Hi Folks, i’ve got a newbie question. I’v been looking around the forum and see that folks cut plywood with DOC of around 0.2" - 0.3" with 70 IPM feed-rate.
Now that confuses me because if I try to cut birch plywood with 0.25" flat head 2 flute cutter at 0.1" DOC and 40 IPM (Dewalt 611 router setting at 3) feedrate it makes these very horrifying grinding noises like it’s having trouble cutting through the sheet. But I see folks and even Carbide Create own guidelines saying cutting at 0.25" and high feed rates should be normal.
So the question is -> am i maybe setting the dial wrong on the dewalt? does it need to be faster or slower? or should i be using a 3 flute cutter to get these insane feedrates?
I use a single flute straight 1/4” cutter for 3/4” maple plywood at 100ipm/50ipm plunge and 0.125 DOC and around 20,000-21,000rpms. I get nice clean cuts, but it is the absolute loudest stuff I’ve ever cut on my XXL. Plywood must have some strange frequency it vibrates at because it’s one of the few loud noises that forces me to wear a headset. That’s saying something coming from an ex aircraft mechanic with bad hearing. If you find a magic formula please let me know. One thing that can help is to avoid slotting, try to add some extra geometry to allow for pockets over profiles. But unless I’ve just been doing it really wrong it’s just a plywood thing. You can also adjust your router speed as its running and listen for some slightly better frequencies.
Is it baltic birch? Most plywood cuts easy for me, but the baltic birch (cabinet grade, no voids in the layers) seems to be glued with epoxy. Getting a nice cut has been difficult, and thin baltic ply leaves fuzzy edges with the c3d cutters and any feeds and speeds. I bought some downcut bits to try and see if it helps.
Carbide Create might assume you have a 3 flute endmill and not a 2 flute. That extra flute helps massively in faster speeds in wood.
Your chipload is good (0.001") so that should be an issue. Make sure your plywood is held down really well and make sure your belts are tightened and you have no loose eccentric nuts. You should be able to cut that at your current settings just fine. Otherwise decrease your DOC, don’t slow down your speed or RPM.
If you are still having issues, I can test some feeds and speeds on Baltic birch ply I have with my 2-flute endmill and let you know what I get.
