|Forum topic by Jeremy Greiner||posted 04-30-2012 01:28 AM||4720 views||2 times favorited||9 replies|
04-30-2012 01:28 AM
I just bought an Incra Miter gauge because my miter gauge is “wobbly” in the miter slot and has not adjustments to make the miter bar fit better. So I had hoped that it’d be square right out the box, but no such luck. Not a big deal, I’m sure such an object bouncing around in shipping and so forth it would be unreasonable to expect it to be but I can always hope right?
The miter gauge has 4 mounting screwed for the front bracket to allow you to adjust it to be perfectly square at the 0 mark on the gauge. I used an aluminum square to square the miter gauge to my miter slot as recommended by newwoodworker.com http://www.youtube.com/watch?v=NrTeFQ0iQ5k&feature=g-all-u
After that I checked it using the 5 cut method a lot of people use for cross cut sleds it it was really close, but 3/128th’s after 4 cuts seemed like a bit high (I know it gets divided by 4 so the error is less than 1/128ths but I felt I could do better).
For a while I had all the screwed loose except the 2 edge screws which I would use the adjust the sides to try and get closer to square. I’d unscrew one side, tap it lightly and all it all that sucked. It just wasn’t predictable enough, what I needed was a micro adjustment type system.
So I made one!
The jig is just a piece of purple heart scrap that I drilled 2 holes into. One to mount the wood to the miter gauge and another for a t-nut that I put a t-bolt through with 2 normal nuts tightened together at the end.
First I tapped the right side of the miter gauge so that it was too close to me, then I used the micro adjust to slowly creap up on a square. It took a while and a lot of patience but I slowly crept up on it and got it about as close to perfect as I’m going to get.
I used the 5 cut method, with an 8’’ piece of MDF and the 5th piece was less than 1/128th of an inch difference (my fractional digital caliper only goes to 1/128ths difference). So that means that over 32’’ the error is less than 1/512th’s of an inch.
That’s close enough for me :)
-- Easy to use end grain cutting board designer: http://www.1024studios.com/cuttingboard.html