1

Hello.
SLA my printer started to confuse one of the dimensions of the model during printing. Can anybody write me possible causes for this problem.

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2 Likes
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What printer are you using? What slicer software?

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printer is similar toForm 1 but I did half alone. Print an 3monts without a problem. Today I made this mistake in size. Software is the Pre Form / problem is not in him /. Do you know the possible reasons for this error in size. Can I read somewhere and began to ignore the reasons one by one until I fix it. if you you have a reason will be glad to read.

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So it’s not a form 1 that you are using? Is it a clone? Have you carried out additional prints and found the same issue in the same axis?

If so then I suspect one of your galvos will need replacing

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looks like the laser or the mirror has moved in the machine.

Has anything happened to it between last print ?

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o It does not sound good. Do you have information / or website / where to read how to change? I took the laser system assembled and calibrated and still do not know how to change galvos.
That sounds logical. laser distracted and did not file the proper place for curing the resin.
What is the margin of error of printers of this type? I think that 2 mm of 7 cm object is pretty big mistake.
Are there other suspected causes of this error?

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Carry out other prints and see if the same error appears in the new print. Also check if the error is different at the front of the platform to the back. If it is then it will be a faulty galvo.

Changing a galvo is fairly easy. Assuming they have copied the form 1 exactly then use this thread to change it out.

Swapping out a bad galvo; the PhenixTech PT-20K is a drop in replacement, +video of tuning - Projects & Prints - Formlabs Community Forum

It’s not a cheap repair but then again, this is exactly why you pay a premium for the real deal product.

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thanks i untherstand all.

this is better info too:

http://www.wtec.org/loyola/rp/09\_04.htm

Thanks a lot for help. I think my printer is with only one mirror not 2.

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have you noticed how your printer has a deviation in all. how much is the normal difference in size for such printers?

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I have my form 1+ dialed in to give +/- 0.05mm over the whole platform.

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this is good. I calculated that my error will be +/- 5 mm from end to end. I will let the test be convinced. thank you again

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One axis may have been scaled slightly in the printing software. Try first verifying the size in a cad program if all is good reimport your stl into the printing software and it should be reset to scale x,y,z to 1 unit

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model is perfect. checked several times. Will try to reduce the mechanical side and let him go. I bother me from what I read that the problem becomes more serious very quickly with mirrors. I will try to return the body to the manufacturer for correction. If they do not accept it will change the mirror.

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Well you can replace / recalibrate the galvos. Expensive and somewhat complex or simply scale the part in one direction to compensate for the error. Not saying it’s the “right” thing to do however it is fast and easy to do. Just like I have found that holes tend to be undersized. So If I want a part that I do not have to do a lot of finish work on I oversize the holes slightly and everything fits perfectly.

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If one of the galvos is on the way out it will only get progressively worse. I had this issue on my form 1+ a while back. Recalibrating would only keep the printer accurate for two prints tops before it would go out again on one axis

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What I see is that the circular object is not a true circle … is that what you are getting at? SLA is not prefect, and neither is any other 3D printing technology or method. They all have innate challenges to deal with.

You do not mention what machine you are running, so that would help in troubleshooting.

This could potentially happen during the peel process, or possibly your galvo/laser system is not calibrated correctly.

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Thank you for your help. Most findings point to a problem with the laser system and mirrors.
I do not have support from the growers of the laser mechanism that would straighten himself. It bothers me that the mechanism is in warranty and nobody answers me emails for repair.
Apparently they wanted to sell the defective mechanism and then leave me to straighten a false guarantee documents.
I read your posts if you do not fix the problem deepens rapidly. I’ll try some more tests to see how the shift.
If not fix will have to disassemble the printer. I’m worried if I myself can correct calibration.
Thank you again