Burnt bit slotting MDF

[Ger21]

How much spindle power do you have? I'd start at 3000mm/min and 12,000 rpm, but you can go a lot faster if you have enough power.

[d4cnc]

Ah I see.. yes, I knew there'd be some hurdles with this machine, but at the price point, it was a perfect choice for me as someone who couldn't even spell CNC let alone know for certain that I'd take to it. I wouldn't have had the confidence to spend much more on what is a very new field. Obviously hindsight thinks otherwise.. ;)

I also bought some straight single flutes.. In HSM it seems to work better..
So having set Feed to 50% (to adjust for lightweight machine), I'm now seeing recommendations for a 6mm DOC of 10k RPM & 1000mm/min. Would this be a good option do you think for initial cutting? (and as recommended.. boost it up on the fly if sounds ok)

Or is single flute the wrong choice for MDF?

*PS.. the plan of getting it done today is out the window..
1/4" router bit shafts in England? Not a good match for the 6mm collet in the machine. New ER11 1/4" coming by Tuesday apparently.




@Ger.. 0.8kW spindle power but just 2860mm/min max rapids..

[d4cnc]

So a little success.. got the slots cut without issue.. no smoke.. no burnt MDF.. much cleaner cut on the top of the MDF too.. I used 1500mm/min with the 2 degree ramp down at 1000mm/min & then upped it 20% where I could hear a little low frequency vibration.. not certain what it was I didn't go further but I'm happy with the cuts. This was at 6mm DOC & I forgot to mention spindle speed before.. but this was at 12k rpm. Before I was at 18k. Much too fast. So both of these changes probably helped..


The T-slot bit next.. Is the strategy the same? ie. 12k RPM and 1500mm/min.

[Boyan Silyavski]

Nevertheless between jobs i always clear the bits with acetone and then oil the for conservation. Using a soft piece of towel and carefull not to cut my fingers. The big benefit of straight bits is that they are much cheaper to run, cause they could be sharpened very cheaply and even by you, just passing behind the edge with diamond file. So a micrograin carbide 2 or even better 3 flutes straight bit will always be my preferred bit for wood, laminate, and similar.

[d4cnc]

Thanks Boyan, I'd not given any thought to bit maintenance, so will go & do some research now.. is acetone recommended for cleaning? I do have some here but would be a bit worried about something so flammable on a router bit..