Pro tools 105 backing block idea. Making it a roller.

[Nutz4sand]

For those who have a PT-105 bender or a bender that uses the PT-105 dies. Or are familier with it.

I am looking at having Doug Heim help me with a project. Instead of the backing block where the tube is dragged across the backing blocks flat surfaces (rounded for the tube but still flat against it). 

Instead of that I am thinking of trying to have maybe two or three wheels that fit onto the backing block area for the tube to roll against.

The pros I can see would be less force required to bend. Less drag on the tube would distort it even less (my bender distorts it but barely) This would make it less. The bushings (or bearings?) would take the grease and not the tube/backing block so less messy. I am thinking bushings would be better for the loads involved.

Below are some pics of the backing block and a simple idea with red wheels "painted in" to show what I am thinking about. As mentioned three wheels might be better?   

The wheels would of course be machined to fit the tube perfectly like the die.

[Admin]

The problem with wheels is contact patch, it isolates all the force to one small spot, thus causing the tube to crush, It may work well I cant say but that is my opinon..

[Nutz4sand]

I know the loads are high. Thats why three wheels might be better?

I feel the area the backing block has is as big as it is due to the force. But it IS dragging vs rollers. Guess have to test it to see.

[Admin]

I bend tubing dry, were livewire had some red bending lube, it did seem to leave less trace of the shoe on the tube...

[Nutz4sand]

I will not bend dry. (The big die is of course) But the backing block is always lubed. Cleaned tube (not polished but close)
Just looking for a better mouse trap.

Might (if surface area is a issue) get a following block like below and flat rollers behind it? If it works in that bender why not a PT-105?

I have never seen one of those benders work before. I wonder how that following block stays true to the front die. It looks like it does not flex. But stays flat. (perpendicular to the bender frame)
 

[Doug Heim]

That is the same Idea bender I use. The block actually follows along with the die. It follows very well. I can see where the contact patch may be too small. Its a simple job. worth an experiment I would think.

Here is me bending...

[fabr]

Personally I have no problem with a better mouse trap but IMO there's little need of one UNLESS you are bending manually over 1.5x.120 4130. Then it would come into play. I have always bent tube dry also.

[Grimm Reaper Racing]

We bend tubing dry as well.  This is the type of bender we use at the shop.  It's a Di-Arco, not quite as fancy as Doug's buddies bender, but it works very well

[fabr]

Doug I see a "real" car in the background.Tell us more!

[Nutz4sand]

The bender Dougs using and the one Grims got there in his pic both have the following block so dry bending is no sweat. (dry tube). I imagine the pivots are all lubed as are rollers for the moving backing block??

When I was at you place Bug I did not see your bender so I do not not know how it does its thing.

I thought at one time I saw that Fabr used a PT-105 himself? If I read what he says correctly then hes bending 4130 with it with no lube on the backing block? I find that interesting if its doing that with no damage to the backing block or tube at all?  No tube distortion? Being 4130 is stronger than mild steel DOM I am using that might account for some of it?

I followed the manufactuers recommendations and cleaned my backing block up a tad with a tiny flap wheel (no sharp ledges for the tube to catch on) I have not polished it's faces yet but am considering it.

I also clean my tube VERY well and nearly polish it where it will be dragging on the backing block. I lube just that area going into the backing block and the blocks faces themselves. (as well as all the pivot pins of the bender of course)
As for the main die I clean the tube area with brake clean to remove the WD-40 I store it in. Once the bend is done I re-WD-40 the die and it goes back inside a plastic container to keep dust/crud off it.

I will still take care of the big die like this and only bend clean tube but to get away from the lube mess on the tube is my primary goal here. Save a little time and trouble and hoping for better setup to boot.     

[LiveWire]

[LiveWire]

My backing blocks are brass too which is probably the main reason the tubes does not get chewed up. If I do it dry, there is a gold hue to the tube. So the lube is to keep my backing block from wearing out so soon.  I think rollers will distort the tube. Making brass backer blocks would probably serve you better.

[fabr]

The bender Dougs using and the one Grims got there in his pic both have the following block so dry bending is no sweat. (dry tube). I imagine the pivots are all lubed as are rollers for the moving backing block??

When I was at you place Bug I did not see your bender so I do not not know how it does its thing.

I thought at one time I saw that Fabr used a PT-105 himself? If I read what he says correctly then hes bending 4130 with it with no lube on the backing block? I find that interesting if its doing that with no damage to the backing block or tube at all?  No tube distortion? Being 4130 is stronger than mild steel DOM I am using that might account for some of it?

I followed the manufactuers recommendations and cleaned my backing block up a tad with a tiny flap wheel (no sharp ledges for the tube to catch on) I have not polished it's faces yet but am considering it.

I also clean my tube VERY well and nearly polish it where it will be dragging on the backing block. I lube just that area going into the backing block and the blocks faces themselves. (as well as all the pivot pins of the bender of course)
As for the main die I clean the tube area with brake clean to remove the WD-40 I store it in. Once the bend is done I re-WD-40 the die and it goes back inside a plastic container to keep dust/crud off it.

I will still take care of the big die like this and only bend clean tube but to get away from the lube mess on the tube is my primary goal here. Save a little time and trouble and hoping for better setup to boot.     

I have never used lube but for 1 time. No damage to die or block and have bent many tubes .  I agree tho that lube would extend the life greatly tho in a production shop but then again it'd be a powered bender. With the lube it does bend easier BUT ,my experience is that it allow too much springback and made advancing to the next notch in the bender  very difficult when you are manually bending tube.It was very bad with 1.5 x .120 4130 and just a PITA for 1.25. I have bent mild tho and have found dry to be very easy in comparison.   As for deformation there was no difference. There is a smalll spot at the very beginning that a person can feel but not really see.I believe all draw benders do that to some extent.If yours is excessive I feel that there is some other factor than lube involved. I do keep the die and shoe CLEAN tho.I wipe it out after every bend.I have no scratching or anything like that occur unless I fail to wipe them out before bending.I take NO special care of them.They just hang on the wall next to the bender. Besides that  I'm too lazy to have to clean up the tube when done.

[SPEC]

I lube
And have many rags around the bender...It is a fooking mess...Old timer in me I guess, But I'm still of the old logger saying that plugs are cheaper than pistons...Mixing saw gas alittle rich...

[dsrace]

I lube
And have many rags around the bender...It is a fooking mess...Old timer in me I guess, But I'm still of the old logger saying that plugs are cheaper than pistons...Mixing saw gas alittle rich...

spec you really kill me sometimes! lol