Bulging effect on top down DlP printer.(solved)

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firecardenal
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Bulging effect on top down DlP printer.(solved)

Postby firecardenal » Mon Oct 06, 2014 1:19 pm

Has anyone been able to eliminate the effect of swelling on a printer from top to bottom?

I've put a lot of time to solve this problem and still not get fix.

I have put a system of flat and clean to force the resin to maintain a proper level and have developed a container with a slot drain excess resin caused by the sinking of the arm platform construction.

Does anyone know how to get professional printers do?

Maybe in the formula of the resin is the secret?

I currently work with Makerjuice SubGenius +

Thank you


Solved.
viewtopic.php?f=20&t=3266#p10842
Last edited by firecardenal on Wed Jul 08, 2015 7:20 am, edited 2 times in total.

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PacManFan
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Re: Bulging effect on top down DlP printer.

Postby PacManFan » Mon Oct 06, 2014 3:49 pm

Professional printers use a wiper assembly that wipes off excess resin from the surface to ensure consistent layer thickness.

Phife
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Re: Bulging effect on top down DlP printer.

Postby Phife » Mon Oct 06, 2014 9:51 pm

Have you tried the Spot-A LV (low viscosity) resin? Also, I larger vat helps a bunch too.

Kvirre
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Re: Bulging effect on top down DlP printer.

Postby Kvirre » Tue Oct 07, 2014 7:00 am

Phife wrote:Have you tried the Spot-A LV (low viscosity) resin? Also, I larger vat helps a bunch too.



At first I thought viscosity was correlated to surface tension, but apparently not
http://www.cscscientific.com/csc-cienti ... -Viscosity

gmoneyphx
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Re: Bulging effect on top down DlP printer.

Postby gmoneyphx » Wed Oct 08, 2014 6:48 pm

You are using "deep dip" method are you not? That is the only practical way to achieve top down in DIY fashion.

Also, forget anything much less than 100 micron layers. You can get flat down to 100 microns fairly quickly (5-10 seconds) I have found. When you go less than that you hit the painful exponential part of the curve. Of course it will settle to 20 microns but you may have to wait minutes per layer - not practical.

I just posted another few items printed at 100 microns in the showcase area. I have been very happy at that layer height.

bjbustard
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Re: Bulging effect on top down DlP printer.

Postby bjbustard » Sat Nov 15, 2014 2:25 pm

In regards to "deep dip" method. How deep do you dip? and does it really matter?

Ben
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Ben

Still tweaking my Sedgwick

kakapoopie
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Re: Bulging effect on top down DlP printer.

Postby kakapoopie » Mon Nov 17, 2014 3:50 pm

Would the spot a lower viscosity resin help the thinner Z layers settle faster?

Also struggling with this problem.

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PomeroyB
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Re: Bulging effect on top down DlP printer.

Postby PomeroyB » Mon Nov 17, 2014 5:22 pm

bjbustard wrote:In regards to "deep dip" method. How deep do you dip? and does it really matter?


I think Uncia drops the platform 5mm, and brings it back up 4.9mm by default. 5mm is probably more than is needed... but testing would need to be done to find the minimum.

kakapoopie wrote:Would the spot a lower viscosity resin help the thinner Z layers settle faster?
\
Lower viscosity would settle faster, yes. Faffer on the Uncia Google Group has tested heating his resin to 48C, and has reported that that lowers the viscosity and improves prints as well.

kakapoopie
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Re: Bulging effect on top down DlP printer.

Postby kakapoopie » Mon Nov 17, 2014 6:42 pm

hmm...finally a reason to use those heat beds from my ramps kit :P

Is there a way to reduce the warping on large flat surfaces? it seems like any thick area on my prints get blobby/lumpy. Even down to 3mm thick im still having warping issues.

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PomeroyB
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Re: Bulging effect on top down DlP printer.

Postby PomeroyB » Tue Nov 18, 2014 1:02 am

Warping is pretty much directly related to the shrinkage of the resin -- Higher shrinkage = More warping. Look for resins that advertise low shrinkage, or compare data if it's available.

One easy way to reduce warping is the shell your models. Shapeways has a very short explanation of this. Very important to remember the drainage hole!