Table Tilt Lock, Mark V Model 510/520

[DLB]

Is that desk top model using the board between the trunnions? If so, I don't think it is a relevant. Totally different geometry to put a beam between the trunnions versus attaching a table on top.

I don't understand why but I do understand what you are saying.

I can do the same thing with the table assembly upside down on the work bench - but not tonight. I even have a table that I can do that with and still not touch the go to machine.

I also don't understand the 'why' part. But let me clarify that I'm currently testing on an 'extra' assembly upside down on the bench. I doubled my dollar bill thickness using a piece of card stock foldeded over. I then measured a gap of .008" between the front trunnion and bosses using feeler gauges, at least double the intent of the dollar bill trick. This gap also closed right up using the tilt lock, and requires very little torque to do so. I confirmed both visually and with a thin, .002", feeler gauge that was gripped as the gap shrunk. Finally, to confirm that this was working the way I thought I released the lock and confirmed that the gap returned to .008".

More clarification - Any time I'm creating or measuring that gap at the front trunnion/bosses, I'm visually confirming that there is no gap at the rear.

- David

[dusty]

I got impatient with the process and decided to swap out parts.

The trunnions and all of the tilt lock mechanism that was in my desk top mockup are now in the go to machine. The parts that were in the Mark V are now bundled together and stored in the shop.

I achieved little "or nothing" in the quest to eliminate the table tilt slippage unless this works. If it does then I have a bundle of suspect parts with NO CLUE as to what is bad.

I can't say I learned a lot because I started this believing I totally understood the Main Table and all of its workings.

Now I'll get back to my effort to understand the issues with extension table interchangeability.

I do appreciate all of the contributions from those who shared their thoughts and expertise.

[DLB]

The purpose of Nick's dollar bill trick was to induce a few thousands of an inch gap between the trunnions and the bosses on the tie bar to permit easier tilting after alignment. This shouldn't create a locking problem because the gap is so small and in operation, the application of the tilt lock will in IMO overcome the few thousandths gap and push/pull the trunnions into contact with the tier bar.

That, IMO, is a great summary of Nick's dollar bill trick (aka the $20 bill trick). And we've shown that in operation the tilt lock does indeed squeeze the trunnions into firm contact with the tie bar bosses. Basically there is a spring effect in play, you open and close the gap by applying pressure to close it, via the tilt lock, or open the gap by relieving the pressure. The table and trunnions bolted together form a "U." The tilt lock squeezes the open end of the U to close whatever gap is present. In an equation where a spring is formed by two steel trunnions, four steel bolts, and an aluminum table, it would seem that the table is going to provide the bulk of the spring function.

Conveniently, I just assembled a main table system with an exaggerated clearance of 8 thou ($40 trick). Sure enough, the table bows upward (also exaggerated, of course) when I apply the tilt lock and returns when I loosen the lock. It is most noticeable to the left of the saw opening, as I would expect based on other experience.

At this point I'm not convinced that this is a wise trade off. At a minimum, we should be using the thinnest shim possible to create only enough clearance to permit easy tilting. I'm looking for a better understanding of why the table is difficult to tilt in the first place.

- David

[dusty]

The purpose of Nick's dollar bill trick was to induce a few thousands of an inch gap between the trunnions and the bosses on the tie bar to permit easier tilting after alignment. This shouldn't create a locking problem because the gap is so small and in operation, the application of the tilt lock will in IMO overcome the few thousandths gap and push/pull the trunnions into contact with the tier bar.

That, IMO, is a great summary of Nick's dollar bill trick (aka the $20 bill trick). And we've shown that in operation the tilt lock does indeed squeeze the trunnions into firm contact with the tie bar bosses. Basically there is a spring effect in play, you open and close the gap by applying pressure to close it, via the tilt lock, or open the gap by relieving the pressure. The table and trunnions bolted together form a "U." The tilt lock squeezes the open end of the U to close whatever gap is present. In an equation where a spring is formed by two steel trunnions, four steel bolts, and an aluminum table, it would seem that the table is going to provide the bulk of the spring function.

Conveniently, I just assembled a main table system with an exaggerated clearance of 8 thou ($40 trick). Sure enough, the table bows upward (also exaggerated, of course) when I apply the tilt lock and returns when I loosen the lock. It is most noticeable to the left of the saw opening, as I would expect based on other experience.

At this point I'm not convinced that this is a wise trade off. At a minimum, we should be using the thinnest shim possible to create only enough clearance to permit easy tilting. I'm looking for a better understanding of why the table is difficult to tilt in the first place.

- David

The object of your quest has changed from mine. I'll be following this (if posted) even though I don't have that issue. My tables tilt with no difficulty. My problem was and remains to be an unwanted slippage with the table tilt lock applied.

Good Luck

[algale]

And we've shown that in operation the tilt lock does indeed squeeze the trunnions into firm contact with the tie bar bosses. Basically there is a spring effect in play, you open and close the gap by applying pressure to close it, via the tilt lock, or open the gap by relieving the pressure. The table and trunnions bolted together form a "U." The tilt lock squeezes the open end of the U to close whatever gap is present. In an equation where a spring is formed by two steel trunnions, four steel bolts, and an aluminum table, it would seem that the table is going to provide the bulk of the spring function.

Conveniently, I just assembled a main table system with an exaggerated clearance of 8 thou ($40 trick). Sure enough, the table bows upward (also exaggerated, of course) when I apply the tilt lock and returns when I loosen the lock. It is most noticeable to the left of the saw opening, as I would expect based on other experience.

At this point I'm not convinced that this is a wise trade off. At a minimum, we should be using the thinnest shim possible to create only enough clearance to permit easy tilting. I'm looking for a better understanding of why the table is difficult to tilt in the first place.

- David

Agree with everything you said David.