August 3, 2019 at 5:52 am #108240
Backstory: I had a 60x60cm MPCNC for maybe 2 years, and kept planning to rebuild it larger because the work area was rather limiting; also, the electricals consisted of an arduino clone + cnc shield and an orange pi zero screwed to the table, and a makita router (the non-adjustable kind, the adjustable one is kinda expensive). I’ve tried a 48v DC spindle for a while, but there was no comparison with the makita router’s power, and I kept blowing up mosfets on the chinesium 555 PWM controller thingy…
Eventually I managed to gather up the energy to rebuild it, and after a hiccup here it is:
- 80 x 120 cm, usable area 49×89 cm, 25mmx1.5mm wall thickness stainless tube (was a pain to find)
- uses the new feet and burly parts
- 800W 65mm liquid cooled spindle
- all electrics in a metal cabinet
- same driving combination as before (had to get a SMA to ufl cable so I could mount the orange pi’s antenna on the outside of the box), but 24V, and with 2.5A steppers
there are still a few things to do (replacing the RC filters on homing switches with optoisolators, replacing the connector for the spindle with a bigger one so there is no chance of someone plugging a stepper into the VFD, adding indicator lights that light up when cncjs is ready, and maybe cycle start / pause buttons for grbl…), but it moves and was able to flatten its table 🙂
the shop assistant was hard at work recentlyAugust 3, 2019 at 8:29 am #108254
I think I need a big controller box like that, but make it ironically controlling something really silly, like a light bulb.
Nice build.August 4, 2019 at 11:52 am #108382
That is border line pro build there. Better hurry and and get that fresh build dirty before we start to make fun of you….
Cool to hear the iterations you went through without leaving the platform.August 5, 2019 at 1:34 am #108447
Well, the vacuum keeps it from getting dirty 🙂 (but now I want a quieter vacuum, since that’s the largest noise maker at the moment…)
I already gave it a try on a quadcopter frame I needed to rebuild and a round thingy my wife requested, looks like I’ll have to dial back the speeds for small stuff (the spindle is slower than the makita, the chip load is higher so the system might be flexing a bit due to cutting pressures; forgetting the screw size I planned for when I added the fixturing holes also didn’t help, the machine … adjusted the head size on a few and then the rest was cut with a chipped end mill) and add some bracing to the table (which was already planned, but I haven’t decided if I’ll add an apron with drawers to the front – it already has one on the back, just without drawers, or build in some proper cabinets; the latter is way more attractive and also way less likely to happen)
 the previous one (https://forum.freecadweb.org/viewtopic.php?f=24&t=36086) had a propeller perform a rapid unscheduled disassembly roughly 10m from the ground, frame didn’t survive the sudden stop when it came back to the planet
1 user thanked author for this post.August 5, 2019 at 3:41 pm #108574
Cool frame. Most of mine disagreed with gravity as well. I gave up on my piloting skills.
1 user thanked author for this post.August 8, 2019 at 2:06 pm #108990
No, they actually agree with gravity. If they disagreed they’d stay up where they belong. 🙂August 9, 2019 at 4:47 am #109061August 9, 2019 at 11:28 am #109098
yeah, the sudden stop is the problem 🙂August 9, 2019 at 11:28 am #109099
“Nature, to be commanded, must be obeyed.”
-Francis BaconAugust 9, 2019 at 2:56 pm #109125
“Speed never hurt anybody. Suddenly becoming stationary, that’s what gets you.”
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