Very Rough Finish on My Parts

My printed parts appear very rough. I used auto-orient and auto generated supports. I am using grey resin from Formlabs. The layer thickness I used is 0.1 mm, despite what it says on the bottom of the screen shot.

What could be causing this roughness? How would I go about fixing it? Thanks!

Was the resin in the tank very well mixed or the bottle well shaken? It looks odd.

Its interesting the way you oriented you part is very similar to the way I oriented somewhat of a similar print and got similar results of the finish… You are also using grey and have a Form1+

I wonder if its resin related + orientation.

You bring up a good point. I will try shaking the resin bottle harder on my next print. I barely shook it before.
I also got in the habit of “topping off” the resin in the tank without thoroughly mixing the old with the new. Could that be the culprit?

Yea that’s probably it. It looks ok in the tank until you mix it. It’s surprising how much thick stuff sits on the bottom. If you glide the scraper against it lightly you can see it.

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Yes always scrape/mix . Josh is right

Great. I will try that when I get into work on Monday. I’ll let you know if it resolves the issue. Thanks!

No problem, good luck!

I tried removing the resin from the tank, shaking it, returning it to the tank and re-printing my part. However, its finish unfortunately still came out rough! I am currently trying another re-print, this time with a fresh batch of resin from the bottle. I removed the old resin and stored it in a separate container. I will see if this corrects the issue.

If if doesn’t work, do you have any other ideas as to what might be causing this roughness? Could it be due to debris on the mirror? Thanks!

The mirror is always a possibility, but I think you are on the right track with the resin. Did the print after shaking it come out better? Monger pointed out once that after you print with unmixed resin you are actually changing the formulation of what is left, messing up future prints.

The print after completely replacing the tank with new resin appears to have a better finish overall but has a couple rough spots like before. Thankfully, the use for the part does not require a smooth finish, so I’m not terribly concerned.

I will clean the mirror tomorrow when I bring in a compressed air tank. Is that the preferred method of cleaning it?

I think they recommend the lower pressure CO2 cans, but yes they say compressed air first and maybe you can avoid the alcohol wiping.

Hello Matt
After the mirror cleaning, please check if your silicone layer of the tank is perfectly trasparent or have cloudy imperfections.
If it is fine, check the laser beam.

Start the diagnostic tool of the software (add -diagnostic to the command line of the exe fole of preform). The beam should be a clear dot, without ligt noises or sparckes.


Just wanted to add that I’ve been seeing this kind of bubbling too on various prints I am doing with grey resin at 0.05. It is usually (but not always) within 2-4 cms of the base and seems to “hit” in a limited horizontal region. But sometimes on thin-walled stuff, it continues throughout the wall.

I just saw it on a tiki print I did and posted in the prints section. Now I am seeing it on another print that I am doing of a reasonably good stl (not too thick, clean topology, etc).

I have tried all the best practices (shake bottle, scrape tank), start with auto-generated supports, no horizontal surfaces, etc with extreme focus.

Also, though I was printing with grey resin in a tank that had been used for many prints, I just last night switched to a brand new tank with black resin and did the exact same print (no changes to the form file except the resin change). And though the black resin clearly has some different characteristics, the print exhibited the SAME bubbling in the SAME spot on the print - despite new tank and new resin (and I shook the resin in the bottle vigorously for a good 2 minutes before pouring.)

What is really interesting is that other parts of the print have stunning accuracy to the original model. And in fact, a parallel section of the part with that is almost identical prints fine in the same slice region with no bubbles. It almost seems as if the location of the part on the build platform may be related to the bubbles? (I am following guidance btw to place tall support regions near the hinge).

So I am running yet another test where I will simply rotate the last print and see if the bubbles persist. That last test should seem to rule out “dust on the mirror” if the bubbles persist in the same location - since it would seem unlikely that specific dust particles would have such a universal effect on a specific region of the model. Does this approach make sense as a way to isolate mirror-dust as a cause?

Sorry to go on, but maybe we are all seeing the same problem? (I really would like to find a way to get consistent quality throughout a single print.)


You know, I bought an air blower for photo lenses and I plan to inspect my mirror when the tool arrives.
When I first got my printer I noticed some particles on it from shipping and packaging. I am thinking that “cleaning” the mirror should be a semi-regular scheduled maintenance item ?

Here is what I bought to maintain the mirror.

I agree Cesar that dust particles would not cause uniform problems. I think he just wants to do maintenance.

I don’t know how much it would impact your prints, but after using the compressed air duster on my mirror today, I did notice some improvement with regard to roughness. Take a look below (old part on the left, new on the right):

Though the final finish isn’t perfect, it will work for my application.

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Awesome, glad to hear!

looks much better. have you changed orientation? I am starting to think the flat areas tilted at 45 degs or I should day not perpendicular to the build plate seems to get artifacts.

Wow. Same form file? That’s quite a difference. I did a retest on mine to rotate only by 180 and The bad area ‘disappeared’. I am starting to believe dust could be the cause. Bums me out tho - I have been pretty careful in my print environment. If true, this thing needs a clean room.