Replacement bite valves for resin cartridge?

A thought if I may, if its the bite valve at the base of the resin cartridge that fails over time -I’m thinking refilling cartridge, then has anyone thought of replacing the bite valve? They do look like something Camelbak have on their hydration systems.
Any other thoughts?

We generally don’t recommend re-using Form 2 cartridges. Having third party resins in used cartridges can cause a number of issues beyond bite valve failure. Level-sense is tuned for Formlabs resins and filling cartridges with third party resins can cause dispense issues and result in major spills. There is a case to be made for wanting to use Form 1 and Form 1+ resin in used Form 2 cartridges so that the resin will automatically dispense but we find it’s easiest for users with bottled resin to print in Open Mode. Bottled resin and cartridges do cost the same per mL.


Joe90, Have you disassembled a cartridge valve from the cartridge? Can they be removed from the cartridge without damaging the cartridge? It would be interesting to investigate.

Mike A.

The bigger problem than the bite valve is the printer telling you the cartridge is old (not empty) and not letting you print anymore.

We use a 50/50 mix of Black and maker juice SF black for our prints. It produces a better part for our use. We have had no issues running it in the Formlabs black resin cartridges under the Black profile. Until it told us the cartridge was used up.

There may be a way to reset it but I don’t know it.

Open mode is a joke. If we had control over temp and the wiper it would be a good thing. But in its current state it doesn’t add much to the form 2.

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Just for clarity, this is more of a theoretical question. I do appreciate formlabs view and the very reliable resin. But orice is something people will always consider.
To me the open mode should either open propely or not. It does seem a half way house at the moment.
I haven’t yet taken the bite valve off, i have a couple of ml left.
I suspect that given time the chip in the cartridge will be reverse engineered to overcome the empty status.



As always I will issue caution against using any 3rd party resin in the cartridge purely from the standpoint of level sense not being tuned for 3rd party resins and risk of overfilling being much higher. Additionally, depending on the viscosity of a 3rd party resin, the wiper can cause spills.


Yes they can be removed or simply fall off like mine did.
They are not held on by any significant mechanical means or adhesive. Just a slight lip at the base of the nipple that the rubber valve hangs on.
one more a bit better focus.

For the two types of resin I have been able to trick the machine into using outside of open mode. Neither had any problem with the wiper. The biggest problem I ran into is with thin resin (like castable v1) is it will spray over the tank walls when filling.
The fill valve needs a bit of a flow/guide tube downstream of the valve to prevent this.
Also programming the wiper to have a safe wiping speed when in open mode would prevent folks from trying to trick the machine into thinking it has a Formlabs resin. Least for me that’s the case. The autofill is not a big feature for me at this time.

Regarding reusing the cartridge. It would be nice to have an option to disable cartridge detection so that I don’t HAVE to put in an empty cartridge just to run the machine when I’m not using open mode.

The valve is either open or closed. There is no inbetween. But the rate at which resin flows out of the valve is a function of its viscosity and the printer is calibrated for the FL resin. The printer doesn’t actually meter the flow.

You use a 3rd party resin that’s thinner, it’ll flow out faster. The printer might over fill the resin tank for example by thinking it’s dispensed 100ml when it’s actually dispensed 200ml.

I understand the problem of viscosity and overflowing. I appreciate your concern and wish you would stop trying to hold our hands.

Most of the people who have bought one or more of your printers are able to take on the big boy (and girl) responsibility of seeing what works for them. The speed of the wiper is adjustable, the timing of the fill is adjustable.
These settings could be implemented in the open mode.

You have had plenty of your customers ask for this but have not as of yet addressed if you are going to do anything about it.
You keep on telling us it will spill, it will splatter, blah blah blah. Please give us a real answer to what is being asked for.

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Keith, while I don’t work for FL, I do manage technical customer support for a large US tech company. Please forgive my bluntness, but your perspective on this is wrong.

It’s not a question of whether or not you or I are competent to use this feature (I sure think that I am). If FL enabled these features, without a doubt some people who are not competent to use them correctly would use them incorrectly and FL would have to provide support to those customers.

I’m not surprised they don’t want the headache. I wouldn’t want the headache. I reject customer complaints all the time when the failure is “customer induced damage” and it’s still a huge headache to manage.

FL’s alternative is “invalidate the warranty” for anyone who uses the features. You can use it, but if you break it, tough luck for you. But I think this would result in even more customer support problems.

Like it or not, FL’s reasonings are valid. They’re a money making business. They can’t be giving away replacement machines to users who mess up the one they purchased by using Open Mode incorrectly. But those users would expect it. They have no choice in the matter but to decline to enable this for all, or open themselves up to warranty “burden” that could be quite expensive.


Randy & Keith,

Randy, I definitely agree with your last statement and Keith I also understand your desire to have more freedom to configure the machine to work for your purpose. I have expressed similar desires on this forum. I believe this discussion would be better served to direct focus to get Formlabs to improve the design of the cartridge valve therefore eliminating the need for this discussion of workaround solutions. The fact that Formlabs is not currently admitting that they have an issue (correct me if I am wrong) is causing Form 2 owners to be nervous about losing there investment (see disaster thread). Formlabs could ease Form 2 owners minds if they would give us some information about the failure and what they are doing about it. This would not be an admission of fault for Formlabs. This is a new product and they have taken a large step in innovation. It is understandable that the printer many have an issue that needs additional work to resolve the failure.

Mike A.
Scout Design & MFG

I’m not sure there is an issue. We’re talking about letting Open mode use the wiper and heater and autofill.

But irrespective of that, your comments are definitely spot-on. This is exactly the way my customers expect me to behave with my products. The issue is considered “guilty until proven innocent”. I’m also expected to improve the quality/reliability of the product over time, even if it started out pretty good to begin with, I still take heat. The best way to deal with quality/reliability issues is to attack them head-on. Arguing that they don’t exist is at best a delaying measure (since failures continue to accumulate in spite of your protestations to the contrary), and when the truth becomes undeniable, you look like an a-hole for having fought so hard to argue against the ultimate reality.

First the machine is not going to explode if FL gives the user more control. All we are talking about is spilling resin and FL could do better to mitigate problems should spills occur.
I can speak with firsthand knowledge of this having had two minor and one major spill.
First spill was all me as I was experimenting, as any curious person would. Cleaned it up and moved on.
Second was using bone stock, castable v01. and on my machine it will always spray over the lip of the tray when filling. This particular issue could be prevented with some minor design tweaks to the bite valve. Cleaned it up and moved on.
Third was by far the worst and also how I learned the most about the Form2.
Running bone stock again, Grey v02, started the job, walked away and when I returned to check up on the machine I found the bite valve swimming in the resin tray. The better part of a liter of resin had been released and overfilled the tray flooding the inside of the machine. The immediate problem was the leveling sensor was no longer reading correctly causing the job to pause.
After making sure FL was ok if I open the machine, I found, with no great surprise, resin covering the mainboard.
The other part that I found that was surprising was the previous two spills had also made it to the main board just not as significant of an amount.
Long story short after complete disassembly and a gallon of IPA it works again.

He is what I learned.
Spill containment protects the optics pretty well but nothing else, there is room for improvement.
Mainboard and microprocessor board are directly under the path spills will likely flow.
Conformal (may only be a solder mask) coating apparently does not protect liquid seeping under BGA chips. It took a lot of IPA and compressed air to remove the resin from these chips.
The electrical connections, are unprotected and also likely to be exposed to spills.
What really raised my eyebrow was the open frame power supply sitting under the front spill containment catch area with no shield to deflect spills if any occurred.

What would make the system even better.
Short of relocating electronics above the water line so to speak, Potting the PCBs or at the very least a conformal coating that prevents liquid ingress for all components.
Sealed power supply or at least guards to better prevent possible spilled liquid incursion.
Under the fill valve is a catch basin, routing liquid that falls into this basin outside the machine may have helped in my situation.

These improvements would go a long way to mitigating issues that could occur when giving the user control over their machine.

Edit: corrected typo. Level should have been leveling

Randy, I appreciate your bluntness. I’m used to people giving me the run around so to speak.

My perspective is in no way wrong though, just different. Hence the name perspective.

I also understand your customer service angle and applaud your ability to do that job.
I am not capable of doing it. Brain/mouth speed thing.

My real problem isn’t them not giving us a real open mode, they are the designers after all, but pretending like it is one.
They haven’t said, “No, it will cause warranty issues.” They just keep beating around the bush.

I would gladly accept full responsibility for errors caused by open mode control.
An easy way around the customer accepting responsibility and FL being able to convey the importance of the risk they may be taking. Would be to lock full open mode down unless a code was entered that would be giving by FL.
It is a common approach to this kind of problem.

I also appreciate the design upgrades that went into the Form 2. It works perfectly for what we make. The Form 1+, while and amazing machine, was just a PITA for us.

I really hope we do find common ground for the users that would love more from this machine.

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Keith, thanks for not taking my comment the wrong way.

I actually think someone from FL may well have said this very thing at some point. But I’m too lazy to go searching for a definitive reference.

I should make it clear that I also want “open mode” to be open. I believe I should be able to set a temperature, and set a wiper sweep rate and frequency. I know I’m competent to manage this properly, and I know if I screw it up I can’t go complaining to FL about it.

I’d be perfectly cool with it if FL had some kind of warranty limitation for Open Mode. Like “we warranty internal parts but not spill related issues if you use Open Mode” and then let me have at it.

No problem. I know how hard it is to not come across as an ahole when typing.
I also try to “really” read a comment and not what I just “think” it is saying.

I hadn’t seen the FL comment. I will have to look.

I agree wholeheartedly about the limited warranty.

I think, since they can’t really do design changes to the Form2, they will likely take these changes into consideration on a new iteration of the printer–I don’t know that they could adjust the design of the valve that would still be compatible with the Form2 so they might not be able to do anything other than software changes. For Form2, to try and fix the problems that people can get they might want to open up the ability to use the advanced features in Open Mode, maybe even customize the options if you want to turn off the wiper or whatever.

-Refilling resin cartridges . . .will void the warranty even if Formlabs resins are used. (Page 2 FL User Agreement )