New Moai 200 - on my way

To cover the cables and the PT100 I made an metal box, fixed on the vat Frame.

I will use two connectors to disconnect when cleaning the vat: The small for the PT100 and the bigger one for the 230V heating belt.

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I realized, that the tilting bar with the tilt motor is not really stiff. So I decided to reinforce with two brass rectangle bars, fixed with M3 screws.

I don´t know, if it´s really necessary.

I decided to install a small cage over the tilt motor spindle to avoid bending it.

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Temporary last modifications are modifications on the vat tilting table. A 6 mm steel plate improves the torsional stiffness. It is fixed with 2 component epoxy adehsive.

The additional weight (roughly 2 kg) could get compensated with two tension springs, if necessary.

In my opinion, the 4 M4 bolts of the vat carriying plate in original design are moving too rough in the 4 holes of the tilting table. The threads are scratching along the 1,5 mm steel plate, sometimes it is bit notchy. So i was not sure, if it will always move back to the initial position. But the correct initial position is important to keep the levelled distance to the building plate.

So I decided to make new guiding parts with PTFE inserts to get very low friction along the M4 bolts.
The diameter of the guiding parts made a change of the 4 springs with expanded diameter necessary. The new ones have roughly the same spring ratio.

Due to my modified building plate I won´t need the springs and bolts for levelling. I will use the 4 springs to get a resilient travel along z axis to avoid damages during adjusting the z reset position.

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I dislike the leveling screw / spring fixing solution on the Moai 200.
There is too much play and low tolerance to errors.
You can try using fixing washers

The lateral play is also much better than in the original design, I think I won´t need some additional washers.

Checking the center of the laser shows the following picture:

I´ve used the cross-center.gcode file from the SD-card comming with the printer. The galvos are not loose.

@peopoly: Have you shipped the files for the moai130 with? The cross-center.gcode is from 2017.

38

Thanks to Bernhard for his suitable calibration files.

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After an easy levelling procedure I filled in my first resin, Peopoly next yellow. I heated up my vat and also a bit the building plate for some minutes with the peolpoly heater. I checked the temperature with a laser thermometer, it was roughly between 28-30°C.I started with the PM_ring-test.gcode.

So my very first print was made:

The pics are not the best, sorry for that. I`m happy that I have no layer lines, but it seems to be a bit overcured. Laserpower was 52.
I´m happy with my first print on the Moai 200 :smiley:

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I´ve printed several rings with different laserpower: 54, 52, 50, 48 and 46.
The following Pictures showing the ring made with laserpower 46.

The holes on the top of the ring are open, the surface is nice.
I just wonder how low the laserpower is?
The recommendation for next resin is between 52-54?

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depended on what you are printing, for larger prints ( which is the optimal type for 200 ) over curing can be beneficial for better structural integrity. So small print under curing can produce finer detail.

New Asura has feature that overcures the supports only, which can help with large jobs. this only works with Asura supports. ( for now ) @peopoly I would still like to see a manual way to select external supports for over curing in future.

Very happy to see your first prints came out without problems!

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it’s recommended for Nex to be at 51, the pigments in Nex resin settles heavily so you would have to put a stick in and stir it from the bottom up, and mix it very well, or not you will have a range of laser power from 45-54

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do you mean select a specific support to be over-cured instead of overcuring all of them?

I mean, I would like to import custom supports from external program and mark these as supports for over curing. This should be fairly easy as the main print should always be a single mesh, then rest rest of the meshes are supports.

that’s really not as easy as it sounds =))
i will pass this on to the team and let see what they can do
i can’t promise you to have this feature yet

Next print was a file with 16 test cubes (thanks to Bernhard for sharing). Not all cubes were printed, but all bottom layers were done perfectly:

Idea was to repeat the print with slightly ohter parameters. First I had to take the resin out and filtered it before reusing, because there were cured particles in the vat from the insufficient printed cubes.
Then I realized, there was air between the glas and the fep-film and cured resin on the glas in that area, where the cubes were not printed:

After cleaning the glas and the fep film I reassembled the vat and took care, that there is no air cushion between film and glas.
Second print with slightly modified print parameters was a success :hugs:

X-distance over all cubes is 130,45 mm, the y-distance 127,9 mm. Both distances are in original 130,0 mm. So i plan to correct this with the print parameters X Size and Y Size in an further print:
x = (900x130)/130,45 = 896,9 --> X Size = 897
y = (900x130)/127,9 = 914,8 --> Y Size = 915
I hope that will work.

Due to the modified gcode-file from Bernhard all cubes are aligning perfectly, the angle between the outer cubes in x direction to that from y direction are exactly in 90°.
Bernhards postprocessor is eliminating all distortions perfectly in the gcode :smiley::smiley::smiley:

@Peopoly:
All the Moai200 users are expecting this functionality wishfully in the firmware. Come on Peopoly, make us a great present for christmas :wink:

During preparing the next print I realized, that there was again resin between fep-film and glas.
With compressed air I could blew air under the fep-film in the suspected area, I created an air bubble. On that way I dedected a very small hole in the film. Replacement is necessary but not done yet.