Brittan, Bender Pump?

[Tools R Us]

I have 2 OTC 4020 air/hydraulic pumps, they appear to be in good rebuildable condition. Like this; http://www.sjdiscounttools.com/otc4020.html Also have some new 6' hydraulic hoses.

Did some quick looking at cylinders, all I found are double acting, this setup only requires single acting. Probably could hook air pressure to the other side and use it to retract it instead of adding springs?

This would make a simple setup, but there are a couple of issues to overcome; The pump reservoir holds about 80 ci of oil, my quick math says that it will need more capacity for a ram of the size you talking about. I haven't found flow rate spec on it, but I am thinking that it will be very slow with that big of a ram.

 

[Tools R Us]

A little more research shows that the large cylinders are low pressure ~2500 psi. The pump that I have is low volume, high pressure 10K psi. It uses the more compact porta-power type rams, they are single acting and spring return.

A little more research shows that JD2 makes a conversion kit that uses this type of ram and they sell the Adapter Kit for $85. Looks like a compact, slick unit and would only need the kit and a cylinder, I can get a better deal on the cylinder.

http://www.patooyee.com/Bender/bender.htm

http://www.jd2.com/m3b.htm

 

[brittan]

I appreciate you looking into this. Lets see how much the ram is through your source. I found the 14"stroke for $500...16" for $550 locally. How much work would the pump need? I like the small foot print even if it takes more time to do the bend.
Thanks again...
Brittan

 

[Tools R Us]

The pumps were brought for repair and the customer decided to buy new. IIRC they leaked, I have an overhaul kit, one is disassembled, a quick inspection of the parts found very little wear, so confident that rebuilding with new seals will net as new performance.

 

[Tools R Us]

Or make a stand and use a Harbor Freight cherry picker jack.

http://www.pirate4x4.com/forum/showpost.php?p=6061678&postcount=227

 

[brittan]

Damn...that setup looks easy. The ram is $80!
Had he mounted the ram lower on the cart I wonder if he could have got to a 90 degree bend on one throw? Thanks for the link...

 

[brittan]

This one you posted up in outfitting...
https://forum.ih8mud.com/showpost.php?p=1655940&postcount=4...
incorporates the HF air over hydro ram with vertical mounting. I don't know where you found it but it looks like it will do a full 90 degree bend in one throw. I need to figure out the geometry but it has everything I want...small footprint, vertical mounting, inexpensive to construct, simple.
Thanks again for the help.

 

[desertdude]

...that would make my next tube bending outing at your place so much easier

 

[brittan]

Dude...yes it will...

I picked up the ram today from HF. I hope to have it done by the end of the month.

 

[Tools R Us]

In my opinion this ram is mounted at the wrong angle, the jack is almost in line with the pin. The first pressure is going to push hard on the pin possibly causing wear or breakage to the pin and/or die.

This angle will be much easier on equipment and require less force to make the bend, but will get less bend angle from the ram stroke.

Probably somewhere between the two would be best, the second one looks too low for easy use? Maybe able to move the ram to the closer bolt on the lever arm, this will give more bend angle from each stroke, but will require more ram pressure.

If your going to use casters, think about only three with the odd one mounted on threaded rod. That way you can stick the angle gauge on the base and level it?