Feeds and speeds. Some tips for a newbie please!

[Richard]

I am looking for a little guidance on feeds and speeds with a 2kw 3040 size gantry router (not chinese - this one has 20mm hiwin linear rails).

I want to take a light skim over a large area of ali plate. (no idea what grade it is).

So after googling about and looking at the feed and speed calculator on littlemachineshop's site, it appears that if I am using an HSS 12mm 4 flute endmill, the spindle speed should be very slow at 1600 rpm and the feed also slow at 275 mm/min.

Switching to a carbide endmill, a much higher spindle speed, 7200rpm and much much faster feed of 2800mm/min.

Does that sound right?

I have seen people using very fast spindle speeds and feeds (16k prm, 4000 mm/min) but not sure with a 12mm cutter?

Any general advise regarding this topic?

Obviously lube/cooling comes into play here, but initially I would like to run the machine dry or with a minimal mount of lube.

I am looking at taking a very shallow cut as I am just getting the plate flat, so no more than a 0.1 or 0.2mm cut.

Any advice welcome.

Cheers!

[Chaz]

I am looking for a little guidance on feeds and speeds with a 2kw 3040 size gantry router (not chinese - this one has 20mm hiwin linear rails).

I want to take a light skim over a large area of ali plate. (no idea what grade it is).

So after googling about and looking at the feed and speed calculator on littlemachineshop's site, it appears that if I am using an HSS 12mm 4 flute endmill, the spindle speed should be very slow at 1600 rpm and the feed also slow at 275 mm/min.

Switching to a carbide endmill, a much higher spindle speed, 7200rpm and much much faster feed of 2800mm/min.

Does that sound right?

I have seen people using very fast spindle speeds and feeds (16k prm, 4000 mm/min) but not sure with a 12mm cutter?

Any general advise regarding this topic?

Obviously lube/cooling comes into play here, but initially I would like to run the machine dry or with a minimal mount of lube.

I am looking at taking a very shallow cut as I am just getting the plate flat, so no more than a 0.1 or 0.2mm cut.

Any advice welcome.

Cheers!

For me, Id run max spindle speed. So 24K, Id start with 1500mm/min and work up from that. For shallow cuts you can probably go faster but 1500 - 2000mm/min is decent. How accurate do you need and how much material are you removing?

[Dave_stoke]

Google feeds and speeds calculator , it will take you to the little machine shop, input max spindle speed, material, mm/inch, cutter size and material and flute count. Hit calculate

Sent from my F8331 using Tapatalk

[Richard]

For me, Id run max spindle speed. So 24K, Id start with 1500mm/min and work up from that. For shallow cuts you can probably go faster but 1500 - 2000mm/min is decent. How accurate do you need and how much material are you removing?

Hi Chaz,

24k rpm and 1500mm/min, sounds crazy fast! (comming from a manual knee mill!)

Only a 0.1mm-0.2mm cut.

How much slower would you go with an HSS cutter of the same size?

[Richard]

Google feeds and speeds calculator , it will take you to the little machine shop, input max spindle speed, material, mm/inch, cutter size and material and flute count. Hit calculate

Sent from my F8331 using Tapatalk

Yes, I have already looked at that. It's telling me 7k rpm and 2800mm/min for carbide and 1.6k rpm and 275mm/min for HSS. I was surprised at the difference beween the two cutter materials.

[Dave_stoke]

Yes, I have already looked at that. It's telling me 7k rpm and 2800mm/min for carbide and 1.6k rpm and 275mm/min for HSS. I was surprised at the difference beween the two cutter materials.

Carbide can take more stick as you can imagine. I didn't see the part you mentioned little machine shop sorry.

Can you override feed rate while it's running? If so use the slider to find the sweet spot. Then use that Feed rate.

Sent from my F8331 using Tapatalk

[Richard]

Carbide can take more stick as you can imagine. I didn't see the part you mentioned little machine shop sorry.

Can you override feed rate while it's running? If so use the slider to find the sweet spot. Then use that Feed rate.

Sent from my F8331 using Tapatalk

I'm running Mach3 (learning to drive this too!) so yes I can ramp up the feed.

I think that coming from using HSS and an old manual mill, the feeds and speeds mentioned seem a bit hair raising to me! LOL!

[Dave_stoke]

I'm running Mach3 (learning to drive this too!) so yes I can ramp up the feed.

I think that coming from using HSS and an old manual mill, the feeds and speeds mentioned seem a bit hair raising to me! LOL!

I'm using 0.1-3mm Mills I have a bin full of shafts without ends lol.
It's scary when it looks like it's smashing side on into a piece of brass stock. But in all honesty since I used the calculator I just back the feed off slightly. It's fine. Then I let it run at the feed rate... Still fine.

My cut depth is 0.5mm I cut at 1mm but scared the shit out of me.

Sent from my F8331 using Tapatalk

[Dave_stoke]

Oh not with mills below 0.5mm I broke all those, my machine isn't quite gentle enough

Sent from my F8331 using Tapatalk

[Richard]

Just found GWizard.

It's telling me, for a 12mm 4 flute endmill in cast ali, 4148rpm and 427 mm/min for HSS.

For Carbide 6222rpm and 525 mm/min.

That seems very consvative.

If I set the surface finish from 1% to 30% the feed rate doubles.


If the tool size drops to 4mm then the RPM goes up to 18666!