power head slipping in vertical position

[oneearth]

I have inherited a '50s Mark V. After a weekend of cleaning and oiling I got it running and actually used the bandsaw. Anxious to try the drill press, I tightened down the clamp on the headstock and lifted it to vertical position. It seemed fine until a couple minutes later it came crashing down into the saw table. I had tightened the clamp as much as I could before lifting it into vertical position.

Questions:
What kind of mechanism holds the headstock tight to the tubular ways?
It obviously need replacing - how is this done?
How is it accessed?

Thank in advance for any assistance.

[dusty]

I have inherited a '50s Mark V. After a weekend of cleaning and oiling I got it running and actually used the bandsaw. Anxious to try the drill press, I tightened down the clamp on the headstock and lifted it to vertical position. It seemed fine until a couple minutes later it came crashing down into the saw table. I had tightened the clamp as much as I could before lifting it into vertical position.

Questions:
What kind of mechanism holds the headstock tight to the tubular ways?
It obviously need replacing - how is this done?
How is it accessed?

Thank in advance for any assistance.

Not necessarily. There are two wedges that travel on a threaded rod that squeeze against the way tubes when you tighten the headstock lock. It is the pressure against the way tubes that holds the headstock in place.

If these wedges are rusted, or dirty with saw dust, wax and oil - the friction grip may be inadequate to hold the weight of the headstock. Also, the wedges may be badly worn.

The easiest way to inspect them thoroughly is to drop the motor pan, disconnect the motor wires from the switch and raise the headstock into the vertical position. The motor pan can be left laying right there on the bench tubes. The drive belt also needs to be taken off.

We are talking about items #50, 51 and 80 in the following exploded view of the parts breakdown.

http://www.shopsmith.com/ownersite/partscat/images/Exp_Headstock.gif

If this is incorrect for some models of the Mark V, someone will jump in ad say so - I am sure.

[oneearth]

Thanks for the .gif - the "motor pan" is 98 in that image I assume. Can I still buy the wedges you mention from SS?

[beeg]

Can I still buy the wedges you mention from SS?

Yep you can and many other parts too.

[dusty]

Yep you can and many other parts too.

Yep, enough to build a Mark V in fact. This is one of the things that makes the Mark V and Shopsmith, Inc so very special. After these many years complete Customer Service is still available.

[kd6vpe]

Are the carriage wedges for the 500 carriage the same of those of the 510/520 carrage wedges. Mine on the 510 have some wear and the ones on my old 500 carriage are nice.

[dusty]

Are the carriage wedges for the 500 carriage the same of those of the 510/520 carrage wedges. Mine on the 510 have some wear and the ones on my old 500 carriage are nice.

I can't speak to possible differences between the 500 and others but I do know that worn wedges make a big difference. For the cost of wedges, it might be a good idea to just replace them every few years.

A free falling headstock can do significant damage to you and to itself. Oh, ow - can you image what that would feel like on the back of your head or on a hand that acts as a landing pad.