Replies

1. 
   forestgirl | Sep 24, 2009 07:46am | #1

   Hmmmmm, surprised you haven't gotten some replies.  I'm not familiar with the Powermatic, but I can give it a stab.

   While stock miter gauges are often lacking in their precision and adjustability, aftermarket gauges can more often be tweaked to ride smoothly on the table's surface and within the miter slots.

   I don't know what the Powermatic gauge looks like, but you could inspect the head and see if there is a way to raise it just a fraction of a fraction above the surface of the table.

   Are the black lines on the wood coming from residue on the table that's being created by the gauge head scratching the table? 

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 
   
1. 
   WoodNicheWorks | Sep 24, 2009 06:34pm | #3

   Thanks for your response. I was thinking more in terms of a wooden mitre gauge!  

1. 
   forestgirl | Sep 24, 2009 06:40pm | #4

   "I was thinking more in terms of a wooden mitre gauge!"  OK....  "any suggestions" was pretty broad, so I thought you were asking for suggestions as to what might be wrong.

   You can put a wooden auxiliary fence on your gauge, yes. 

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

    

   Edited 9/24/2009 11:42 am by forestgirl

2. 
   RalphBarker | Sep 24, 2009 05:41pm | #2

   I have no experience with PM saws, either, but my assumption would be that there is some contaminant on the head of the miter guage that is transferring to the table, and then to the wood. I'd clean it well and check for burrs that might be scratching the table surface.

   I'd be cautious about altering the bottom surface of the miter head, however. Most are designed to ride flat on the table surface, providing a fairly precise right angle on the face. Altering the bottom improperly might through off the face angle. Putting a slight chamfer on the bottom edge of the face, particularly if there's a burr, should be OK, though.

1. 
   forestgirl | Sep 24, 2009 06:46pm | #5

   Ralph, I suggested checking for an adjustment (not an alteration) to the head of the miter gauge, because on the Incra gauges, you can loosen the Allen screws that hold the head to the bar, slide a spacer between the table and the head (a piece of paper, for instance) and then tighten the screws, to create just the tiniest leeway between the head and the table.  It slides freely, but does not alter in any way the 90* set of the head.

   I am guessing that some other miter gauges might have the same adjustment.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

   Edited 9/24/2009 11:47 am by forestgirl

1. 
   RalphBarker | Sep 24, 2009 07:12pm | #6

   FG, my intent wasn't to contradict your previous suggestion. I was thinking more in terms of the temptation to clean/smooth the bottom of the head by rubbing it on wet/dry sandpaper. Your shim idea, however, might introduce some side-to-side wobble on the head, which could be problematic in operation.

1. 
   forestgirl | Sep 25, 2009 02:21am | #7

   With the Incra, there is no wobble or see-saw effect -- must have something to do with the way it rides in the miter-slot.  Very solid.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

3. 
   9619 | Sep 25, 2009 03:18pm | #8

   Woodhard,
   There are many ways to skin a cat.
   My suggestion is to make a simple sled to replace your miter gauge. FWW has given many designs for sleds. There are lots of them on the web. You can make one or two or three quickly. You can make a small one with a single runner which operates on just one side of the blade, or you can make a small one which uses two runners. Obviously you could also make a BIG sled, but I am thinking of one which you would use when you ordinarily use your miter gauge.

   It won't leave black marks. It's fun to make your own jigs (up to a point), and it is easy to do.

   If you don't want to make one, my personal recommendation is the Dubby, which Jerry Cole sells. YOu can see it at:

   http://www.in-lineindustries.com/products.html

   It is quite light, easy to move around and store, and you can adjust it down to a gnat's eyebrow. I mean "dead on". I bought one years ago and use it frequently. However, if I was to do it now, I'd just make one. Back then, I wondered if I could get the fences really square. Now I know, that it is easy to do, and if the thing warps a bit, you can always shim it up to perfection with a piece of masking tape or two.

   By the way, there are a number of aftermarket miter gauges (Incra, Kreg, Jess-em, etc, and I have tried them all. To me, they cost far too much money, and don't do as well as a simple sled ---IF YOU ARE ONLY DOING 90 degree cuts. I bought the Dubby, which allows you to make any angle cut instead of the aftermarket miter gauges.

   Hope you find this useful, or at least interesting. I thought you might like an alternative.

   If you are doing tenons on a table saw, there is more than one way to skin the cat. You can make a simple tenon jig that fits over your saw's fence and slides along it. I made a larger complicated one a while back. It works fine. But now that I have tried simpler ones, I'd do that. I am not a fan of the $100 tenoning jigs that a number of companies sell.

   My message, as always, is filled not with facts, but with the results of my personal experiences. I leave facts to others.

   Have fun.
   Mel

   Measure your output in smiles per board foot. 

4. 
   boilerbay | Sep 25, 2009 04:57pm | #9

   Woodhard,

   If it is the default miter that comes with the PM66 unit, the blade rides.0015 to .0002 below the TS surface in a 3/8 deep. The Head rides directly on the PMs surface. It should be flat and smooth. They don't come that way from the factory. Remove head and flatten(lap) on Carbide paper on saw or on granite/plate glass slab.
   Probably do same with whatever came with PM2000.
   Most aftermarket miters have nylon or other friction glides on bottom or are precision ground.

   Micro scrathes on TS are normal.

   Black marks on wood? Don't understand where they would come from.

   Are you using something on the TS surface? Don't lube bar or slot with anything -just keep it clean and smooth.

   Boiler

5. 
   RalphBarker | Sep 25, 2009 07:24pm | #10

   Forgot to ask - I'm interested in how you are cutting mortises on your table saw. ;-)

6. 
   SARGEgrinder47 | Sep 25, 2009 09:14pm | #11

   Take the miter out of the slot and turn it over so the bottom is facing you. Now.. apply a tab of "slick tape" on each side so the "slick tape" will ride the table and not the metal bottom itself. If you have some "slick tape" on hand you are back in business in about 3 minutes.

    

   Sarge..

   Woodworkers' Guild of Georgia