How I squared (trammed) my router

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.

  1. 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.


  2. 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.

  3. 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.


Well that really improved my cut quality and noise! Just knocked out this cabinet door with a 1/4 endmill and there are no ridges! Also much quieter

I surfaces the spoilboard with a 19mm cutter I had around. 2mm deep at 40mm/sec. Didn’t even complain.


i am stealing this method

I am in the process of making some aluminum tops for my lowrider at the moment, and once they are on, im going to have the same problem you had.

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