Tab problem

Morning all,

Would someone mind having a look at these photos and telling me what I am doing wrong to get these little cutter notches in the wood?

It seems to put the little notch on the job side rather than the rest of the plywood side if you follow me?

Brand new 4 sided cutter was installed for these photos.



Looks like there may be something loose in the movement of your machine. Look for loose belts, or bearings not in contact with their rails, allowing the machine tool to move unexpectedly.

Is this a Primo or LowRider?

That happens to me too. Super annoying.

The cutter deflects outward slightly when cutting and when raising/lowering Z for the tabs it is stationary in X/Y so it settles to its non-deflected location slightly inward from the rest of the path.

A finishing pass helps a lot but it may still be slightly visible. Maybe vibration while stationary in X/Y causes it to cut a bit extra at the ends of the tabs.

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I think every machine does it, but not to that extend. My markings are very hard to see.

Oh yeah, that’s a pain in the ass. I’ve tried several different things to avoid those marks. Try thicker finishing pass offset. Helps, but not perfect depends on material also. Lately, I’ve been setting cutout depths to 1mm less than the thickness of the material with no tabs. After job is done run razor knife around part then sand the little bit off. No marks. That’s just what works for me.

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perhaps a slanted penetration angle will help

Is it possible your but isn’t perpendicular? If it has an angle, it may be cutting into the wood when it lifts. Or maybe it has a lot of runout.

I’d suggest Diet Coke or Coke Zero. But avoid Pepsi. It’s too sweet.


Most tools (drill bits excepted) suck at plunge cutting, they will flex and wander. Fritz’s suggestion will help, I’ve been happy with a 30 degree ramp setting for all my flat tools.

Also try shallower tabs. I never use full height tabs, even when cutting 3ply veneer (~1.5mm).

…and never use a four flute tool on wood.

Lowrider mate.

Thanks, have been avoiding finishing passes on these longer bits. So that is a good point. Just been running it slower. Good enough for what I want for the boat.

Will have a closer look and see.

30 deg ramp angle. Where is that setting in Estlcam?

Why not 4 flute? (pretend I am a three yr old)




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Our routers are spinning too fast for more than 2 flute. We can’t move the router around fast enough to keep a good chip load.

Even if you have a VFD and can slow your spindle way down, four flute tools are designed for metal cutting. Their blunter cutting edges (smaller rake and clearance angles) and shallower flutes don’t cut or eject wood as well as two flute wood cutting tools.