OpenPrintTag reader in s multi filament printer.
Open print tag looks like a very good solution.
Some questions I have in relation to multi filament printers such and the XL or INDX coreOne.
1. How will the RFID reader connect to the printer main board.
2, What will the reading range be
3. Will you need one RFID reader per spool holder.
4. For a multi spool holder setup where the spools are close how will the reader be able to tell which spool is in each slot - I presume rotating the tag in an out of range like on the Bambulab AMS won't be possible.
5. How often will the printer be expected to update the filament usage info - and how will print cancellations or failures handle usage info.
6. Will RFID readers/writers be able to handle multiple tags in range.
RE: OpenPrintTag reader in s multi filament printer.
- There is already and RFID reader connected to the main board since the MK4S. They just need to move it.
- Low frequency RFID is a few centimeters
- Yes
- See #3
- As often as needed, presumably on a fixed frequency
- See #3
- Bob Marley
RE: OpenPrintTag reader in s multi filament printer.
So I guess if the printers already have NFC - then the main usage is going to be moving the spool next to the printer and registering it - and then putting it on the spool holder.
Usage info would possibly be tracked by the printer and then have to be flashed back onto the spool by moving it back near the printer to de-register it before moving to a different spool.
If the solution involves multiple RFID readers in the spool holders I think the big circular antenna might mean there is a risk of two spools next to each other being close enough to the RFID reader for them both to be picked up - especially if two adjacent spools have their RFID tags on opposite sides.
RE:
You are over-thinking this. RFID readers are quite small. The "antenna" is in the device being scanned. Each device has it's own unique ID. This system is already in the Bambu AMS. The technology itself has been around for decades and all the engineering hurdles were worked out a long time ago.
- Bob Marley
RE: OpenPrintTag reader in s multi filament printer.
Wish the edit period was longer...
To answer your questions, imagine an RFID reader next to the spool holder. You mount the spool, the RFID transmitter transmits to the spool which powers the tag in the spool. The tag responds with a unique ID for the tag and information about the spool (filament type, amount remaining, etc). If another spool is placed nearby, the reader won't acknowledge the "other" spool since the first spool is still close by and registered. This would still apply to a multi-spool setup.
- Bob Marley
RE: OpenPrintTag reader in s multi filament printer.
Bambulab RFIDs don't have big antennas going right around the spool inner - they are just tiny little stickers - which are duplicated on both sides of the spools.
There is one RFID reader between each 2 filament rolls - so 3 in total.
The AMS spins the spools around to a) Move the RFIDs over the readers, and b) Move the RFIDs from the other spool not being read away from the RFID reader.
The AMS can also estimate how much filament is left by measuring how much filament move is required for each revolution of the spool - which it can detect by the RFIDs coming in and out of range.
The OpenPrintTag design of having the much bigger antenna around the whole spool means I think the RFIDs won't be easily movable out of the way by spinning the spool, won't be compatible with the AMS even if BambuLab decide to join the party, and might even interfere with Bambulab spools if they are in the same AMS as OpenPrintTag spools - but I guess maybe that is being done on purpose.
RE: OpenPrintTag reader in s multi filament printer.
My previous answer was written before you latest response - where I guess you are saying in response to my question 6 that you can have multiple RFIDs in range - and communicate with all of them individually one at a time then I think that helps with some of my concerns.
RE:
Yes, multiple readers, say in a row, can detect which spool is close to it by signal strength. Also, the size of the antenna not only affects the range but the amount of power that can be generated inside the tag from the transmitter's RF signal. Prusa slicer can estimate the amount of filament being used in a print so a simple method would be to send a m-code to the spool and simply subtract this out over time. Would definitely be cruder than the AMS solution however since things like variable spool sizes, width etc would need to be programmed into the tag.
As I was pointing out tough, all of this would have been well thought out before they release it.
- Bob Marley