I had previously done a different post about how I trammed my rails by using two metal levels and adjusting the four XY brace screws at the bottom of the thread here How do I tram the LowRider - #20 by RobP.
Well, I have changed up some of my components to aluminum so I no longer have the ability to adjust my ZY braces so had to find a different way to tram it. I can’t take full credit for it because I saw a youtube video on how a guy did this on a big CNC but I am taking credit for not having to buy a $100 + traming gauge.
Note: I have a spindle clamp for my router but the same principles will apply to the standard mount that comes with the router.
My steps were as follows.
I used a magnetic base dial indicator, took it apart and played with the different clamps until I got a combination that would allow one end to clamp onto a 1/4 endmill and the other would hold the gauge.
I used an old vanity mirror because I needed something completely flat and smooth. I put this on the spoilboard and probed one corner with the dial indicator. After setting Z to zero and the dial indicator to Zero I probed a square and shimmed the mirror with playing cards until all corners were reading Z on the dial indicator. Note: Don’t drag the dial indicator as it will spin the chuck and then your runout/angle of spindle will come into play.
I then set the router to the middle of the mirror and spun the gauge and boy was mine out of wack. I was reading a 0.050" deviation from one side of the 7" swing diameter to the other. I loosened the four screws that hold my router to the 611 plate and noticed one side was not able to clamp all the way down. After some messing around I fixed the gap. I still had some deviation when swinging the gauge so I loosened them up again and then used aluminum foil (the stuff you bbq with) and folded little strips together to make shims. I over compensated where needed as there would be slight compression when tightening the bolts again. After a bit of messing around I now have a deviation of 0.001" on a 7" swing diameter. This is well within the margin of error of this process. Also a light touch on the top of the router can swing the gauge quite dramatically.
I’m curious to see my improvement on cut quality, I never really had an issue but I seem to have a high pitched squeal when cutting with carbide and I always wondered if it was because the router was not perfectly square.
Next step is going to be to surface my spoil board with a 0.75" flat bit I have laying around.