Chattering when cutting pine


Im having an issue where the bit is chattering when cutting from left to right. Im cutting pine with a .250" bit. My depth per pass is .125", Stepover is .1", Feed rate is 75" per/min. and plunge rate is 40" per/min. Anyone know what would cause it to chatter line that?

There are many reasons, but I’d start with asking if you squared the Router to your table?

If the cutter isn’t square, the back (or the front) of the cutter drags and can produce chatter in one direction.


I’m going to check this today.

Started checking and found this. Looks like my z plate is not true. What would warp that? All I have done was a few things on mdf.

Also my x beam is good it’s just that front z plate

Probably it was like that to begin with — it might be that the plate bent during use, but I think you’d notice anything which would cause that — use the spindle mount as the reference surface and hopefully that will work. If not, you could either try to straighten / reinforce the plate (a number of folks did that) or order the new bent edge design (included since Summer 2016):

  1. Yes you have the wrong Z plate, please upgrade.

  2. That’s not how you square your spindle (router). Please watch Winston’s video:

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He squared his spindle by making a checking jig out of plywood with a spindle that wasn’t square?

I am confused WHAT is out of square in your sentence… If you are insinuating that the check fixture is out of square, My reply is that it doesn’t matter, since it is only being used for a height reference, and squareness (OF the test block) does not affect the height difference caused by a machine that is out of square.

I was hoping that he used a dial indicator, as I asked, but he did not have on at the time of the video.