Calibration problem Z azis bar pressing vat down

#1

Hy everyone, i just assembled my moai and ran into a problem, so i placed the calibration paper into the vat and noticed the circle is a little bit left and towards the front of the printer, based off of that i also noticed that the z axis bar in pressing down the vat slightly. I’m guessing just like FDM printers i need to adjust the screws bellow and lower the vat slightly. Is that what i need to do?

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#2

I just assembled my Moai and it was behaving exactly the same. Somewhere on a video I saw that they say to tighten all of the leveling bolts to compress the leveling springs then do leveling. I suspect but haven’t seen in writing that they didn’t want to send out the springs in a compressed state so they are uncompressed and you need to compress them with the nuts from the bottom. BTW - the quality of the socket mounted to the green handled socket driver is not real good and mushroomed out enough that it wouldn’t fit through the holes in the metal frame. I ground mine down in my shop to get it to fit through the hole. You might run into this also.

I am doing my first leveling print. Result TBD!

EDIT: Only the back right post adhered. Need to figure out what the means…

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#3

Thanks for replying, in one video ( Practical Printing on youtube) he was using a piece of paper between the screws to get all of them at the same level. Between the manual, and the videos online there are multiple inconsistencies in them and part of the reason maybe because they keep updating the printer and the objects that come with the printer.One example is the plastic laser protector, in the manual they recommend using a silicone gel to stick it over the mirrors but that piece has holes on mine where the metal protector was so now they updated it so you just need to screw it there, the other this is the FEP vat, there are very few videos online about it so will be using that later once i get comfortable with this printer like i did with my FDM one. Will tighten the screws on the bottom next and probably use the “easy to level build plate” next, hope that’s the reason the laser isn’t aligned with the paper.Cheers

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#4

My laser wasn’t aligned with the circle I printed either but it was really easy to adjust the galvanometers. Look at advanced adjustments. Seemed like it was going to be scary but it wasn’t.

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#5

I used the settings they mentioned in the setup and advanced adjustments, if it doesn’t get fixed by this will delve deeper into the advanced menu, thanks for clarifying where the problem can be fixed.

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#6

Hi guys.

I’m having the same issue. After levelling with easy to level build plate and FEP vat when I go to do a print the build pushes down the vat by quite a bit. So the the first layers the build isn’t actually moving up off the base of the resin tank so the prints aren’t even getting started. I haven’t found anywhere in the instructions about how to overcome this or anything I have done wrong to cause it. Need Peopoly to jump in here I think.

KS

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#7

Well I’ve tighten the screws under the vat and the z axis bar isn’t touching the edge of the vat anymore, it’s maybe half a centimeter above it, the laser still isn’t in the right place so i guess i need to modify the compensate X and Y values. I wonder if i am using the correct file for PDMS vat test, p_yuan-test2.gcode in the gcode folder.

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#8

Well i found the advanced moai calibration document and used the cross and the circle gcode to match it up as close as i could, it’s ridiculous how simple the system is. Next i need to buy an sd card reader for my pc to get the moai-adv-calib.gcode to test the circles. The laser is very close to the outer circle when using the p_yan-test2.gcode so i’m not sure if i need to adjust the galvos screws.

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#9

hi guys,
@mickeal_alex @tmostad, The original build plate and old user guides, ask the user to reset leveling after installation. That is no longer needed as we start with printing pegs and make minor adjustments to the leveling screws under the vat. That video was also updated with text on the video saying the same thing.
Now that you have reset it stick with Leveling Wiki
http://wiki.peopoly.net/doku.php?id=moai:leveling

@KomodoSim
Make sure your zreset is 1815, the 4 side screws on the leveling plate is loosen before doing level. the guide is here: http://wiki.peopoly.net/doku.php?id=moai:levelingnewplate

DO NOT TRY TO LEVEL with platform screws as the other two users do. If you still find it press down much. please take a picture of the vat on the build platform

It is also natural to have the build plate press down on the vat slightly. Unlike FDM printing, the “leveling” in SLA printer is to have enough pressure from the build plate to the vat for high print success rate. This means there is no gap between plate and vat. The upside is that it does not need to be very precise, as long as there is enough pressure, the print will work itself using the elasticity of the silicone/film layer.

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#10

Hy Peopoly, i was going to use the easy to level build plate after i tighten the screws under the vat so the z axis bar wasn’t pressing down on the back edge of the vat but i guess as you stated it should have some pressure for the layer. Should i loosen the screws under the vat in order to use the easy to level build plate or use it the way it is right now?
I know it has it’s own screws so i’m guessing it shouldn’t be a problem if it presses down enough on the vat.

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#11

I am a bit confused by your directive to not use the nuts to level the vat. I can tell you that the arm pressed substantially down on the back of the vat when first assembled. There is no way it was calibrated before shipment. I had to tighten the nuts maybe 3/16" before the arm would clear. I suppose it could have been adjusted with the digital z settings but it would have required substantial changes to the z-axis values and the only numbers I saw I believe were 1877 and 1880 which couldn’t have worked. I am a hobby machinist with experience with CNC machinery and so perhaps my bias is to adjust machines mechanically so that default digital settings work as described. Anyway, my Moai’s default digital settings all match what is in the documentation and it produces beautiful prints with good adhesion so I guess if I did anything wrong then I am not sure what.

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#12

@tmostad What is the distance between the z axis plate and the edge of the vat? Mine has a small space, maybe 1 cm but i’m guessing it should work on the easy to level build plate.

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#13

Perhaps 2 or 3 mm. It is hard to access when the printer is printing. Certainly a lot less than a cm.

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#14

Will measure to make sure, thanks.

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#15

He was talking to KomodoSim. The easy-to-level build plate and FEP vat do not use the platform nuts to do the leveling. It is all done from above.

If you are using the same set up, then be careful to say-so. Different leveling processes are used for the standard vat/build plate and the Easy-to-level build plate/FEP vat.

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#16

tmostad

what is the vat you are using? for pdms vat it is 1877 but for metal vat it is starting with 1815. a quick picture of the vat + the platform would help answer a lot about how to leveling.

The reason why you should not level with the platform underneath the platform when using the EZ-to-level plate is that every system has to have an absolute reference to the laser scanning plane in order to be leveled correctly. The leveling of the plate is about adjusting plate/vat so that it is parallel to the scanning plane and have enough of pressure on the bottom of the vat. With classic Moai vat, it is rigid so it is the reference point. But with EZ-plate, the vat becomes the reference point. If you adjust both the build plate and the platform, you may reach to a point where the plate has the correct amount of pressure on the vat but both are not parallel to the laser scanning plane. This will lead to distortions and potential exposure issues.

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#17

I have the standard build platform. I looked back in the thread and didn’t see anywhere in the beginning that mentioned the EZ-to-level plate. Makes sense that it would be leveled differently.

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#18

Hi.

Found the problem of why it was pushing down on the VAT. Every time I set the Z reset 10 1816 (which works for printing) and then turn the printer off after use and then back on again to use later it resets this value back 1877, which I didn’t notice before. Is there a way for it to stay set ay 1816.

BR

KS

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#19

The printer should remember the settings. I would contact Peopoly/reseller.

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#20

Sorted!!

School boy error! I left the firmware file in the main directory on the SD card so it was flashing the firmware every time I turned the printer on. Did wonder why it took so long to start! :smile:

BR

KS

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