FEP Vat failure


#63

This just shows how very important it is to have a heater installed. Peopoly has a heater for sale in the store.


#64

I wouldn’t be surprised if the issues here are temperature related. I’m not totally convinced the supports in the photos are done correctly for the FEP vat either.


#65

What is the “ideal” temp for resins to be sitting in the vat? I have a heater keeping the chamer at 30-35c and I’m still getting failures… Less, but still fails.

I’m guessing since the vat is aluminum, it’s going to stay a LOT cooler than a plastic or similar. I’ve been testing with measuring the actual resin temps and would really appreciate knowing the ideal temps.

Can they be too hot?

If the chamber is 40-45… 50-55?.. Is that TOO hot? Is there a temperature that we should stay away from? I’m tempted to just try running at 50c to see what happens. I’ve changed every single setting possible.

Releveled multiple times.
Tilt speeds down to 3…
Over powered laser
Under powered laser
Peopoly FEP
.05, .1 and .2 FEP
Every kind of peopoly resin and other brands

I can’t afford to buy a PDMS vat every single week… I run prints 24-7, FEP is awesome in theory, but I can’t get a single totally solid print off of it.


#66

Ideal is between 25-30C. Higher and you may trigger polymerization throughout the resin. FEP is much stickier than PDMS, so you should probably look to your peel motor speeds and z-follows.

As for replacing PDMS vats on a weekly basis: if that is not hyperbole, then there is a problem with your models, resin, or settings. A typical PDMS vat should last through 2 liters of resin, barring issues. Which resins and what laser settings are you using? Are your models very large? Also, it is possible to recover a damaged PDMS vat. This means both removing polymerized resin and repouring the PDMS.


#67

I’ve done all that. So far only higher resin temps and supports generated in Asura are helping, I am going to do a full post on solving these FEP issues when I’m done testing.

For one, I am running the Moai 24/7 and currently have 2, so it is very very easy for me to go through a PDMS vat per week, I am using them for production parts as well as functional prototypes. As for recovering the PDMS I literally don’t have the time to do that, so its not an option for me.

So far the FEP is ideal, but I need to find the right film, settings, temps, and fine tune other factors to make sure I don’t get any failed prints. After about a week of testing I am close, it comes down to the air temp inside the printer being warm and consistent, and the resin temp being between 28-32c.

Support generation and the type of supports and base are important too. I am actually pretty impressed so far with Asura and its options.

For now, for people having serious failures like other in this post, use a heater either from peopoly or make one your self like I did, use insulating foil foam pads on the inside of the printer to help regulate the temperature, and keep the chamber between 33-38c (as measured right in the middle of the upper chamber) which seems to keep the resin in the 28-30-32 range depending on color and brand, some seem to hold heat differently. AND use asura for support generation and use a LOT of supports. Coupled obviously with slower PM motor speed.


#68

on the topic for film, please stick with our FEP film as laser SLA printer has much higher requirement for the FEP film than LCD printers. We literally test over 100 films before finding one that is suitable and cost effective.

Temperature is a big factor, 30C will help a lot. Thick support with 1.2 support tip in Asura will help. the dense but tiny LCD style supports are not ideal for SLA printing in general


#69

Yea, I’ve tried. I’ve still got a few of your sheets I got through matterhackers, but switched to a slightly thicker film to try and rule out the film as my issue and so far I am having really good results and they’re about $2/sheet.

And yea, I agree. I really wish the documentation during assembly, setup, and even on the bottles of resin said the ideal temperature range and its importance. That is honestly my biggest complaint with the Moai so far, lack of support, documentation and instructions. It is all so spread out over the forum, wiki and google docs… It takes 10 minutes to find the results I am looking for sometimes because it’ll be written in one place an not another.


#70

thanks for the feedback. wiki is the central for official information so stil with that.

sticker film can produce unpredictable results so keep an eye on it.


#71

Jesse - What FEP are you using?


#72

Price has changed but it’s this stuff, I’ve done about 40 medium sized prints so far and haven’t had any issues, even with the stickier tough resin.


#73

In summary: By heating up the build chamber the chances of a successful print when using a FEP Vat are increased significantly.

I promised to get back on the subject of building an (alternative) heater out
of a 220V 200W 200x200 mm silicone pad.

I have put my post under the “heater-installation” topic: