Son of Resin Printer Help 240208

Hello 3d Lab forum,

Grateful shout out to gtometich who actually gave
some constructive advice that addressed the issue
in the post (‘Unknown file format!’) rather
than replying with general musings about how
experienced the poster is with resin printing.

The LycheeSlicer was the key.
The software was downloaded and installed and it produced
a CBT file that was recognized by the Mars 3
It would seem that the problem was
the Chitubox software would produce a CBT file
but not a CBT file that would be recognized
by the Mars 3. That is, the names of the CBT and .CDBDLP files
produced by the Chitubox app would display
at the Mars 3 menu but, unlike the the older files that had been
left there by other users, the files I produced
and copied to the USB drive would not display
an image of the models. The LycheeSlicer, even before
the STL is loaded, offers for the printer
machine to be chosen.
(Extensive search was done on Chitubox
v 1.9.4 and v1.9.2 5 softwares but it
was not found how one chose a certain
printer machine.)

The issue now is getting the CBT file to print.

The Mars 3 took over two hours to go 100%
but when the cover was removed it was
discovered that there was nothing there.

Well, almost nothing. While cleaning the
tray (which was acquired for $47) there
was found a thin layer (.5mm) of
hardened resin on the clear bottom of
the tray which was approximately the
horizontal outline of the model. A similar
thin layer was found when cleaning the head.

So after four days and $100 for the resin,
isopropyl alcohol, and the tray the
goal of printing the model is not attained.

Once again it is asked that someone accept
a request to let me know when they will
be in the 3D Fab lab in the next few days or
weeks so they could review the process
being taken and perhaps point out where the
mistake lies.

I am and will remain

Madams and Sirs,
Your humble servant,

Allen Pitts
[email protected]

Screenshot of model in Lychee Slicer
Screenshot_Lychee_Slicer_Eod_240208.jpg (1367×835) (

I do have a lot of exp rience with resin printing. What it sounds like happened is that your print failed to adhere to the print bed. I do plan on being at the Makerspace tonight for a sheet metal class and will probably be there tomorrow after 6pm.

Hello 3D Fab lab and the DMS forum,

Got some advice from Mr. Darby but still unable to get model to print.

On advice the model was tilted thirty degrees. It was also suggested
that holes be put on any surfaces that cold cause a suction cup effect.
But there are no cupped surfaces so don’t think this will help.

With the model tilted a CTB file was made in Lychee Slicer and
loaded into the Mars 3 Elegoo printer.

This time the machine went to 1% and stayed there for about forty minutes.
Thinking that print would not advance the print was cancelled.

It was conjectured that the model is too complex.
This message system does not seem to allow attachments
so an attempt has been made to share the STL through DropBox

Just trying to get something to work a very simple model was
downloaded from Thingiverse

and sliced with the Lychee Slicer.
This model also went to 1% and would not advance.

Please accept a request for help with the resin printer.


Allen Pitts
[email protected]

1 Like

What USB are you using? A bad USB on the printer can cause all sorts of headaches.

Edit: Ok, I pulled up the files in LycheeSlicer and these files are fine, the largest is a 764kb .stl, that’s tiny compared to some of the miniatures I have printed at home. I use LycheeSlicer for an Elegoo Saturn 2 for reference.

My thoughts:

  1. Calibration with that particular resin. I know the translucent resins are much tougher to dial in. The best guide I have found is this one from J3D Tech. It is pretty detailed, but it does cover just about everything. That being said, I tend to run the XP2 Validation Matrix because it is a quick print, and it does enough for my purposes. I mostly look to see how the points meet in the middle, the sizes of the bars and spaces at the bottom, and lastly the number of posts and holes(the hole does not need to go all the way through to read for the test.) I rarely have messed with the “Burn in Layers” section, most of my issues have been with the “Normal Layers” exposure settings, so your mileage may vary.

  2. If you’re confident that you’ve dialed in the settings for the resin(again I would start with a baseline profile in Lychee). Then it’s the supports. If all else fails you can beef up the auto-generated supports in LycheeSlicer. You can click which level of support(Light, Medium, Heavy or Custom) and even Support Density. When I have failures that other parts on the plate turned out fine, that’s usually what resolves my issues, more and/or beefier supports.

  3. The USB. These printers are very particular about the USB stick. Most of the ones that are shipped with these printers aren’t even suitable for the job. For reference, I use these and so far I haven’t had issues with the USB. Now a random suggestion I read and have stuck to, save the file to your computer and then copy to the USB flash drive. I don’t know why this would be an issue, but it’s easy enough that I do it anyway.

Hopefully that helps!

Hello gtometich and the 3d Lab forum,

‘bad USB on the printer’ By this it is surmised that what is meant
is USB drive, right?
The USB drive being used is a small gold/copper colored thumb drive
marked ‘Verbatim 16 GB’ which has a key ring at one end.

Will take photo of Verbatim USB drive when I am at the
lab at 10 AM Thursday Feb 15.

Please accept a a request for some hands on adult
supervision on 3D resin printing


Allen Pitts

Hello @gtometich and the 3D lab forum,

Photo of the USB drive:

Studied the articles on J3DTech Guide to Resin 3D Printing
(all 72 pages) and XP2 Validation_Matrix. Got some good
info from those. Not sure how all of the material applies to
the process of using the Lychee Slicer to print on the
Elegoo Mars 3.

Having made some adjustments, the CTB was reloaded.
This is a video of the beginning of the print process.

The print head lowers into the resin. The read out says “1%”
From the class (which was taken three years ago) it
is expected that the print head would after lowering initially,
would rise up a little, pause
and the go back down and pause. And that every
time it rises up it would rise up just a little bit higher to
add a new layer at the bottom
But after it lowers the first time it never
seems to move. If the video, which is three minutes long, is viewed
there is no need to watch it after about twenty seconds because
nothing changes after twenty seconds.
The machine display never gets higher than 1%.
Also, I don’t think you can hear it in the video, there is rather
disconcerting sound coming from the printer which sounds
like a motor that is straining to move.

After about the ninth or tenth attempt it was conjectured that
not enough time was being allowed for the printer to move and for
the panel counter to go to 2% and despite the nasty sound
the print was allowed to go on for five minutes. Is realized that
the process is slow, but should not the print, which is not large,
have gone to 2% after five minutes?

Made first post on making this resin print model about two weeks ago

and still trying to get it tp work.

I am truly grateful for all the forum posts but there
is beginning to develop doubt that the issue can
be brought to succesful solution without some
hands on help.

In this process of posting and replies, a question
is developed. Sometimes, after some days, an
answer is posted that may or may not answer
the question posted. But the questions are about
a fairly complex process that require a dialogue
in real time.

And there are many more queries about the
process: curing, finishing clear resin with
varnish, and others that have not even
been as yet touched.

If someone would be willing to act as
a consultant, with the goal of getting
one model to print, up to $50/hr
would be considered reasonable


Allen Pitts
[email protected]

Is it cold in the room? The only time the motor has sounded like it was struggling is because it was cold.

My best guess at this point is the USB flash drive isn’t fast enough or stable enough. I know it sounds ridiculous, but I’ve seen it be the issue enough that it’s possible.

Even if the print fails the printer should still be going through the motions. You’d just have cured resin at the bottom of the tank and maybe some supports sitting on the plate, something. Sitting at 1% sounds like it’s hung up at the initial layers. You do longer exposures the first few layers, but we’re talking like 30 seconds vs a normal 3 second exposure. Nothing like you’re experiencing.

I’m not an expert, I’ve just read too many posts on Reddit and played with the settings on my printer. I have mostly used the SirayaTech Fast Navy Grey resin, which is very popular and has lots of settings available. So I’ve had an easier road to printing successfully.