I have a Porter-Cable Model 444 profile sander. I’m not sure where I got it, and I’m not sure I’ve ever used it. I think I either bought it used, or got it from my father.
In any case, I wanted to use it the other day. I got it out, put some sand paper on it and got to work. Suddenly it started making a different noise and shaking really badly.
The head was really loose and shook from side to side. That’s not right.
So what do I do next? I take it apart to investigate.
Step one – Make sure it’s UNPLUGGED. Then remove all the screws. They are a Torx T-20 and there are seven that are longer and self-tapping and two (one on each side) that are shorter machine screws. They hold in the vibratory assembly.
The guts. If you look carefully at the right end, you can see the problem.
The problem. The vibrating head runs on two shafts that pass through four bronze bushings. The bushings are just press fit into the plastic head with no means of retaining them. So they just fall out. That’s some crappy, lazy design work. Actually surprising from Porter-Cable, but if you search on the internet the Model 444 is not a popular tool. (Maybe this is the reason?)
So how do we fix it? Set screws!
You might want to mark or measure the shafts so that you know how far they stick out of the assembly. I didn’t, and had to fuzt around a little to get them re-assembled properly.
There are two set screws that hold the shafts in place. They are Torx T-8. Loosen them and slide the shafts out. Then you can remove the rotary assembly from the head and press out the bronze bushings to get them out of the way.
We are going to add four #2-56 x 3/16″ long set screws to hold in the bushings. The first step is to get a #51 drill bit and drill a hole through the top of the bushing housing. Get it as centered as you can. If you have a center punch to make a starting spot that will help. You could use a nail and just press it in to make a spot.
Grab your #2-56 tap and a tap handle and tap the holes.
Press the bushings back into the bores and thread a set screw into each hole. Tighten them down (but don’t strip them) and then re-assemble the head assembly.
Put the thing back together and test it out!
Here are all the tools and parts I used:
- T-20 Torx driver
- T-8 Torx driver
- #51 drill bit
- #2-56 tapered tap
- Tap handle
- #2-56 x 3/16″ cup point set screws (4)
- .035″ hex key
- Penny for scale