# Tube Bending



## Omnimill (May 31, 2012)

I have a small project in mind that involves making 180 degree bends in some 4mm OD Stainless Steel tube, ID is around 3.5mm. What do you guys think is the tightest radius I'm likely to be able to make in this size tube? 

Vic.


----------



## Maryak (May 31, 2012)

A standard bend is radius = 4 x pipe OD. They can be made tighter, a lot depends on the material and its' wall thickness.

Hope this helps

Best Regards
Bob


----------



## Omnimill (May 31, 2012)

Actually that sounds good as I saw a tube bender somewhere and it had a 5/8" dia former for 3/16" tube. I need to come up with a simple tube bending jig now!


----------



## gbritnell (May 31, 2012)

I don't know if you could build a 'simple' tubing bender to do what you want but I'm sure this one will work just fine.
gbritnell
http://www.homemodelenginemachinist.com/index.php?topic=17814.0


----------



## Omnimill (Jun 6, 2012)

Thanks for that George, handy looking jig!

Vic.


----------



## shred (Jun 6, 2012)

I made a simple bender from some plans Bogs posted here years ago-- not too different than George's. The trick was cutting the grooves in the rolls-- somebody came up with an ingenious way to do that using a simple drill rod tool held in a lathe toolholder and running the lathe backwards.


----------



## Omnimill (Jun 6, 2012)

I found this:

http://www.bifabuk.co.uk/benders/tube-pipe-bender-10.php

Looks to be the simplest one I've seen so I'll build my own copy ;D

Vic


----------



## Blogwitch (Jun 6, 2012)

Vic,

I hope you realised that one is a floor standing model, and most probably costs megabucks. That's why you have to phone for a price.

If you want some easy plans, similar to George's, let me know.


Roy, 

I showed how to cut perfect semi circular grooves in pulleys etc a while back on Modders, using either a rotary table or spindexer and the correct sized cutting tool for the pipe diameter. No need to grind up very accurate lathe tools.

http://madmodder.net/index.php?topic=4219.msg53046#msg53046


John


----------



## Omnimill (Jun 6, 2012)

Yes I realised it was a large unit, just seems a very simple design to copy!

I like the idea of using a spinindexer to cut the grooves John, clever idea!

Vic.


----------

