Fluffy mdf

[Steven W]

Jazz - just tried Medite MR mdf at a feed speed of 20mm/sec and this has stopped the fluffy core. Not sure what the spindle speed as its reading a frequency number (3000) not rpm. DOC was 3mm through an 18mm board. Its a beautiful finish even better than the manual router finish which I was pleased with. The issue now is it takes a nation to route so next trial will be to step the feed speed up a bit and maybe try and increase DOC. Not sure how much life I will get from the cutter
Thanks for everyones input on this one as I was giving up hope. Hopefully this will be of use to anyone else with the same problem.

[birchy]

3000 won't be the frequency as it's far too high. It's probably the RPM!

[JAZZCNC]

Unless the MDF is damp you shouldn't get fluff no matter the manufacturer. If you getting fluff then your cutting wrong for the density of that material, the Medite MR will just be a different grade or density and you've got lucky on Feeds etc.

20mm/s is far to slow for MDF not matter what size cutter or DOC and even if you were cutting at 3000 Rpm which again is ridiculously slow for MDF or wood it's all wrong.

Every machine needs feeds & speeds tweaking to suit it's build but even allowing for that these feeds are way off. I think you'll find the cutters will wear very quickly.

Give some details of cutter and an idea of the strength of machine, also spindle your using IE: picture and will suggest some feeds to try.

[Mad Professor]

Just to give an idea.
With my DIY cnc router, I can do 18mm MDF cutting at around 3-4m/min, full doc @ 24k rpm, with a 10mm twin straight flute TCT cutter.
I am left with clean cuts, no fur's etc.

[JAZZCNC]

Just to give an idea.
With my DIY cnc router, I can do 18mm MDF cutting at around 3-4m/min, full doc @ 24k rpm, with a 10mm twin straight flute TCT cutter.
I am left with clean cuts, no fur's etc.

Ye but that's only because of them brackets I cut for ya . . .

Now that's more like the speeds and with a decent sized cutter, thou I would suggest doing faster in 2 passes for increased tool life.
I always work on 50% cutter Dia has max DOC thou in soft stuff like this I'd do 100%.

[birchy]

I think a lot of people under estimate the importance of speeds and feeds and how they affect tool life.

[Steven W]

Mad Profs calc are to run at 50 to 60mm/sec. What would you recommend with a 6mm twin straight fluted bit. Also would it be possible to do this in say 3 passes? Still not sure what the VFD readout at 3000 means. The readout can go to 4000 when up full. The max spindle speed is 14,000rpm according to the spindle spec.
I agree that speeds and feeds will have a big influence on tool life. Obviously I am looking for the best running conditions for longest tool life on this type of mdf