Resin 3D Printing - Setup Help Please

[Bulbous]

Hi all,

I have picked up an Elegoo Mars 2 Mono for Christmas (the green one, not the Mars 2 Pro), and am trying to pluck up the courage to start printing with it. I have started with my designs for an Sn3.5 four wheel van (will likely change back to TTn3.5 depending on the outcomes of this printing test and finding good 6.7mm wheel sets), but have no idea where to go after bringing it into Chitubox. The design is as shown:

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(Please ignore the poor assembly on this one, the tabs for the chassis line up with the holes in the body floor, but the locking tabs between each chassis half stop it assembling correctly)

When I import it into Chitubox, I can stage it as shown below:

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Now to start on the support. When I use auto support, it seems to not care that there are multiple models on the print area, and the supports are sometimes run through the other models to support another one. Also I am not sure if I should raise it by 5mm or 10mm, or just print off the build plate, or how to make it so that the supports are only on the 'non-visible' sides of the model.

Is there a good resource to read or view online to determine the following:
- Best way to setup the printer and how to calibrate it
- How to use either auto-support or manual support for the models in Chitubox (or even another slicer that may be more appropriate)
- How to get the courage to press the Go button for the first time!

Any help here is very much appreciated.

Cheers,

Matt

[Chris333]

I'm  at work so just a quick responce. I have never used auto supports ever.

Flip the screen view till you are looking at the bottom of the model and then add supports one at a time. They will show you what layer you're on so you can make sure to support all the lowest areas. You want to make sure from the bottom going up that there are no unsupported "islands".

[Stephane]

I remember seeing this not long ago, thought it was a nice intro...

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Also, I recommend spending time going through videos by 3DPrintingPro on YouTube.  He's got a year's worth of videos that have taught me a lot about supports.  Okay so this guy is all about printing Dongeon and dragons figures, but the basic concepts are the same.  I've never found any videos specifically for train stuff.

[Bulbous]

Thanks for the feedback Chris and Stephane, much appreciated.

I have a long weekend coming up this weekend, so I might binge the Youtube videos and get something fired off the printer for the first time.

Cheers,

Matt

[IronPenguin]

If this is your first attempt at printing, as indicated by your comment about hitting "go" for the first time, may I suggest a better course of action?
Slow down. You're trying to run a marathon before you've tried running a mile.
Make a few simple test models mimicking in a small way the larger model you're aiming at. Play with the orientation of the models and how supports work or don't work.  It's  not a waste of resin, it's testing and refining the black art of 3d printing.
Enjoy.

[SkipGear]

Exactly what @IronPenguin said. Your first print should be one of the many exposure calibration/test models. Don't even bother trying to print your model till you have successfully printed some of the test files.

[Bulbous]

I had a chance to print off a couple of the XP2 validation matrices, and have good results from the settings below:
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The printing came out like so:
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While going through the online information, I set the printer to print out the pre-sliced rook model that comes with the machine for my girls, thinking that a couple of hours would be plenty of time to get the next test print ready. However, the print seemed to detach after around 40 minutes, so I got a couple of very solid plastic biscuits about 6mm thick on the FEP. I think I cleaned the printing plate with IPA and forgot to properly dry it before starting the next run.

Still fun, the next run will be trying less time on the bottom layers, to see if the blooming can be reduced, and possibly a little less time on the rest to keep the slots from filling out a bit. My youngest daughter is eying off the various Pokemon models on Thingiverse, and getting her paints ready for decoration!

Cheers,

Matt.

[IronPenguin]

Matt:
When you say it detached 40 minutes in, did the model detach from the plate or did the supports fail?
If the raft detached from the plate,  reducing the time on the bottom layers is opposite of what you need to do. Increase the number of bottom layers and/ or increase the time slightly.

[Bulbous]

The model detached from the build plate, so you are correct, I should increase the bottom layer exposure time for that. However, the XP2 print had bottom exposure time of 35 seconds, and that stuck fast, yet the rook test had a bottom exposure time of 40 seconds, so I was thinking that there was another factor in it - possibly my cleaning regime. It could also be the larger surface area of the XP2 test piece versus the much smaller area of the rook piece that encouraged it to hold fast to the build plate.

So many variables, time to start limiting some of them and get more tests through the printer!

Cheers,

Matt.

[IronPenguin]

Matt:
Is the rook solid? That might account for the difference.
If it's solid it might need a grain hole.