drawings for tubing benders...

[dsergison]

I need the functional dimensions of a pro-tools bender and 1 die.

Because: I'm cheap, and it looks fun
I'd like to make a copy of the pro-tools bender

http://www.pro-tools.com/mb105.htm

And I'd like to make (most of) my own dies too.

The reason I dont want to just eyeball my own dimensions is that I would like to be able to buy a die if I don't have the time to make a different size one in the future.

So, does anybody know if such plans are available? or, would anybody be willing to measure and work with me on their own?

I am willing to pay for a set of dimensions. (I'm not not that cheap). I can draw it up, and give a fill_in_the_blank dimension scheme.

Thanks, Dan

[morpheus]

I have a JD2 (www.jd2.com) which has slightly different dimensions than a pro-tools

have you seen this: http://www.blindchickenracing.com/to...bingbender.htm

- jack

[dsergison]

Wow, just wow.

holy mother of home built benders. thanks

[morpheus]

he bought the die ...

- jack

[dsergison]

is there any real science to the dies?

I mean if I take a big round peice, and spin it under ball end cutter, (radially) or a whatever inch fly cutter (tangentally) I'll have a perfect spherical path cut, (a torus). and if the die O.D. lies on the c/l of the tube,.

and I make the follower just a straight trough, and the follower ends on the c/l there will be only a perfectly round guide.

how much, if any oversize or lead in chamfer would be good?

thanks.

[Franz]

Having been up close and personal with both conduit benders and exhaust benders, I can assure you neither employs a lead chamfer.
One shot benders~
The biggest part of a kink free bend in either machine is that both halves of the die meet tightly enough to maintain proper tube diameter thru the entire bend. Exhaust benders do have a bit of kinking allowence on the inside die because of the tight radius they bend to.
Segment benders~
usually employed on heavy wall pipe make the bend in multiple strokes, and do not use an outer die. The ends of the bend are supported by saddles about the length of the pipe's diameter, and the bending shoe on the piston tends to be twice the diameter of the pipe in length.
Rotating benders~
employ an inner shoe that encompasses 50% of the pipe's circumference, and a roller that supports the outer half of the diameter at the stress point only.

[DaveD]

I have had access to an old greenlee air over hydraulic bender that had the shoe mate and interlock into a flat follower on the other side of the tube. The follower with esentially the other 180 degrees of a circle was about 15" long and had two grooves in it where the outside edges of the bending shoe set into about 3/16". What I liked about it was it (shoe + follower) basically encased the tube 360 degrees as it was being bent and there was mo way for the tube to ever flatten out. Most modern benders I see don't have this feature. Usualy they just have some small follower plate that the tube drags across. Did 1-3/4" x .095 DOM perfectly.

[dsergison]

I am thinking that the main advantage of the long follower is that it moves with the tube rather than dragging across it which probably makes the bending effort substantially less, and does not mark up the tubing from dragging.

[Franz]

The followers in thinwall conduit benders are a little longer than the outside radius of the bend.
The bender for heavy wall conduit uses wheels that follow the outside radius. This aparently is indicitive that there is less need to support a heavier tubing wall to prevent deformation during the bend.
We even have a set of teflon lined follower shoes for bending PVC coated heavy wall, because the force on the bend is so high the bender will strip the PVC off the outside of the conduit.
If you look at a manual conduit bender for thinwall conduit, the cheaks of the bender extend well past the centerline of the conduit being bent to support the sidewalls during the bend.
Exhaust benders fully support, by encompassing the tube being bent. The basic principle in all benders seems to be the thicker the wall the less support is necessary.

[Wood-N Steel]

Benders

Check out this bender the company I work for has had this style
for 30 + years ( used mostly for home projects works great)http://w.w.w.hossfeldbender.com

[morpheus]

woodnsteel got a couple of extra dots in his link. here's the correct one: http://www.hossfeldbender.com/

hossfeld is THE bender that most all other companies try to emulate.

- jack

[Dirt Rider]

There is a guy on ebay making/selling a bender, much like the Protools, comes with 4 sets of dies (1" - 1 1/2") 90 degree, for $680...for everything. Do a search for "tubing bender". Not too bad a price if you need all those dies. My plan is to use the compact HF bender and some of the cheap dies for 3/4-1" stuff and get the JD2 with a 1 1/2 round tube die for the bigger stuff.

Those dies are a bite in the rear, I can't believe they cost that much....well, yes I can. But still.

Good luck making some, that would be great if it works out!

[morpheus]

I've seen that bender on eBay. $680 + $50 shipping ... they've come down alot. Back before I bought my JD2, they were selling for about $850 + shipping ... I've heard of problems with other benders with aluminum dies so beware ...

- jack

[Dirt Rider]

I personally like the style of the JD2 a little better too. What we need to do is form a "share the die" program and just swap out the odd dies we need from time to time.

I was reading up on the Hossfeld bender and man do they have a TON of different odd ball dies for that thing...square tube dies set at a diagonal, dies for angle iron bending, etc. Too bad all their stuff is rediculously priced as well. That would be cool to have a do-all bender...but you would have $2000 in it with a few sets of dies and angle benders! I'd rather spend it on a TIG welder.

[morpheus]

Originally posted by Dirt Rider
I was reading up on the Hossfeld bender and man do they have a TON of different odd ball dies for that thing...square tube dies set at a diagonal, dies for angle iron bending, etc. Too bad all their stuff is rediculously priced as well. That would be cool to have a do-all bender...but you would have $2000 in it with a few sets of dies and angle benders! I'd rather spend it on a TIG welder.

yep, a Hossfeld is The Bender of All Benders. It can do it all if you have the right pieces. All that ability comes at a price though.

- jack