old and I've never seen another like it.
It strikes me as early post WW2, it is a monster and lucky I have a gantry crane built in my workshop as I'd never be able to lift or move it. It has a 32mm input shaft and a 52mm output shaft.

[Esteban]

That does look heavy!

It might bend the bender!

[Oddbod]

Well time to figure out a chassis design to hold all my components.
I am going to be winging it here as I have not drawn up design, but will just run my tape over everything and see what is possible.
I will need wheels on this unit as it is going to be heavy.

In the meantime I am still trying to come to terms with a final rotation speed.
If I have 1 rpm, this means that to complete a 180 degree bend will take 30 seconds and a 90 degree 15 seconds.
When I sit and look at my watch it seems even 15 seconds is like a long time to do a bend, so I thinking to maybe shoot for 2 rpm and get it done in half the time.
Some machines I've watched run at around 6 rpm, but I'm not sure I have the horse power to achieve this.

Anyway time to cut up some rectangular tube to form the chassis for my bender.
I need to make it as compact as possible...