Converting the JD2 Mechanical Tube Bender to Hydraulic … on a Budget

I have a bit more work to do before starting the roll cage on the exo car build. One of those tasks is converting my 15-plus-year-old mechanical tube bender to hydraulics. To risk sounding like a broken record, my workspace is small and not tube-bender-friendly. I can save space by converting the tube bender to hydraulics and mounting it on a portable kart instead of anchoring it to the floor.

JD2 Model 3 Mechanical Tube Bender

I am using my old JD2 Model 3 mechanical tube bender for this process. It is north of 15 years old, has been in storage for 5 years, and looks ready to bend tubes again, aside from a little surface rust. However, JD2 no longer sells the Model 3, but the dies and pins are still produced. Instead, it has been replaced with the Model 32, which has a similar price point and a sturdier design.

An old JD2 Model 3 Mechanical Tube Bender. after being removed from storage.
I’ve pulled the old JD2 Model 3 from storage. It looks a little aged, but I am confident it can still get the job done.

Mechanical vs Hydraulic Tube Bending

Mechanical tube bending is cheap at the expense of space and ease of use. Promoted as using a ‘high-ratio ratchet mechanism’ for easy bending. In practice, you will find extension arms the norm with these benders. These arms, usually a long piece of square tubing slid over the action arm, greatly increase leverage. They also increase the operator’s distance from the bend, making precise, analog bend measurements difficult to see. And finally, that leverage has to go somewhere to keep the bender itself from moving around. Mounting the bender to the floor via concrete anchors and mounting pedestals is the norm.

Pro Tool 105 Mechanical Tube bender demonstration
Here is the Pro-Tools 105 bender, which is very similar in design to the JD2 unit. As you can see, the operator moves the lever, which moves the ratchet in the same direction. This rotates the tube die (A) to bend the tubing. This force must be resisted by mounting the unit solidly to the floor.

By converting the bender to hydraulic, all of these disadvantages disappear. And it is a surprisingly easy conversion. As you can see in the picture below, the standard mechanical bender arm is replaced by a mount that holds a hydraulic cylinder. The cylinder is then used to press against the bender action or swing arm. The result is that while bending, the bender is now pressing against itself instead of sending torque through the floor, which opens up a world of mounting possibilities.

JD2 Model 32 mechanical tube bender converted to hydraulics.
The JD2 Model 32 converted to hydraulic. The cylinder replaces the leverage arm and ratchet.

Hydraulic Conversion on a Budget

JD2 sells a conversion for the Model 3 and Model 32 benders. It has three components. the adapter kit ($145), the hydraulic cylinder ($450), and either the air/hydraulic pump ($720) or the electric/hydraulic pump($1,125). Prices add up quickly.

Looking to spend significantly less, I did a little research and came across SWAG Off-Road. They sell a machined ram mount for most mechanical benders, allowing you to install a long-travel air/hydraulic jack from Harbor Freight. This route costs $150 for the mount and $120 for the jack. Another advantage of this setup is that there is no need for an additional pump, as the jack and pump are a single unit.

The simplicity and cost savings of the SWAG conversion made the decision easy. (Swag $270 vs JD2 $1315)

Mounting the Tube Bender

Now that I have the conversion sorted, I can mount the tube bender several ways. There are rolling bender stands and vertical mounts, but I saw an image of a repurposed engine stand that works perfectly. Having access to an old stand, I am repurposing it to become my mobile tube bender. It will be similar to the image below.

Engine stand used as tube bender mount.
Honestly, this is genius. I have a different style stand that I no longer use, which is perfect for conversion.


Another day and more progress. Although this will be the first cage I have built in around 10 years, it won’t be the last. With all the projects queuing up, setting up everything properly for my next venture seems like a reasonable approach.

Up next, I will mount the tube bender on the engine stand. (link incoming)

By Chris Simmons


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