There must be a logically reason why prints tend to fail near the end

I’m sure this is familiar to you guys. Perfect print all the way and the printer seems to go mad towards the end of a print.

I’m not even talking about a particularly long print, average 500-700 layers, printing time of 2.5 to 3.5 hours.

I’ve seen repeated issues with different objects that have similar geometry all having issues nearer the end of a print. Some kind of “ragging” occurs and sometimes I end up with a complete failure, other times, some minor ruined feature. The weird thing is that sometimes I see floating “ragging” bits stick to the tail end of a print but seemingly, the print wasn’t affected. Where did these extra bit come from?

I’m pretty sure it’s not a mirror issue.

Do you have a Form1 or Form1+?

Almost all the time, similar failures can be seen with models that are not properly supported. Sometimes in preform it can show that the model has no issues and there are no red areas, however some little overhangs can break off, or grow in midair and if those fall in the path of the laser, you will get failed prints at the end of the print, or sometimes mid print.

Without looking at a specific file, and all the other parameters, such as tank condition, etc, it’s hard to say for sure what’s causing the failure.

I have a refurbished 1+.

I’ll post some pictures tonight.

So this is my latest print. As you can see, there are some floaty bits sticking on the print. These are what usually cause print failures if they build up internally and obstructs the laser path.

This is how it’s like in Preform. It’s a fairly large chunk.

After the wash, this is how it looks like. Notice that the print turned out OK. So surface are not so defined but definitely a success. So the question is where does the floaty bits come from?

Another print. 1 before the previous one. Again, some parts that attached to the print. But it turned out well too.

Yet another print before this. It wasn’t so lucky, the floaty bits took out a chunk. Not quite a failure but I’ve had comletely trashed prints that happened in the same way.

As you can see, the majority of the print was pretty much perfect… I really can’t tell what’s causing some floating bits to build up over time causing the print to fail and it always happens near the end of the print.

Since it’s a Form1+ let’s rule out laser. I’m wondering if your tank has clouding? This would disperse the light slightly and weaken it too. Dispersed light makes resin beside the model begin to cure. If you have a wall going straight up like you do it eventually becomes a flake and attaches to the model.

This is a tank that I newly applied the PDMS. In fact, this

was the first print on the tank. Tanks might not be perfect but surely we aren’t expected to make every print with new tanks.

Wondering if these issues are related: Ideas on why these prints fail? or Why does it hate my sandwich?

I didn’t know it was cloud-free. Then I wonder about dust or hazing on the mirror.

I went thru the whole shebang with support on the mirrors too.

If there’s issue with the mirror, why does the failures always occurs so specifically? No matter how I orient the print?

Just find it really weird.

Well your second object just needs more support in that area or a better orientation. Orientation would probably fix the first object too. Aside from the details you mentioned your printer seems to be doing great. Good luck.

Hi Josh, I’m interested to know why you rule out laser failure on form 1+ I have recently upgraded and believe that my laser is failing. see my post Messy build lines on print

I ruled it out because while laser failure on a Form1 was very common, laser failure on the Form1+ had not been an issue for anyone back in early November. It seems today, in December, that we are discovering Form1+ lasers are getting old enough to have issues too.

I was getting some “floaty” bits on prints and cleaning the mirrors, including the galvo mirrors, fixed the problem completely.