PowerPro upgrade question, quill and upper drive pulley

[shopsmithpaul]

Can anyone explain why it is necessary to install a new quill and upper drive pulley with the PowerPro. I have new bearings with little time on them and they are in great shape. I work in the machinery maintenance field and also did headstock rebuilds for SS many years ago. I will admit I don't know everything. Do they use different bearings or something. I talked with SS and did not get a suitable answer and no way to buy PowerPro without the added expense of those parts. I understand the need as far as making sure worn out parts are replaced. Thanks for your input.

Paul

[nuhobby]

I think you know as much as anyone. I've heard from rebuilders that the upper drive-sleeve bearings on an old machine are the first to wear out, I think. They (SS) may also want to ensure all PowerPros have a solid-aluminum piece rather than the 2-piece (steel shaft) upper sleeve structures used for earlier models. Furthermore they (SS) may wish to get rid of any odd-size pulleys such as have been used on 50Hertz induction models.

[dusty]

I don't know and I have done no specific research but I believe that the higher RPM capability of the PowerPro necessitates that those bearings all be validated. Said another way, I believe that Shopsmith may just be verifying that the bearings are capable of those new performance levels.

[larryhrockisland]

Somewhere in the Powerpro upgrade pages it states these items must be installed for warranty and to keep yours as spare. Forgive the lack of a link, me and my IPhone don't work well searching and pasting.

[billmayo]

The Power Pro headstock can operate at almost twice the RPMs of the regular Mark V headstock. The old bearings would most likely fail at the higher Power Pro RPMs. I find I have to replace the drive sleeve bearings on almost all headstocks when rebuilding them. I use higher quality bearings than the original for a longer life span.

You may want to save the removed parts and assemble another Mark V headstock. I find the MINI Shopsmith setup does not take up that much room and is excellent for powering the SPTs. This helps reduce setup time for projects. I have any extra headstock available with all the parts needed to complete another headstock using the removed parts.

[shopsmithpaul]

Thanks for the input. That is pretty much what I was thinking. I was hoping to find out if the bearings were better grade. I am trying to do upgrade with less cost, but does not appear to be an option.

Thanks, Paul

[larryhrockisland]

I found the web page http://www.shopsmith.com/shopsmithpower ... rchase.htm
In the DIY option.

[JPG]

I think Dusty nailed it!

It makes no sense to me re keeping the old parts as spares for the PP. Now if you rarely run above 5200, then it would.