The prints away from the direction that the rabbit ears are pointing to are fine. So in the center and away from the hinge.
But once I get them close to the hinge side, I get fusing details and distortion. Almost like the laser spot is not round anymore. So when I have a ring with prongs, the prongs look tear-shaped from the top. Rotating the rings position shows that the tear-shape of the prongs always points towards the hinge, and the direction that the “rabbit ears” are pointing to.
I’ve been working through various unrelated printing issues. My most recent prints have been fairly good, although with some flaking and some patches of irregular surface. I’ve not got to the point yet of linking flakes or quality issues with flare direction.
I can verify that the flare seems unrelated to mirrors and must presumably be generated from the laser itself. I took a video of the laser spot test while I rotated the laser in it’s “socket” - the flare turned with the laser,
In that video you can see a separate spot like @Monger_Designs one, but it moved as I moved (I left the camera still so you can’t see the effect in the video), so while I don’t think it’s an reflection from the hood, I do think it’s an artefact of the hood.
@JoshK’s talk of a choke got me thinking - I might try making one myself and see if it improves my prints any -
Send me an email at joshk03@yahoo.com. I will send along my design file, an STL file, and a picture. But they don’t come with permission to distribute. I have a couple concerns with distributing them. First, it’s a delicate area of the machine to mess with. Second, it should be the last thing a person tries. But if FormLabs says they don’t have a fix for rabbit ears, here it is.
@Monger_Designs in my case the flare is not straight at the hinge it is diagonal pointing to the back left corner, and that is the side that comes out wrong. I mention this as evidence to the contrary if anyone thinks your artifacts might be oriented to the hinge side due to the peel process as opposed to your flare.
@Formlabs the best way I have found to replicate this is to print the classic rook at 0.025 directly to the bed. I use a slightly modified version with the hollow area on the base filled in to prevent blowouts.
@RocusHalbasch I specifically mentioned that the bad prints/fusing of details is happening towards the direction that the rabbit ears are pointed at, which for me happens to be in the direction towards the hinge.
From what i see your laser “may” be defective but i don’t think so … What i’m saying is, i had a lot of different printers from the start of the kickstarter campaign and i always do a spot test everytime i received a new/ repair unit .
Almost all my printers had the little rabbit ears even when my printer are working perfectly well. I don’t think it’s definite argument for a defective unit.
Maybe because the rabbit shape are not necessarily powerful enough to cure the resin. ( i think it must be taken case by case )
If you seeing a problem in a specific area ( apparently on the hinge side, it’s definitely a mirror problem ) You should look at the small and galvo mirror.
KevinHolmes, this is a great video ! But I’m confident the little spot will disappear if you use a magnet, open the cover and do the same thing. ( curious to see the result … )
@Monger_Designs I know you did I was just concerned since yours points right at the hinge someone might say it’s not the cause, having two different directions and the same effect is harder to argue. I was just trying to back up the theory with more evidence.
@Gillesalexandre yes - as I said I think the little spot is an artefact of the hood - and is not actually shining on the paper.
As for the rabbit ears indicating a defective laser or not - I think the consensus here is that it won’t cause print “failures” but may be causing quality issues - I haven’t looked at it in detail (I’ve only just seen my rabbit ears) like @Monger_Designs or @RocusHalbasch, but they’re both independently saying the same thing - or at least something very similar.
@Gillesalexandre it’s not in a certain area. It’s also not a mirror problem. It is specifically on a certain side, no matter what area the object is printed. This side is the side corresponding to the flare, which is completely consistent with the flare being the problem, and not consistent at all with it being a mirror problem.
And i totally agree that a rabbit shape won’t cause a failure.
I haven’t look in details too for problems but my point is that i have rabbit shape too and i can assure you that all my prints are perfectly detailed.
I already had problem like you have. (bad quality of the prints always on the same side no matter how i orient it )
Do you see in the base for supports a really thin layer of cure resin all around the " bad’ side of the print ? I think i could be related to dust or oil on galvo. ( it was my case )
I’m pretty much convinced by what Rocus and MD are saying - and I don’t have a much faith in FL claims that rabbit ears are a non-issue,
What if @RocusHalbasch or @Monger_Designs tried twisting their laser (remember to ground yourself first) and then confirming if their print quality issues track the new flare direction - that might help convince others here and maybe FL support too.? …
@Gillesalexandre My galvos and mirrors are spotless and trying to clean them did not change a thing. I’m fairly certain it’s the flare. Perhaps the degree of flare makes a difference.
However joshk had similar issues and the flare he designed and installed his choke to get rid of the flare and his issues went away. My distortion is on the same side as the rabbit ears as is Monger_Designs who I thought was saying he had the same problem, but perhaps you are right and his problem is different. Also I would like to point out that my printer seems to print some things ok.
I would like to know how others with “rabbit ears” fair trying to print the rook at 0.025 directly to the bed preferably in black as that’s what I have been using. I would really like to see both those people having problems with print quality if they find the same thing I have, and also for those who say their machines work fine with rabbit ears to see how well it comes out. Having info on that could shed a lot of light on this topic.
@KevinHolmes I would try that but I do not want to risk my warranty. If Formlabs will give me permission with no threat of loss of warranty then I’ll be glad to try it, and any other experimenting they would allow. However I seriously doubt they would allow me such liberties.
Here is the rook I print for anyone who would like to try it. Just use the select base tool on the orient object menu to get it to be oriented straight up, Print it at 0.025 with no supports.
