Hydraulic tube Bender Question

[guinea13]

I am looking at making a Hydraulic tube bender and I have done a lot of research but am not sure on one thing. Anyone ever make one using an Air hydraulic pump instead of an electric one.
I have seen two people that have made hydraulic tube benders but both were electric. Any Air hydraulic people out there.

This is the pump I am look at:

http://www.harborfreight.com/cpi/cta...emnumber=40611

And this is the ram I am looking at:

http://www.northerntool.com/webapp/w...categoryId=425

OR

http://www.northerntool.com/webapp/w...categoryId=425

I know this is a double acting ram but am also wondering if you can plug the one end and use it as a single.

Will this work?

[Ultim8kaos]

I use a Nike air over hydro pump for my Pro-Tools 105 bender. It works just fine. As for the rams, I bought the one specific to my bender from Pro-Tools but the ones you showed should work fine.

I don't think I would plug the port not being used as it needs to vent for proper movement.

[bheadrick]

Had the air on my Model 3 bender, slow and used alot of air. The worst problem was not being able to bend a full 90 without having to re-pin the die. For those that have a bender you will know what I am talking about.

Finally I made my own mount and used a 24" double acting cylinder so I could make those bends in one sweep, used a electric over hydralic pump and three position valve. The power return is nice also over the spring return most air systems use.

[Scott@Rockstomper]

Everybody I've talked to who's got an air-over-hydro bender setup says theirs is really slow. Usually in the line of commenting that mine is really fast.

Also, I have a DA cylinder, plumbed with a standard directional valve, so I don't have to manually retract it or bend against spring retract. More complex setup, but IMHO, a more production-friendly one. Sure makes it nice to work with, anyway--nowhere near as exhausting as it once was, to build cool stuff.

[Ultim8kaos]

Agreed on the speed of the air over! LOL It does use a lot of air and you do have to repin the die for a full 90* bend, twice!
However I only use mine at home and not doing production stuff.

[GOAT1]

The air over pumps run at high pressure and low flow because the rams they are designed to work with are small and require the high pressure to get the high forces out of them. The air over pump you are looking at is for a 10,000 psi system and the ram you are looking at is 2,500 psi, just be carefull. Your proposed set up will be very slow because the pump is low flow and the ram will have to be bigger (piston size) to get enough force at 2500 psi. I dont even think the pump will have enough oil volume to fill the ram anyway.

[zuknut]

My pro tools bender was air over for several years and I went thru three units before I changed it over to 12volt hydraulic unit from Pierce wrecker sales

I live in Reidville S.C. Just let me know and you can some and see how I have done mine.

[jdjanda]

Anyone use this to power the ram?

http://www.harborfreight.com/cpi/cta...emnumber=46169

[Scott@Rockstomper]

The HF 110/220 flavor looks good, except they don't list a GPM on it.

Mine's 12V, with a battery and a trickle charger (got the pump and a cylinder I couldn't use for $50--too good a deal to pass up, despite the useless cylinder) for power. I've seen quite a few built on 220 pumps, usually the same pumps that are used for shop vehicle hoists. Works well.

FWIW, I personally prefer the control valve to be separate from the pump. Here's a pic of all the components except the battery 'n' charger.



I know it's ghetto, but it flat works, and it's nowhere near as scary as my shop press with a 28" lift kit.

Also, I believe you can get a 220 hydro pump out of Northern (instead of HF) for about $2-300, should be better quality. Add a cylinder and a control valve for another $200ish (for both), $100 worth of fittings and hoses, and build mounts, and you're bending with more power than you should ever need (I can bend 1.75 0.500 in mine!) for probably under $600.

[guinea13]

Originally posted by jdjanda
Anyone use this to power the ram?

http://www.harborfreight.com/cpi/cta...emnumber=46169

Thanks for all the good info.

I saw this at harbor frieght too and am interested. I also would like to know if anyone has used this one.

[guinea13]

Originally posted by Scott@Rockstomper
The HF 110/220 flavor looks good, except they don't list a GPM on it.

Mine's 12V, with a battery and a trickle charger (got the pump and a cylinder I couldn't use for $50--too good a deal to pass up, despite the useless cylinder) for power. I've seen quite a few built on 220 pumps, usually the same pumps that are used for shop vehicle hoists. Works well.

Is that a plow pump? Can't seem to find it.

What is the GPM of your unit?

[Scott@Rockstomper]

We've guessed (not flow tested) mine at around 2 GPM. It's a used pump, and I don't know where it came from originally, but I know I've seen stuff like it in Northern. I'll go look.

Edit: This one
http://www.northerntool.com/webapp/w...roductId=20824
appears to be approximately similar to what I have.

With a little plumbing work, a little electrical work, and/or some mechanical fun, you could probably make any of
http://www.northerntool.com/webapp/w...ategoryId=1502
do the job, but I'd personally go for one without any integral valve assemblies--I like valves and pumps to be separate parts. Also, as you can see from my above pic, I like the control valve on the bender, to be up away from the pump anyway.

[guinea13]

Can't you get a AC to DC converter for the pump. I think they are about 20.00

[jdjanda]

This place has just about anything needed for a hydro setup

http://www.surpluscenter.com

[guinea13]

I wish I could find a used pump for a decent price.

[Scott@Rockstomper]

Originally posted by guinea13
Can't you get a AC to DC converter for the pump. I think they are about 20.00

For one that can supply 200 amps (with a spike of potentially 400)... they're a little more than $20. It'd be cheaper for me to buy a new pump, than to try and run what amounts to a starter driving a hydro pump, off a converter.

As for a cheap used hydro pump, try someplace that repairs trucks with Tommygates.

[Overkiller]

Originally posted by jdjanda
This place has just about anything needed for a hydro setup

http://www.surpluscenter.com

This is where I got the pump and ram for my setup. Great service. I had to return the first pump (my fault) and they took it back no problem.

[LAME]

got this pump on mine http://www.northerntool.com/webapp/w...roductId=23499

hooked to a 1hp Baldor motor that was a $15 garage sale deal. 24"x2.5" ram. Seems to bend very nice.

[guinea13]

Hey wouldn't this pump:

http://www.northerntool.com/webapp/w...roductId=23502

be better than this one:

http://www.northerntool.com/webapp/w...roductId=23499

You may not get a high of a GPM but you will get ~6000 more inch lbs of bending torque. This was figured out using this cylinder:

http://www.northerntool.com/webapp/w...categoryId=425


You would have a full stroke time of 29 sec for the first pump and 19 sec for the second pump (assuming a 1800 RPM motor). But the first pump would have more bending torque. I guess it is really dependent on big a peice of tube you want to bend or how fast you want to bend a peice of tube.

Does anyone know how much in/lbs of bending torque is needed to bend a 1 3/4" DOM .120 wall tube? how about 2" DOM .120 wall tube.

[guinea13]

Hey LAME,
What RPM does your motor run at?
I just found a 3/4 pool pump motor that runs at 3450 RPM.


I want to run it with this pump:
http://www.northerntool.com/webapp/w...roductId=23502



And the cylinder above.

It should be a good match up. Since I will be running close to 4 GPM with a pressure just under 2300 PSI, which is just under the max load for that cylinder.

Now All I have to do is make the frame and order a die set.

What is a good die set for a tube buggy? Aren't they all made of approx. 1 3/4 DOM .120 wall?

[guinea13]

anyone?

[Wazzobie]

I am new to the bending thing and just orderd up a bender from Mtech suply I have what apears to be the correct pump on my car hoist, a little pluming and a ram and Iwill be in business, the ram that they offer with the unit was a 14 inch 10 ton ram is there any thing different about that unit compaired to the agracultural units for tractors and stuff enough so that I would need a unit thats more than 3X's as much?

Reason I ask is cause they want $400 for there ram and it seems the farm store models go for around $115 whats the difference?

[Scott@Rockstomper]

Originally posted by Wazzobie
is there any thing different about that unit compaired to the agracultural units

The Enerpac cylinder that is typically used with the bender setups is a 10k psi cylinder. The ag stuff is usually 2500psi at best. More pressure = more force with the same size cylinder, or the same force, with a smaller cylinder.

With the auto hoist pump, you can't make enough pressure to drive the Enerpac cylinder reasonably; it typically operates in the 1-2k psi range, not in the 5-10k psi range. So you'll want a bigger cylinder, like one of the ag ones, to get enough force to bend tube.

[Wazzobie]

thx for the info, I think your truck kicks a$$

if I understand corectly

I had no idea they took that much psi to bend tube. So sounds like my car hoist pump wont create enough psi to feed either ram enough to bend tube same with the ag ram so, cost the $400 or close to it like they said for just the ram is probably normal + a different pump (ouch!).
Sounds like I will be doing all the pumping and the raming myself.LOL

[Scott@Rockstomper]

Originally posted by Wazzobie
I had no idea they took that much psi to bend tube. So sounds like my car hoist pump wont create enough psi to feed either ram

Look up. ^^^^^ Same thread. See the pics of my setup? That's a dumptruck or tommygate pump or something, and a 3" bore ag cylinder. About the same pump as on an auto hoist, just a different layout of reservoir and whatnot.

You can use the auto hoist pump, in fact, I know other guys who do, but you can't use it with the typical cylinder that Mtech or JD or ProTools or whoever, wants to sell you; you'll have to use a bigger cylinder (like my 3") to get enough force. Actually, you can do pretty good on a 2.5", but I bend some pretty gnarly stuff sometimes, so I wanted overkill.

If you opt to use the auto hoist pump, you'll need a directional valve and a cylinder, and a custom mount for that cylinder, onto your bender. Nobody makes the adaptation kit that I have; I've seen more than a few guys who've copied mine, and a few who've done it much more elegantly than mine. Hell, I had one guy over here to measure my setup, with a notepad, specifically because he was planning to copy it almost exactly.

It doesn't take that much psi; it takes that much *force*. The little cylinders get there by having a lot of psi; the bigger ones get there by having a lot of piston area. You get there by having a superduperlooooooongass cheaterbar and very little psi (or you'd rip your hands up) if you use the manual bender option. Kinda make sense?