Feed Rates and cutters for wood panels

[jimbo_cnc]

OK thanks.

You are correct, I need single flute to get the chip load OK. They are a bit harder to find and more expensive than 2 flute it looks like.

For 19mm MFC I think I need 22mm or 25mm cutting length? I have seen some 20mm length is that too short?



6mm 1flute down spiral
0.3mm chipload
10k rpm
= 3000mm/min feed
= 3.1 m/s cutter speed

Is that getting better. Now I've lost the cutter speed tables I saw earlier.

[gavztheouch]

OK thanks.

You are correct, I need single flute to get the chip load OK. They are a bit harder to find and more expensive than 2 flute it looks like.

For 19mm MFC I think I need 22mm or 25mm cutting length? I have seen some 20mm length is that too short?



6mm 1flute down spiral
0.3mm chipload
10k rpm
= 3000mm/min feed
= 3.1 m/s cutter speed

Is that getting better. Now I've lost the cutter speed tables I saw earlier.

What about a compression cutter to prevent chipping that melamine facing?

[jimbo_cnc]

Isn't compression cutter just a different name for down spiral?

[Shinobiwan]

Compression cutters have both up cut and down cut flute patterns.

[jimbo_cnc]

Ah right. I see a lot of them have mostly down flute and a small up flute, that explains how I got confused because people were talking about them pushing the work down.

I've cut a few small pieces of MFC on my little 6040 using my standard manual tools, 1/4" with 2 straight flutes. They haven't damaged the melamine edge.

I was hoping to use the same tool for cutting the 19mm edge and for grooves which are about 6mm deep. It looks like I might be lucky and that the melamine will still be on the down flute for grooving.

[JAZZCNC]

You can ask 1000 people and they will all tell you a differant feed n speed, WHY.? . . . Because every machine is differant.

No one tell you exact speed N feeds you'll get away with unless they have the exact same machine and even then material and tool grades play some part.
They can only guide you to small degree based on machine spec which is what I did on the phone, the fact you have removed the machine spec makes this harder for folks to help. (And giving attitude when spec is questioned isn't endering)

Now if it was the same you told me with single 32mm ballscrew using steppers then 3500mm/min will be close to rapid speeds which is differant to what you'll get cutting making things worse. Hence why I told you it would be too slow for cutting MFC or MDF and maintain any decent tool life. The spec you told me was IME mixed up and wrong for any decent machine for cutting wood.

By your own searching you can see that average feeds are much higher so what do you want to hear.? . . Best advise in the world isn't worth a cracker if it's ignored, like wise all the sweet words you'd like to hear don't mean a thing if there wrong. They won't make the machine any better suited.!!

[jimbo_cnc]

As I've said, I'm trying to get away with a slower machine than what is recommended for tool life and productivity. And I'm hoping I can because my requirements are very different to a cnc shop.

And I wanted this thread to be about minimal requirements for a machine, not about any particular machine I'm looking at.

I'd be happy to hear about what machine design WILL fit my needs though, if anyone wants to make suggestions.

I've got another thread about designing a machine, it's still at the stage of choosing steel frame or aluminium extrusion. I got a bit hung up with straightness of rails I think after reading all Sylvaskis epoxy endeavours. So it hasn't got on to drive system yet.

[Ger21]

Forgetting about tool life and cut quality for a minute.
3500mm/min is painfully slow, and will get old very quickly. Imo, there's really no excuse for a machine to be designed to have a maximum speed of 3.5m/min.

Now, yes, you can cut at 3m/min with a 2 flute cutter, at 10,000-12,000 rpm, and get good results.

Fwiw, I cut 19mm melamine at about 25m/min every day - on a $100,000 machine.