Resin Tank is not straight, normal?


#21

Ok it makes sense to limit the flat surfaces printed in the FEP vat but do I need to adjust other settings?
Does that mean that every object I print should be tilted?

To be honest I would be really pissed if I were to destroy another FEP film…

Talking of it, where in Europe namely in France can I buy FEP films that works with the Moai?


#22

Hi! Almost evey time it is better to tilt the object on supports to minimize the contact area with the FEP/PDMS vat throughout the object.

The tilt settings in firmware 1.18 are tuned for your needs.


#23

something is off with your z-reset.

even with fep vat, it should be around 1810-1820. generally 1815.

Where did you get this machine from and was there anything done to the platform screws

the shift suggests too much adhesion at the bottom such that the build plate or the vat was moving during each layer peel.

let’s make sure everything is tighten up first:

Moai Checkup guide
http://wiki.peopoly.net/doku.php?id=moai-checkup

and then let’s look at leveling. since you are printing the pegs at 10.7-10.9 range. it should be okay but make sure the pegs are not tilted as well.


#24

Bought it from you.

I know it seems a little bit crazy but my z-reset is set to 1800. It’s the last value I can dial in before the EZ-leveling build plate start pushing again the vat so that the resin tank move downward.

I even tried putting pieces of paper in the FEP vat and set the z-reset to 1800 which caused the paper to be stuck almost without making the resin tank move so I guess it’s all good, right?

I also adjusted the platform screws to get the pegs within the range of 10.75-10.81 and I’m pretty happy with it, the pegs did not seem titled too…

I just printed (with the damaged FEP film) a 3DBenchy at 80µ and I came out pretty fine actually also I did not use Asura for this, I used Meshmixer + Cura 3.5 Mac OS version BUT the calibration cube was printed with Asura (latest) version at 20µ.

I placed the 3DBency on the left side of the printer (from the door point of view) and I ran the heater for like 30 minutes before printing (I turned it off while I was printing).

Maybe the issue was caused by the software?

EDIT: The 3D Benchy was not so good after all…
I messed up the support removal but it seem that the last few layer had not enough support or that the build plate did not go up at all…

Here is a picture of meshmixer with the supports.


#25

that is a lot of supports. I think you could have print the benchy straight up without any support. as long as the surface area on x/y plane is not very large (like 10x10cm) you can print straight off the plate without rotation


#26

I have found my PDMS ends up similarly. Get 3 corners close and the 4th (D) just doesn’t want to play along.


#27

Well I would like to believe you, but I printed a 20x20x20 millimeters calibration cube and it failed due to the peeling force (talked about it sooner)…

So what am I suppose to do ? When should I print directly on the build plate and when should I print the model tilted with support? I’m kind of confused because I receive some contradictory advices from you guys :confused:

Just to make it clear, I use the FEP Vat with the EZ to level build plate.


#28

while the standard vat can easily have small prints printed directly, the FEP vat is not, it would require much smaller peeling force.
@peopoly said it could print directly at about 10x10x10, but since yours are 20x20x20, and already failed.That’s why i told you to tilt the model


#29

I think what there is a flat bottom and that the surface area on x/y axis is less than 1/3 of the entired print area, you could consider printing flat.

On FEP vats, make sure you use setting recommendations in
http://wiki.peopoly.net/doku.php?id=moai:fep
which is different than PDMS vat. the slower PM moto speed helps a lot

a quick look at the edge of your vat platform shows the platform has been pushed up by a lot
image

did you adjust the screws under the platform? your leveling may be off as well which can put too much pressure on the initial layers.

If you still have PDMS vat and the one piece build plate, it may be best to set your leveling before switching to fep vat and ez-level plate


#30

Well to I assembled the Moai as instructed so I don’t get why I have to use such a low z-reset value…
I adjusted the screw underneath the resin tank holder but just a little to have the corner pegs height within tolerance so I doubt it comes from that…

I tried to print the test ring provided in the SD card. The rings surface look great but the holes are filled in… I tried lowering the z-reset and decrease the laser power but still get the same results with only minor improvements…

The last one (the one to the extreme right) have more holes that the other ones but it’s not really that much different…

The two first rings was printed with the default 1.18 firmware values with a z-reset of 1800 the last one was printed with the default 1.18 firmware values with the exception of z-reset set to 1799 and the laser power set to 56 (instead of 58).

What should I do now?

It’s really annoying to have all those problems because I don’t quite know in what direction should I go to solve them.

For now I have the following issues:

  • When doing the circle calibration test I noticed that the laser was doing a slight ellipsis going maybe 1 or 2 mm to far on the X axe near the opposite side of the door.
  • The cross in the cross-center test was a bit skewed (the lines were not perfectly perpendicular)
  • The z-reset seem way to low (1800 against the recommended 1816).
  • The test rings does not have all the holes open and we can see some layers lines inside the ring at the bottom.
  • The acrylic galvos protection plate seemed a bit dirty like a bit scratched. Should I try without?
  • I tried twice to print a 20x20x20 calibration cube and it got stuck to the Vat (with or without the heater on).
  • I printed a pistol grip and the dimensional accuracy was really really poor…

What should I do @peopoly ? Should I re-check the printer again and re-run all the calibration tests?

With all those problems I see my dreams of making dimensionally accurate engineering parts slowly flying away from me…


#31

Easy one first: the galvos protector has protective plastic film on both sides, which must be removed prior to use. And, yes, you should use it.

The galvo calibration, e.g elliptical shape can be adjusted out with settings. However, making sure that your printer delivered the correct size and shape of test pattern will save a lot of grief. Pictures of the pattern are helpful.

As for the apparently higher than expected z-reset, pictures would help. Particularly of the platform, the z-mechanism, and the z-follower trolley. Xheck that the frame is square on a known flat surface. And also check the installation of the Z-Stop at the top of frame.

The Moai can deliver high-precision prints, but it must be set-up and calibrated. And it takes time.

Layer lines are normal in all additive printing. The resolution used is important. What were the printed resolution of the rings? The closed holes, if not due to inadequate cleaning, are probably related to the Z-axis calibration and, possibly, heating.

As for the pistol grip, resin shrinks. Without knowing more about the model and the axes of dimensional error, it is hard to determine what caused the issue. However, printing directly on the plate will compress the first couple of layers.


#32

there are multiple things going on here

  1. what is the resin you are printing? the color is hard to tell. is it nex grey or model resin grey? both have different exposure (laser) value. if you are printing nex grey at 56, that is way over curing.

  2. for the distortion, it sounds like you have not center the laser and do a close galvo calibration and then use the software to get everything dial in.

here is the Asura use guide, there is a section on custom calibration that covers both hardware and softwar calibration
http://wiki.peopoly.net/doku.php?id=moai:asura

it will solve a lot of your issues you mentioned. also if you are overing resin, your size will be off too.

@peopolysupport
please make sure users share resin type and printing temperature in the future.

http://wiki.peopoly.net/doku.php?id=moai:asura