Miter gauge 'Alignmnent'

[danscot]

Progress made - The stud came out with the aid of a pair of waterpump pliers. I now know that the washer is locked on by the stud & both are liberally coated with a red sealant. I'm now going off to get some red Loctite

This allows me to rotate that washer to an unworn area &, because that seems to be a factory fit, it has confirmed that the washers are all correct.

But the unworn part of the washer raises the back end of the protractor so do I have to shim the washer at the pivot point to bring the face of the protractor back to 90 degrees to the table? This would also have the benefit of lifting the leading edge of the protractor above the table edge when sliding in.

[saminmn]

Dan, your configuration sounds like what I started with. I changed it to match the parts list diagram. It turned out that 269 is just like (or is) a standard 1/4" flat washer. The doubled washers on both the nyloc machine screw and under the lock knob make it easier to lock setting without pulling off line while tightening. I made sure I had graphite between the washers.

[JPG]

Progress made - The stud came out with the aid of a pair of waterpump pliers. I now know that the washer is locked on by the stud & both are liberally coated with a red sealant. I'm now going off to get some red Loctite

This allows me to rotate that washer to an unworn area &, because that seems to be a factory fit, it has confirmed that the washers are all correct.

But the unworn part of the washer raises the back end of the protractor so do I have to shim the washer at the pivot point to bring the face of the protractor back to 90 degrees to the table? This would also have the benefit of lifting the leading edge of the protractor above the table edge when sliding in.

I think the 'red sealant' was intended to secure the stud to the bar, but too much apparently also did the same for the washer. I do not think a non-rotating washer there was intentional(nor the localized wear to the washer).

I would use BLUE locktite on the stud and clean up the washer and the bar surface where it sets. If you got the stud out using pliers, that to me says the 'red sealant' was NOT red locktite.

The powdery stuff 'was' what makes it a Nylok screw. It provides a thread jamming that allows the screw to rotate with the protractor and 'not come loose'.

So I would use BLUE locktite on both the stud and the pivot screw.

I tighten the screw until the protractor drags, then back it out slightly until dragging ceases.

I verified that the bottom of the protractor is indeed flat all across the bottom. So with same size washers(the thinner ones) the protractor face should be perpendicular to the top of the bar.

Re the table clearance: I would swap the thin washers(move the worn one to the pivot etc.). That would provide a more consistent reference for the protractor segment bottom surface and the edge wear of the worn washer will have small effect on the pivot spacing. If the front of the gauge is hitting the edge of the table top the bar may be too 'thin'(setting too deeply into the slot). I also suspect the pivot screw too tight will have a contribution(as per your description).

The use of two washers under the lock knob is of recent origin. By using two washers, the tightening of the knob should not cause the protractor to move.

Finally I would adjust the glides for face/table squareness assuming that is possible.

Finally consider that inserting the miter gauge into the slot is more easily done from above(drop the bar into the slot) than inserting it from the front. When a workpiece is clamped to the gauge, the workpiece will hold the gauge(bar/washer/bottom of casting) up off the table.

[danscot]

I've re-assembled using blue Loctite as JPG suggested. The excess sealant on the washer was just a red herring - the unthreaded segment of the stud is slightly greater in section than the hole in the washer so the washer is actually clamped in place by the stud. I swapped the 2 special washers over as suggested so I'll try that set-up tomorrow once the Loctite is set - I've run out of time tonight!

[JPG]

I've re-assembled using blue Loctite as JPG suggested. The excess sealant on the washer was just a red herring - the unthreaded segment of the stud is slightly greater in section than the hole in the washer so the washer is actually clamped in place by the stud. I swapped the 2 special washers over as suggested so I'll try that set-up tomorrow once the Loctite is set - I've run out of time tonight!

Not on mine! ???

[saminmn]

Please explain!

I wonder how 'flat' the bottoms of the glides are. Back when they were merely 5/16-18 nylon screws, flatness mattered not.

We are dealing with a 500 still?

So I was lookig at this agin and noted that I did not address anything after the please explain request. Yes it is a 500. And I did not notice any issue with guides.

I did try some sand paper, backed up by narrow piece of steel, on the sides of the left miter slot. As I think I mentioned earlier, the miter guage was dragging (by dragging I mean that as I pushed the miter gauge I experienced some resistance) on the left in one place while moving freely on the right. I sanded a 2" area where the miter bar's taper screw was at the time dragging occurred. This helped in that the miter bar did not drag as much, but on tightening the taper screw a bit more, the right side still slid freely, but the left side was now dragging on a 4" or 5" area. So, I am getting closer, but I am not sure sanding sides of miter slot is a great idea. I could use some advise here.

The other problem of the miter bar hitting the table rail on the left seems to have lessened. Also, I think most of the teeter totter is attributable to bar not being quite flat.

[JPG]

First your question. The tapered screw should be retracted so as to not cause the side to drag. Its purpose is to expand the bar and act as a lock/clamp.


Now for my experience with my later version miter gauge(wide glide screws).

The major difference is that the pivot boss is not co-planer with the rest of the bottom.
It is a mite short(about 0.015"). The rest of the 'bottom' is square to the gauge face.

Also the rear stud does secure the rear washer(stud has a shoulder).

This requires the front(pivot) washer to be thicker than the rear washer. I found a 3/16" flat washer to be about 0.050" which is about 0.015" thicker than the oem washer including the captive one in the back. Using that thicker washer compensated for the short boss.

The bar does not teeter-totter and the face is square.

Whodda thunk there would be variation. Apparently the casting redesign for the larger headed glide screws caused the boss height 'error'. Gotta wonder if there was a lack of communication('boss height changed so std 3/16" could be used instead of the more expensive thin washer but the same washers were continued to be used).

[danscot]

JPG, I'm glad you confirmed that the stud locks the washer - and that I checked for new posts before heading out to the garage to take it apart again to check. My nice blue Loctite seal on the pivot screw can remain intact

I had to add an extra washer at the pivot point so it's now a special washer + a slightly thinner stainless washer as a shim. When the lock is tightened down, this now gives me a perfect vertical & the miter block base sits off the table, bang in the middle of the height tolerance of 1/32 to 1/64 - the glides are adjusted so the height is equal on both sides.

No teeter, no totter & no clattering into the table edge when sliding across.

I'd have been happy with that but once that was fixed I carried on & got all the table alignments done. Real progress!

If I'm not careful I'll actually start making sawdust soon

[algale]

First your question. The tapered screw should be retracted so as to not cause the side to drag. Its purpose is to expand the bar and act as a lock/clamp.


Now for my experience with my later version miter gauge(wide glide screws).

The major difference is that the pivot boss is not co-planer with the rest of the bottom.
It is a mite short(about 0.015"). The rest of the 'bottom' is square to the gauge face.

Also the rear stud does secure the rear washer(stud has a shoulder).

This requires the front(pivot) washer to be thicker than the rear washer. I found a 3/16" flat washer to be about 0.050" which is about 0.015" thicker than the oem washer including the captive one in the back. Using that thicker washer compensated for the short boss.

The bar does not teeter-totter and the face is square.

Whodda thunk there would be variation. Apparently the casting redesign for the larger headed glide screws caused the boss height 'error'. Gotta wonder if there was a lack of communication('boss height changed so std 3/16" could be used instead of the more expensive thin washer but the same washers were continued to be used).

I know this is an old thread, but I was trying to tune up my miter gauge today and I gotta say, you are right on the money, as usual, JPG.

Any way, the miter has been bugging me because of what you rightly call the teeter-totter effect. I found this thread and adjusted the glides as you described and it fixed that problem. Next, I checked the face of my gauge and it wasn't square to the table. I took the bar apart and put a caliper on the the front and rear washers under the miter head/protractor. Front washer was 0.060 and the rear was 0.032. I swapped out the rear washer for another of the same thickness (0.060), which left the face not square in but in the other direction. Then I remembered I had some 0.005 washers Jim McCann sent me when he fixed my fence rails. I took exactly three washers in the front for a total of 0.015 shimming to get the face of the gauge flat to the table, just as you had measured. In retrospect I could have left the 0.032 washer at the back and added the 0.015 back there to get the right difference in height (give or take 0.002).

FYI, I have a circa 2001 miter gauge but I replaced the bar in 2012 because the screw holding the washer that rides in the T-slot broke off and I discovered that the threads had been stripped and the PO had put JB Weld or some similar expoxy in the hole. Anyway, the new bar did not come with a captive washer on the back stud, which does not have a shoulder on it, and I simply transferred the old washers from my old bar when I replaced the bar.

To make a long story short, I don't know whether Shopsmith has corrected the issue but the front and rear washers that shipped with my circa 2000 gauge were not of the correct relative thicknesses for the casting.

So, thanks, JPG!

Al

[keakap]

...if you think of the miter bar as running along a 3-6 o'clock line.

3-6 o'clock line... hmmm...

does your saw rip and crosscut in one pass? cut 90d corners?

;-)