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Form 2 dust optical cleaning esp of galvo mirrors

I’m going to clean the optics of my form 2 (first time!) due to formlabs support’s suggestion. They have been very helpful by email, over my prints not adhering to the build plate, and this being the first thing they’d like me to do given it looks like I have some dust that’s settled out of the air onto the glass beneath my LT tank. They’ve kindly sent me some detailed pdfs detailing the procedures to clean the glass, mirror, and galvo mirrors.

I am really surprised where this has come from, as the machine is sitting in a spare bedroom, not in an industrial environment. The machine has been used very little by me, and has been sitting unused through covid, and over 6 months has gone from 50 % print failures to 100% print failures.

Does anyone know what is in the cleaning kit I’ve read on the forums that formlabs sell for this ? I can’t find it described anywhere on the web. I have pec pads, IPA and a “visible dust” static brush for dry cleaning. I am a little nervous what will be the best tool for cleaning the galvo mirrors. I see the formlabs pdfs talks about using cotton buds, but that goes against the grain given the lengths I’m going to to not use cotton cleaning the mirror and glass in case I deposit any hairs. Is there a better off the shelf tool anyone would recommend ? I read on the forum somewhere there is a special tool that makes cleaning the galvo mirrors much easier, but don’t know what it is or if there’s an STL for it, if anyone could point to such a thing?

Does dust somehow really make its way inside the machine to screw up the mirrors just from ambient air?

I’ve read online how one of the early design tests was having a machine in a sand blasting cabinet being fired at with talc, for 6 hours, and afterwards it still printed. How come if they did that : that the machines in the wild need cleaning every 6 months, when not in a talc blasting cabinet ?

Can dust on the glass really result in complete non adherence of prints? I understand it causing local problems with prints, but complete and utter failure ? I’d be interested if anyone has found cleaning the topics cures such a problem rather than just increasing quality a bit.

Thanks for your experience and advice!

I found that the biggest problem with this is when the machine sit’s idle for and extended period of time. I know it’s a sealed unit but yes dust particles can get into anything. I have my 3L now but i still run my form 2 once in a while just to keep things moving.

I have not used there cleaning kit. I used pec pads and the cotton swabs. Done this twice and it always brings the laser back to a 100 %.

Don’t buy the hype - once you take it apart to get in and do the cleaning you’ll see how dust penetrates. It’s not sealed hermetically or even with rubber gaskets. Basically it’s just some cardboard baffles that are pinned around the optical chamber. That said, those definitely help, and it’s an improvement over the Form 1+. I’m sure it stood up to the sandblasting test, but over time contaminants accumulate (probably a mix of wear from moving parts already inside, and from the environment). I’ve also noticed a coating of residue after printing a lot with certain resins (may have just been coincidence probably the outgassing Randy describes below). A bit of dust won’t stop you in your tracks, but a buildup on the main mirror and galvos definitely has a big impact on print quality. It can cause the issues you described (e.g. prevent adhesion) along with others. I’ve had to clean my optics a few times now since I’ve owned my Form 2. The good news is each time after doing so my print quality went back to pristine.

It sounds like you’re fairly well equipped. Gloves (the nitrile ones work great), PEC-PAD’s, IPA. You should also pick up a blow bulb to get any last bits of dust off before you seal it up. You’ll find dust comes off of you as you work. I suggest something like a hat worn backwards, shower cap or hairnet. I used to wrap my forearms in saran wrap too for work like this, but don’t anymore as it was overkill.

Like you, I was a bit taken aback when I saw the instructions about cleaning the galvo mirrors directly with a Q-Tip. Previously they advised you wrap a PEC-PAD around the cotton swab. I asked about it, and apparently they discovered over time that wasn’t as effective as just directly applying an alcohol-dampened cotton swab. The last couple cleanings I used the direct swab approach and it worked very well. Just be careful and sensible when you do it. The angle is pretty awkward, but you can monitor visually to make sure no strands are left behind (shine a light onto the mirrors at a low angle, almost parallel).

Not sure about that special tool. If you do go with a different approach, follow up here and let us know how it works out.

Follow their instructions and you’ll do great. Once you’ve done it a couple times it’s not as scary as it sounds.

Thank you so much for your detailed thoughtful reply.

I will report back how it goes.

I have picked up a spinny electrostatic brush off ebay as well - as I figured right at the end there was bound to be pesky dust that won’t go away - or at least sneaks in just as you think you’ve got it nailed, which has always been my experience when trying to fit phone screen protectors, and I’m guessing this will be similar.

I’m wondering if i might get a hepa air purifier in the room a for some hours before I get to work, to get dust out of the air (I’ve got one elsewhere as I’m allergic to our two cats (ha) and it’s amazing how much that takes out of the air in our living room which is nonetheless hoovered twice a week .)

I’m wondering if I can seal it up a bit more on reassembly to stop or at least slow down dust getting in there, perhaps with judicious use of some 3m tape.

I’m thinking I might make myself a cover like the z-vat one … as prevention is always better than cure.

I’m kind of excited now to see if it will all work. I somehow can’t believe just cleaning everything will make prints stick again - but it seems it can or at least has done for others. Exciting !

I would not use a brush on the mirrors, no matter how silky soft the bristles are. Lens brushes are made for glass, not primary mirrors. Even the Pec Pads can do damage if you rub too hard. With these mirrors, the reflective aluminum coating is on the front side of the glass, not the back. It’s very soft and it’s very thin and even you don’t physically remove the aluminum, you can scratch it which will increase specularity and diffuse the laser beam.

I’d be surprised if dust is your problem. The printer’s internal space is shared with the mirrors, mechanical components and electronics. The mechanical components have grease that will “outgas” over time, and so will the materials in the electronics. Those outgassed components are what hazes the mirrors (as well as volatile organics from the ambient environment like plastics and paints and a million other things we all have in our homes).

Thank you Randy - I hadn’t thought about out gassing (something I’d only ever thought effected satellites - but of course, it can effect more “mundane” objects on the ground especially if cleanliness is critical as with our printers).

I suppose the presence of the (liquid) resins close to the optics may well have an effect in this regard, and different resins could well behave differently.

Do you know if anyone has explicitly studied what of the components in the printers might be causing our gassing, and if so what, or is it more of an interesting highly plausible hypothesis on your part?

I shall heed your caution to be … cautious.

Do you have any views on cleaning the end of the laser tube which I’ve read about recently in another thread , which seems intuitively sensible when doing the cleaning, albeit it isn’t referred to in the formlabs PDF’s about cleaning the optics for maintenance, as another critical thing for the laser light to go through, and therefor presumably requiring utmost cleanliness.

Outgassing is a fact of life. You can reduce it but not eliminate it if there are organic compounds present. The ambient environment is fully of VoCs, which is why you periodically have to clean the inside of the windows in your house. Which is why FL has instructions for cleaning the printer’s optics. Preventative Maintenance is the solution to the problem.

Yes, I do have a view on the laser - you’re in there anyway to clean the mirrors, not cleaning the laser’s lens is leaving part of the job undone. I just wadded up some Pec Pad on the end of a toothpick, dipped it in IPA, squeezed out the excess IPA then then poked it in to the opening in the laser mounting bracket opening and gave it a gentle twirl.

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