Mark VII motor belt

[bigk01]

I hate to open this can of worms again but....

Finally got the time to tear into my new (to me) mark VII. After a little (ok a lot) of spray contact cleaner / lube on the fwd, stop, rev switch, the motor ran fine in both directions.

How does the switch come apart? Does the back just pry off? I did not want to break anything.

Anyway, now the belt question. The belt that was on the machine was / is an original? SS Magna belt p/n 507490 DF. Actual measurements 29.5 outside, .50 to .54.wide .28 to.29 thick.

I purchased what was supposed to be 30 inch belt at a auto parts store an put it on. Everything looked ok untill I ran it up to high speed, then, excessive slapping. Would have completely tore the plastic gear rack to shreds, (headstock was moved so belt would clear the rack). Turns out the "30" inch belt was just under 32 inches. Should have checked in the store.

I put the old belt back on. Every thing seems ok then.

Has anyone tried the dayco 17295 or 17300? Looks like they would be pretty close.

Also, speed control cam is very close to hitting the cam yoke / follower,
No apparent adjustment except with the eccentric on the Idler shaft which I don't want to mess with. Maybe I will just make a new control shaft, .125 longer.

I put a piece of self adhesive UHMW tape (.010 thick) on the cam / yoke follower where it
Rides on the cam. We'll see how that holders up.

[JPG]

I hate to open this can of worms again but....

Finally got the time to tear into my new (to me) mark VII. After a little (ok a lot) of spray contact cleaner / lube on the fwd, stop, rev switch, the motor ran fine in both directions.

How does the switch come apart? Does the back just pry off? I did not want to break anything.

Anyway, now the belt question. The belt that was on the machine was / is an original? SS Magna belt p/n 507490 DF. Actual measurements 29.5 outside, .50 to .54.wide .28 to.29 thick.

I purchased what was supposed to be 30 inch belt at a auto parts store an put it on. Everything looked ok untill I ran it up to high speed, then, excessive slapping. Would have completely tore the plastic gear rack to shreds, (headstock was moved so belt would clear the rack). Turns out the "30" inch belt was just under 32 inches. Should have checked in the store.

I put the old belt back on. Every thing seems ok then.

Has anyone tried the dayco 17295 or 17300? Looks like they would be pretty close.

Also, speed control cam is very close to hitting the cam yoke / follower,
No apparent adjustment except with the eccentric on the Idler shaft which I don't want to mess with. Maybe I will just make a new control shaft, .125 longer.

I put a piece of self adhesive UHMW tape (.010 thick) on the cam / yoke follower where it
Rides on the cam. We'll see how that holders up.

http://www.shopsmith.com/ss_forum/viewtopic.php?t=13906

[bigk01]

Yes, thank you JPG. I read all the info on the MKVII with great interest, especially your posts and threads.

I was kind of asking about the shorter belts.

Any advice on disassembling the FWD / REV switch ?

Thanks for all of everybodys help

[JPG]

My recollection is not very good, but there are those two screws in the corners. The third screw retaining the lamp contact may also retain it. I attribute my not remembering to its not being difficult. Do be careful and take note of where everything is so you can get it back together. The push levers shift a sliding contact bar between the terminals on the back. Those tend to separate and fail to make contact. Both sides should wipe the contacts. Keep in mind, the slide must move onto the contacts(they must be centered.

Sorry I did not take pix of mine disassembled.

If by 'shorter belt' you are referring to the poly-v belt, it is the same as the Mark 5/V poly-v belt except it is 4 ribs wider. A Mark 5/v belt will work. I would center it on the 13 groove pulleys.