Consistent layer shift


#1

Hey all

So I’ve slowly been making my through my list of issues and fixing them as I go. I’ve had issues with a layer shift from the start but it only effected prints above 70mm tall. Until recently I hadn’t printed anything that tall except for one thing but at the time I put it down to not enough supports.

Lately i’ve been trying larger prints and this is a consistent problem now.

This is the first time I’ve clearly seen it and it was obvious it wasn’t any other issue as the lighting clearly shows that layers are indeed shifted.


I wondered if peeling was an issue so I slowed the PM motor speed to 10 and increased the PM motor reset to 60.

Exactly the same result, in exactly the same place.

I suddenly realised today after making a post in Software about the Cura print bed being oriented incorrectly that my galvo control boards were likely wired up the wrong way around. I’ve switched the cables over and am trying another print right now. Hopefully I’ll have a new result tomorrow morning.

I’ve read a few other forum posts about similar issues and some found that a bad galvo board was the problem. I’m hoping that in switching the cables over that I see a shift in the direction of the layer shift itself, at least then I’ll know it’s the board.


#2

Hello Ben,

I believe I have an issue that sounds like this as well, I only notice these lines above some height, the ring and cube tests are ok, but after that, I start to get these horizontal lines, linear spacing, no matter what orientation I use. At least, it´s replicable.


Printed object with deep stepped lines
#3

Hey Ricardo

I’ve been following your issues for a couple of days and saw you’ve not had any success with any solutions either. I decided to create a thread of my own thread as this seems to be quite a common thing cropping up lately and I think it’d do @Peopoly good to see a few more concerns about it. So far i’m not massively impressed with my investment


#4

Agreed. By the way, I´ve been in touch directly with @peopoly for almost three weeks now , but honestly, I´ve done a lot of redundanct testing, long delays and still didn´t see any proper solution, I feel like my complain has been delayed as much as possible, which sounds awful.

My impression is, if you get a “good” Moai, you´re fine for some time. But, if you get one with troubles, it may become a nightmare. I don´t know for how long you have yours, but I got mine 3 months ago, spent a good amount of time working with it, but mainly focusing in the software aspects, supports and slicing/quality tests.

I really think that in the long term, Moai doesn´t sound like a solid investment at all, some parts have very bad quality screws, as noticed by other users as well, and unprotected delicated/critical systems (laser/mirrors).
Also, the firmware and control board doesn´t seem realiable and have some coding/implementation glitches.

I just hope I can make my printer work until I finish some prototypes and my base models for further casting and my small production run.

Anyway, if I can help with anything, count on me.

p.s.: Did you buy directly from Peopoly? I got mine from Matterhackers and already got in touch with them to see if they can assist me.


#5

Yeah I’ve mostly been printing smaller things and noticed issues when they got larger as I got more confident with the processing side of things. I put a lot of the early issues like shifting and layer lines down to my settings and supports etc, but as I’ve gotten used to it more the one thing that’s been constant has been the layer shift and only now am I realising that this is definitely hardware related and not a user thing.

I’ve lost count of the number of times I’ve re-levelled the bed, messed around with peel settings etc.

I switched the X and Y galvo cables around last night and got a print off this morning. Unfortunately I had to reslice and reorient the model so I’m going to have to switch the cables again and reprint again to see if there is a shift in the direction of the shift to be sure.

At this point in time it seems to me like the shift HAS changed direction from front to back to left to right, but i’m going to have to print another one with the wires switched to make sure.

Everyone cries out that it HAS to be something mechanical when this sort of thing happens consistently, but there have been several threads that resulted in “Replaced galvo board, issue fixed” despite everyone’s insistence that the issue was mechanical.

My fiance bought me mine as a gift about 1.5 months ago as a way of cheering me up after one of the worse years of my life and I think she got it from a place called IMakr.com.

Depending on how this issue works out I might end up flogging it and save up for a Form 2 and get an Ender 3 in the meantime as right now the quality difference in the printing between the Ender 3 and the Moai is about the same.


#6

Hi @bendouglas86

Im sorry you’ve been having a tough time with your life. Im sure things will get better.

Now… to your problem… from the photos… i can see some pronounced layer lines…

I’ve been printing those models for a while since a client asked to for a few chess sets…

I’ve tried to minimize supports without sacrificing stability. He asked for the lowest quality setting so im printing them at 100 microns…

I have tested every angle, every support software many many times, i found a good way to print it, its stable, wont use many supports and the parts came out great.

Would you be willing to print that Chess Knight again with the same configuration just to see how it turns out?

Those lines look like peel lines but as you said, you already messed with those settings alot, i would say to use the latest fw 1.18 with the latest settings (http://wiki.peopoly.net/doku.php?id=moai:firmware)

I will show you how i printed in a few min… not in the computer right now.

Also… if the printer was bought from iMarkr they should provide assistance and replacement parts if you end up needing them.


#7

Hey Leonardo

I thought they were pronounced layer lines at first but they’re total shifts of the layers. Looking under the light one side has a highlight and the other has a shadow showing there’s a “ledge” and an overhang on either side.

I’d definitely be willing to test that print if you can link it to me.

I’m currently running 1.18 with the latest settings - since the peel didn’t seem to make a difference I’ve reset them to the standard as per the wiki for the second print, can see from the photos it’s made no difference.

Tonight I’m planning on taking all the sides off and tightening all screws mentioned in the checkup guide. i’ll also switch the galvo cables over to see if the shift changes direction. Right now they are going from left to right. So i’ll see whether they change to front to back, if they do at least I know it’s a galvo controller problem.


#8

Changing the Galvos cables might help understand better what is going on and if its really galvo related! Do that!

The print is this same as your first photo: https://www.thingiverse.com/thing:1826018

I hollowed the print with 2.5mm walls (SS bellow)

I put my drainage hole at the backside of the model (SS bellow)

Used XYZ to generate supports and this is how i’ve been printing them lately

If your worried about suction, dont be, that drainage hole in the back is more than enough (5mm) to prevent that, as the piece goes in and out of the resin, air can get in and out of there so you wont have any suction problems from the part.

I’ve tried every angle possible and believe me… 45º didnt make any difference here, and uses alot more supports that will restrict resin flow so printing them straight up has been working great and thats how i’m going to print all the 64 pieces (2 chess sets)

And honestly… i bet i could do it with even less supports!!!

Let us know how it goes.

EDIT: i forgot to mention, there are supports inside the model. They will help the model hold on to the buildplate


#9

Thanks man i’ll definitely give it a try. I think I’ll try the galvo cable switch and tightening screws (if needed) and see how that goes, then I’ll try the way you’ve got it. At least It’ll narrow some things down that way.

As for making 64 of them, have you considered making a silicone mould or 2 and just using a resin mix to cast them? seems like it’d save you a lot of time?


#10

That might be a good idea (at least for the pawns)… i never done that before.

Do you know how much detail the mold can actually keep? Do you loose some?


#11

From what I’ve seen it’ll provide a more or less 1:1 copy, though there may be a little shrinkage. The main thing is to get the silicone and resin bubble free. the moulds will degrade over time the more you use them. Usually they wear out about 50 copies, so doing maybe 32 in each would give a good measure of quality. I’m pretty new to it myself but intend to produce copies of my products in that manner once i’ve worked this issue out.


#12

when possible it is always better to print straight as @Leonardo is suggesting. I would remove the hole on the bottom though and print on a raft of supports.

silicone mold is definitely the way to go if you need 60 copies. You don’t lose detail, but you may need a degas chamber if you want low failure rate.


#13

I’ll definitely give it a try. Lately i’ve been tilting 45 degrees but I’ll do some straight up prints as well. I’ll do one more with my current setup with the galvo cables switched so I can at least remove that as a possibility. If that’s fine then i’ll do another straight up and see how that goes.


#14

Hi Ben,

I´m also doing some mold making tests, I´ve already worked with molding and casting in my graduation (got a BFA in fine arts, sculpting) and even did some resin (epoxi) isolation work during my two years studying electrical enginering, some epoxi resins are very good for circuitry encapsulation. I agree with Matt, a pressure chamber helps a lot with bubble free castings, but if you use a fast resin (I use poliuretane resin, which I really like), you may need another stratregy. Having the mold slightly rotated, pouring the resin in the lowest point and having air vents in the higher points improves the success rate of each casting a lot.

I like this guy´s process, if you want to check: https://www.youtube.com/watch?v=C7uMkBzOMaM&t=6s

And about your Moai, I´m pretty sure we have a similar issue, my layers shift as well, in the front of the model the layers are going slightly back and in the back of the model, the layers are a bit foward.


#15

Thanks for the tips Ricardo, I’ll definitely bear them in and mind, and thanks for the video too. I’m hoping I can get some stuff into production and ready for next year’s game expo and comic cons in and around Birmingham. I’m a 3d artist, got my BA in Fine Art, but never specialised in sculpting until I ventured more into video game art. i’m looking forward to seeing your work when it’s less…stripy :smiley:

Yeah it looks like we have similar issues. i’ll keep you updated with what I find (if anything). Hope we can both get some nice prints going soon.


#16

Quick update.

i’ve tightened all the screws in the checkup list, found that the ones on the side of the vat holder were a bit loose, tightened them. Even tightened the screws on the back of the Z rail behind the leadscrew itself that weren’t on the list, they were tight.

I also switched the galvo cables around. The print rotated 90 degrees on the printbed and guess what? the layer lines shifted direction as well. I printed the original length ways along the Left of the print bed and the layer shift went from left to right. With the print rotated due to the galvos being switched it was now printing lengthways along the door side and now the layer shift travels from front to back.

I’m going to do one more test to make sure this is the case. I will print a very simple shape vertically with one side shaped into an arrow to point in the direction it is oriented. I’ll place it in the centre of the bed. I’ll switch the galvo cables back over. Print it. note the layer shift direction and then switch the cables and repeat.


#17

I’m now super confused.

I printed a test and got a massive layer shift front to back. Switched the galvo cables, tried again and while the test print is rotated 90 degrees on the build plate there now no layer shift at all in any direction. Running another test to see what happens again. I’m hoping the issue has miraculously cured itself


#18

Man, that´s wierd. But at least we´re back to work. Let´s hope our problems goes away.


#19

Part of me hopes the test print I left going is absolutely fine. But the other part of me hopes it sees the problem I was expecting, at least then I know I can take care of it instead of it sneaking back in to later prints :confused: I guess I’ll find out in a few hours!


#20

I’m starting to loose my bloody mind. I left the anubis print going while at work and the layer shift is still present. Is it possible it was a bad slice?

I’m trying Leonardo’s suggestion of printing one vertically with similar supports shown in his images. Wish me luck.

Would love to hear something from @peopoly this damned machine has already cost me a litre of resin and christ knows how many hours wasted. Starting to wish I’d never got the damned thing.