Delta Contractor's Saw Motor Mount Bracket

If you own an older Delta contractor's saw (mine is model 36-635, manufactured in 1997) and have a warped motor mount bracket you've come to the right place. I recently picked one up for next to nothing only to find that the bracket was badly twisted. These brackets were made out of cast aluminum and given the weight of the motor and the torque transmitted through the belt they fatigue over time, twisting so that the drive side of the motor sags down toward the floor. This is well documented on various woodworking forums. The brackets are discontinued which is unfortunate, because other than the bracket these saws were really built to last. I've included a picture of my bracket for your reference, which I straightened out with a torch and clamps to have an accurate model to work with.

I would imagine that if you own a table saw you might be the kind of person that could figure out how to make a bracket, so I'm not going to go into a ton of detail regarding how I did it. The real challenge was figuring out how to recreate the geometry of the bracket without either a welder or a brake. So my primary contribution is the discovery of this long leaf hinge strap that I found on Amazon that is oddly perfect for the task.

Supplies

4" wide steel flat bar; I got this at a big box store, I think it was 4"x8"x1/4"

Buyers Products B2426FSLL Long Leaf Formed Hinge Strap (Amazon link)

Some form of a hacksaw; I primarily used a jigsaw with Diablo high speed thick cut jigsaw blades, and also a Dremel with a metal cutoff wheel

Drill

Screws (8), washers (16), nuts (8) for assembling the mount; I used M6 screws because that's what I had

6" 1/2"-13 screw for mounting the motor to the bracket

Cutting oil

JB Weld (optional)

Step 1: Cutting the Substrate

The hinge strap is used for creating custom weld-on hinges for something like a utility trailer. The leaf is a single piece of 0.3" thick steel flat bar bent to an angle in the middle and rolled into a cylinder at the end, and is about 2 1/2" wide. The hinge cylinder is bored out at both ends to accept plastic bushings, and has a zerk fitting. At first I planned on reusing the aluminum pins to mount the motor to the bracket. They fit perfectly into the plastic bushings. But it would have required a lot of additional work. More on that below. The reason this is so perfect is because the angle in the leaf is almost identical to the angle between the screw mounts and the bracket body, and the hinge cylinder is the same diameter (1/2") as cylinders at the other end of the bracket where those aluminum pins are used to mount the motor. This means you can use this one piece to construct the tricky geometries at both ends of the bracket. The only problem is that it's not wide enough. The screw mounts are about 3 1/8" wide (OD) and the pin cylinders are about 4 1/8" wide (OD). So that's where the 4" wide flat bar comes in. I figured I could cut the hinge strap into four pieces, and attach them to a section of the 4" flat bar to construct the bracket.

I first cut the 4" wide flat bar to about 4" long. I stopped every 30 seconds or so to add cutting oil. This will be the body of the bracket.

Then I cut the leaf in half the long way. I wouldn't recommend trying to do this by hand. It's hard to estimate how long it took with the jigsaw because a few times I burned through both of my batteries and was forced to stop and wait to recharge them, but I would guess something like 30 minutes of continuous cutting. It took quite a while to get though the hinge cylinder. Cutting the leaf strap in half left two 1 1/4" wide cylinders, which are substantially wider that the cylinders on the original bracket. In order to reuse those aluminum mounting pins I would have to cut these to be narrower, which didn't seem like it was worth the effort when I could just use one long 1/2" screw. Once you've finished cutting it in half, cut each of the halves on the flat section between the hinge cylinder and the bend. This section is 2" long, and I cut that section in half. This section was too small to get my jigsaw into, so I made these cuts using a Dremel with a metal cutoff wheel (three cutoff wheels, to be exact). Once you're done, deburr all of the edges of your cuts.

Step 2: Assemble the Bracket

Once I had my five pieces - the bracket body, the two screw mounts, and the two hinge mounts - I drilled the holes to attach the mounts to the bracket body. It's a little tricky to get everything lined up properly - the right widths, making sure everything is square - but this is where having the original straighten bracket was essential. On the origin bracket the hinge mounts are also at an angle, but since the motor is attached by round pins this angle serves as an offset. By attaching the screw mounts on one side of the bracket body and the hinge mounts on the other I was able to generate this offset without needing to generate the angle. After the new bracket was assembled I lined up the screw mount surfaces of new bracket to the old bracket to transfer the hole placement for the mounting screws. After dry fitting everything together with screws, I attached the bracket to the saw, and the motor to the bracket using the 6" x 1/2" screw and the washers and lock nut that came with the leaf hinge to make sure everything was aligned. I then took off the bracket and disassembled it to apply JB Weld to the mating surfaces (after scoring the surfaces with a Dremel). This is definitely overkill, but can't hurt. There you have it. A new straight and strong motor mounting bracket that should last forever.

PSA - You can see in my photos I'm using a link belt. I had never used one before, but they're fantastic. The belt that came with this saw was pretty badly warped into an ovoid shape from sitting unused for so long, and unsurprisingly the whole thing vibrated like a jackhammer when the motor was running. I had a new toothed belt sitting around, but to my surprise it didn't really make much of a difference. So I got this Accu-Link belt (Jason Industrial), and man, night and day difference. Smooth as silk. I'll also plug the place where I got it, Agri-Sales; they sell it by the foot for an unbeatable price.