Just curious on the max feedrates for T6061 Alu (1/8" 3 flute high helix endmill). Ox is pretty standard with the 20x60 X-axis epoxied together and double belts. Spindle is a 0.8kW VFD controlled spindle (24,000rpm). Speeds and feeds calc puts out numbers but I would imagine that the overall strength of the machine would limit the feedrate.
For 3 flute you need at least 75ipm at 16k rpm. You really should use single flute up cuts instead.
have you got flood/mist/air blast coolant setup?
I am getting good results with a single flute at 14k @1200mm per min. If I was feeling super keen I may swap to a 2-4 flute to do a finish pass but they have very small chip clearances so they often gum up when roughing unless you have super good chip removal/coolant
air/mist: not yet. Still setting up and manually vacuuming out the chips. For the above what depth of cut are you looking at?
0.25-0.3mm on my OX, I could maybe go a little more but things get very rough sounding. I also lead into all cuts with around a 10degree ramp angle
You’ll have better luck using your shop vac as a blower then sucking up chips. A 50+ psi air blast would be ideal. You want to remove chips and heat ASAP
I cut at 0.8mm but start at 0.2 and see how your machine deals with it. Aluminum is hard to mill with high RPMs and weak machines like hobby cncs
The tool I stumbled upon is the following: Destiny Tool V30805S (http://www.destinytool.com/viper-dvh.html). I’m much too slow but have been at about 9,000rpm, 0.25mm DOC and about 275mm/min. It’s understandably producing small slivers of alu - time to up the feed rate. The finish at that cut spec is great though. Chips staying in the cut channel hasn’t been an issue so far - but it’s been small test cuts. Having said that, the tool is still sharp and seems to cope well… time for more experimentation on feed rate.
I went hunting for more info on my specific bit yesterday and came across this: https://discuss.inventables.com/t/production-level-aluminum-milling-with-8kw-water-cooled-vfd/13557. Looks like the bit I’ve got is actually pretty good. I found the feed/speeds used as " I cut at about 18946RPM with .30mm DOC at around 300MM/M speed and get super smooth sides on all my cuts. with air blasting like you to keep the cuts clean also.". (this is closer to what I’ve been using). Thoughts? Or is it just a case of ‘if it works for the tool…’?
Hi
Milk
Laâllâl