Does anyone have any good feeds and speeds for flattening cherry? I’ve tried everything from 2000mm/min up to almost 5000 with varying router speeds and I cannot get it clean. Anyone help out here? It’s a 1 in bit.
Shine a bright light on the cutting edge of the bit - if you see a reflection the bit is blunt. You didn't mention your doc or your stepover, but that bit is being worked too hard and getting hot. What sort of router speeds have you tried? Alex.
I tried steppers from 50-80%. I have the router 11 and setting 3 is 18000rpm and I went up to setting 4 at 23000rpm. I was honestly just experimenting but nothing worked.
I use a (actually a Chinese clone) Makita - it's bottom speed is 10 K rpm and I rarely use anything else. Try reducing the speed, keeping the feedrate reasonably high, but 2000 mm/min should be OK, depth of cut 0.5 mm max and stepover at 40% or less. First though you will almost certainly need to clean that bit and check it is still sharp. Once you have the bit cutting cleanly you can experiment with more aggressive cuts. I've been using routers for over 50 years now and have never found a use for the top speeds on any of them. Alex.
I actually I just ordered a new flattening bit that I’m going to use for hardwoods only. The one in have now I used exclusively for flattening my mdf spoiler board. So that’s probably my problem. What process have you found the best for cleaning the bits?
I clean resin off with alcohol (meths) or cellulose thinners if its particularly obstinate, but looking at your piece of cherry you might now have a build up of carbon on the edge of the bit. If so you could try scraping it off, but will more than likely need to re sharpen the bit - it can be done, even with a carbide bit, but it's often easier to buy a new one. Alex.
Looking at the attached picture I knew immediately what the problem is. Too shallow a cut at a way too high speed. I know since I had just recently have the same problem. I had flattened my sacrifice board. The cut was about 1.5mm deep. It cut perfect most of the board until it reached the end, which was lower then the rest, and it just skimmed the surface and it burned the MDF just like your wood got burnet. On shallow, skimming, cuts run the spindle at low RPM at a high mm/min as possible. You'll have to experiment to find the correct combination for your setup. What Alex said about the cutter not being sharp and so on is true too and just adds to what I've said.
