Tank life and infill

Hi folks. New here today. And somewhat new to SLA. I have a Form 2 arriving tomorrow, it’ll take me a couple days or organise space and get everything setup, so while waiting…

I have only 2 questions at this point.

  1. How many times can you use the same base area of a resin tank before running into problems? Does this depend on the type of resin, or which tank you’re using? And on this note, would it not be an idea to hollow out the build raft that Preform creates? Therefore reducing the amount of base layer deposited? I guess this is an equation of strength vs resin used.

  2. Again I’ve looked, but can’t find, any infill settings within Preform. Form what I can see in forums and reviews there are 2 basic thoughts on this, print solid models or make your models manifold with drains. Is there no software around that will create infill for solid models? A vertical triangular infill wouldn’t trap much resin, if any. I know this would depend on the model, but it seems a bit of a missed trick for those wanting to save resign. I can’t think of any modelling software that will do this, it’s always been the job of the slicer.

Many thanks.


Per #1, it depends on the resin and tank, but in our uses, a Standard Tank lasted about 1L before ghosting on the film became very apparent, at 2L entire sections of prints were missing due to the clouding (this was with Black V4). With the LT tank, we’ve put 3L through it so far without any fogging on the sheet, so we’ll be sticking with those from now on.

As for #2, there is no infill settings, its 100% infill all the time. If you want infill, you’d have to include it in your STL to begin with when importing to PreForm.

Hope this helps!

  1. you can’t really hollow out the build raft. It actually compresses the first few layers when printing for adhesion purposes so leave the rafts alone.

  2. Infill is not a thing with preform software. What i’ve done a few times with my prototype prints is shell them out in Inventor. The one thing that preform WILL do is if you have a hollow print it will allow you to have internal supports which i find work very well. But ultimately, once i’ve done my prototyping and fit testing i will print it as one solid piece.

welcome to the formlabs world. Plenty of frustrations but 9 times out of 10 it’s worth it in the end.

SLA is a different animal.
Its a liquid bath… so, really, you can’t even HAVE a hollow, fully enclosed print.

There ALWAYS has to be an opening to allow air to flow into any internal space. And how that opening is oriented is critical to the success of the print.

To that end, you do not import solid models and have the software hollow them out with infill- rather, if you want something thin walled, you have to MODEL IT thin walled.
If printing an object you want to fully enclose a hollow interior… then you might have to cut it into two pieces and assemble them after printing.

As mentioned above- the interior may need supports, but it does not need infill.
You are not so worried about a DRAIN- because that is only needed for SLA machines that IMMERSE the part in a tank of liquid resin.

What you need is a VENT opening on the build platform side of any cupped form to prevent a cupped contour from becoming a suction cup that yanks the part off the platform mid build.

As to the rafts- they don’t use much material, but they need to cover enough area to provide good adherence to the platform so the part stays on and stable.

Its a balancing act- it need to stick good enough to remain stuck thru the build- but not so good you can;t pry the part off when its done.
By and large- aside from a tendency for parts to stick harder over time that requires sanding the platform- Preform does a pretty good job of striking that balance.

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Hey there Munty.
I’m still relatively new to the Form2 myself. One of the best ways to save on material (the SLA version of infill) is to use a program such as Meshmixer to hollow out your piece. Add drainage holes at the same time, strategically placed around the model. Export the STL as a new file from Meshmixer.

Then, take that hollowed out STL and bring it into Preform. You may have to try a few orientations of the main print to get it so that the bulk of your drainage holes face downwards. (I didn’t know this until Support told me about this - if you don’t like the positioning, just keep re-clicking that button and it’ll try different orientations.)

Finally, allow Preform to determine your supports - and when it does so, it’s going to strategically add a few supports inside the hollow area of the figure. You’ll never know that they’re there unless you’re printing in a clear or translucent resin, but they’re just enough to insure a successful print.

This works on even some fairly small prints, much to my astonishment. It often saves you a considerable amount of resin as well. If you find you REALLY want a solid figure, I’ve heard that you can later on fill the figure with two-part epoxy resin, but I have yet to test that idea out for myself.

Best of luck and have fun!

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Thanks Iconover, this is what I’ve been doing so far, but in Blender, all manual and time consuming. I spent some time last night looking around for mesh apps and hope to get a good look at them today. I’ll add Meshmixer to the list.

Thank you.

Going back to cjrussell0’s post above, I tried to start the printer up with a new LT tray and some tough resin a couple of days ago and it wasn’t having it, I couldn’t get the code out of preform for errors.

To mix trays do I have to run the printer in OPEN mode? I’m a little nervous of this at the moment as I haven’t been through all the ‘balls up’ learning curves I’m undoubtedly going to!