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Sheave Spacer missing

Posted: Tue Jul 08, 2025 12:15 pm
by jimbeaux
I have a Shopsmith (with the small table) that I bought directly from Shopsmith about 45 years ago. So, I guess it's the Mark V model 500? I have been hearing a clicking / ticking / rubbing sound from the drive belt end of the headstock for quite a while, so I did a little research and discovered that it is most likely caused by a worn sheave spacer behind the fan sheave. I dismantled the sheave assembly only to discover that there isn't a sheave spacer.

Did Shopsmith not put a spacer in this year Mark V, or do you guys think it was just mistakenly left out during assembly? I did have quite a bit of struggle to remove the sheave in that the set screw was set so tightly that it bent the end of key.

I've ordered a replacement sheave spacer (#504205) from Shopsmith.

Re: Sheave Spacer missing

Posted: Thu Jul 10, 2025 12:11 pm
by chapmanruss
jimbeaux,

Welcome to the Shopsmith Forum.

If you purchased your Shopsmith directly from the factory about 45 years ago, 1980ish, it would be what became known as the Mark V 500. That designation began for the original Table System Mark V when the Mark V 510 and 505 with the larger Table System were introduced in 1985.

The Motor Fan Sheave to Motor Spacer part number 504205 has not always been included and is not found on early Mark 5 motor shafts. Mark 5 became Mark V in 1980 as seen on the Vent Plate attached to the Belt Cover. I don't know when the Spacer became a standard part. Prior to the inclusion of the Spacer the Motor Fan Sheave was held in place only by the Set Screw. Since the introduction of the Mark 5 in 1954 the majority of the changes to the tool has been to the Headstock.

Re: Sheave Spacer missing

Posted: Thu Jul 10, 2025 1:11 pm
by jimbeaux
Hi Russ, and thanks for the information. My Mark V is serial number 83461, which appears to be manufacture date of March 1981.

I'm guessing that it's okay to use the spacer on my generation Mark V even though it appears that it didn't originally come with one.

Jim

Re: Sheave Spacer missing

Posted: Thu Jul 10, 2025 1:17 pm
by JPG
I am confused! The spacer was included with the Mark VII. Why not in SSInc Mark 5s?