New solution for blowing off dust on mirror

So what do you guys think? We know that aerosol duster sprays are a definite no as they spray a liquid. How about an airbrush compressor generator? This blows out pure air no liquid. Has anyone tried one? I have one next to my form and may try it on the dusty mirror :wink:

I’ve done it using a small compressor (airbrush) and Formlabs warned me not to, because they are afraid that it might damage the galvo mirrors. Though I don’t think it’ll do any harm at low pressure myself.

One extra thing is that you’re blowing all the dust towards the small mirror and galvo mirrors making them even dustier.

If the compressor is internally lubricated, which it probably is since it’s a reciprocating pump, it’s going to deliver a fine aerosol of oil with the airflow. I wouldn’t use this type of compressor. The type that’s centrifugal (like the vanes on a turbocharger, or what’s usually inside a vacuum cleaner) would be a better choice since there are no parts that move (that are in contact with each other) in the airflow. Just the spinning impeller inside its housing.

If you use compressed air, make sure there is an air drier hooked up as well. When you compress air, you generally compress the water out of it too. Shop compressors have a drain in the bottom that you have to open to let the water out so the tank doesn’t rust. When our air driers at work aren’t working like they should our air hoses turn into high pressure squirt guns :smile: of course we don’t spray people with them because that would be unsafe :wink:.

Haven’t tried this, but wondering about the issue myself. Was thinking about using one of those compressed air canisters you used to clean out a keyboard, I hadn’t considered there could be other fine particles.

What about a vacuum technique? rather than blowing it around, you’d be sucking it all away out of the whole chamber. Something like this? You’d have to be careful not to touch the mirror or inside components, but perhaps it would work?

sadly those vaccums are woefully underpowered for anything more than a novelty stocking filler (I know, I was given one in a stocking a few xmas ago).

I’ve had my Form1+ for almost 5 months now. I’ve made dozens of prints using FL Flexible, Clear, Grey and MJ SF Resin, with only a few print failures (all do to my mistakes in positioning the model or trying to reduce the support density and point size too much). I have NEVER cleaned ANYTHING inside the printer. Once, I think I noticed a spec of dust on the mirror and I gently blew it off the mirror with my breath. Besides that, nothing.

The room I keep the printer in is also where my computers are, and this is also where I regularly smoke cigars (the room has about 300CFM of exhaust fans, but it still gets a bit smokey). Now, I did make a dust cover for my printer, and it’s covered whenever it’s not in use and in use or not, if I’m smoking a cigar. And I do used compressed air to blow-off the external surfaces before I change a Tank. But that’s it. I keep expecting the “other shoe to drop” but the printer continues to work pretty much flawlessly.

I read these postings about cleaning the mirrors and have to wonder if you’re doing more harm than good. The primary mirror is actually mirrored on the reflective side, not on the back side of the glass panel. There’s a very fine coating of Aluminum, and Aluminum is very soft. I don’t care what you swab it with, Pec Pads or other, you are definitely going to abrade the surface by wiping it with anything. The more you do it, the worse it’s going to get. The laser beam is easily distorted/diffracted and scattered by scratches, and your print quality will have to suffer as a result. The more you clean the mirrors, the more scratched they’ll get (even if you can’t see it). The more scratched they get, the less operating margin you have, which means you end up having to clean the mirrors more often as the optical path between the laser and resin tank degrades and so becomes more sensitive to contaminants on the mirrors.

There are only a few sources of contaminant, moving parts inside the machine, the ambient environment, and the resin tray insert/removal operation. The stepper and galvo motors, their bearings and ball screw and hinges are going to generate small amounts of fine aerosol lubricant and small metallic particles. Aerosols might cloud the mirrors over time, but probably not for a pretty long time unless there’s something wrong with a Bearing or there’s way too much oil/grease. Any metallic particulate will fall to the bottom of the machine, it won’t float around. Ambient environment is probably the next biggest culprit for particulate. The machine isn’t particularly well sealed and I suspect opening and closing the cover generates some “pumping” action with the area in the lower enclosure. I tend to blow the machine off before I open the cover, if the machine’s been sitting with my home-made dust jacket removed for a while.

I think the worst source of particulate getting on the mirror is likely to be the resin tank. Aluminum mounting rails with a near-interference fit with the Acrylic resin tank, where the thank has to be slid along the rail a distance of nearly 6" during tank insertion and removal. That is unquestionably generating a lot of particulate (I used to make HDDs, I know a lot about particulate) and since the tank insert/removal operation takes place directly over the mirror, the particulate is going to end up on the mirror. After you remove a tank, before installing another, it’s worth wiping down the tank mounting rails with a damp cloth (without dripping water in to the machine), particularly if you see any white residue on the surface of the aluminum. That white powder is ground-up Acrylic dust that’s going to end up on the mirror if you don’t do something about it (IMO, this is probably the most disappointing component of the machine’s design. Friction fits generate tons of particulate and particulate is really bad for anything that uses laser optics and depends on a clean beam path. FormLabs ought to have looked for a better, less “frictiony” mechanical mounting scheme).

But bottom line, if your mirror is dirty and is requiring you to clean it off regularly, I think that means you’re doing something else wrong. You should look to identify and eliminate the source of the contaminants that get on the mirror, vs. a regimen that involves cleaning the mirrors regularly… IMO, YMMV.

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No it won’t. Airbrush compressors like the one depicted use a diaphragm. There is no contact between the air and the oil lubricating the piston. There mustn’t be, or you’d have a fairly bad time using it to power an airbrush :wink:

On top of that, there’s usually a filter and a moisture trap at the exit.

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Common misconception about first-surface mirrors. While it’s definitely not as hard as glass, it’s not as soft as aluminium either, as first surface mirrors usually consist of an aluminium layer coated with a layer of SiO.

You’re right, though, the more you clean, the greater the chances of damage.

I stand corrected on both the pump and coating. However. Having worked in the HDD industry for many years, where we dealt with very thin/hard coatings deposited on the surfaces of disk platters and on the “flying” surface of the recording heads (called the “air bearing”), Thin amorphous crystalline films applied over soft surfaces are very easily disrupted. SiO may be more to keep the Aluminum from oxidizing than to offer any true mechanical protection. On HDDs we used Carbon Vapor Deposition to generate near-diamond-strong coatings on the flying “surfaces” and these coatings were still very easily damaged. More so on the disk surface which was comparatively soft compared to the recording head which is typically ceramic.

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My fix is a CO2 duster PLUS a high-power vacuum.

Using a compressed CO2 can from any electronics store works quite well as long as you DO NOT TILT the can (otherwise you get gunk on mirrors) AND, and this is Super important, you simultaneously use a high-power vacuum cleaner right above the CO2 spray point. This makes sure that not only you dislodge dust but you actually remove it from the machine.

Don’t put the CO2 air too close to the components just use it to dislodge the dust.

My 2C.

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