Form 3 - What is the minimum resin tank volume required to print?

Hi all, how many mL of resin should the Form 3/3B tank hold in order to successfully print? For example, pre-form says my part is going to take 70mL. How many mL of resin should be in the tank for me to be comfortable clicking “print anyway” when my cartridge is empty?

More details:
My Durable Resin appears to be empty (I looked inside). My print is not starting because after quite a long time of trying to fill the resin tank, the Form 3 says that the cartridge is either empty or not dispensing. It asks if I want to continue printing anyway.

I weighed an empty v2.1 tank with the mixer (I have an unused one laying around), and found that it weighs 464 grams. I weighed my resin tank V2.1 that has Durable Resin in it, and it weighs 888 grams. Therefore, there is 424 grams of resin in my tank which should be about 353mL of resin (assuming Formlabs’ typical resin density of ~1.2g/mL according to their website).

So the question is should I be comfortable “continuing anyway”? I want to do another 70mL print after this one…should I be comfortable “continuing anyway” on that one too?

Any advice is welcome, thank you!

The printer will continue to print successfully until there isn’t enough resin to uniformly coat the bottom of the resin tank. On my Form2, I sometimes had prints that completed successfully, and after they finished and the tank had sat for a while there were spots in the tank that were dry due to surface tension of the little bit of remaining resin pulling it in to a thicker blob. So at least in my experience the printer will print with very little resin in the tank.

My understanding is that there is a limit to the number of times prints can be started after the Cartridge is Empty warning. I don’t know whether this is related to the number of starts or the volume of the resin left in the tank because I have never wanted to explore that situation.

Thanks everyone for the input! What I ended up doing is starting my print, and since I didn’t want to wait several hours for it to keep “filling” and then generate the error message, I instead let it get to the fill stage, and during that stage I physically lifted the right side of the Form 3 up with my hands so that the machine would be tilted so that the resin would lean more towards the left of the resin tank. Suddenly, I would get a “machine is not level” error. I put the machine back down, clicked “Try again” or whatever the button said, and immediately the machine continued and moved onto the tank preparation phase.

My 70mL print completed successfully at which point I re-weighed my tank and it was around 780g (so I should have around 263 mL left). I then ran another print that required an estimated 80mL according to pre-form and used the same method.

In both of the above prints, my resin cartridge itself was empty.

Both prints were successful. I will keep doing this while I wait for another resin cartridge to come in the mail.

Thank you!

Just as a bit of advice, you can just poor a little resin from the cartridge directly into the tank, then you won’t need to tilt the printer and you can mitigate some of the filling time. Just be pretty conservative with how much resin you put in. Don’t need much! Maybe only a half-inch at the most.

Thank you DKirch, in this case my resin cartridge was already completely empty so there was no resin to pour into the tank. All the resin I had left was in the resin tank.