Restoring Di-Acro Benders

Di-Acro benders are very powerful and versatile benders. They are found fairly frequently on the used market. A used #1A goes for roughly $300 and a used #2 go for roughly $500 with no stand or tooling.

These machines often need some help to get back into working shape. They usually need a repacking of the rotary bearing, have their holes cleaned out, and various nuts and fittings replaced. Benders #1A through #4 have needle bearings. I understand that the #1 has a bronze sleeve bearing.

Here's how to repack the rotary bearing:

1. Make sure you have a grease gun that will fit the zerk on the ring.
2. Take the bending nose and nose backup off of the handle.
3. Clamp the handle ring in place with a couple of C clamps. If you don't, when you lift the center disk out, the handle ring may come loose as well and you may end up chasing small steel pins all over your workshop floor. With the weight of the center disk, the ring should not flip over, at least on the #2. I can't be sure of the others.
4. There are three cap screws and two pins holding the top disk to the main body of the bender. Remove the pins by pushing them up from the bottom with a pin punch and persuader (aka hammer).
5. Remove the cap screws.
6. Lift up the top disk. Carefully. Some of the pins (needle bearings) may come with it, and there is a fragile wax paper shim underneath.
7. Don't screw up the shim!
8. Place the top disk in a container to keep the pins from rolling everywhere.
9. Pull the rest of the bearings out of the ring. Wipe each of them off with an old towel that you will be throwing away after the cleaning. Place the pins in a clean container.
10. Pull the bearings off of the top disk, again wiping them down and placing them in the clean container.
11. Un-clamp the ring and handle.
12. CAREFULLY brush or wipe the debris off of the wax paper shim.
13. Put a grease gun on the zerk of the ring, and push out the old grease.
14. Clean the base, top disk, and ring/handle. You may want to use a solvent. Scrape off old grease with a wooden stick. If there is any galling or raised bumps on the bearing surfaces, sand them down with some fine sandpaper wrapped around a flat block, such as a 1-2-3 block. Wipe off any sanding grit.
15. Now would be a good time to clean the holes in the top disk and base. Use a bottle brush, or push a rag through.
16. Squirt some grease in a few places on the bottom of the ring and place it back on the base. Clamp in place as closely as possible.
17. Squirt a fillet of grease around the inside of the ring.
18. Now place the pins around the inside of the ring. This will take a while.
19. After all the rings are in place and pushed against the ring, put some dabs of grease on the top of the ring.
20. Align the top disk in place and push down.
21. You can now un-clamp the handle and ring carefully.
22. Push the disk so that you can align the bolt holes.
23. Put the bolts back in, but don't tighten.
24. Put the pins back in, but don't hit them with a hard hammer, you might dent the top disk.
25. Now you can tighten the bolts.
26. Squirt some grease in the zerk and then rotate about 45 degrees. Repeat all the way around.
27. It should now turn smoothly.

Some tips on replacing nuts, bolts, and pins:

• Make sure all the holes in the base accept the right size bolts and top disk accept the right size dowel pins. If not, clean or ream them out.
• Check the nose springs. If they don't snap the nose back in place after you push it from the straight position, re-bend them.
• You can make bend stops with some bent bar. Bend some 1/8" x 3/4" bar into a U shape with a bending die the same size as the holes around the rim of the base. Use bolts with Whiz nuts to hold them in place. Make two, for a bend stop and return stop. You need the return stop to use the work stop.
• The work stop uses a 5/16" diameter rod. You just get some rod at the hardware store, bend it at 90 degrees, and use that. You will need a 1/4-20 thumbscrew at the top of the bending nose to hold it in place.
• Make sure the nose and nose backup have thick washers to protect them.
• If you are missing pins, you can get dowel pins at the hardware store or McMaster.com. If the holes are really worn, you may want to get oversize pins, which are .001" over the standard fractional size.