Problems bending Kunifer pipe

[Robotstar5]

For some reason I have it in my head that the rollers need to be offset rather than inline,

O O O O
..O O O O

Like that so the pipe goes between 3 rollers rather than just a pair?

That's right, the rollers in wire straightens are offset

 

[JOEPRO]

My friend is making a straightener for thicker pipe, intended use is aluminium pipe, might not work on steel. View attachment 387257 View attachment 387258

There is a company already making these:

Tube Straightener - Javac.

www.kwixuk.com

£60 on frost for 8mm od version

 

[JOEPRO]

This is a video showing a very similar bender to the Ridgid. And shows what the markings mean on the die which are clever

 

[JOEPRO]

There is a company already making these:

Tube Straightener - Javac.

www.kwixuk.com

£60 on frost for 8mm od version

I did end up ordering one of those 8mm od tube straighteners. I think this will speed up the process and give a better result. My OCD wasn't going to let me away without it!

By the time I have all new fuel pipes in my cars I can always sell the bender and straightener on if I want and recoup some £.

 

[mike os]

The swagelok and rigid are practically identical ... the only way to bend hard tube ... always defect free and repeatable

 

[armalites]

https://www.lasaero.com/products/article/R03RDJXXX

I have used this for 5/16" Kunifer, worked well, 8mm should be close enough to 5/16"

Seriously I've got things I should be doing instead of looking at a website that has loads of interesting tools

 

[armalites]

I did end up ordering one of those 8mm od tube straighteners. I think this will speed up the process and give a better result. My OCD wasn't going to let me away without it!

By the time I have all new fuel pipes in my cars I can always sell the bender and straightener on if I want and recoup some £.

I have a 3/16 Kwix and when I bought mine they were only about £40, worth every penny. One of those things that maybe seems like an extravagance but you'd never go back to having wavey pipes. It's another one of those tools that puts a smile on my face every time I use it.

There are some unbranded ones kicking about on the web now that clearly come out of the same factory but are a bit cheaper.

 

[JOEPRO]

I did end up ordering one of those 8mm od tube straighteners. I think this will speed up the process and give a better result. My OCD wasn't going to let me away without it!

By the time I have all new fuel pipes in my cars I can always sell the bender and straightener on if I want and recoup some £.

So this thing works! It leaves the pipe straight for sure. But - you have to be careful uncoiling the roll. If you put kinks in the tube they will still be there as very minor wavers in the pipe.

So uncoil evenly and use the tool and you'll have a straight pipe ready to put bends in it

 

[Morrisman]

That's right, the rollers in wire straightens are offset

I think commercial straighteners/decoilers actually bend the wire/tube/bar a set amount before straightening it, so they know exactly how much to re-straighten it. That takes any errors from the spring in the material. Holding anything against a flat surface, to straighten it, will invariably leave it with a bit of a bend still in it, depending on how much it was bent before.

I wanted a nice copper coil for some gimmickry on my old hot rod, so I filled the pipe with fine sand, using a tiny funnel, tapped it down, the squashed the ends to hold it tight. Then I hand bent it on a cheapo brake pipe bender, just using the former part. It came out quite well.

 

[Maker]

So this thing works! It leaves the pipe straight for sure. But - you have to be careful uncoiling the roll. If you put kinks in the tube they will still be there as very minor wavers in the pipe.

So uncoil evenly and use the tool and you'll have a straight pipe ready to put bends in it

View attachment 387813

I've got one too, I was very impressed how well it works.