Estimated remaining resin in cartridge way off

Hello everybody,

I recently experience an unexpected print failure due to a wrong estimation of the resin remaining in a cartridge. The print (around 400mL) could go to trash as resuming a print after few hours leads to a shift of layer.

I contact the client service and explained my problem. They were kind to send me a new cartridge and apologize for the inconvenient.

I write this message to share with you the document that I shared with Formlabs to suggest a small modification on the dashboard, to have an accurate way to measure follow the remaining resins that a user has.

Here is the message:

How to allow a precise monitoring of consumable on the dashboard ?

Where are we now ?
The resin quantity used by the printers seems to be estimated and not measured by any way on the Form3/+. This leads to values on the dashboard that are way off. For example, on the two first liters of white resin, after finishing with a error due to lack of resin, I observed on my dashboard that one cartridge was supposed to be half full and the other one with 128 mL. Those values are completely wrong. I should have 0 mL or close to it. In addition on the tab “Statistics” I observed that supposedly consumed only 1.1L instead of 2L.

This error in estimation is a problem for the consumer as it could lead to fail prints, and moreover a problem for FormLabs in two ways. The first one, consumer realize that the ecosystem is not reliable and this could make bad advertisement to Formlabs and damage your reputation. The second problem is that, when a customer call Formlabs for this problem, Formlabs apologize for this issue and send a free cartridge to the consumer (which is great to apologize for the problem). Both of this consequence cause you to lose money.

How to improve the tracking of resin volume easily ?
In order to avoid by changes in printer hardware of firmware. I think that the change should be done in the dashboard to be minimal. Nowadays, in the dashboard for each cartridge we have an estimated volume of resin associated with. The goal of the following input it’s to make this volume as accurate as possible, to allow a better experience for the user.

To improve the tracking of resin volume, Formlabs could add for each cartridge a weight input field. This field would be used by the user to input the weight of the cartridge before the first print and after each print. This field should allows input in a range 0 to 1000 x density of the cartridge. With this value, the volume of resin inside the cartridge will not be estimated anymore but calculated with the following formula:

Volume left = (input weight)/(density of the resin) - weight of an empty cartdrige

The actual way of estimated the volume left needs to be kept, as default value if no weight is input by the user, and when a weight is input all the Formlabs ecosystem should be used the volume calculated on the weight. I don’t own an automated system and therefore I don’t know how volume are estimated with bigger cartridges. This “weight” functionality could be only used on “normal” cartridge for the beginning.

In addition to the weight input field, a small disclaimer should be added to the dashboard, to explain the user that the volume displayed by default is an estimation, and another disclaimer could be added about the weight that the user input. To explain that any mistakes in the input filed could lead to print errors.

How this would work ?
Case 1: User does not want to input the weight. The actual way of estimating the remaining volume is kept.

Case 2: The user inputs the weight when he received and inserted the cartridge and after each print. The new way of calculating the remaining volume is used during all the life of the cartridge.

Case 3: The user inputs the weight of the cartridge at the beginning (when inserted), but after few prints he stops doing it. After the last input, the weight of the cartridge is actualized after each print by subtracting the full volume (converted in weight) of the print to it. A disclaimer should appear close to the value in the input field of the dashboard to say that this value is estimated and the user should input the weight again.

Case 4: The user input back the weight after being in the case 3. The system goes back to calculating the remaining volume based on the input weight.

Case 5: The user doesn’t input the weight of the cartridge the first time he inserts it in the printer, and after few print he inputs the weight of the cartridge. Before the user inputs the weight of the cartridge, the actual way of estimating the volume remaining is used, and after the weight is input, the suggested way to calculate the remaining volume is used.

End of the document

If you want to give you point of view about this method, please feel free to post a comment on this thread.
Have a nice day.

1 Like

I had suggested the same method of user entering the weight in preform some months ago, but I never heard anything back about this since then…
The user entry weight would override the aproximate calculation of preform, thus all future calculations would be more accurate.

Well if we are enought to suggest them this solution, maybe they will implement it. Hopefully

see my messages back then…