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5mm holes chipping out in melamine11/25
We've been using the same brand of Melamine (Roucke) and 5mm drills (Vortex) in our CNC for years. The combination has consistently yielded nice clean holes.
A month or so ago, everything changed and now we can't drill a clean hole. We've been back and forth with Vortex trying different drills with no success. We've swapped collets and tool holders.
This is in a spindle, we don't run a drill bank.
I'm now suspicious of the melamine, and I have a call in to Roucke.
If it's the material, what changes to spindle speed and feed rate should I try? We're running 3,000 RPM and the feed rate is 150. No pecking.
If it's not the material, I don't know what else to check. Any ideas?
I believe Vortex sells CMT boring bits, at least that's what I've gotten from them.
I would suspect the melamine. You will not get an answer on the board other than it's the tooling's fault.
Long and painful experimentation has ruled out the melamine and the CNC. We're pretty sure it's the tools. I've ordered a handful from another supplier (Amana) and we shall see if they perform.
We use Vortex 1206 bits, 150 plunge at 13600 rpm
Fly cut the spoil board so it is flat.
Take a machinist level and check for a level bed.
Have you replaced the tool col let lately and are you using a torque wrench ? And are you over torquing creating eccentricity ?
We switched to solid carbide brad points and have never gotten any chipping again. We used to get chipping in some boards, but not others, but with solid carbide, we don't get any chipping. And on top of that, we haven't changed bits in over two years.
This is driving me nuts. We've tried different tools, collets, and tool holders. All to no avail. We have some solid carbide drills coming, but they're not here yet.
I increased spindle speed to 4,000rpm and reduced the feed rate by half, and we're now getting clean holes. I have no explanation as to why that was necessary.
Almost as a joke, we chucked a drill into a DeWalt cordless. On low speed and pushing down hard, the drill cuts nice clean holes. You really have to work at it to get a hole to chip. It's amazing to me that we can so readily chip out holes with a cnc when we can hardly duplicate the phenomenon with a hand drill turning 400 rpm.
Solid Carbide usually does solve the problem, but it is usually because the board in the first place as far as what we have seen.
Solid carbide did not fix it. We've given up trying to figure it out. We have it solved, but I guess I'll never know what the heck changed. Maddening.
3000 rpm seems really slow! So does the 150 feed. We also use Roucke and it has always been better than most of the others. Carbide tipped running clean holes. Drill box @ 4500.