CNC Toolpath Strategies for smaller machines

Hi Bill,

Thanks for your feedback. I should have made clear that I was talking about the G0704. It weighs ~300 lbs soaking wet. Your 1100m weighs 1600 lbs according to the spec sheet. I’d love to have one.

The other thing is I’m using a Chinese DC motor that is rated for 1100W(~1.5hp). In reality it’s probably closer to 1hp.

I can watch the column on my mill flex when I’m pushing it with a 3/8 HSS end mill. Adding another flute and carbide isn’t going to help my machine work any harder. I do use carbide on anything under 1/4” though.
 
Last edited:
I had a couple projects in the last week that I really wanted to use a 3/8" 3F end mill on . I picked up a couple Best Carbide 601-33750-1 end mills this morning to try again. They recommend 1200-2400 SFM at .0036 to .0042 IPT. Well, we're going to have to settle for 662 SFM (6750 rpm).

I have a project where I'm cutting two 5.75"x5.75" parts out of a 12x6x.375". They have a large notch out of one corner so I'd like to use adaptive clearing to remove that section. I'm planning to use .375" DOC, .075" WOC, 81 IPM at 6750 rpm. I'll have t do some test cuts and see how these end mills work on my machine. I used a couple of these when I first got my machine running, but I crashed them and decided to stick with HSS. We'll see how they do with the current configuration.
 
I was watching my mill closely the other day and noticed it didn't seem to chatter when conventional milling. I re-posted the toolpaths and the result was a much better MRR and no chatter at all. I kept getting more and more aggressive until my fogbuster nozzle(on a mighty-mag) vibrated so much it wouldn't stay put. The adjustment screw would open itself up as well. The cuts were nice, but vibrations were high, obviously.

Now I have to rip my mill apart when I get a chance, something has to be loose if climb milling is the underdog.

Edit: this test was done @2500 RPM ... .31DOC Axial, .07 Radial .. 64IPM. 4fl 3/8 solid carbide end mill stubby.
 
I did a test starting with the following parameters this morning:
Best Carbide 3F 3/8" Carbide end mill
6750 rpm
DOC .75"
WOC .032"
81 IPM
2"/min MRR

I let the machine run for about a minute and then slowly increased the feed to 98IPM (2.4"/min MRR). The machine was definitely pushing hard. Once I reached 98 IPM the spindle motor popped the 15A/220V breaker it was plugged in to. I reset the machine and continued to cut at 81IPM without a problem. I did follow on tests with the DOC/WOC at .5"/.05", .375"/.065" and .1875"/.130" maintaining the 2"/min MRR. The machine seemed happy enough through all of these test runs.

IMHO at 2"/min MRR my machine is giving me all it is worth. I've had my machine for 7 years. I mostly do prototype/small run parts so saving a few seconds here and there isn't worth as much to me as having reliability and consistency. Occasionally I have a job where I need to hog a significant amount of material away and I'll save these 3 flute end mills for those jobs.
 
Back
Top