Headstock slide lock doesn't work

mountain4don · Post by **mountain4don** » Thu Jul 19, 2012 8:11 pm

I haven't moved the headstock lock that locks its position on the upper tubes for awhile, after unlocking it today, and now that I want to set it up as a lathe I can't move the wedge lock handle to lock the headstock back down to the tubes again. I tried to get the two drive hubs off the cover on the back of the headstock so I could get inside to clean it out and maybe lubricate the wedge lock screw with graphite. So I went in from the back access cover and blew out the inside of the headstock with air at 120 psi, and put some graphite on the wedgelock screw. And I can turn the handle maybe 20 degrees back and forth and slide the wedgelocks in and out maybe 1/16". But now the lower drive hub that powers the jointer won't come off the shaft after removing the setscrew and dumping WD-40 in the screw hole. What am I doing wrong? How can I dismantle the headstock wedge lock? Its a 1984 model 500.

JPG · Post by **JPG** » Thu Jul 19, 2012 10:16 pm

The front(left hand thread) has a nasty habit of getting stripped and siezing to the rod threads. You need to get a penetrating oil(not wd-40) into the outside end(and inside end if accessible) of the wedge. The hub also!

Fortunately you can apply torque to the idler shaft hub while holding the quill. Same for the upper rear hub.

As for the lock:
The secret at this point is to not over power anything. This is not an endeavor that has a high success rate, but gradually increasing the distance turned when alternating in/out may get it to unsieze. However it may be stripped so severely, that it must be cut out(saw rod into two pieces and remove with headstock off the way tubes).

Wish I had a better answer!

mountain4don · Post by **mountain4don** » Fri Jul 20, 2012 10:50 am

How does the headstock come off the way tubes? And how can I get a hack saw in to cut the threaded rod off? I can move the dial back and forth a little bit. And I have tried graphite and vacuuming out the debris and blowing it out with air without getting any better yet. So I will try some penitrating oil on the threads on both sides and see what happens.

beeg · Post by **beeg** » Fri Jul 20, 2012 12:19 pm

Ya remove the Way Tube Tie Bar and slide the headstock off the tubes. Here's a PDF that might help ya.

[ATTACH]18019[/ATTACH]

dusty · Post by **dusty** » Fri Jul 20, 2012 12:30 pm

beeg wrote:Ya remove the Way Tube Tie Bar and slide the headstock off the tubes. Here's a PDF that might help ya.

[ATTACH]18019[/ATTACH]

I would set the Mark V to high speed.

Unplug the headstock.

Lock the carriage

Lock the headstock.

Remove the drive hubs.

Remove the belt cover.

Disconnect the power wires from the switch.

Remove the drive belt from the lower pulley.

Remove the five screws that hold the motor pan to the headstock casting.

This allows the motor and pan assembly to rest on the way tubes.

Tilt the Mark V into drill press position.

Now you can see what you are doing and you might not have to hacksaw the threaded rod at all.

mountain4don · Post by **mountain4don** » Fri Jul 20, 2012 2:53 pm

I see from the Shopsmith site that this lock, including the threaded rod, handle and wedges are three of the 17 most replaced items on their parts list. So it must be a real common problem. So, what is causing the failures in these parts? Are the wedges made of aluminum and the steel threaded rods getting rusty and chunking off pieces of the wedges that then gets jammed in the threads?

JPG · Post by **JPG** » Fri Jul 20, 2012 3:01 pm

mountain4don wrote:I see from the Shopsmith site that this lock, including the threaded rod, handle and wedges are three of the 17 most replaced items on their parts list. So it must be a real common problem. So, what is causing the failures in these parts? Are the wedges made of aluminum and the steel threaded rods getting rusty and chunking off pieces of the wedges that then gets jammed in the threads?

JMHO Insufficient lubrication and gorilla hands.

dusty · Post by **dusty** » Fri Jul 20, 2012 3:07 pm

I have wondered why these parts are on that list. I have had only one incident with the headstock lock and it was the direct result of using the table saw to cut aluminum and then not cleaning up adequately.

Somehow, aluminum shavings got between the rod and the wedges.

I worked on the rod using vise grips in the middle of the rod rather than using the lock handle. In this way, I could apply a bit more force than I could have with the lock handle.

I haven't cut any aluminum on the table saw since.

JPG · Post by **JPG** » Fri Jul 20, 2012 3:18 pm

The wedges are soft(compared to the rod threads) and if a 'piece' of thread is stripped and moves, a jam occurs. Forcing causes more 'pieces' to break off compounding the problem.

I like Dusty's approach with the viselocks(better than breaking off wing nuts:D). By alternating direction, you might dislodge the piece and get it to move. Then you need to remove the wing nut, then the wedges and clean up those threads(both ends).

dusty · Post by **dusty** » Fri Jul 20, 2012 3:27 pm

JPG40504 wrote:The wedges are soft(compared to the rod threads) and if a 'piece' of thread is stripped and moves, a jam occurs. Forcing causes more 'pieces' to break off compounding the problem.

I like Dusty's approach with the viselocks(better than breaking off wing nuts:D). By alternating direction, you might dislodge the piece and get it to move. Then you need to remove the wing nut, then the wedges and clean up those threads(both ends).

I escaped disaster. I got lucky. Now I just try to never apply force to the locks. If I am not going vertical, I barely lock the locks. Just tight enough to keep the carriage and headstock from moving.

I spin the levers finger tight and then about 1/4 turn.

Shopsmith Forums

Headstock slide lock doesn't work

Headstock slide lock doesn't work

Headstock off way tubes?

Headstock lock