Tube bending guide

marty79

marty79

Well-Known Member
Joined
Nov 24, 2013
Location
Newton, NC
Finally getting the bender out and dialed in, getting some bends done so I'm reading up on stuff....
I'm trying to figure out about this CLR bend measurement I'm reading up on...can anyone shed light on is it the Dye that allows you to bend a closer CLR like a 3 versus my current centerline radius is 7. It seems from a site I was reading this is based on the die you use but not sure, maybe I'm reading it wrong. I'd love to be able to mix and match bending radius to be closer so just trying to figure out what this will take. thanks
 
this is what I'm referring to and can't really understand what you do to achieve the 3" from the 7" CLR...


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So first, --it won't let me format on phone but this is a link to the original how to articles--Pirate4x4.Com - the tube bending Bible for years.

Second, I mean you have to be able to see how a die that was at one point a piece of 14" round stock can only ever bend a 7" radius. You are drawing the tube tightly around the die and it's radius. That being said, you can bend larger radii than the die by incrementally pushing the tube through and only bending a little at a time. If it were easy to make multiple bends with one die set people wouldn't have $3k worth sitting around

:Edit: unless you consider a kink to be a usable bend.
 
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braxton357 said:
So first, Pirate4x4.Com - The largest off roading and 4x4 website in the world. the tube bending Bible for years.

Second, I mean you have to be able to see how a die that was at one point a piece of 14" round stock can only ever bend a 7" radius. You are drawing the tube tightly around the die and it's radius. That being said, you can bend larger radii than the die by incrementally pushing the tube through and only bending a little at a time. If it were easy to make multiple bends with one die set people wouldn't have $3k worth sitting around

:Edit: unless you consider a kink to be a usable bend.
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ok so I was reading right that you need to have a smaller die in order to achieve a smaller radius bend...thank you for confirming.
and I will check out the Pirate tube bending platform for more FAQs and such.

I've learned one thing...Air over Hydraulic bender is so slow, I can go run a marathon while it's bending a 90 LMBO hahaha. I apparently struggle with patience with slow work lol, this thing drives me crazy. I like the "accuracy" of it, no doubt about that but daium, freaking slooooooow. I DEF see upgrading to full hydraulic motor in the future.
 
I don't know what setup you have but are there more holes on the pivot arm closer to the center die pin that you can put the hyd cylinder eye in?
 
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I have this one, came on a roller base and facing vertical. Air over Hydraulic 8 Ton. Strong, accurate, works good so far, slow lol.


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this is the 1.75 die I have
 
It's a Protools 105HD with the copperhead Fab mount and the harbor freight air/hydro cylinder.

The CLR of the die is the Center Line Radius. It's the distance from the center pivot point to the outside edge of the die. Half of a circle, hence radius. You cannot make it smaller. With a smaller one, you can manipulate it to do larger radii, but it will be tedious and probably inconsistent.

And to everyone else, I have enabled this science of metals experiment, so you're welcome. :D
 
jeepinmatt said:
And to everyone else, I have enabled this science of metals experiment, so you're welcome. :D
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OMG no you didn't.
Im liking it mostly except gotta make it faster faster faster. I'm gonna die of old age before reaching the 90mark hahaha
 
And, not every piece of tube can be bent with a smaller CLR. The thinner the wall, the more deformation of the tube on tight radius bends.

Unless you want to go broke on dies, take the advice of seasoned builders on what dies work best with the tube you use in lieu of buying a 3” CLR die expecting the bend quality to be the same as a 7” CLR.
 
rockcity said:
Patience is a virtue.


If you want to make it faster, get the handle and do it manually. It’s more work but faster.
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@marty79 I’ve got an old JD2 model 3 handle. Looks similar to that. Not sure if it would fit another brand.
It’s useless to me and @hurt4x4 cause we have a model 32.
It is faster, and a workout, but that fits your style.
 
Van-go said:
@marty79 I’ve got an old JD2 model 3 handle. Looks similar to that. Not sure if it would fit another brand.
It’s useless to me and @hurt4x4 cause we have a model 32.
It is faster, and a workout, but that fits your style.
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I've got the handle lol. I'll manage till I switch over to hydraulic setup
 
rockcity said:
Unless you want to go broke on dies, take the advice of seasoned builders on what dies work best with the tube you use in lieu of buying a 3” CLR die expecting the bend quality to be the same as a 7” CLR.
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Good point and dually noted, thanks
 


Electric over hydro
 
Not all air/hydraulic are created equal. If yours uses a harbor freight air/hydraulic engine hoist ram, it will be slow.

Mine uses a spx power pack and ram. 90* in a matter of seconds if I hold it wide open.

The larger the CLR, the stronger the tube will be after bending.

IIRC 3x diameter for minimum CLR.

1.5” x 3 = 4.5 CLR
1.75 x 3 = 5.25 CLR
2.0 x 3 = 6.0 CLR

Those are minimum CLR for common tuning sizes without having a giant reduction in strength at the bend.

You can always diy an electric/hydraulic setup for yours.

Electric motor, coupler, hydraulic pump and reservoir, valve. Can even do a metered flow control for bending faster or slower for better accuracy.
 
Mac5005 said:
Mine uses a spx power pack and ram. 90* in a matter of seconds if I hold it wide open.
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Wow, how pricey is this vs going electric hydraulic.
 
Mac5005 said:
Mine uses a spx power pack and ram. 90* in a matter of seconds if I hold it wide open.
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Also is it the ram that's slow or the air motor or little bit of both. Thank you
 
I’ve used one with the spx set up and it was pretty darn fast
 
marty79 said:
Wow, how pricey is this vs going electric hydraulic.
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marty79 said:
Also is it the ram that's slow or the air motor or little bit of both. Thank you
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Pricey is an adjective that is open to personal interpretation and perspective.

My spx power pack runs several different tools I have. Quick detach no loss hydraulic couplers on items.

It’s definitely not cheap or homebrew. It is professional level stuff and dependable. I also didn’t have to figure anything out. Hook it up and use it. Works every time. I didn’t buy the setup new either.

I cannot speak about why the HF air/hydraulic system is slow, I can only guess.

Small air piston/motor to drive the hydraulics that’s not efficient. Almost anything air powered is going to consume a ton of air, bad for speed and efficiency but great for environments that require air or hydraulic tooling. (Think coal mine).

Could also be sub par air volume supply or could just be cheap parts.

I haven’t been inside one to tell you for sure.

If I had to build one from scratch, it would be electric motor driving a hydraulic pump with a manual valve with a metering valve for speed control.

None of that is super complicated just takes common hydraulic items to make it work and some math to get everything sized/specd correctly to be happy together.

Tons of info on web about diy elec/hydraulic tube benders.

My main point was that it’s not fair to say air/hydraulic sucks. They aren’t all equal. Building from scratch, do electric/hydraulic. Far easier and safer than air/hydraulic. The air in these systems acts like a spring. On diy stuff with high pressure and volume, you can get hurt easily.

I guess I’m trying to say bigger safety factor doing diy elec/hydraulic than air/hydraulic.

If I had to guess, I could probably do 90* in about 15 seconds. Takes longer to get tubing in die perfectly and nail the rotation than to make the bend.

SPX Power Team 10,000 psi Air / Hydraulic Pump

This is very similar to my power unit.

Most of the rams are 2” dia or larger and below 6” stroke.

Pressure is the force applied to the ram piston. The power. Volume of flow is the speed you can move that piston.

High pressure low flow = high force low speed

Low pressure high flow = low force high speed

High pressure high speed = high force high speed

Multiple the pressure of the pump output (psi pounds per square inch) by the area of the piston ( sq inch) to get force of ram. Smaller piston equals less force. Larger piston equals more force.

Longer stroke needs more volume (flow) per unit time compared to a shorter one if psi is the same, for the ram to move at same speed (short vs long)
 
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Van-go said:
@marty79 I’ve got an old JD2 model 3 handle. Looks similar to that. Not sure if it would fit another brand.
It’s useless to me and @hurt4x4 cause we have a model 32.
It is faster, and a workout, but that fits your style.
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The floor mount and ratchet handle went with the bender so they should be in his possession.

marty79 said:
Also is it the ram that's slow or the air motor or little bit of both. Thank you
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It's the air motor. The ram is as fast as you can flow fluid into it. The air motor is typical harbor freight stuff. It does have a latch on the valve, and I have been know to latch it and walk away for a minute to do something else because I was born with no patience. It's only a problem when you forget :D
 
jeepinmatt said:
It's only a problem when you forget :D
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Bruh I did that without knowing the other day and yeah I was flustered. It was a test piece (but for my bumper) and yeah that was funny. It's no longer a part of the switch lol. Would suck to accidentally mess up someone else tubing that way so I'll learn some patience .
 
jeepinmatt said:
It's the air motor. The ram is as fast as you can flow fluid into
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I see me tearing into it in the future to see about giving it the "Fuller" mod hahaha
 
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