Add an alcohol rinse 10 minute countdown timer to the printer firmware

OK just finished my print and I’m scraping the part off the build platform, and the printer is asking me how the print turned out. Well, I won’t know that for at least another 20 minutes, after it gets through the alcohol bath and I pull off the supports.

A more useful thing for the printer to be doing upon completion of the print is offering me a 10 minute countdown timer on that front panel instead of asking me something I won’t know the answer for right then.

Instead I have to dig out my phone (not easy with resin-splattered nitrile gloves), and activate the stopwatch app. Let’s put that app on the printer. The printer’s right there, powered on. Give us a 10 minute countdown timer in the firmware please.

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Buy a digital kitchen stopwatch. It costs only a few Euros/Dollars.

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At first blush I thought that was a really cool idea, and I was even working out the details: “Have it start when the lid is closed after removing the print so you don’t have to push buttons with resinated gloves!” But then the reality of the situation hit me… at least half the time, I start a new print WHILE the previous one is still soaking. I normally decide “Success/Failure” immediately upon print removal, based on fairly basic criteria: did it finish all the way intact or not. However, I could understand if others may wait to see final cured minute detail before answering, though. Still, I for one wouldn’t do well waiting for the printer to finish a countdown before I could start my next print.

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Its a neat idea perhaps the countdown could run at the bottom of the screen while the machine is still doing the next print. I also decide on the success or failure of the print on limited criteria when i take the print off the printer and then sometimes it hasn’t actually worked well but you can’t see that its actually failed when its on the print base. So I would like the facility to be able to revoke a success decision in the dashboard and a comment window so you could write a note to yourself about what went wrong. - Might be useful for the Fomlabs team to be able to see those comments too.

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The problem is that this idea assumes you remove the part and immediately put it in the IPA bath. It can’t account, for example, for prints that prove challenging to remove from the build platform (Tough has been particularly troublesome in this regard. It sometimes takes me 5 minutes just to get the damd print in to the IPA).

It also assumes that you’re using the “recommended” soak. In my experience, 10 minutes is not required. I put the part in the cleaning tank and agitate the IPA (either shaking the cleaning tank or more recently, magnetic stirrer). 2 minutes for the preliminary wash and 2 minutes for the final wash and that’s about all it takes.

randy, magnetic stirrer? would YM7 work in that maybe thats the answer? because YM7 doesnt work in my ultrasonic at all :slight_smile:

I haven’t tried YM7 but I’m guessing it’s fairly viscous? I know nothing about it, but I am an engineer so I’m guessing Ultrasonic probably cares about how dense/viscous the fluid is. You’d need more power to achieve the same “agitation” with a thicker liquid.

Magnetic stirrer is easy to make, you can cobble one together with an inexpensive Radio Control hobby brushless DC motor and electronic speed control and a “Voice Coil Motor” magnet from an old HDD. I think I remember seeing something in a blog recently with a how-to guide that used most of the parts from a HDD, not just the magnets. Maybe “Hack A Day”…

I used to make HDDs, so I have some pretty powerful magnets. And I fly electric-powered radio control aircraft so I have motors and speed controls. So I just raided my parts bin to put mine together. And probably it’d cost a lot more to replicate if you had to go buy stuff you didn’t already have. But if you’re tempted to make one on your own, it’s not that hard. You need an electric motor (a cheap brushed toy motor would work fine, it just won’t last forever) you can spin at different speeds, and a powerful magnet and a way to mount it on the motor shaft so the magnet spins when the motor spins. Position the motor below the wash tank with the magnet near the bottom of the tank. Drop a 3" long 1/4" diameter (or so) steel dowel (with smoothly rounded ends to minimize wear on the tank bottom) in to the tank and add some spacers to the bottom of the parts “basket” so there’s enough room for the dowel to move. Turn motor on, magnet rotates, dowel follows. The dowel may not sit in the center of the tank (depends on the shape/size of the magnet and the dowel), but that won’t matter.

The only thing you need to watch out for is wearing away the bottom of the wash tank, which this scheme will do. A better method would mount the stirrer on a bearing attached to the bottom of the tank, so no moving parts contact the tank bottom. I had the stuff to do this, but I was too lazy.

YM7 is water thin. I never tried it in an ultrasonic machine but it didn’t work for soaking the parts in it. On the other hand, it helps me clean up the buckets when they need a good cleaning. For me, it has its place, just not for part cleaning.

Put the buckets in the sun for 10 minutes, still full of IPA. Resin cures to particulate. If you wait a day, it’ll all settle to the bottom of the tub. Pour off the clean IPA, rinse out the particulate (or run it through some cheese cloth), put the clean IPA back in and you’re good to go again!


“OK google set a timer for 10 minutes”

Or whatever the Siri equivalent is. Personally, I use a kitchen timer (set up before I get resin on the gloves) - I don’t hang around either the printer or the wash tanks while the prints are rinsing.

I would prefer not to litter up the memory of the Form 2 with anything not directly associated with printing parts. It’s a single-function device and unrelated functions add to testing time and run the additional risk of unintended behaviours.

Y’know, you guys with your simple and cheap external solutions are missing the whole point of programming and engineering. Why spend 10 minutes at a dollar store when you can spend weeks writing and updating code? Have you no sense of elegance???

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My phone does this for me and also beeps when it’s done too :smile:

alexa set a timer for 10 minutes :slight_smile:

…And spend further weeks debugging an occasional (and mostly untraceable) glitch where a rogue pointer dereference stomps across your memory causing seemingly unrelated defects. The joys of embedded work…

That said, to create the really obscure defects a certain amount of hardware involvement is useful - missing ground planes, inadequate decoupling causing stray signals, that kind of thing.

YM is much like a standard cleaner, watery and fairly low odor. Unlike IPA it does not dissolve uncured resin but will coagulated it and lift it off the surface of the parts. This makes YM reclaimable by being able to cure out the waste and will not saturate as IPA does. It is non destructive to plastics and rubbers making ideal for delicate parts or parts that require close tolerances that may be prone to warping and shrinking that IPA can cause.

Unlike detergents and most cleaners YM is engineered to work in ultrasonic cleaners so it does not cloud when heated as detergents would. I have been using YM for quite a while and find that it works well usually in one 8 min pass in the US cleaner when slightly heated followed by a light once over with a chip brush to make sure there are no globs left behind. I rinse the parts off after then post cure in plain water with a laser pointer to take the tackiness off.