Anyone know when the heated chamber patent is supposed to expire? Looks like 2020 from the patent I found (20 years after the Jun 23, 2000 date on US 6722872 B1), but I was under the impression it was closer.
Patents are awesome…
So what stops anyone from selling a cabinet for a printer, or designing a printer that is easy for the end user to enclose and heat on their own?
Whats been done around ‘climate control chambers’ (or whatever) to control humidity and reduce noise that just happen to get hot due to the heat bed.
Patents don’t stop you from making anything, it allows the company to sue you if you do. As part of the patent they can charge a licensing fee. They would own the patent, but would agree not to sue you for duplicating.
Also patents are not as awesome as copyrights. They are practically indefinite and free to get, they just don’t cover hw
The latest Makerbot have closed the “holes” in the frame, they obviously get around the patent or pay royalties?
Maybe it is ok if there is no active control of the chamber?
@Tom_Oyvind_Hogstad isn’t that patent held by Stratasys? You know, the owners of makerbot?
@Jasper_Janssen of course 
@Tom_Oyvind_Hogstad That is kind of what I was getting at. At what point does a cabinet become a heat chamber? If you make a printer that is not enclosed, but make it easy for someone to do so and then add controls to could you be sued for patent infringement? I would think not since you did not sell it with the intent of being enclosed (otherwise you would have). It would be a happy accident.
The patent seem to cover a heated chamber around the build area. So if you enclose the entire printer you can be good to go? I’m thinking of putting up a tent of mylar around my printer, but I also will use it to control the fumes.
@Tom_Oyvind_Hogstad I already do that and it helps with ABS printing. Depending on your bot it can also cook your electronics.
Surely Willis Carrier’s work could be used to invalidate this patent?
@Qitian_Dasheng_Sun_W sure, if he wants to take a chance and get into a legal battle
@Tim_Rastall , that’s why I’ll be doing some modifications to your design and having the stepper motors outside, and the electronics under separated from the heated zone.
The patent I have found is specific in that it encloses the print area but not the motors. Also it states the the temperature of the enclosure is actively heated. https://www.google.com/patents/US6722872
@ThantiK fair enough Im leaning towards direct drive stepper for the x/y anyway
A heated workshop is a heat chamber so it all comes down to the exact wording. Really is a stupid patent as definition of chamber implies a large area as opposed to box which implies a smaller area.
Deltabots bypasses this patent, btw. Their patent specifically calls out a heated build chamber with a cartesian robot system for depositing the fused filament. I hope that there is enough prior art now with deltabots (and enough discussion in public forums enclosing one) that prior art had been established and they can’t patent it. 