thin walled pipe bender??

[johnakay]

I have a deaf friend who is planing to make exhaust down pipes for motorcycles.
he seem to think he can buy a bending machine the will bend thin walled pipes from 80mm down to 32mm for around £1000'
and he ask me to see if I can find one.
even for a used one cost about 3 grand but he's adamant that you can buy one for a grand.
do you guys know where I might get one for him?
a manual one yes but?? john

 

[hotrodder]

Pipe not the same as tube... pipe bender = tube kinker (at best)
80mm (3.16") capacity and motorbike exhaust doesn't make much sense but very generally as dia goes up and/or wall thickness goes down bending difficulty goes up. A LOT.
Thin wall needs qualifying (presumably 1.5mm and under?) and bend radius (CLR, centre line radius) effects things but, again generalising for the most part, exhaust stuff is typically well into the realm of needing something inside the tube to prevent the tube 'necking' or even collapsing. Price (or time involved) goes up exponentially

Rotary draw benders are the type he wants (mandrel bending kit uses these + extra tooling for the mandrel and extra wiper dies). Can pick up a manual rotary draw bender that'll do upto 2.5" for less than half his £1000 however that'll be without any tooling which is what eats all the money...
Note that the CLR will be a minimum of around 3.5D (D = tube dia) and above ~1.25 or 1.5" dia tube the min wall thickness typically starts rising above 1.5mm. Above 2" it's gonna be closer to 2.4 - 3mm min wall
'Off the shelf' mandrel bends that you cut and weld are typically 1.5 or 2D and sometimes available down to 1D/upto 3D

 

[johnakay]

he explained a bit more clearly what he wants.
yes I should of said tubing..the wall thickness he is going to use is 2mm.
the bender he's after is along the of motorised hydraulic bender.
what he wants is that the roller rotate around the tubing into the former if you understand what I mean.
he doesnt want the two outer pin type like this one or similar.

thanks for your reply anyway.
.

 

[normspanners]

The way to bend thin walled tube is to plate the end fill it with water and freeze it, up right in a tall freezer then bend it frozen you dont end up kinking it and it will bend with a cheaper bender, perfectly.

 

[Shox Dr]

The first question I would ask is what is his target market. If it's mid to high end then I would say the competition will be using Mandrel type. The reason been, anything else will deform the tube, I don't mean ripples, just the transition point between straight where the bend starts: there will be little to none with a mandrel.

You could buy a Protools bender and 1 maybe 2 dies for a grand. However it will be manual, and not funny bending anything but small dia. I built a Protools clone, using their dies, bends beautifully. However I've not used anything less than 2.64mm wall.

You can fill the tube with a material that solidifies stopping the tube from deforming. I have some WS8, cerobend is another well known product. However it is a faff, and not something I would be using if I was to bend a lot of large dia tube

 

[chevy2]

Heres the machine i use, works on the same principle as the jd square/ pro tools benders,

Theres no tricks reqd with these machines to bending thin walled tube so long as its setup correctly, i've done as thin as around 1mm wall or 0.040" in old money in mild steel and chrome-moly without any wrinkling at all.

 

[hotrodder]

i've done as thin as around 1mm wall or 0.040" in old money in mild steel and chrome-moly without any wrinkling at all.

What diameter and on what centreline radius though? 1mm wall tube can be extremely easy or incredibly difficult to bend cleanly depending on diameter and CLR

 

[chevy2]

What diameter and on what centreline radius though? 1mm wall tube can be extremely easy or incredibly difficult to bend cleanly depending on diameter and CLR

It would have been on fairly small diameter stuff as on 1-1/2" - 2" i rarely use thinner than about 0.065" wall,

Probably 7/8" and 1" o/d, the 7/8" was the tightest former available at around 3" CLR? at a guess without measuring it,
the 1" former isn't as tight, i'll measure both later.