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New tube bender, U-strap problems on a Pro4

12K views 34 replies 16 participants last post by  TMI 
#1 · (Edited)
My Neighbor just got a new tubing bender.
I believe it's a Pro4

Setting up the bender, and calibrating bend tech.
1" die works great! Bend the tube and pull the U-strap pin out.

However, the 2" die is having a problem.
You need to use a punch to drive the U-strap pin out after a bend. See video in post #8
U-strap & pin goes in fine. Coming out you need to punch it with a hammer.

Any suggestions? Are we doing something wrong, using the equipment wrong? Or can a there be a hardware issue?




It NOT coming out like this..


U-strap


His Bender
 
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#2 ·
Is it because there is pressure from the tube pushing back against it?

I am sure your bender dealer/manufacture would do a good job helping to explain what is going on and if/how to make it easier.

.
 
#3 ·
Correct, the tube is causing pressure against the u-strap.
He is trying to dial in the Bend Tech software. The 1" is done, as the die worked well. My neighbor said the software is very nice and intuitive for a non computer guy.


Bent some cheap tube to 92*, release pressure from the jack and it springs back to 89.7*. Remove pressure from the tension bolt and tube is loose, except for the u-strap.
Then remove the U-strap pin with punch, the tube spring back to 88.8*

Also during the bend with just the 2" the die hits the follower block. Using Mobil 1 for lube, and some good grease on the follower block.


Is there anything WE could be doing wrong?

My Neighbor has contacted the seller, and will be trying a new u-strap...
But we wanted to make sure we are not doing something wrong, both of us are new to this type/style of tube bender.
 
#4 ·
theres nothing wrong with your u strap or die. i can see in the pic your tube has pressure on it. hit the moveing arm with a rubber hammer to loosen the bender then hit the tube to get the u strap out.
 
#9 ·
Is this normal?
Video of u-strap removal on a Pro4.
I have had this happen in the past.

  1. If the U-strap bolt is not tightened tight enough
  2. If you lubed the Die and the tube is slipping causing too much pressure on the U-Strap "causing the u-strap to kinda pinch the tube"
  3. It was the material that I was using. Was it a piece of DOM?
 
#12 · (Edited)
My pro tools 105HD does that now and again too. I just loosen the follower and pull the tube away from the die. Then I can normally pop the u-strap off with no issues. I think it is just due to the tube being really snug in the dies, if it were looser, you'd see more deformation.

Later,
Jason
 
#13 ·
Have you tried a different piece of tube? It might be the tube. Like I said, I have seen that in the past to create problems as long as every thing else is right. If the problem persist you might have to call Dean over at Pro Tools because they do all that warranting of there dies.
 
#14 · (Edited)
I've bent probably around 4-500 foot of tube with it. It's 5 years old and bent my complete chassis as well as lot of other stuff, so yes, it's had a bit of tube through it. I personally don't see it as a problem, and maybe mine isn't as bad off as MR.N's neighbors, or maybe it's not even the same issue. I don't know, but I like that I need to put my hands on the tube and give it a quick tug before the U-clamp will release, It saves me from dropping parts.

That's all mine takes though, is a little tug and it pops out of the die and releases the tension on the strap...

Later,
Jason
 
#17 ·
Rob, I don't think he's badmouthing the ProBender, he just wanted to make sure they weren't doing something wrong (operator error):confused:

I don't feel the thread needs to be removed, I don't see it a detrimental to ProBender, it sounds like you have gone above and beyond to get Mr. N's neighbor (Paul?) sorted out, like any good vendor would :beer:

And he changed his post to "Pro4" rather than "Pro32" he can't edit the title.
 
#18 · (Edited)
Pin for the u strap looks awfull short, the hole also looks egged out. If the end of that pin is tapered then the strap isn't going to stay put for long.

Looking at the video, you're going to ruin the strap taking it off like that.

That being said, with my homebuilt bender that has about the same configuration as the one you are using
- I had to let the pressure off the ram and then grab the tube that was still being fed into the bender, push and pull pretty hard to get it to pop loose and remove the u-strap.

It also looks like you are already scratching the heck out of the follower die. That piece of tube in the picture doesn't look nearly clean enough. You'll have better luck getting the shiny tube from Discount steel, rather than the grey stuff. The shiny cleans up a lot better.
 
#19 ·
Personally, I think it is either a material issue, or a die/strap issue. And since Rob says they tested the die at his shop and it performed correctly, that would leave the next logical step to look to the material as an issue.

I know that personally I have had similar problems on two different benders, using the same material - so thanks to this thread I need to check my own materials for the problem, where I thought it was "operator error" (me :p )
 
#20 ·
Had similar issues with mine - pushing back the die has seemed to have fixed the issue... Although I've only made 3 or 4 bends with it so far - need to pony up and get the bend-tech software :p
 
#21 ·
When I got my bender all set up I had a similar problem, but not that bad. I just had to tap on the tube open fist to pop it loose. I found that after the first 2 pulls of the handle (mine was manual) I could snug the bolt up a little more. This is what I did, and have been doing. Getting the bolt a little more snug early on kept my u-strap from sticking like yours is. Get a wrench that will fit yours, and try snugging it up a little more that way. Don't be like the hulk or anything, but just a full turn or turn and a half. That is what I got in the habit of doing and it works like a charm.
Clay
 
#30 ·
i have the same issue with my u-strap on my pro 105. i have to punch it through... i'm gonna try a few different things. i'm sure its something i am doing wrong as i am new to bending. as far as dealings with rob at TMI i have had nothing but good luck, he sold me my die set and was very helpful.
 
#34 ·
Try leaving the pin in the die while you release the cylinder pressure, tube should pop loose allowing you to get the strap off.
I was pulling the pin out of the die and then collapsing the cylinder and had to beat the pin out, no more probs now.

Mine is a go-trikes style bender.

If someone else mentioned this earlier sorry I didn't read the whole thread.
 
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