Table Tilt Lock

[forrestb]

Just logged on Dusty, but we have had this thread before and I have yet to see anyone with a solution other than using other methods such as you mention.

I have disassembled mine, cleaned the tunnions and once even used P600 sandpaper to try and clean up any oxidation. All to no avail.

I find that using the 520 fence without locking the main table to an aux table, I will slip at least 0.5 degree after just a few rips. So I, too, now set the table 89.9 to 90.1 degrees to the blade with the table at the using height and use at least the 3 foot tubes to lock the main to aux.

The funny part is when trying to move the table to get that setting even with the lock very loose I have to hit the table (with my hand!) to get it to move.

I am doing some work that requires that my cuts are spot on 90 degree to save messing with the made assembly a good bit.

I guess those of us with the problem learn to 'live with it.'

Forrest

[BuckeyeDennis]

Just logged on Dusty, but we have had this thread before and I have yet to see anyone with a solution other than using other methods such as you mention.

I have disassembled mine, cleaned the tunnions and once even used P600 sandpaper to try and clean up any oxidation. All to no avail.

I find that using the 520 fence without locking the main table to an aux table, I will slip at least 0.5 degree after just a few rips. So I, too, now set the table 89.9 to 90.1 degrees to the blade with the table at the using height and use at least the 3 foot tubes to lock the main to aux.

The funny part is when trying to move the table to get that setting even with the lock very loose I have to hit the table (with my hand!) to get it to move.

I am doing some work that requires that my cuts are spot on 90 degree to save messing with the made assembly a good bit.

I guess those of us with the problem learn to 'live with it.'

Forrest

Nah, if the table doesn't move and lock properly, it just means that some dimension or adjustment is out of spec. The trick, of course, is to figure out which one!

Having been on this forum for only a couple of years, I had never heard of the dollar-bill technique. Google turned up this post from Nick. Is the the tip that everyone is referring to? If so, the dollar-bill method might just fix your table-sticking-while-unlocked problem.

But failure to lock tightly is a different issue. I still think that something must be preventing the brake wedges from drawing up tightly. That little ledge stopping the wedge was just a first guess. It could also be something like the wedge springs compressing solid -- due to having the wrong springs, or maybe too shallow of a bore. I've even seen taper-lock reliability problems result from a poor surface finish on the tapers. But whatever it is, it's bound to be some mechanical detail, and it will not be mysterious at all once it is identified.

[JPG]

Look at 13 min mark.
http://www.shopsmithacademy.com/SS_Archives/SS101/SS101_Alignment.htm

[dusty]

Yes, this has been discussed more than once here on the forum and there have been some "solutions" offered. Some of those work fine.

If working at 90°, tying the main table to the extension table with the extension tubes works fine except when it becomes necessary to move or tilt the table.

When working at other than 90° that does not work. Like others have done, I have a "work around" but that should not be necessary. I will employ the work around for now but I want to resolve the slippage issue with my table tilt lock.

Here is a picture of my work around in use to set the tilt angle when using the conical disc.

I have two of the adjustable stop collars set up this way (on main table legs) that are used to secure the position of the main table whenever I must be absolutely confident that it does not change,

[davebodner]

When I set my 510 up, I simply followed the standard instructions from the mothership. The table tilts easily when unlocked and is unmoveable when locked. I can really put some weight on it, and it just won't budge. If your machine has always had the condition you describe, maybe either your trunnions or the shoes were simply manufactured out-of-tolerance.

If you're considering replacing the shoes, anyway, maybe you can first try this crazy suggestion I'm stealing from a motorcycle forum post on bedding in drum brake shoes: Put some sticky sandpaper on the trunnions and tilt the table back and forth to grind the shoes into shape. I'll say again, probably a little crazy.

I just looked up some prices. Those shoes are only $6. Even the trunnions aren't terribly expensive.

[dusty]

When I set my 510 up, I simply followed the standard instructions from the mothership. The table tilts easily when unlocked and is unmoveable when locked. I can really put some weight on it, and it just won't budge. If your machine has always had the condition you describe, maybe either your trunnions or the shoes were simply manufactured out-of-tolerance.

If you're considering replacing the shoes, anyway, maybe you can first try this crazy suggestion I'm stealing from a motorcycle forum post on bedding in drum brake shoes: Put some sticky sandpaper on the trunnions and tilt the table back and forth to grind the shoes into shape. I'll say again, probably a little crazy.

I just looked up some prices. Those shoes are only $6. Even the trunnions aren't terribly expensive.

The $6 is for the front shoe only. The rear shoe is sold only as part of an assembly (includes the rod) and is a bit more expensive at $24.38. Yes, that threaded rod adds $18.00 which equates to about $1.00 an inch.

[dusty]

Algale: Help me, please. I am having some difficulty understanding your comment in post #10 where you say that "In addition, the wedges force the trunnions inward toward the center of the table a fraction of an inch until the flat, backside of the trunnions contact part of the table bar/tube assembly which creates additional friction at that point".

Never mind, I understand that statement (if your meant outward) BUT keep in mind that the trunnions don't move. They are hard mounted to the underside of the table.

It is important to know that the brake shoes are spring loaded so as to be pushed away from the trunnions when the lock is released. Then as you have said, locking the table pulls the shoes outward toward the trunnions where the wedges create the friction lock. As I see this mechanism working, the outward sides of the trunnions (where I wax) are not intended to function as part of the locking mechanism nor are the inward sides of the table bar (where the dollar bill is installed. That relationship is altered only when the four trunnion bolts are loose and the table is moved around while doing Main Table Alignment. The dollar bill simply insures that the trunnions and the table bar are not in contact with one another (a dollar bill apart).

I sure wish these discussions were face to face. It would be so much easier.

[algale]

Inward/outward depends I guess on your point of view. I could be wrong but I believe the trunnion moves slightly under force or the table flexes slightly and the trunnion is against the table bar assembly where I indicated when the lock engages. I am not where I can verify this currently but will try to verify by seeing if a feeler gauge can be slipped in on the flat back side of trunnion when the table is locked.

Algale: Help me, please. I am having some difficulty understanding your comment in post #10 where you say that "In addition, the wedges force the trunnions inward toward the center of the table a fraction of an inch until the flat, backside of the trunnions contact part of the table bar/tube assembly which creates additional friction at that point".

Never mind, I understand that statement (if your meant outward) BUT keep in mind that the trunnions don't move. They are hard mounted to the underside of the table.

It is important to know that the brake shoes are spring loaded so as to be pushed away from the trunnions when the lock is released. Then as you have said, locking the table pulls the shoes outward toward the trunnions where the wedges create the friction lock.

momentary interruption here

[dusty]

Inward/outward depends I guess on your point of view. I could be wrong but I believe the trunnion moves slightly under force or the table flexes slightly and the trunnion is against the table bar assembly where I indicated. The lock engages. I am not where I can verify this currently but will try to verify by seeing if a feeler gauge can be slipped in on the flat back side of trunnion when the table is locked.

I'll look also. Yes, the trunnions might move IF the table flexes when the tilt lock is engaged but I find it hard to believe that that flexing is part of the design concept of the table tilt lock.

[Ed in Tampa]

Dusty
Could the problem be with the table piviots? If there is wear there they could allow the table/trunnion to lift up instead of holding everything in place to allow the locks to put sufficient pressure on the trunion to lock it.


After all the talk about this I am now pondering the wisdom of the dollar bill. If the trunion is pushed against the ledge seen in the pictures adding the dollar just adds more movement room. And I would guess causing the table to flex. Seems unlikely. I suspect there is things yet undiscovered about the SS and the table lock.

PLEASE keep us informed on what you learn! THANKS