Fixing a Shopsmith Mark 5 headstock

jldinark · Post by **jldinark** » Tue Jan 29, 2013 4:56 pm

I am not real sure where to begin here. I purchased a shop full of Smopsmith stuff for pretty much a song. Everything seems to be working in very well with the exception of the headstock on the Mark 5. The motor ran fairly well the first time I started ip up and now seems to have developed some problems. When started now, if it starts, the speed remains constant at a slower speed dial setting. I have no idea what setting it is because the dial seems to be wildly off. Most of the time, the motor will not start at all and simply sets there when the power is turned on. The back of the speed mechanism has an arm that connects to a drive shaft on the inside of the headstock. I have had to push a metal "plug" that slides back and forth into this shaft back into it several times after realigining it. I did manage to change the speed dial enough to keep it in place and keep it from popping out of the shaft. It also appears that the sheaves (spelling?) appear to be stuck on both the lower and upper shafts. There is a kind of metal on metal scraping sound if you manually rotate the drive shaft from the spindles on the outside of the headstock. If any of you can get me started in a direction to repair this headstock it would be greatly apprecaited! I am fortunate in that just a few months back I acquired a MV 520 that had never been used since the owner passed a few weeks after purchase RIP. So having a machine to work on is not an issue, I just need to get this other one up and running as a spair or as one to sell. Once again, thanks for any help you can give, or direct me to. Sincerely, JLDinArk

joedw00 · Post by **joedw00** » Tue Jan 29, 2013 5:57 pm

Welcome to the forum. I'm not too good on the maintenance side but I'm sure someone will help you soon. We have a lot of good people here.

wa2crk · Post by **wa2crk** » Tue Jan 29, 2013 6:26 pm

Can you post a few pics. We love 'em here. Your problem does not sound catastrophic but please do not turn the switch on any more if the motor is hesitant or only hums when the power is applied. Doing this too many times WILL damage the motor. You referred to a shaft that you had to push back a couple of times and that sounds to me like it may the bearing in the end of the control sheave.
Look at the SS website for the sawdust sessions and you will find a segment on a complete rebuild of a MK V headstock.
Anyway come back here and there a lot of people that will walk you through your difficulty.

Oh yeah, Welcome to the farm.
Bill V

marballizer1 · Post by **marballizer1** » Tue Jan 29, 2013 7:49 pm

Here's a link to the Sawdust Sessions.

http://www.shopsmithacademy.com/Sawdust_Sessions.htm

joshh · Post by **joshh** » Tue Jan 29, 2013 8:49 pm

I'm in the middle of a full restoration and I had trouble with several of the sawdust sessions playing on my computer (not really sure why) but if you google "Shopsmith Reborn" you can find sites that are hosting the video. You are after part 3.

JPG · Post by **JPG** » Wed Jan 30, 2013 2:45 am

Sounds like more than one 'problem'.

The motor 'just sitting there' I hope is in silence(no hum). If that be the case, the power switch is suspect. If it does hum(do not make it do so repetitively) the internal start switch is suspect.

The 'plug' is most likely the bearing on the end of the control sheave. It is not supposed to come out of the hub.

Now for the likely cause of its coming out, and the speed adjustment woes.

Both sheaves are likely sticking/stuck(not moving/opening-closing). The lower pulley is what provides the tension for both pulleys. The spring on the motor shaft presses the floating sheave. When the control sheave is moved by the 'arm', the change in the belt tension is taken up by the floating sheave moving oppositely. The arm should not 'pull' on the bearing/loop.(you did not mention the loop, but one should be in that 'plug' and loop over the 'arm')

Proper operation requires the sheaves to be easily moved by the varying belt tension.

At the least, the both movable sheaves must be freed and well oiled.

Best 'fix' is total removal of both movable sheaves so as to remove all gunk and get them properly lubricated.

P.S. Do you know which version of the Mark 5 you have? Greenie?(early/late) Goldie?(early/late) Gilmer? Poly-v?