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

[SPEC]

I aim to please...

[fabr]

You ought to be around him in person! SOB is mild here!

[Doug Heim]

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

Johnny Greaves. If you know who is is I may not need to say more.

If you dont know who he is here is is web page. Surf around. I know these guys personally and make alot of parts for their trucks. Everything from the wheel studs to Transmission Cases. At work we carve out 100# blocks of 7075 aluminum into transfer case halves. I make alot of the internals on the lathe including a planatary gear set up we designed from scratch and magnetic clutches. All pretty trick $hit!

http://www.johnnygreaves.com/index.htm

[fabr]

Now THAT'S cool.

[Stomper]

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.

Nutz4sand.
Just wondering if you tried this out or not and what the results were if you did.

[Nutz4sand]

Nutz4sand.
Just wondering if you tried this out or not and what the results were if you did.

I have not yet as I keep getting delayed working on peoples stuff (I hate to put mine on the back burner but extra income is just that)
I am working on the bender stand and I had talked to Doug Heim about getting the rollers cut so I could build the block (roller mount) to try it out. First I need to get this stand done and get the hydraulics on it. I will recontact Doug to see if he can cut me the rollers. So they will be here ready to go. When I first contacted him he was busy on s tuff himslef so asked me to check back when he might have a bit more time. (I can sooo relate)

I would be working on the bender stand today but trying to get two quads of my own reassembeld to get them up for sale. Seems like everytime I turn around something else needs love and attention.
I could understand if it was one off wierd shit I was working on but it just seems the common shit is stopping evey few steps. Missing a piece or a special bolt or a gaskets wrong etc.

I really wanna see if this works too. I have seen many other benders use nothing but rollers and they make fine bends. I see no reason it will not. But of course need ot prove that. 

[Admin]

Only bender i ever seen with a roller was a pipe bender, Do you have any brand names handy? It may very well work, But i think you will end up disapointed...

[Nutz4sand]

[Admin]

There round die is rolling around the work edge, it is not on the holding edge... notice they dont have a round one on the other side...

[Nutz4sand]

The big round die is the one giving the contour of the bend.
The little round die is holding the back part of the tube straight. It is perfroming the same function as the backing block on the Pro tools 105.

The funny little squareish block in the other arm is what grips the tube and pulls it around. PT-105 have a clamp thats attached to the die.

But the smaller roller still is just performing the same job as the 105 backing block.

I thin the cornfuzion comes in when people see the large area the PT-105 backing block has. But you NEED a large area when its a friction area.  With a roller much less should be needed. As Hossfelds seems to think so too. So I am thinking if I get two smaller rollers (or maybe three?) in the right plane they should hold and guide the tube quite well.

[Admin]

The big round die is the one giving the contour of the bend.
The little round die is holding the back part of the tube straight. It is perfroming the same function as the backing block on the Pro tools 105.

The funny little squareish block in the other arm is what grips the tube and pulls it around. PT-105 have a clamp thats attached to the die.

But the smaller roller still is just performing the same job as the 105 backing block.



I thin the cornfuzion comes in when people see the large area the PT-105 backing block has. But you NEED a large area when its a friction area.  With a roller much less should be needed. As Hossfelds seems to think so too. So I am thinking if I get two smaller rollers (or maybe three?) in the right plane they should hold and guide the tube quite well.

The round die is attached to the moving arm, If it were holding the tube, were the square one is, it would crush the tube...

[Nutz4sand]

The big round die is attached to nuthin but the pin through its center. It basically can free wheel.
 
The funny little squarish block actually rotates and "grabs" the tube then holds it against the big die. In the picture you can see how the hole is offset and allows this squarish block to "cam lock" the tube into the big die.  Still thats just the parts to hold the tube as it rotates agaisnt the big die and takes the bend you want. I liek it but at the smae tiem I have no real isses with the PT-105's tube holding methoed. If my roller idea works then even less force will be needed and my stock holder will be even betetr off. Not to mention even less deforming to the tube. 

Point is thats not what this thread is about.

I am refferring to the replacing a friction inducing flat surfaced backing block with a roller.

The rollers bearing/bushing will be greased and make for the tube to stay dry (Big plus). Plus less power required to overcome the bearing/bushing than the friction area of the PT-105 stock backing block.

[Admin]

your refering to replacing that block you show in the picture with a round roller, that block does the same exact thing your pro tool block does, the difference is the pro tools turns the die instead of using the small roller you have in the picture to roll around the die... same basic principal, if that block in the hosfiled bender was round, that is were all the force is, the little tiny contact patch would bend the tube...

[fabr]

I'm inclined to agree with bug but want to see the results.i could be wrong. I'm also wondering why the concern with friction? Hell I bend manually 1.5x .120 4130 with my PT.

[Nutz4sand]

I don't think so. It might damage the tube but I am betting not.

With a roller backing block my Protools will bend just like the Hossfeld but in the opposite way. Same forces put to the tube.
The tube being bent by the roller on the hossfeld is really not that different than using that same contact patch to keep the tube on my protools aligned. Plus I plan to use two rollers to split the load. 

If not. I will have to go back to the blocks. But I don't think I will. 

Side note. Magnum built his own tube bender with rollers. I was relooking at it and can not see his backing block. I will ask him how he does it. But I think he told me that the big rollers have a simple "U" clamp. I will ask him again.

Heres a link. His pics are at the bottom or end of the link. (I am to lazy to do it the right way! lol)

 http://www.minibuggy.net/forum/shop-talk/10395-air-hydraulic-set-up-bender-3.html