Project Tripod. 1.0


#1

PLEASE NOTE… as of right now this mod only works with the easy to level build plate! Sorry for any inconvenience, but I may look at a workaround in the future.

I have had my Moai for almost a year now and have always told myself that the Moai (as good as it is) COULD be better… A LOT better! I rely on the Moai for jewelry so there really needs to be a strong degree of accuracy preferably without little lines, warps, etc etc. Now I know some people have pretty good machines that are calibrated just right and have no mechanical issues, but I believe the Moai (along with most resin printers) have one design flaw…having only one z-axis rail for support!

If you look at the Moai and just barely touch the build plate you notice it can wobble without using much force. I know many will say that it really does not matter and that it really does not move during printing OR the popular… did you tighten all the bolts!!

I personally believe that even the smallest bend in the z-axis screw, or rail can deform a print or cause wobble. Some of don’t even notice it because you are printing small non-geometric shapes. Heck, sometimes I don’t even notice it…that is… until I am doing cleanup on my casted jewelry and I notice bumps/waves in the metal.

With all that said I wanted to share a project I have been working on that I have named Project Tripod!!

It’s just one photo that shows the whole prototype, but I will take more detailed pictures soon. It’s pretty much in testing phase but with a few 3D printed parts I have made along with some others from Thingiverse and a few cheap parts I designed a dual gantry system that pairs with the existing z-axis. It uses an t-slot extrusion that attaches to the neck of the build plate and virtually eliminates all wobble, jiggles, etc from the z-axis to the build plate!

Early testing is VERY promising as I have not had one failed print (even with multiple settings) and eliminated 95% of lines and NO MORE WAVES in the prints at all. The other 5% of lines are super small and almost unnoticable (especially after post processing).

Before:

AND…After:

These were all printed at 100um and the stress plate was printed at 40um.

Now I know this is not for everyone but it would be interesting to know how many would be interested in doing something like this or having directions/kit. I don’t want to put a lot of effort if there is not a lot of interest. It’s not super difficult but there needs to be some precision and patience (especially when making it level). You also need access to an fdm printer with PETG/ABS filament (or I can send the parts and charge enough for the shipping, time and materials).

I also understand that this can be a design that evolves over time with other people’s input.

Link to Thingiverse page: https://www.thingiverse.com/thing:3435013

Okay, that was long winded… Like I said, I will update with more detailed as the project evolves but in the meantime I look forward to everyone’s input.


Formware3D for Moai - what is the best print logic / speeds?
#2

I’m telling that to @peopoly since forever :smiley: Someone on the discord server is also working on a more radical replacement of the Z axis removing the current one and adding two rails on a C-beam


#3

I’m very interested - nice work!!!


#4

the Moai 200 runs on 2 rails instead of one, so i think this problem will not happen in the Moai 200
If you can talk more about the project, please do and share so that other users who have similar problems be happy with the Moai 130


#5

I think than only half of the problem is how stable is the Z axis.
The other problem for parts that needs geometric accuracy is the peeling involved in so called “reverse SLA” printing.
My believe is that a top down system is better due to easier supporting of the printed object and absence of the peeling. Of course you have to fight the leveling of the fluid.
My next project would be to get second moai and use it as a base to create top down system.
Peopoly removed this project from their website and there are not many resin printers with top down in the consumer market . I wonder why


#6

I agree the top-down is a great config, but it has its share of issues. It’s definitely a messier solution, you need a lot of resin (or a mix of resin and some kind of solution), you need a wiper if you want high quality and of course everything needs to be leveled accurately.

I wanted to build a DLP based top down, but the hassle is not worth the quality gain which is very low.


#7

I would be very interested in hearing more about your modificaations

Debra


#8

I did actually build one an year ago , but my second hand projector died on the second print.
I just got Arudino uno or mega with shield and used the marlin clone of one of the dlp projects in instructables
Got Z axis assembly with ball bearing from open builds , produced SS vat and some frame from alu profiles.
The wiper was 2 linear guide rails with Aluminim plate run by a steeper and belt as X axis. So every time you do a slice a G91 movement of the X axis forth and back is done
It was run with ancient version of CW, so I just add a custom G91 G00 X150; X-150 ; G90 after each slice.
The experiment cost me about 200 EUR, but the build area X and Y were small due to cheap projector.
It worked a 20 mm cube and a benchy :), then projector died.
It was fun but never continued , as far I got XYZ Nobel to play with. then moai , then DWS


#9

DWS are great machines, it’s another league compared to XYZ and peopoly. What model do you have? How do you like it?


#10

If I have time i am thinking about getting 1 more MOAI, building a new frame with VAT and Z axis column, and just moving laser , galvo assembly and electronics into this., for the wiper I’ll use the tilt motor signal.
And may be external system to maintain resin level. May be some fluid gravity based solution .


#11

I got 1 year old XFAB, their entry level.
So it is damn fast
When it got delivered. I started , cleaned the used vat , pour resin and printed 20x20 cube, it came ot of the machine 19.99 x 20.00
Also the resin have almost no smell at all
And the nobel is a joke it is 2d printer with z axis. There is on linear Y axis ,with stepper two rods and plastic bearings run by a belt , and cartridge with laser and mirror wheel, just like most of the office laser printers for paper.
It is witchcraft , how they fit it in 0.15-0.3 accuracy


#12

I’ve tinkered with the phrozen shuffle and it’s a nice machine for being an LCD. I’m desperately looking for a decent DLP but it seems nobody makes them anymore so I was thinking to build one myself

The moai needs: 1) better Z, 2) a dedicated slicer because what we have now doesn’t really work


#13

For now my Z it is ok I think
Asura is going forward very fast and I think at the moment it works , a few bugs but it do the job


#14

More pictures:

My first 20um jewelry print without ANY lines… lol

More to come… still testing.


#16

so you basically stabilized the Z axis with two additional rods. well the result speaks by itself, but remember to keep those rods well lubed :wink:

Asura is not the slicer


#17

I know , but from user point of view
You can input STL in asura and output gcode to the sd card


#18

Ohhh they are lubed… best lube for linear bearings—

I wanted a solution that was cheap and anybody could do (I already had all the parts laying around… only had to buy a few screws) I also did not want it to be intrusive to the machine i.e. no drilling… if Peopoly would make an upgrade that fit the machine than I would have bought it. 2 or 3 mounts is always going to be better than one. I know its a larger build plate but look at the Moai 200 z -axis mount… WAYYYYYYYYY better.


#19

the problem is that curaengine is not for laser and it shows, unfortunately

you did great, from your initial pictures your moai seemed to have some serious issues on the Z, I’ve never had that kind of wobbliness. But anyway I always wanted to replace that 1 rail with 2 rails and the leadscrew with a ballscrew.


#20

My first intention was to replace the screw and motor, but decided on something easier. I only had to use this solution because I realize that some machines that come from the factory just have some basic issues. I have replaced the boards, galvos, and even the motor and screw to eliminate this problem, but to no avail.

It begs repeating… if you have a nicely calibrated machine with no issues and its printing great, than this mod is likely not for you. I have seen other peoples prints and they look fantastic so I just finally told myself I would fix it myself. I will say though… I primarily wanted to get rid of the “waves” but this mod came with an unexpected byproduct and that was the elimination of most print lines (not layer lines). Small lines in prints are somewhat easy to eliminate when finishing jewelry… waves are not!


#21

Could you please share stl files for the FDM printed parts.