About to try sacrificing a goat


#1

So over the last 36 hours I’ve managed to get the printer as accurately calibrated as I can. I’ve managed to get the cross centred, the circles as close to perfect as I can, i’ve got the corners levelled to 10.7 or 10.71. I’ve got the ring printing out with holes open at laser power 57 and I’ve also set up the X and Y size to give a 20x20 cube.

Settings are default except for peel speed which I set to 10 as I’ve had better results in the past with that. Running 1.18 firmware.

So, now my prints don’t stick to the build plate. I get some parts of it to stick and some parts end up as sludge just barely hanging on to the parts that did print and some of it stuck the PDMS.
I reduced my Z height to 1877 to relieve some pressure and the parts that were stuck became unstuck and the parts that were unstuck became stuck…so no real improvement.

I’ve also tried reslicing using 60um profile in Cura 3.5.1 with the latest profiles.
I’ve tried setting the slow layers to 6 instead of 3. and I’ve also tried by slicing it inside Asura too.

the build chamber is between 30-32 using the Peopoly heater.

I’m going to try a higher laser power when I get home but hoping someone can suggest another solution as well.

If this doesn’t work then I will be sacrificing a goat upon the altar and dedicating it to @peopoly in hopes of actually getting at least one decent print out of this machine after 3 months and 3 litres of resin.


#2

Undercured resin will have a hard time sticking to the plate so that could be a possibility.

You can try increasing the laser power as you said or reduce the printing speed in Cura, i would try the speed first. For the 60um profile try 105-110 instead of 120.


#3

we’ve all been there. Virgins also work, but they are harder to come by.

PS: try slowing it down as @Leonardo suggests


#4

Cheers both, I’ll give it a shot tonight.

I’ve recently switch to 96% ethanol to clean with instead of IPA that I’ve used to clean the build plate and vat, which are the only other difference since I last printed. I’m wondering if perhaps the ethanol I’m using could leave some form of residue or film over the PDMS making it stickier as well?


#5

I have never used IPA, i always use 96% Ethanol and havent had any issues so far


#6

Yeah didn’t think so, thought I’d better ask just in case, trying to retrace steps back to a working print :stuck_out_tongue:
It’s weird though, I was printing at laser power 55 before without issues. I guess in changing out the power board for the new one might have had an effect


#7

some people here on the forum use dish soap and they are totally happy with it :slight_smile: As long as it is clean… it is clean

55 laser power is pretty low for standard gray resin. you probably had something wrong going on there


#8

I’m guessing that maybe the power board was putting out too much power? Despite being at 55 it might actually have been at 58 or so? I dunno, there’s a lot of black magic and blind luck that seems to go into getting this outputting good results. I know they’re possible as I’ve been salivating over the “Show your bits” thread


#9

now you say blind luck, you’ll soon call it “experience”


#10

To be clear when I get back from work: What speed setting am I adjusting in Cura? The general print speed or the speed of the first several layers?


#11

if you get ZERO layers sticking to the build plate you gotta raise the laser power. Also be sure the vat and the build plate are clean. If layers peels one from the other you can try slowing down the general print speed. First layer speed is already the minimum you can get.


#12

hi @bendouglas86

for slicing, you can use Asura 2.0 as it has everything baked in. Just pick a profile and export. That way you know your setting is good.
http://wiki.peopoly.net/doku.php?id=moai:asura

For printing, stick with original system settings so you can get more reliable output. 57-58 for grey resins.


#13

I tried Asura and got the same results but also don’t have the flexibility to edit the profiles. I’m using black resin if that makes any difference?


#14

the color does somewhat effect to print, try to print the ring test file with it, see what happens,also some pictures would help


#15

I’ve already done the ring as I mentioned in my original post and it comes out fine with holes open.

https://drive.google.com/file/d/1KJJK3HoRAgQmTVa-Zlvf0z4qWuU193Rs/view?usp=sharing
https://drive.google.com/file/d/1EzuBICIUgfNI6rW9Z-jSTEUvMG7Bx6q0/view?usp=sharing
https://drive.google.com/file/d/1PYZ9Rw9puo_sAkLIn6KFPT-Vzk1o6cnh/view?usp=sharing


#16

black is a bit harder to print at 100um because the color blocks out more lights. The sweet spot is 40-60um. And you need power at least 58 for it. 59 is to be on the safe side. There are a lot the setings for Cura but for SLA printing, not much should be edited as it is very sensitive to print speed. (unlike FDM) Those settings are pretty well tested over a year so maybe you can stick with Asura initially and then switch to Cura later on.


#17

So should I just up the laser power and use Asura or should I use Cura and slow the speed a bit?

Also, as I mentioned the build chamber is around 31-32 most of the time as the Moai Heater doesn’t turn off until it gets to 35C. All recommendations I’ve seen have been saying 25-28C


#18

use Asura and recommended power level at 59 for black. If that works out good, you can dial it down to 58 if you like. For resin colors, blue red grey are the eaiest to print, follow by clear/green. White / Black are the more difficult ones to print because they reflect / absorb much of the light.


#19

Ok thanks. What about the build chamber temperature? With the Moai heater it’s usually around 31-32 at the top end as it’s supposed to turn off at 35C according to the product page. Is that too hot considering most recommendations I’ve seen have recommended 25-28c?


#20

I think I may have figured out what was causing the problem. I went back into Cura to inspect the model and after switching to orthographic view I noticed that the model itself was only very slightly (barely at all) raised off the print bed. It seems that a couple of the supports generated in Asura actually went into the negative Z axis, and so when put in cura it actually elevated the base of the print a tiny amount off the build plate.

I’ve put it in Meshmixer and plane cut the offending support tips. Hoping this will sort as I believe this would explain the weirdness