Shopsmith Forums

What is the recommended procedure for replacing a PowerPro drive sleeve assembly? I'd like to avoid any unnecessary disassembly. Thanks!

Take this with a grain of salt, I don't recall actually doing it without major disassembly.

1) You have to remove the lower belt from the motor pulley because you won't be able to loosen the upper belt without doing so. What I'm calling the early motor is the one where the motor mount mounting screws are hidden by the motor pan. (I have no experience with the later motor.) To do this on the early motor you'll need to remove four of the six mounting screws furthest from the pulley. The other two mounting screws will give the motor an axis to tilt on, just loosen them slightly. Tilt the motor and the lower belt will slip off easily. By removing only the four mounting screws that hold the motor mount to the headstock you avoid messing with the alignment. These are countersunk metric machine screws and use a 4mm hex key.

2) Loosen the upper belt by rotating the Idler Shaft Eccentric in the headstock housing. To do this, loosen the bolt and nut that clamps the headstock around the eccentric. When you but it back together and adjust belt tension, do not overtighten as you can break the casting. (see 5 below, I would fully remove the Idler at this point.)

3) Remove the outer spirolox retaining ring from the headstock. This functions similar to an internal snap ring, goes into a small grove inside the headstock bore and engages the outer bearing race to retain the Drive Sleeve Assembly. Unlike a snap ring, you need a small screwdriver or similar to work the end of the spirolox and just work it around until the whole thing disengages from the groove.

4) At this point, there should be nothing holding the Drive Sleeve in the headstock. The amount of persuasion it needs to come out varies. Best case you can extend the quill until it disengages the splines and simply pull the Drive Sleeve out. If that doesn't work, you can rotate the quill slightly so that the splines don't engage and gently press the Drive Sleeve out using the quill feed. If that doesn't work remove the quill completely and you can use a dowel and mallet to tap it out.

5) As the Drive Sleeve comes out you need to slip the upper belt over it as you're feeding it out. There may not be enough slack in the belt to do this even if it is loosened all the way. If this is the case you may need to remove the Idler completely. (I prefer removing the Idler anyway to inspect the bearings, which tend to have a limited life on the PowerPro in my experience.)

I hope this is helpful and that I haven't missed anything.

- David

Thanks David. I'm trying to determine the source of my noisy PowerPro headstock. I thought the drive sleeve assembly bearings were the most likely source, but after exposing the motor per your instructions and running it with belts removed I think it may be the motor itself (see link to YouTube video). I checked both ends of the motor for loose set screws/scraping but found no issues. Are the motor bearings shot or is this normal? Note the extra noise when the motor starts up as well as while running.

https://youtube.com/shorts/yr1BNapFLAs

Also, before I removed the belts I noticed some sideway movement of the idler shaft within the exposed bearing when I squeezed the sides of the idler belt together. Also a problem?

I couldn't view the link, it showed "Video Unavailable."

That said, the motor should be extremely quiet. I think it has ball bearings at both ends though I've never had one apart. IIWM I'd try spinning it by hand and checking it for axial and/or radial free play on both ends to confirm a possible bearing problem. IIRC the motor has a five year warranty. If you end up tearing the motor down for bearing replacement consider doing a 'how-to' thread with pictures.

The Idler Shaft movement sounds suspect to me. The shaft has two separate ball bearings so movement or runout should be minimal. The PowerPro Idler runs very fast if you use the machine in the upper RPM range (1.6 X commanded RPM). It also gets fairly hot, even at more modest speeds and especially if the belts are tight. The bearings are pretty small and are shielded, not sealed. Bearing failure would not be unheard of.

- David

I don’t know why the video won’t open for you - it works for me. Any YouTube experts know if there are any settings I need to tweak in YouTube to give general access?

My motor is definitely not very quiet. I’ll have to check my purchase date. Warranty would be nice!

Try this video link of my noisy PowerPro motor. I specified the link as "Public". Please let me know if it works now.

https://youtube.com/shorts/yr1BNapFLAs?feature=share

Yes, the video is accessible now. What speed are you commanding for the video? I do notice more sound from mine at very low speeds, I think this is related to how the system measures and corrects for actual Vs. commanded RPM. It's not really possible to determine how loud this is from the video. I'm not hearing anything as the motor spins down, which to me suggests it is not a bearing problem.

On mine, if it isn't in the headstock, the air noise from the fan is louder than anything else at preset speeds 2000 RPM and up. At 1350 RPM, air noise and motor noise are about the same volume. At 900 RPM, motor noise is louder than the air. (Note: these are all main spindle RPM, not actual motor speed.) (Mine has the air plenum on, looks like yours is off in the video.)

- David

I'm pretty sure it was the default speed on startup (500 rpm?). I've got the headstock all zipped up again so it's not easy to check. Agree about the lack of noise on power down. The shaft spins silently by hand. I've sent the video link to Shopsmith customer support. I'll report back any response I get from them.

Feedback from any other PowerPro owners?

Here's the sideways movement I see in my Powerpro idler shaft when I squeeze the sides of the idler belt together. Looks like my idler shaft bearings may be shot,

https://youtube.com/shorts/njhjZap5zF4?feature=share

There have been a few threads on bearing failure on the PowerPro Idler, but I haven't seen one yet that actually documented successful bearing replacement. The inner bearing is the tricky one, so if you were very lucky maybe only your outer is bad. For the inner you evidently have to remove the pulley. One member reported success applying heat to the pulley to remove it. I plan to try that, but haven't done so yet. If you go this route, I'd love to see some pictures of the shaft especially underneath the pulley. The key to the operation, I think, is whether this is a straight interference fit or if there is something else ensuring no movement of the pulley on the shaft.

- David