Only getting about 800ml out of each Resin Cartridge?

I am only getting about 800ml out of my latest resin carts. I know some is lost that is rinsed off of the part, when completed, but 20% seems high.

I am charging the customer based on the volume of resin used for each part, using 1000ml as my $/ml, but I did not account for 20% loss, so I have probably been undercharging for the components. I’ve been through 5 carts x ~$160 (cart and shipping) = $800 * 0.2 = $160 loss in material cost alone.

Anyone else have this issue, or know what might be the case?

I looked all around the forum, and didn’t find any answers, so excuse me if this has already been answered.

Hello @skr3pind -

This is a good question on the cartridges; the short answer is that the Form 3 line doesn’t precisely measure resin use - it uses dispense times as an approximation. It might look like you’re losing 15-20% of resin, but it’s more often than not a consistent inaccuracy in how the system measures and the loss is much smaller.

If you’d like more details, I’d reach out to Support for further clarity.

Kind regards,

Why doesn’t it use total build volume to re-calibrate each time? That coupled with when the float determines that more resin is needed in the tank should account for a decently accurate measurement no? I guess the flexible film bottom makes the volume a bit sloppy but not 200 mL of slop

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Best method I’ve found so far for tracking resin use is a basic digital scale, YYMV

Hi all,

As @RD_lab suggested, using a scale will yield the most consistent resin volume estimation. I recognize that this doesn’t make for an ideal user experience, but this rules out variance in the way the printer estimates resin usage.

Hmm… I see why it would be measured this way in the case of possible change of tanks, or spills, etc. It would be nice, however, if the preform part volume was incorporated as well. If the tank is the same and the cartridge is the same, then just subtract the part volume from the cartridge volume. 20% is pretty inaccurate. I suppose I will have to measure each of my parts on my next cartridge and double check whether this is the case or not.

Why not just use the preform volume?

Hi all, I just wanted to provide some clarity on this topic. The printer does actually use the PreForm volume estimation when determining cartridge fullness. However, some resin dispense would not be covered by this, for example when filling a resin tank from empty. Due to this, the cartridge fullness estimation is sometimes higher than the actual fullness. We are working on narrowing this discrepancy, and in the meantime weighing the cartridges will yield the most reliable results.

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Well the tank was not filled from empty, so does that mean that I am in fact losing 20%. I imagine you have a QC on the cartridges going out making sure they are actually 1000ml, correct?

Hi @skr3pind,

Yes, we are quite confident that cartridges are shipped with a full liter of resin. Some of the discrepancy may be due to resin dripping off each part or being washed off the part surface. Another portion may be due to filling that happens during the print, which would cause a discrepancy if the print finished with more resin in the resin tank than there was at the start of the print.

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Ok, Jesse_K. I will troubleshoot what may be the case on my end. Thank you for taking the time to address my concern.

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Scale is the best way, comparing its weight against the weight on the same cartridge when it was full

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All resins have a marginally different density, 1 cubic centimeter “weighs” about 1.1 Gram. Hence the only reliable way to get the most out of your cartridges is to “Tare” them in the software, which resets the mass of the resin left in the cartridge, as this baseline mass of the cartridge will change a bit with time and temperature (It’s the way such loadcells works), hence re-taring is a very good idea to get the most out of a cartridge., I guess I do it maybe twice every cartridge (I run two Form 3 LB’s). Whatever resin is lost during the wash process is just part of the manufacturing technique.

I should add that I don’t own a Form 3, so am not too sure if the “Taring” option is available on that machine. If it isn’t then the amount left in the cartridge can realistically only be calculated from how much material Preform “thinks” it has used.

Taring the load cell is an added feature on the Form 3(B)L which is not available on Form 3 series printers. With that said, the taring process can definitely improve the accuracy of cartridge readings for the large format printers.

Well, for one, I would never use the Formlabs statistics page to gauge my true volume use. If you want to keep finer plot, calculate the volumes from the Preform program, and measure your 1L container before each use. That statistics page is helpful for a broad view of your projected use. It’s not meant for accuracy.

I will say this, though. I mentioned on another post that I have been losing a lot of resin because I can’t get it to drain back into the tank (due to orientation that optimal for print, not for draining). I am suggesting to Formlabs that they implement some sort of tilting stage where we might rotate the stage away from a flat orientation to a vertical orientation… thereby allowing pockets of clingy resin to drip back down. This could cause issues with alignment, flatness and not to mention it may not fit under the current orange covers. But if I can save some money on that expensive resin… i’ll take what I can get.

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