Fuzzy cuts on birch plywood

Hi there
I own the xxl shapeoko for a year already. Recently I start to have problems when cutting .
The cuts are not clean on top and bottom surface .
Thing I try
1.New cutter down cut bit (same problem)
2.Check all wells
3.Check all screws
4.Change router
5.Check level
No changes
Any suggestion

If you want clean edges on both the top and bottom surfaces, you might want to try using a compression endmill, check out these posts from @LiamN with good info for example.

Did you have perfectly clean cuts before ? Any chance it might just be the quality of the plywood you procured that changed ?

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Hi there
Yes for a year I had clean cuts .I use amana down cut 1/4 without problems .Top was always crisp .Recently something happened even the noise when router cuts is stronger feels like more vibration

This may be an early sign of wearing carbon brushes in your router, or possibly even the bearings going out.

If you have a Carbide Compact Router and are still under warranty (12 months), let us know at support@carbide3d.com and we’ll do our best to work this out with you.

Hi there
I check the brushes and they are good .I even installed new router nothin changes .

I check all eccentric nuts they are ok .Is there any way hot to check if eccentric nuts are properly tight .
Is there any reference for torque how much ?

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The eccentric nuts should be just tight enough that if you move the (bottom) wheel itself with your finger, the gantry moves (i.e. the wheel does not spin freely anymore)

Did you visually check that no v-wheel is damaged/cracked/worn out ?

The big thing for the nuts is that they hold the wheels securely and don’t vibrate loose, see:

also with plywood, one thing that can reduce these fuzzies is to make a first initial cut that is not very deep (say 0.02") and likely not at max F&S just to gently make the first indent in the wood; later deeper cuts then have a place to break away the wood chips in the place where you want that to happen


Hi there
The problem is that also on the bottom of material fuzzynes is even more ,so when you try to sand off it is breaking the lamination of plywood .
before it was not happening . Top is fuzzy but doesn’t break the lamination

can you say what speeds and settings (F&S) you were using? maybe one of us can compare it to their own F&S for plywood

one sort of “quick check” for the v-wheels/nuts is to turn on the machine, but not the router, and then by hand try to see if you can make the collet underneath the router wiggle in any direction.
It’s supposed to be rock solid (at least upto reasonable amount of pull). If it can wiggle somewhat easily you have a V wheel or other thing loose.


I have dewalt router 611 I keep the speed at 2.5 which is 25000

more like 18500 RPM ? 25000 RPM corresponds to a dial between 5 and 6 I think.
Anyway, 75ipm@around 19K at 0.1" depth per pass is nothing crazy, so it must be something loose somewhere.

As Fenrus says, this could be slack developing in the machine. Mine starts to make a nasty noise and the cuts go fuzzy when things get slack.

You’ve already checked the V Wheels, have you measured and checked the belt tensions? If the belts have gone a bit slack this would let the cutter vibrate.

I will note that it would be best to avoid slotting — add a roughing clearance equal to the largest splinter being raised and then take a finishing pass.

What is the best way to check the belts ?
to make sure that are tight proportionally ?

for belts, the magic word is “guitar string tight”
so if you lift them a little bit (like half an inch) they should just snap back

if you cant’ lift them that far without extreme force, they’re too tight

if they don’t snap back but sort of gravity level … they’re too loose

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Should I move the y all the way to front to touch the hard stop ,so it will be even when I re adjust the belts ?
Guitar string tight is so bad practice