by Jay Kopycinski

I recently purchased a JD2 Model 3 tube bender and wanted to convert it to hydraulic operation. I wanted to be able to make single shot bends of greater than 90 degrees without resetting the cylinder or repinning the die.

I designed and built a metal stand to support the bender and hydraulic equipment and also hold all the parts for three bending dies. The stand is about 36" high x 40" long x ~27" wide at the base. It rides on casters so I can roll it around as needed.

The bender is powered by a 1hp 110V electric pump and drives a 3" bore x 24" stroke double acting cylinder. My setup can bend up to about 105 degrees with a single cylinder stroke. Full stroke extension takes about 25 seconds. The cylinder provides plenty of power and has bent 2" x .120" wall HREW without problem. I originally thought a 2.5" cylinder would also be strong enough for this setup but have been told by someone that tried it that it was not sufficient.

I laid out the Model 3 bender on the floor and studied the geometry a little to figure out my cylinder size and mounting.

Movement is controlled by a standard 4-way valve that is spring loaded to return to center.

I made hangers to hold three dies on the side and their followers on the end of the bender frame.

A switch located on one end turns the pump on and off.

The bender works great in all aspects, except I made one mistake. I didn't allow enough room in the frame box that holds the fixed bender link to clear the follower for a 2" die. Here you can see where I plasma cut a chunk out of the box to allow for more clearance. Needs a little cleanup.

Here are the parts I used to build my bender:

Hydraulic pump (Northern Tool part #105871-B959)
1 HP 115/230V, 1.5 gal reservoir, 1.25 gpm, max. 2000 psi
(Note: Northern does not pack these well and they are often damaged in transit.)

Hydraulic cylinder - Prince model # SAE9224
(Northern Tool part #909224-B959)
3" bore x 24" stroke with 1" dia attachment pins, " working ports
(may or may not come with reducer bushings shown below)

4-way control valve (Northern Tool part #2010-B959)
1000 to 3000 psi relief valve, " inlet/outlet, " working ports

Four " x 24" 2-wire hydraulic hose (Northern Tool part #50124-B959)
(may need one longer hose depending on your layout and ram movement)


(1) Port return plug (Haldex Barnes part #1300191)

(2) Six 90 deg " NPT elbow (Northern Tool part #50ARC008)

(3) Two reducer bushing " M-NPTF " F-NPTF
(Northern Tool part #50CSC128-B959)

(4) Connector (Caterpillar #8M-0506)

(5) Two Union (Caterpillar #6V-2481)

(6) Elbow (Caterpillar #4K-6297)

Scrap of 1" tube used to mate moving link to cylinder end

Electrical parts: metal box, cover, switch, flex conduit, wire, plug, etc.


Thanks for reading!

Copyright (c) 2002 by Jay Kopycinski, All Rights Reserved.