Some successful and not-so-successful prints

Hello,

I’ve been using my form 1 for a few months now with mixed results. I chalk up a lot of my initial failures to learning the process and whatnot. What seems to be happening in my case is once a print fails, it sticks to the bottom of the resin tank and continues to cure for hours on end until I wake up or come home to cancel the print. At this point, even after removing the cured resin there seems to be a permanent film of cured resin adhered to the bottom of the tank in some spots which in turn causes future prints that occur in that same spot to stick and fail. Is there some means of removing this from the bottom of the tank? I read that you aren’t supposed to use rubbing alcohol to clean the tank as it damages the silicone and I’ve also gotten a lot of damage occurring from the metal putty knife that came with the printer. I attempted to print a plastic scraper but in both attempts it failed and I had to scrape off the scraper :stuck_out_tongue:

Here’s the first bust I printed, originally sculpted in zbrush by myself. I’ve noticed I can usually get small versions of a bust to print but as soon as I start printing larger, the likelihood of a failed print rises dramatically. I have a bin of failed versions of this bust. I’ll post a painted version once I finish and paint these.

Here’s the second bust. In this case you can see how the smaller versions print fine but once I scale up the bust, the print fails. Initially I used the auto orient, which printed correctly at a small scale but the face failed to print at a larger scale. The pedestal did print correctly. In this case, I also hollowed out the bust and used the new .9 version of the software. I tried orienting the bust to print head first and leaving the opening in the bottom of the bust open so uncured resin doesn’t collect in the bottom but all that printed on the larger version was the supports. I have no idea why non of the bust printed.

I’ve gotten a lot of failed prints. Not sure if my printer is defective or what is going on.

The first image shows all the failed prints from the first bust. The second images shows the failed scraper, which should have been a pretty simple and straightforward print. The second attempt I rotated the scraper 90 degrees and moved it to a different edge of the platform and only the base printed. In the last image you can see the permanent residue on the bottom of my first resin tray.

I suggest to change  the tank and see if the print still fail, if it still fail then it maybe the problem of the machine. The form1 is a very accurate and delicate machine, it requires too much care, it may because of some weakness of the design which we don’t know and can be fixed in the future but currently we have to be careful. Even a finger prince can ruin the print, the cloudy tank is definitely not suitable for STL printing, it avoid the laser to come through and weaken the strength of the laser therefore makes the resin cure less and lead to a failed print.

By the way, I suggest you to watch carefully when it prints, do you notice the movement of the platform when the peeling movement is processing? If the print is very large, the peeling force will become so strong that it even pull the platform down and this will cause some accuracy problem I guess, Try to make your model hollow and thin, it will help.

Did anyone try to replace the tank with a tank made from glass?

I was thinking the same thing … Why the resin tank is made of silicone ? A Glass will stand forever …

Maybe because of light refraction factor of the glass? The resin tank is made of acrylate. Even the resin tank of the much more expensier DigitalWax 3D printers is made out of acrylate. I think they should have done the whole system upside down, the tank lowers, laserbeams hit the top of the resin, like the printers from 3D Systems do.

Ya, but even the silicone have refraction ( around 3.5 ) and for glass 1.5. I don’t know how formlabs deal with refraction but maybe there is a material who can do the job as the silicone without curing during the print like the thin layer of silicone do. ( glass or something else )

I will certainly said bullshit because i’m not an expert at all, but maybe they can put 2 glasses to double the refractive factor ( if they want to be higher ). But i’m almost sure that won’t work like that because they would certainly did that.

I think that making precise glass parts might be very expensive, but I don’t know how such parts would be made for this application, so maybe its some other issue?

The resin will cure to the glass, because oxygen molecules cannot get in between the resin the and the glass. With the silicone layer (PDMS), a thin layer of resin touching the PDMS does not cure, therefore the peel mechanism can work.

So, no…glass won’t work. It has to be a non-stick surface that prevents curing of the resin that touches it, PDMS and Teflon Film will work.

Hello again,

I think I am running into support problem others have commented on in version .9 of the software. I’ve seen a lot of missing supports on finished prints. Yesterday I attempted to print the strainer:

https://support.formlabs.com/entries/23728866-Handy-resin-tank-strainer

and handle tool pieces and half the supports for the strainer part stopped printing or fell away at some point while the tool still printed (to some degree) below the missing supports. The handle on the other hand only partially printed a couple supports and none of the handle. The fact that the tool printed in the same area of the tray where the supports were missing suggests the supports themselves are failing.

I have ordered a 3rd resin tray and a bottle of the gray resin. I am holing off printing anything else until there is a new software update available however. Printing solid busts in an older version of the software is expensive as is printing failed hollow busts.  It’s too difficult at this point to track down if the problems I’m experiencing are related to the resin tank or the software and where/when to expect a print to fail.

Hi everyone,  I have been having similar problems.  Recently I found some information about replacing the silicon layer on the bottom of the vat as a DIY project.  I’m probably going to give it a try when I feel my vat is on it’s last leg.  It still will not resolve problems with scratches on the bottom side of the bottom (the outer side that faces the mirror) but the guy that wrote the blog below claims he has yet to have a failure since doing so.

http://blog.madesolid.com/2013/09/changing-pdms-coating-form1-printer-vat/

Hello everyone,

I’m sorry to see that some of you are experiencing printing issues with your machines. Please make sure that you submit a support ticket to support@formlabs.com and we will do everything necessary to have you up and running again!

It is a priority for us to address any Form 1 related printing problems as promptly as possible.

A tip for people who had a few successful prints in the beginning and then the quality went down or they started getting more and more failed prints.

I started doing this with my latest printer and it works like magic. Before you start any print, run the scraper across the inside bottom of the vat (on the PDMS) for about a minute in both directions. The key is to expose the PDMS to oxygen as much as possible. In my experience, by doing a lot of printing and experiments, the more you leave the resin inside the vat, the less oxygen the silicone layer gets and we get failed prints as a result. This is also true for the clear resin, not just the grey.

Just when running the scraper on the surface, apply pressure, just not too much to damage the pdms. It’s easier to see with the grey resin, but when you scrape the surface, you should not see streaks of grey pigment, but instead a clear silicone surface.

Hope this helps some people. Just be careful not to damage the resin tank.

Thanks Monger Designs, that a really really nice tip :slight_smile:

I’m doing that all the time now, and seems to work very well.

I wonder what are the chemical properties of why the PDMS have to “breathe”

I do the same thing as Monger has said. seems to work. you can kind of notice the resin on the bottom has a different consistency when you first glide the spatula across the bottom. after a few times it will all be the same in consistency.

Hi Gilles-alexandre. Glad it’s working out for you. The reason the PDMS has to breathe is because it takes on a thin coat of oxygen molecules that inhibits curing and helps the resin to separate when pealing. You get easier separation of the layers and smoother prints. If the form 1 had some kind of sweeper/scraper mechanism to do that after each layer, or every few layers, it would have been great.

something like that ? :  http://www.youtube.com/watch?v=gCj2709X890

maybe for the form 2?