Question about tube bending

[deuce4]

I am wondering if there is an ideal distance between the main die and the roller die for a tube bender of this type.

i currently use a Bramley manual tube bender, and notice if I put the roller cam too close, the tube will crimp when bending.

It seems there would be an ideal distance based on tube diameter and bending radius, but cannot find anything anywhere on the best placement distance for this roller. Perhaps it does not matter, as long as it is not too close?

any ideas on how to calculate optimal location for roller cam for this type of long arm tube bender would be appreciated.

cheers

[Tooler2]

It looks like you are missing the long straight die that goes between the roller and the tube?

[javelin68]

There is a calculation. It is called "take up" and can be found in bending conduit for electricians. The booklet is part of training for electricians. Works very well

[Tuomas]

It looks like you are missing the long straight die that goes between the roller and the tube?

That bender is for bending square tubes. It doesn't need straight die.

[Tuomas]

I am wondering if there is an ideal distance between the main die and the roller die for a tube bender of this type.

i currently use a Bramley manual tube bender, and notice if I put the roller cam too close, the tube will crimp when bending.

It seems there would be an ideal distance based on tube diameter and bending radius, but cannot find anything anywhere on the best placement distance for this roller. Perhaps it does not matter, as long as it is not too close?

any ideas on how to calculate optimal location for roller cam for this type of long arm tube bender would be appreciated.

cheers

Can i ask. Where did you get that picture?

Distance doesn't matter. But, i can measure it later.
It would have been better to make the question to its original thread, i think.. Homemade manual square tube bender

Edit: in that bender. Distance is 2 * radius of the die + tube width + 10mm clearance. ( 50mm radius and 25* 25 square tube, =135mm

[deuce4]

Thank you for replies. As mentioned, I use a Bramley round tube bender, but I have been sharing ideas on bigwalls.net, and a friend made his own bender.

the image I used was just to indicate the distance, the image came from this site. I should have mentioned the question was for a round tube bender.

attached is a picture of a friend’s homemade wood bender, which had the roller wheel too close and it crimped the tube, he did not know why, but I told him to add some separation, which he did and it apparently works now.

i know from my own experience that I don’t want the roller wheel too close, but I am still wondering about the optimum distance, if it in fact matters (seems there would be an optimal separation). In the post above, i do not quite understand he logic of the formula of 2x radius plus tube size plus 10?