Working with MDF

[Miguelflores]

hi.
I work whit MDF of thickness (12mm and 15mm) and tools of carbride tipped of diferent diameters we use surfcam but the MDF material its not in his data base of materials and the question´s are:
how i can calculate the surface speed, the RPM, the Chip Load Factor, Feedrate for MDF?
where i can find information about these parameters?
tank you.

[ger21]

We cut it with our router at full depth 400ipm, 16,000rpm.

[JRoque]

Hey Gerry, how many flutes you use again? You've probably mentioned it before... And how much HP does that operation require - or how much you have on the machine?

Miguel, I think Gerry is trying to say 'hit it as hard as you can'. So if you can spin at 15K RPM and above, chances are you can feed it as fast as your setup will let you. My humble home machine does MDF 12mm deep at 70 - 80 IPM spinning at 7000 RPM or so.

JR

[joecnc2006]

Originally Posted by JRoque Hey Gerry, how many flutes you use again? You've probably mentioned it before... And how much HP does that operation require - or how much you have on the machine? Miguel, I think Gerry is trying to say 'hit it as hard as you can'. So if you can spin at 15K RPM and above, chances are you can feed it as fast as your setup will let you. My humble home machine does MDF 12mm deep at 70 - 80 IPM spinning at 7000 RPM or so. JR

What bit? I use a 1/4" 2 flute upspiral carbide.

[CNCRob]

At work we usually cut it at a down feed of 250" ipm, with a cut feed of 600ipm. The spindle speed is usually around 16000-18000 rpm.

[ger21]

Originally Posted by JRoque Hey Gerry, how many flutes you use again? You've probably mentioned it before... And how much HP does that operation require - or how much you have on the machine?

We have 9HP. Our router will only go 400 ipm, but I could go a LOT faster with the 9HP. With MDF either 2 or 3 flutes work. We usually use 3 flutes because we also cut a lot of plywood with the same tools and 3 flutes cuts the plywood better at high speeds. We also use chipbreaker bits, they need much less power than regular spirals. I'd guess that a 3HP PC router can cut 1/2" MDF in 1 pass with the 3 flute tools I use at at least 250ipm

[ger21]

I just remembered, before I left work today we had to cut a bunch of 1/2" MDF parts. I had to cut a series of 1/4" slots 3/8" deep. 2 flute downcut spiral, 235ipm at 18K RPM. I would've used a 3 flute upcut and went a little faster, but I just used what was in the machine, as I was in a hurry. All the tools we use are from www.vortextool.com

[Miguelflores]

well i use 2 flutes tools at 17000 rpm, 250ipm in one pass. in MDF 1/2" if i speed up the pieces vibrate, the diameter of tool is 1/2"
I must reduce the speeds or the revolutions if the diameter of the tool is major?
There is a formula to calculate it?
tank all you again

[ger21]

I'd slow down both, or getting a better method of holding your work, if it's vibrating.

Your tooling manufacturer should be able to give you a recommended chip load. This is trhe amount of material removed by each flute per revolution. You adjust either feeds and/or speeds to stay within the recommended range for the tools you're using. You can download catalogs from www.onsrud.com which have chip loads and feed speed charts for all their tools.

[airforce1]

there are formulas but that's useless without the surface feet/min you can cut mdf. that being said it sounds like you can cut it quite fast. it sounds like everyone is running 1/4" bits at 16-18K a 1/2" cutter should go half the rpm as a 1/4 so i'd start at 8500 rpm. it may be that you can go higher. maybe they have the spindal maxed for the 1/4" i dunno.

as for feeds, there are calculations, i never use them, it involves cutter rpm which you should've already determmined, and chip thichness and #flutes. i find the larger cutters can take a larger chip, in the end the calculated speed is often similar across the board for cutters with the same # of flutes despite the lower spindal rpm's. then at some point hp comes into play, that depends on your machine.