PM30 CNC conversion begins

When I was involved with salt water aquariums, we would make sumps where water needed to go through a series of over and under baffles to allow air micro bubbles out so suspension. Same tech would be perfect for an application like this.
 
Here are a couple ideas. On my CNC Mini-Mill I use this RC Fueling Pump from Jersey Modeler as a coolant pump. 12VDC and very easy to control flow with a dc speed control. Reservoir is a 2-gal Rubbermaid Cooler
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For the CNC Plasma-Jet Cutter,I use a Rule Bilge Pump to flood the water-table. Reservoir is a 18Gal Sterilite bin.
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For my Water-cooled TIG Torch I use one of these. Reservoir is a piece of 6" dia PVC drain-pipe with endcaps.
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The machine has been running great for a few weeks now, but after a small mistake of letting the table rest on the pan taking it off. Well it seemed like the fiberglass just didnt like it and decided to make a few small cracks and started leaking. Im sure i could of just patched it, but i figured while i have some time off from, i redid the enclosure the way i should of the first time.



Currently looks like crap as i need to scrap off a bunch of silicone, use rivets on some of the joints instead of screws, and give it a badly needed paint job, but the aluminum sheet will be a much better plan in the long run i think.

As for the pump, it is still going strong. Once, or if, it quits on me ill replace it with a prober pump. But for now it is working great.

The motor and bearings getting swapped is very high on the list of things i need to do. the 2900 rpm i get just quite doesnt cut it in aluminum. I've seen the cheap servo motors on ebay/aliexpress and a few videos on line have used them as spindle motors. But does anyone around here have any experience with them? a 2.6kw motor that can be ratioed up to 3 or 4:1 will give me 7.5 - 10k rpm which sounds amazing and it should still have enough behind it to do the low speed even being geared i would think. Using that instead of the marathon motor will also be a huge weight savings and wouldn't necessitate the head spacer as much.

Any advice on the motor option would be appreciated as this is super high on my wish list right now.
 
Did @clough42 not do a spindle motor mod to accomplish just that? I recall something about an
air-bearing too. Looking for the vid now to confirm.
Maybe check this out?
 
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Cletus said:
Did @clough42 not do a spindle motor mod to accomplish just that? I recall something about an
air-bearing too. Looking for the vid now to confirm.
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Saw that. But he got an entire replacement atc spindle. I was thinking along the lines of what the guy in the practical renaissance did with his g0704

 
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Ahhh, ok I'm not familiar with that.
That ATC spindle seems pretty cool though :)
 
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Cletus said:
That ATC spindle seems pretty cool though :)
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Oh I know.. but it's almost 4k when I looked into it. Bearings, servo motor, timing pulleys, and a belt. I think I can keep this around a grand. With some other tooling I want to buy, I just can't justify it especially when I need to swap out all my holders as well.

Starting over and maybe one day, I wish I could find a pm940 size casting to have a blank slate and none of the "extras" I don't need in a conversion.
 
theNOTORIOUSmo said:
Saw that. But he got an entire replacement atc spindle. I was thinking along the lines of what the guy in the practical renaissance did with his g0704

Click to expand...
ooooh! .....That's pretty darned cool too and leaves some $$$ back to buy more tooling! :grin:
 
well as an update and a Christmas present to myself, i bought a china 1.8kw servo motor, cables, and drive from aliexpress for 330 bucks shipped.... it has a rated speed of 3k rpm and a reasonable power curve to the max speed of 3600 rpm. 100 and 40 tooth are surprisingly cheap there too. while big, that is the only way i can fit a 2.5:1 ratio until i figure out a way to drive it by the splines instead of that outer shaft that drives the splines.

bearings seem to be the most expensive part of this, but im not going to cheap out on that. the spindle bearings will be just almost much as that entire servo setup. still looking into options, but the SKF angular contact bearings i found are good to about 18k on grease. I dont ever see this going past 10k honestly so there is a set of tapered roller bearings that are a direct swap with no spacers for a little cheaper that are rated to 10k. i think fag or skf makes them so they are not some knock offs. i may go that route, but everyone else uses angular contacts.

The only other thing of substance i have to add is how i routed the coolant and "filtration" system.

i am now using a dual drain setup. makes a small puddle in one spot, but maybe if i stand in it some more i can dent it enough so it drains perfectly. in each of those drains i have some steel sponges to catch the bigger chips.



from there both go into a plastic 50 cal can with scotch bright pads as a secondary filter. that pipe leading to that can is just press fit so i can remove it easy if needed. From there that is connected by a bulkhead fitting to join that to the 30mm ammo can with the submersible pump in it. from that it goes through the pump and the finer stuff is captured by a 100 micron water filter.

not the most elegant solution, but it seems to be doing a good job. when i finish the final placement of everything I'll make those hoses a proper length.


Hopefully when i get all this stuff over the next few months i can update this with a better update. And if it this thread dies here, well i failed miserably then.
 
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