Sanding Build Platform Surface?


#1

I scanned the threads for something similar but couldn’t find anything.  Please let me know if this has been discussed before.  My prints are not sticking to the Build Platform surface.  They use to using the same cleaning methods that leave the surface like it was before.  I’ve swapped out a Resin Tank and poured new Resin only to see it fail at with the original platform.  Anyone else have similar issues with the Build Platform?  Thinking I need to “rough it up” to have the Resin stick but not so sure…

Thanks in advance for any insight,

-Will


#2

I too am interested in how to maintain a build platform. They are well constructed, but scuffing can happen quite easily.

Best solution is to use a Razor Scraper instead of the scraper which comes with the printer. Use the Razor Scraper to loosen your models from the build platform. They will pop off quite easily, and you will not scuff the build platform.

If your build platform has scuffs already, I would use the scraper in the kit. Take the kit scraper and run it over top of the build plate, use a little bit of elbow grease, and you will start to feel it get smoother. If you run your finger over it, thats the best test. You want the platform smooth, not “roughed up”.

If Formlabs has any advice, it would be appreciated!


#3

I am surprised this has not been answered yet.

Ryan, I disagree.  The aluminum build surface should not smooth.  Flat yes.  It needs to have a tooth for the resin to stick to.  I have gouged, scraped, dug at, etc.  my build platforms.  After a while it looks terrible and the resin gets into the grooves.  I take 120 grit and lightly sand the surface until I see the old scrapes uniformly disappear into the back and forth pattern I sand into it (it looks like a new build platform).  I think 80 grit would be better and more consistent with how FL ships them.  Keep in mind, I am not really removing material.  I am just changing the pattern scratched into it.  Since there is no care and feeding instructions for build platform health, use my suggestions at your own risk.

Good luck.

David


#4

@David

Very true… I am glad you have had success with the platform and keeping it in shape. I think my scratches were much more minimal. But I try to keep mine smooth and, in doing so, I have had good results with things sticking. So maybe while I am making it feel smooth to the touch, it is in fact leaving a small tooth within the aluminum. But your suggestions sound great! I will pick up some sandpaper soon.

I think we would all agree, though, we would like to hear from Formlabs about this.


#5

Same problem. Resin Does not stick to the build platform about half of the time. Seems to happen more frequently with .025mm or .05mm layer builds. Would love to hear from Formlabs.


#6

David is correct in that the build platform will get scratched over time and will not negatively effect adherence. A rough surface can actually be advantageous for parts gripping the aluminum plate.

If you are having big issues with parts sticking, the build platform could be sitting a little too high above the silicone, but you can drop the build platform slightly to resolve the problem.

We have a writeup on how to use the Fine Tuning tools in Preform here: support.formlabs.com/entries/40866853

Hope this helps!


Build platform, when is a good time to change it?
#7

Hi Jory,

I have big issues with parts made of rigid resin sticking on the build platform.
Do you have any other information on fine tuning that could solve this (your link if off) ?

Thanks in advance,

Ben


#8

https://support.formlabs.com/s/article/Fine-Tuning-the-Form-2?language=en_US


#9

Thanks John but I saw this article and there is nothing about resolving sticking issues by lowering the platform in it.
I will probably do the test to see what’s happening.

Fine tuning these 2 parameters could help too I suppose :


#10

The settings in preform do not help at all. The height above base only influences the height of the printed part above the top of the base, and the base thickness influences the rigidity of the base but not the adherence to the BP. There are two reasons that I know of to modify the base thickness : saving resin at the risk of having a brittle base, and compensating for extreme Z offset values.

The link I pasted is the one originally given by Jory, and it is the right documentation for your issue, even though it doesn’t state exactly what you want it does say that Z offset influences BP adhesion.
Tuning the Z offset is the only parameter that influences the adhesion of the part to the BP, AFAIK. It serves to increase of decrease the pressure that the BP applies on the tank. By reducing the pressure (increasing Z-offset value) the adhesion to the BP is reduced with the risk that the parts stay attached to the tank rather than the BP during the peeling operation. Increasing pressure (reducing Z offset) will increase adhesion.


#11

If the parts suddenly don’t stick and your using the same resin, settings and tank then scuff up the build plate and wipe it down with IPA.

If it is a new tank with same resin and settings and they don’t stick then lower the build platform in PreForm just a click at a time till they grab. Usually do minimal adjustments at a time.