The largest action in the history of Prusament is here. We’re upgrading the Prusament spool! The new spool comes with a familiar yet different design and several cool features you’ll love. This includes improved thermal resistance when drying, easier refills, and...
If you mean, why not install a load cell in the spool holder instead of an RFID reader, well…
I just happen to have four empty 1kg spools lying around, because I’m a total packrat. Let’s weigh them:
343g
319g
300g
254g
So that’s a range of 89 grams, out of just four spools. And these are all visually similar 1kg black plastic spools. I’ve seen skeletonized spools that tried to reduce plastic, I’ve seen cardboard spools, and I’ve seen spools of different sizes. How is a printer supposed to tell a mostly empty 2.5kg spool from a full 1kg one?
Then…What happens if you load one new spool, use some of it, unload it, use a different spool for awhile, then switch back to the first? Will you have to manually key in a tare weight for that first spool?
If you install a load cell in addition to an RFID reader, well then the spool’s RFID chip could store the weight of the spool, the initial weight of the filament loaded, and the weight of the remaining filament, and the printer could weigh the spool to verify that, which could catch and correct errors caused by oozing, miscalculation, using the spool on another printer, having to cancel a job mid-run because of a problem, etc. I’d kind of like this for reloadable spools. Somebody is coming up with split spools that you can buy just the filament for, and then you could reload the spool with another load of the same filament, and a printer with a load cell could automatically weigh and recalibrate a reloaded spool including an updated tare weight.
All told though, given how much it matters, I’d be fine with the dead reckoning approach done by the slicer. I mean, my personal 3D printer just turned 11, it has no auto bed leveling system, no filament runout sensor, no auto loading system, hell I haven’t updated the firmware since Barack was president, and I’m in the habit of running one spool all the way empty, and just shoving in the start of the next spool as the printer runs. I’ve done that for two-color signage and such, something with colored raised lettering on a white background or something. You can get away with shit on a primitive old clanker like mine that the newfangled units won’t put up with.
You obviously need to ID the spools and store values for all, the different hub weights aren’t a big issue if the printer knows the length of its filament path, how much filament the spool started with, and how much filament has been consumed it can work out the hub weight
Regularly changing filament fixes the problem of the load cell drifting, by allowing it to zero occasionally
You could warn on low filament, or not enough for this print, but load cells aren’t accurate enough to be certain about the last few metres, along with errors from cosmetic trimmed before feeding, or some is damaged and cut off, so I would still use the normal no filament sensors for stopping
Not saying it’s worth it compared to a software solution in the slicer
If you mean, why not install a load cell in the spool holder instead of an RFID reader, well…
I just happen to have four empty 1kg spools lying around, because I’m a total packrat. Let’s weigh them:
So that’s a range of 89 grams, out of just four spools. And these are all visually similar 1kg black plastic spools. I’ve seen skeletonized spools that tried to reduce plastic, I’ve seen cardboard spools, and I’ve seen spools of different sizes. How is a printer supposed to tell a mostly empty 2.5kg spool from a full 1kg one?
Then…What happens if you load one new spool, use some of it, unload it, use a different spool for awhile, then switch back to the first? Will you have to manually key in a tare weight for that first spool?
If you install a load cell in addition to an RFID reader, well then the spool’s RFID chip could store the weight of the spool, the initial weight of the filament loaded, and the weight of the remaining filament, and the printer could weigh the spool to verify that, which could catch and correct errors caused by oozing, miscalculation, using the spool on another printer, having to cancel a job mid-run because of a problem, etc. I’d kind of like this for reloadable spools. Somebody is coming up with split spools that you can buy just the filament for, and then you could reload the spool with another load of the same filament, and a printer with a load cell could automatically weigh and recalibrate a reloaded spool including an updated tare weight.
All told though, given how much it matters, I’d be fine with the dead reckoning approach done by the slicer. I mean, my personal 3D printer just turned 11, it has no auto bed leveling system, no filament runout sensor, no auto loading system, hell I haven’t updated the firmware since Barack was president, and I’m in the habit of running one spool all the way empty, and just shoving in the start of the next spool as the printer runs. I’ve done that for two-color signage and such, something with colored raised lettering on a white background or something. You can get away with shit on a primitive old clanker like mine that the newfangled units won’t put up with.
You obviously need to ID the spools and store values for all, the different hub weights aren’t a big issue if the printer knows the length of its filament path, how much filament the spool started with, and how much filament has been consumed it can work out the hub weight
Regularly changing filament fixes the problem of the load cell drifting, by allowing it to zero occasionally
You could warn on low filament, or not enough for this print, but load cells aren’t accurate enough to be certain about the last few metres, along with errors from cosmetic trimmed before feeding, or some is damaged and cut off, so I would still use the normal no filament sensors for stopping
Not saying it’s worth it compared to a software solution in the slicer
I enjoyed this engineering talk