Head Stock Lock

[ChrisNeilan]

I find Beeswax to be almost a "non-slip" wax, and relatively expensive. Save it for woodturning finishes.

[Mike907]

Shopsmith recommends powdered graphite on the headstock locks. Beeswax would jam the locks in a cold shop.

Mike

[commnthings]

Success! (so far, anyway). I got the old, stuck wedges out. Had to cut the bar but that's no problem. I am ordering new wedges and lock assembly today. They're out of stock for a few days on one wedge.
Now, I need guidance on setting the "timing" of the wedges. I assume there is a 'magic' formula for setting them. Should I use some graphite during the assembly?
One last question: is there a trick to popping out the roll pin? I whacked on it (with bracing under the handle) but it wouldn't wiggle. Don't need to do it now, but who knows when I might need to again?
Thanks,
Bob

[sehast]

The roll pin has given me a lot of problems too. I finally ended up using a broken 1/8" drill bit to drive it out. It came out hard all the way to the bitter end. Getting it back in is no picnic either.

[reible]

The use of the proper size pin punch helps. I'm not home to check the size but can later unless someone else can chime in?

I've also stopped reusing the old drive pins. Again not home but I seem to recall the being 7/8" which is not in the normal hardware stores so when I placed an order from shopsmith I added a few of them.

A little care and these parts can last a lot of years, I do have a jack up set but have not needed them.

Ed

[JPG]

When replacing a headstock or carriage(M5/V) lock the wedges need to be properly positioned on the threaded shaft.

The shaft has right hand threads on the rear end and left hand threads on the front end.

There is a short non-threaded area in the middle of the shaft.

Since the wider end of the wedges need to be facing each other and the bores the wedges slide in will not allow the wider end to enter the bores, the wedges need to be positioned further towards the middle of the shaft than the normal operating location in order to insert the shaft/wedge assembly into the headstock/carriage(M5/V) bores from the 'inside' of the casting.

Once the assembly is inserted the the bores, the wedges need to be repositioned further out from the center of the shaft.

This point is where 'timing' becomes critical and must be done correctly.

It is not complicated and can be accomplished by more than one method.

However the goal is to insure both wedges remain the same distance(though varying) from the unthreaded center area as the shaft is rotated and the wedges are restricted from rotating with the shaft.

I find the simplest method is to rotate the wedges individually until the 'fatter' end of the wedge is pressing against the inner end of the casting bore. Keep in mind the goal is equal distance of the two wedges from the middle unthreaded area. This can be 'verified' by measuring the distance from each wedge to the start of the unthreaded area closest to the each wedge.

This will however position the wedges too far apart and they need to be moved towards the center far enough so the ramp on the wedges will be clear of the way tube bores so the headstock/carriage can be remounted on the way tubes. This can be accomplished by rotating each wedge an equal number of turns thus moving them closer to each other. Again they must be equidistant from the unthreaded area.

Once the headstock/carriage is remounted on the way tubes, rotating the shaft so both wedges each just contact each way tube will verify proper positioning by checking the amount of shaft protruding from the rear wedge(should be near flush) and the front end should have sufficient shaft projection to allow the wingnut to be reinstalled on the shaft.


It is critical to make sure the wingnut hole and the hole in the shaft(that the retaining pin MUST pass through) are perfectly aligned.

I find pressing the pin in place works better than beating/hammering. Channellock pliers or a small drill press vise is my 'presser' of choice.

[commnthings]

JPG,
Thanks. That sounds reasonable and I think I understand. I'll get back when the parts arrive from SS. I missed ordering them today so will have to wait until Monday.
Bob

[sehast]

JPG, can the wedges be re-positioned on the shaft so both touch the way tubes properly when the headstock is mounted on the way tubes or will it have to be taken off?

[JPG]

JPG, can the wedges be re-positioned on the shaft so both touch the way tubes properly when the headstock is mounted on the way tubes or will it have to be taken off?

NOPE!

That is why it is critical to get them correct before mounting(and to make sure they do not get mis-positined when the headstock is off the way tubes). Once on the way tubes, the wedges cannot be rotated and the threaded shaft is captive.

Precise positioning is not absolutely necessary but it may prevent future 'issues'. A bad case is if the wingnut bears against the wedge as the rear wedge has not yet 'clamped'. Another is the shaft runs out of the rear wedge.


Extreme, yes, but it can happen.

[commnthings]

I got the lock wedges and am waiting for the new lock mechanism (bar and T-handle) from SS. I think I am comfortable with the "timing" process.
Thanks to all who have commented and helped.
Related question: I completely disassembled the headstock and inspected the bearings. All are fine. Will replace the drive and Poly-V belts (25 years old). Is it advisable to grease the worm gear on the speed control? If so, what kind of grease? I have some white lithium grease. Is that OK?
Thanks again,
Bob