Sequel: Homemade CNC Router Milling Steel High Feed Milling Strategy

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2 жыл бұрын

Cut data was all wrong. see updated here:
• Pt 3: Merlin High Feed...
Learned a lot about modern toolpath strategies and cutting forces.
We are moving a pretty respectable amount of ferrous material now for a homemade machine that is big enough to handle full sized sheet goods.
The data indicated to me I could go much faster tha this. The limitation becomes the motion control system losing torque at these higher speeds. My system is closed loop so I can probably push it, but this is pretty good to start with.
Material: 1018 Mild Steel 0.4" (10.16mm) thick
Carbide Endmill TiAlN Coating 1/4" (6.35mm) diameter 2 flutes square
7880 rpm (~ 510 sfm)
0.0025" DOC
0.25" WOC
0.25ci/min (4.1cc/min) MRR
400 in/min (10,160mm/min) feed rate

Пікірлер: 8

@aarondcmedia9585 2 жыл бұрын

Impressive. Might pay to slow the subtitles down a bit? I read pretty quickly and had to rewind to finish them most times. Merry Christmas and Happy New year.

@calphis 2 жыл бұрын

Thanks! I realized that after posting it. I need to spend more time "proofreading" after editing before posting. :)

@crabsshed 2 жыл бұрын

Does it actually reach 400 IPM? The toolpaths are quite short, what are your acceleration settings? But good job, tried similar similar solution (fast low WOC 2D adaptive toolpaths) on mild steel and it works really nicely even on less rigid and hobby machines.

@calphis 2 жыл бұрын

I found myself last night lying in bed wondering the same thing. Fusion said the toolpath should've taken 7 seconds, and at 28 seconds real time it seems the only conclusion is that it's not able to achieve full speed because of the short distance run. I currently have the accel set to 28in/s/s as I recently rebuilt the drive system and haven't pushed it far enough to find the stall threshold. It's closed loop NEMA34 12Nm hybrid drive on 5mm pitch ballscrews, so I think I can likely go quite high, perhaps 80in/s/s. I'll post another video soon with both accel addressed and a longer toolpath so I am sure we are getting the speeds the toolpath intends.

@crabsshed 2 жыл бұрын

@@calphis that would be great. I've been trying to up my accelerations recently. But am limited by the leadscrews and stepper motors on Y axis which can do only about 1200mm/s² (or 50 in/s²) at 400 ipm reliably. And that's not very fast. Need to upgrade it to ballscrews and servos, I already did that on X axis and it can do 1200 ipm and 600 in/s² for comparison. Anyways good luck with the tuning and look forward to your video update.

@calphis 2 жыл бұрын

@@crabsshed I've got some mechanical tuning to do as well. My X axis is 2300mm long and using an experimental drive to combat critical speed/whip. So the screw is stationary and the nut is spun between a pair of bearings to transmit drive while the drive motors travel with the gantry. I went from 2000mm/s to over 10,000mm/s this way but there are still some issues I need to fine tune with regard to resistance and rotational balance of that assembly. So my accel is currently pretty low until I sort that out. Getting high precision long screws also running fast and with high accel is quite a challenge.

@calphis 2 жыл бұрын

That is, 2500mm long but 2300mm travel being used (less the bearing, double nut, etc)

@crabsshed 2 жыл бұрын

@@calphis Well that's huge compared to my 1100mm lead/ballscrews :). Definitely more challenging with the lengths you've got. I've seen your rotating nut video. That is really cool, and probably much better solution than rotating the whole (long and heavy) ballscrew .