A small amount where each hole is located would assist.
I had the thought to have a small pot of cutting fluid at known coordinates and program in to dip the tool between passes.
Sounds like you are getting some parameters dialled in, good job!
Pug
The dipping into a lube pot sounds like a neat idea. It wouldnāt be hard to do either.
I just used a little WD40 on the path the is being cut and it made a world of difference. Where it was creating a frequent discordant harmonic vibration, it is now smooth and quiet along the entire path. I let it make 4 passes. then vacuumed out the groove and applied a little more WD40. What a great idea! Thanks!
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Yeah, HSS would definitely do better than carbide. I usually brush some lubricant on the bit before plunging it into the hole (though, as should be apparent, I havenāt used CNC for drilling), but with such thin stock putting it on the drill location as pugs suggested is likely better. My goto is 1/3 mineral oil 2/3 mineral spirits or kero. Iāve heard wd-40 works well but have not tried it.
Sounds like you got it dialed in though 
Now to tap the holes and wet sand it on glass to make sure itās perfectly flat.
My current project (Saitek FFB yoke) has 7 printed parts, 2 laser etched parts, and 1 CNCāed part. This machine is pretty awesome.
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I was skeptical but that definitely turned out well.
Like most things with SM itās just figuring out how to get past the limitations.
Itās a much more capable machine than sometimes given credit for.
It just takes care and does it much slower than might be preferable.
-S
Since I received my A250, more than a year ago now, I CNC mostly polycarbonate, carbon sheets, aluminium 6065 and even steel front panel recently with 2mm bit without any issues.
For metal Iām using cutting oil to help and slow advance. I think thatās the trick to workaround the overall lack of rigidity of the SM. It takes times but honestly it does the job pretty well.
Iād like to hear more about the steel cutting. Speed, depth, bit, etc.
For the still it was a bit an experiment which turn well and allows me to cut out a 2mm thick front panel. Iām really a newbie in this CNC world, so I can say wrong stuff and make huge mistakes too, but it seems that this is also a path to follow to learn a bit.
I used a bit which was clearly not a good one for this job, a carbide, double flute, (Carbide two flute router bits, 2-flute end mills and CNC cutter bits with 2 flutes.)
My setup in F360 was a simple 2D contour with the following params:
Spindle speed : 6500 rpm
Surface speed : 40m/mm
Ramp spindle speed : 6500 rpm
Lead in : 40m/mm
Lead out : 120m/mm
Plundge feed rate : 30m/mm
It took a lot of time, but it does worked on the first attempt without breaking a bit.
Maybe I could have go at higher speed, with a better bit (I used what I had in my stock) but result matters 
If anyone have some tips to enhance this, let me know!
Just so you know. F360 will not control the spindle speed. It will always be spinning at 12,000 RPM.
You must open the CNC file and manually edit the M3 value.
It will look like this: M3 P100. Itās near the top of the file.
The P100 means that the spindle is spinning at 100%. If you want to run it at 6500 RPM then you have to do the math 6500/12000=54. So, your M3 line will be M3 P54.
Hope this helps.
John
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Oh, I didnāt know that - thanks for the tip. I will manage that in the future. So it was 12000rpmā¦
Well, you probably know this, but there are recommended speed and feed rates for different combinations of cutter size and workpiece material. The Snapmaker only accepts small-diameter cutters, so you need to have pretty high RPM for those to work at all, and even then move very slowly.
But the thing that I would be worried about most is chip evactuation. Aside from completely-incorrect speed or feed rates (like trying to take a 20mm depth of cut at 100mm/s or something), thatās what breaks cutters. I am considering a low-pressure air setup for clearing chips, because I donāt like flood coolant (and I donāt thing the linear modules would either), and cutting oil tends to trap chips even though it lubricates the material (quick side note: sulfurized cutting oil works some magic on steel, so a thin layer brushed onto the workiece may improve the machineability). Low-pressuere is the key, because you donāt want to blow chips into the controller; also, directing the air a safe direction is important. I am thinking that a nozzle on the toolhead, blowing towards the enclosure door, with a shopvac connector on the enclosure door, is the way to go.
Have you seen the vacuum shoes? Lots of good stuff to either make or remix
One of these days I want to make one of these with the standard cnc router dust shoe skirt like this
Yeah, Iāve downloaded quite a few. Thatās actually the first thing I mention when some of the older guys with shops ask me what you can do with a 3D printer - custom shopvac nozzles! Like a decent T-slot cleaner.
The reason I suggest air instead of a vaccum for the toolhead is that the size of the hose should be much smaller. With a small hose, I would worry about clogs, which arenāt an issue when pushing air instead of pulling it.
What about a hose of a size similar to the Festool hoses? https://www.festoolusa.com/products/sanding-and-brushing/hand-sanding-blocks-and-abrasives/495019---d21,5-x-5m-hsk
~21mm at high flow I would think would clear chips just fine, and they are very flexible. Festool wants a lot for their hoses but I think a similar hose could be sourced locally, I have a few from Rockler I use on sanders, these guys: https://www.rockler.com/dust-right-flexiport-power-tool-hose-kit-3-to-12-expandable
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Hmm, maybe - I have some hose that size, which came with some micro-attachments for the shop vac. Probably not long enough but I could at least use it to verify that thereās sufficient clearance around the rails in the enclosure. Should be.
Actually hang on, the slot I made for filament in the top of the enclosure is adjustable for exactly this reason - that reduced-size hose might be a go.
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I can confirm that works pretty well, especially if you add a brush. The dust shoe I am using (Snapmaker 2.0 CNC vacuum dust shoe by Domi1988 - Thingiverse) had some supporting structures on the inside which did cause blockages. I ended clipping those of and (for me) it works pretty good without any issues.
And the hose is indeed connected to the spool holder to keep it suspended.
If youāve got sufficient air speed through your hose, itās not a problem. That means, of course, that you need a strong enough blower to overcome the head loss (friction) through a small flexible pipe. If even thatās not enough (unlikely, but possible since nominal atmospheric pressure of 15 psi might not be enough), you can use pressure-assisted evacuation; blow compressed air through a nozzle near the inlet to increase the air flow.
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I didnāt want to pull the wd40 out of the cut groove with my shoe. The shoe I made works great though. Iāll take a pic of it tonight.