This topic contains 15 replies, has 7 voices, and was last updated by 
Roberto 1 year, 5 months ago.
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AnonymousBefore I realised that raising the bed temp to 75C would stop the problem, I was having big prints detach from the bed at the final stages. Thing is, big prints take a long time, so you are not going to sit there for 5 hours watching over it. But it’s surprising how big a mess a detached print can make of your head in a relatively short time. I don’t know what the dangers are, but even cleaning it is a bit of a pain:
What are the best proposed solutions to this? Anyone tried modding a usb camera to the case to check on a print’s progress?
It would be nice if Robox could either stop the print or text / email me there’s a problem, but at the moment it doesn’t seem to even know there’s a problem. It just keeps ploughing on, making an ever bigger mess.
Every 3d printer has this problems and I would recommend not leaving your printer alone when you are not having enough experience to know if a print would go well. Generally higher objects need enough surface to stick to the build plate during the printing process. Therefore you should print with a large enough brim or raft to avoid that the print ist getting lose from the build plate. At least for the first layer you absolutely have to watch your printer. If something is going wrong there it often goes worse for the whole print.
AnonymousEvery 3D printer has this problem, but quite a few are now integrating cameras & wifi into their machines so that you can check on your print on your phone or whatever. After all, there are prints out there that take 20+ hours. You have to walk away from the printer and go to sleep at some point!
What would be nice is some decent automated error detection. It might not actually be that difficult. We already have the model of the object, and we know what it should look like during the intermediate stages, we could simply do a rough image comparison (with the appropriate error margin) between what it looks like and what it should look like at a particular stage.
It would certainly pick up those instances where the print gets lifted off the bed and wrapped around the nozzles!
“It might not actually be that difficult.” Seriously? http://www.xkcd.com/1425/
It’d be easier to laser scan the model at the end of each layer.
Or, precision weigh the bed at each corner to deduce the centre of gravity of the piece so far.
(Note my use of the word “easier” rather than “easy”.)
Tom Gidden -- Bristol, UK
Anonymous@gid - ok, point taken!
But seriously, for long prints we need some form of error detection don’t we? This thing could be dragging around hot molten plastic for several hours. Could something bad happen?
Yes, it is a problem, and something Bad™ could indeed happen.
It’s a question of how to sense a problem though. I wonder whether it’s worth fitting an MQ-2 smoke sensor inside the Robox. Hmm. Off to eBay…
There is a hidden USB connection (unpopulated) inside the Robox for future expansion. Fitting an internal camera (and perhaps sensors, fire extinguishers, etc.) is something that’s come up a lot before. Exposure and focussing are problematic though.
Tom Gidden -- Bristol, UK
How about mounting a laser object scanner on the head, that way we’ve got a 3D scanner as well? 😉
Hi all, Pete mentioned at some point that they are working on (or have the idea to work on) a camera that fits in the circular window on the left side wall of the printer and uses that unpopulated usb port. In the meantime, I am working on a cam using a Raspeberry Pi, but it’s nowhere near finished as my job has been a bit over demanding lately. I’ll let you know when/if I make any progress.
AnonymousLooks like this could be the safest option
Smoke alarm for 3D printers: Not a bad idea, but some kind of notification system (a WiFi-based push notification would be state of the art) or at least an audible alarm is needed to make it complete. Because the fire doesn’t necessarily stop just from “pulling the plug”.
Just came across this USD 9.00 device which connects to any cheap $15 smoke alarm from the same manufacturer and can be wired to switch OFF (or on) up to 10 Amps. Unfortunately available in 120V only.
Another option is this $50 smoke detector with integrated GSM module. When smoke is detected, it not only set off the audible alarm, but also can call up to 10 different numbers and additionally send text messages (SMS) to 10 different numbers. If you don’t mind the bulkiness, you can get for the same money an entire GSM wireless alarm system, which does the same and more.
To the latter one could furthermore add a GSM-controlled power switch (to be remote controlled manually) and a webcam.
AnonymousI just wonder if error detection isn’t so hard with the temperature sensors we’ve got already. In my case, the print got stuck to the head which meant a build up of hot plastic that completely covered the nozzles.
Surely the nozzles have to be getting hotter as a result? Couldn’t the software check against any sudden rises in temperature of the nozzles and pause the print?
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