PowerPro Idler Shaft Bearing Knock

[lpollett]

I have a SS 520 which I purchased used in 2003. It was about 1 year old. Mostly not even used. In 2014 I did the DIY upgrade to the PowerPro headstock. I love it. Last week I finally got around to installing a 220V circuit in my shop, and changed the plug on my headstock. I'm loving it even more now.

But here's the problem. I had to remove the motor to do some cleaning and maintenance on the headstock lock. When I reinstalled the motor, I could not adjust out the bearing knock on the idler shaft. SS phone support suggested I had a bearing going out. I order a new idler shaft and eccentric. After installing these new items, I still cannot adjust out the bearing knock.

I'm getting pretty frustrated. Of course SS tech support does not respond to any emails, nor do they fulfill the promise to have someone call me back. So I'm hoping someone here can provide a suggestion. Maybe it has something to do with the initial position of the eccentric when installing the motor. Or the initial tension of one of the drive belts.

Thanks

LCP
Shopsmith owner since 1975.

[claimdude]

I have had to rebalance my belts before on my DIY powerpro (7 or so years old). Check out this thread https://www.shopsmith.com/ss_forum/view ... ro#p191831
You can also search the forum using "powerpro rebance tension" and get some more ideas. I suspect the issue is just a matter of getting the belts tensioned correctly and that can be rather fussy.

Jack

[lpollett]

Thanks for your response. After several hours of adjusting, I still am not able to eliminate the bearing knock. I have watched this video several times. https://www.youtube.com/watch?v=xCLkH6T1uQE&t=6097s but cannot duplicate the clean sound that I had before, and that is shown in the video.

It appears that the most noise comes from drive sleeve assembly. I don't understand what caused my problem, since all I did was take out the motor to do maintenance on the headstock lock. Then put it back.

Any insight someone has would be appreciated.

Lyle

[jsburger]

Thanks for your response. After several hours of adjusting, I still am not able to eliminate the bearing knock. I have watched this video several times. https://www.youtube.com/watch?v=xCLkH6T1uQE&t=6097s but cannot duplicate the clean sound that I had before, and that is shown in the video.

It appears that the most noise comes from drive sleeve assembly. I don't understand what caused my problem, since all I did was take out the motor to do maintenance on the headstock lock. Then put it back.

Any insight someone has would be appreciated.

Lyle

I think we need to know where the noise is actually coming from.

When I first got my SS built Power Pro head stock in Jan 2013 it had a slight knock on startup when it was cold in the shop (under 50 degrees). It would go away in less than a minute of running. This was a brand new Power Pro but I really didn't want to send it back. After a few weeks I decided to removed the belt cover and used an OLD mechanics trick. It is called a stethoscope. No not one the doctor uses. It is a wood dowel about 1 1/2" in diameter. One end to your ear and one end to various parts of the SS. Trust me you will find the source of the noise.

In my case it was the idler shaft bearing that is held in the split housing bearing seat. I would think the bolt has a torque from the factory but there are many things that contribute to an incorrect torque. I really don't remember why I decided to do what I did but I tightened the bolt just enough to make it move. Problem solved.

[lpollett]

Thank you for your suggestions.
With the help of a mechanic friend, we did the "stethoscope" method of isolating where the bearing knock is coming from. We found the noise was coming from the main drive shaft. I will attempt to post a picture showing the exact location. And also a short video so the sound can be heard.
Lyle

[JPG]

Is the upper poly-v pulley(drive sleeve) set screw 'tight' and positioned correctly?

[lpollett]

I'm not sure what you are referring to. Is there a set screw on the drive sleeve? Would i have to remove that sleeve to see the set screw?

Thanks

Lyle

[JPG]

I'm not sure what you are referring to. Is there a set screw on the drive sleeve? Would i have to remove that sleeve to see the set screw?

Thanks

Lyle

IIRC it is on the rear end of the pulley, but is hidden by the headstock. Since you are suspicious of the front end, it may be irrelevant. The drive sleeve would need to be removed to access it.

[lpollett]

Thank you. I plan to pull it apart before the weekend and see what I find.
Lyle

[lpollett]

OK. I finally got around to pull out my drive sleeve assembly. One bearing was bad. i took the assembly to a local shop, and they replaced the bad bearing for me. (In and out the same day.) After reassembly, all is good.

Thanks to all who offered suggestions.

Lyle