Accelerometer - The Machine level sensor has nothing to do with the absolute accuracy of a built part. Which is what’s at stake when “messing” with the tank-tray as I call it - there is the carrier, which is mounted to the optical housing then the tray that holds the tank, which is the only part that can be adjusted. Just to clarify my use of words.
The machine level sensor or better it’s display is not particularly accurate as the system accepts the machine to be level even if the small circle is not dead center. Even if it looks to be dead center visually, it still can be off slightly, since it’s a visual calibration in the end… so we have an inaccuracy here already.
Further the accelerometer has to be calibrated to the building platform not to the tank. The building platform is fix and therefore the only reference to the accelerometer, and tray. The accelerometer is dialed in by the factory so I assume it is right on out of the box, if that is so this won’t cause any problems when re-calibrating the tray as everything else stayed the same (Machine level sensor, laser unit), unless it’s been “messed” with.
Possible that when reattaching the base plate it won’t be in the exact same position as before therefore throwing the accelerometer off. Unlikely and if it’ll be so slight that my machine didn’t detect it.
The Z-Axis is fix, the carrier is fix, the PCB is fix - as you say @fantasy2 we assume the Z-Axis is perpendicular to the PCB and all other horizontal planes (to absolute precision).
I also assume here that we have an accurate PDMS layer - if we don’t that is not too critical as, again the tray can be adjusted to a slight imbalance, unless we have “waves” within the PDMS, which can happen but is unlikely within such a small surface area. This however is another point of possible inaccuracy. The play of the Z-axis and the tank unit within itself is rather small but there is some play, not so much the tank unit, but Z-axis. More potential inaccuracies.
The Form 2 still kicks out some layer shifting, right out of the box, rarely but it still happens.
Having this said - it is important to have the machine level or else we might encounter a resin level imbalance, which could cause spilling, therefore the accelerometer. If the machine is not level it won’t work - or better if it’s not level enough…
For the machine to spill resin (without parts or particles floating around) the tray would have to be off by quite a bit, we’re talking millimeters.
Yes @fantasy2 essentially the final calibration is the distance PDMS surface to build(ing) platform. Even with my crude calibration techniques. Let me add here that my brother bashed me for trying what I did and wanted to drag in his calibration equipment - he also was the one checking the PCB and resin sensor board in the video - I wouldn’t know where to start looking if I had to test the PCB myself or any other circuit board for that matter, so I do have some good help if needed in that field.
The machine nevertheless was dialed in with my crude tools as this is what I wanted to test. Most don’t have any calibration equipment and for those this is a possibility to get the machine back on track. The final question, which I don’t seem to get an answer for is how close is this calibration. Far off or not quite accurate enough to achieve the desired tolerances (that doesn’t help) what are these tolerances @Frew? I understand that you most likely are not allowed to tell me (us).
Of course I agree 100% that with my crude ways I won’t be able to get it dialed in to absolute perfection.
The machine - as all machines, operates within a certain window of accuracy - that window starts at a certain point and stops even if the machine can be dialed in better. The question here is how far am I away from that window with my crude way of calibration - it looks like I am at least close to it, judging by the parts it kicks out.
Thanks @fantasy2 for the numbers - 1/10th of 0.025mm I am not so sure if the machine can be dialed in to that then again maybe it can, maybe even more accurately …@Frew?
In any case thanks for chiming in here @fantasy2 - crazy the spilling on your machine - I heard that from a few people - I did have one part breaking off but luckily no spilling even when resin was stuck on the PDMS. The new tank is apparently spill proof…and lasts 20 times longer - i want to see that - 20 liters instead of 1 (which is typically what I get out of a tank 1-1.5 liters), that would be something!
I did have the resin sensor error and I also get - off and on - the no resin cartridge error, even though the cartridge is inserted…and we are talking about accuracy here…
Here is an Optical test, using a file my good buddy from the support team sent me. There are 2 tiny parts on there which I need for my latest project - no problem for my machine as “off” as it is, to get this optical file done “perfectly”.