RE: newest INDX picture
You would most definitely need run out sensors. It would be even better if they were motorized as well. I can see this becoming a PITA. But then the other problem is that filaments that need to be printed from a dry box or a dryer also need an enclosed (and hot enough) chamber. I have a feeling after printing a few multicolor and multi-material projects I'm going to soon outgrow it. Especially if I don't have a functional 55° chamber.
RE: newest INDX picture
If you want the printer to push the rest of the filament back (so you can remove it), you would need a filament sensor right at the entry point to the PTFE tube. Otherwise one would have to disconnect the tube somewhere to get hold of the leftover filament.
For what it's worth, the "Kit Comparison" table on https://www.bondtech.se/indx-by-bondtech/ mentions that a "Runout Sensor" is part of the Core One INDX kit, but not of the generic "Development Kit". Which would suggest that it is an additional sensor, not just the one in the extruder itself? Well, wishful thinking maybe...
RE: newest INDX picture
Hello,
It seems to me that there is an I2C bus on the xBuddy board, so they can make a module with 4 sensors that will communicate on the I2C bus.
RE: newest INDX picture
If you want the printer to push the rest of the filament back (so you can remove it), you would need a filament sensor right at the entry point to the PTFE tube. Otherwise one would have to disconnect the tube somewhere to get hold of the leftover filament.
For what it's worth, the "Kit Comparison" table on https://www.bondtech.se/indx-by-bondtech/ mentions that a "Runout Sensor" is part of the Core One INDX kit, but not of the generic "Development Kit". Which would suggest that it is an additional sensor, not just the one in the extruder itself? Well, wishful thinking maybe...
I honestly think they'll have to have external sensors set up if they want to compete. Change over is a basic feature in all their competitors set ups, and one of the big benefits of mutli spool set ups. I'm wondering if they've finalized it yet though. Heres hoping for more info soon.
RE: newest INDX picture
If you want the printer to push the rest of the filament back (so you can remove it), you would need a filament sensor right at the entry point to the PTFE tube. Otherwise one would have to disconnect the tube somewhere to get hold of the leftover filament.
For what it's worth, the "Kit Comparison" table on https://www.bondtech.se/indx-by-bondtech/ mentions that a "Runout Sensor" is part of the Core One INDX kit, but not of the generic "Development Kit". Which would suggest that it is an additional sensor, not just the one in the extruder itself? Well, wishful thinking maybe...
I honestly think they'll have to have external sensors set up if they want to compete. Change over is a basic feature in all their competitors set ups, and one of the big benefits of mutli spool set ups. I'm wondering if they've finalized it yet though. Heres hoping for more info soon.
I think we all agree that the sensors are a must and the point made by Jürgen on recovering the run-out piece (that will be rather long in the INDX setup) is quite good as well. If Prusa want to do it right, it means a new expansion board that need to connect into the main board (or replace the expansion board) by adding the connections for 8 sensors. from there bringing the cables out would be the next challenge but not unsurmountable.
Given that some sort of new HW is anyway needed (the nextruder and the love board are gone, probably the whole cable tree as well) so another board is not a huge problem. I start to see why we do not see any updates to the FW... to implement this new stuff is a lot of work... and end of Q1 2026 is near...
RE: newest INDX picture
As @jurgen-7 says, it does say that runout sensor is provided in the Prusa kit, but I just cant see how they've implemented that without holes in the acrylic or steel frame....so maybe they are just referring to the one in the toolhead, but if that were the case then surely the dev-kit would also have that ?
My understanding is that there will only be minor, if any differences between the toolheads on the Prusa version vs the dev kit version. I guess the obvious differences will be wiring and cooling.
RE: newest INDX picture
I think we all agree that the sensors are a must and the point made by Jürgen on recovering the run-out piece (that will be rather long in the INDX setup) is quite good as well. If Prusa want to do it right, it means a new expansion board that need to connect into the main board (or replace the expansion board) by adding the connections for 8 sensors. from there bringing the cables out would be the next challenge but not unsurmountable.
Given that some sort of new HW is anyway needed (the nextruder and the love board are gone, probably the whole cable tree as well) so another board is not a huge problem. I start to see why we do not see any updates to the FW... to implement this new stuff is a lot of work... and end of Q1 2026 is near...
There are options for expansion already, though the expansion bits do need a bit of brains. The current xBuddy Expansion board is CAN BUS capable. According to the schematic (page 10) the transceiver should already be populated on the boards. The sensors would just need at most ATtiny class processors to communicate over CAN BUS. This is already a solved problem if one looks to the automotive industry. (Yes, I know integration is at least the second 80% of the work needed for implementation. 😉 I'm just pointing out it is possible without _completely_ reinventing the wheel.) How Prusa actually ends up cracking this nut is anyone's guess (who doesn't work on that team at Prussa, but I don't think they are talking).
I expect the existing connector/wire harness from the xBuddy board to the Love Board to be repurposed for the INDX active head. Maybe with some signal lines re-purposed, but that connection seems set.
See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs
RE:
As @jurgen-7 says, it does say that runout sensor is provided in the Prusa kit, but I just cant see how they've implemented that without holes in the acrylic or steel frame....so maybe they are just referring to the one in the toolhead, but if that were the case then surely the dev-kit would also have that ?
My understanding is that there will only be minor, if any differences between the toolheads on the Prusa version vs the dev kit version. I guess the obvious differences will be wiring and cooling.
I saw a Prusa video on YouTube where they are replacing the rivets in some places with screw mounted brackets since the rivets are sitting in M3 holes. So there shouldn't be a need to get out a drill.
RE: newest INDX picture
Having a sensor for each spool is certainly a nice to have, but it isn't an absolute necessity. If the filament sensor is on the print head, then you can just check the filament after each tool change to see if the filament is present. All that is required is a way of sensing filament which doesn't obstruct tool changes, which is entirely possible.
RE: newest INDX picture
Having a sensor for each spool is certainly a nice to have, but it isn't an absolute necessity. If the filament sensor is on the print head, then you can just check the filament after each tool change to see if the filament is present. All that is required is a way of sensing filament which doesn't obstruct tool changes, which is entirely possible.
The problem with that though is if you have a run out, how will you retrieve the filament. The runout detection needs to be closer to the spool.
RE: newest INDX picture
Hello,
I think there will be a sensor for each filament in the small box on the side, along with an OpenPrintTag reader.
RE: newest INDX picture
I saw a Prusa video on YouTube where they are replacing the rivets in some places with screw mounted brackets since the rivets are sitting in M3 holes. So there shouldn't be a need to get out a drill.
Those holes are good to mechanically mount the spool holders. But not large enough to route a cable with pre-attached plug through them. Let's wait for more info from Prusa (or Bondtech)...
RE: newest INDX picture
Let's wait for more info from Prusa (or Bondtech)...
What's the fun of waiting if you can speculate and get it completely wrong...
RE:
Having a sensor for each spool is certainly a nice to have, but it isn't an absolute necessity. If the filament sensor is on the print head, then you can just check the filament after each tool change to see if the filament is present. All that is required is a way of sensing filament which doesn't obstruct tool changes, which is entirely possible.
The problem with that though is if you have a run out, how will you retrieve the filament. The runout detection needs to be closer to the spool.
I agree that, while it would be nicer to know the status of all tools at all times, but it is not absolutely necessary to know which tool has filament at all times. Knowing whether just the tool mated to the print head has filament is enough. The rest can be entered into the printer through the loading filament menu prior to the print. You just test for filament when you load a new tool as part of the tool change macro. If the sensor detects filament, you go on with the print. If it is empty, then you either pause or change to the roll-over tool. If the roll-over tool reports empty after changing or if no roll-over tool is defined, you pause. You just need to keep in memory if there is a roll-over tool defined and if so if that tool was empty the last time the printer changed tools, which can be cleared with a menu item function if the filament gets refreshed mid print. In case of power loss you write it to USB, together with all other power-loss info.
RE: newest INDX picture
I agree that it would be nicer to know the status of all tools at all times, but it is not absolutely necessary to know which tool has filament at all times. Knowing whether just the tool mated to the print head has filament is enough.
I think you misunderstood @hyiger's point. It is not about the necessity of individual sensors for every filament. Rather it is about the necessity to have a sensor right at the input of the PTFE tube. That's the only way to detect the end of filament early enough, to allow the extruder to push the filament end back out of the tube so the user can grab and remove it.
RE:
I agree that it would be nicer to know the status of all tools at all times, but it is not absolutely necessary to know which tool has filament at all times. Knowing whether just the tool mated to the print head has filament is enough.
I think you misunderstood @hyiger's point. It is not about the necessity of individual sensors for every filament. Rather it is about the necessity to have a sensor right at the input of the PTFE tube. That's the only way to detect the end of filament early enough, to allow the extruder to push the filament end back out of the tube so the user can grab and remove it.
If I understand the workings of the INDX correctly, then there is no pushing filament back when changing tools. The extruder disengages by reversing direction of the gears after the tool has cooled down, so that the latching force for the clamping action is overcome. As far as I can tell, the notch in the tool path above the extruder but below the top of the tool is for the filament sensor.
RE: newest INDX picture
If I understand the workings of the INDX correctly, then there is no pushing filament back when changing tools. The extruder disengages by reversing direction of the gears after it has cooled down, so that the latching force for the clamping action is overcome. As far as I can tell, this is exactly what the notch in the tool path above the extruder but below the top of the tool is for.
The present discussion is about filament running out when a spool is used up.
RE: newest INDX picture
If I understand the workings of the INDX correctly, then there is no pushing filament back when changing tools. The extruder disengages by reversing direction of the gears after it has cooled down, so that the latching force for the clamping action is overcome. As far as I can tell, this is exactly what the notch in the tool path above the extruder but below the top of the tool is for.
The present discussion is about filament running out when a spool is used up.
And I already gave the explanation how that can be handled with a single sensor and some firmware settings?
RE: newest INDX picture
And I already gave the explanation how that can be handled with a single sensor and some firmware settings?
Please take a bit more time to read before you shoot from the hip again.
Yes, it can be detected which filament has run out. But then, how does the user remove the remaining filament strand from the printer? The present solution in the Core One is a filament sensor right next to the input side of the PTFE tube. The extruder only needs to push the filament back a few cm, and the end will come back out of the PTFE tube. This is where the user can grab and remove the filament.
A sensor in the extruder does not allow this. You would have to detach the PTFE tube from the extruder (or fro the INDX nozzle) to get hold of the filament. That issue is exactly the reason why the Core One has that second filament sensor at the input.
RE: newest INDX picture
And I already gave the explanation how that can be handled with a single sensor and some firmware settings?
Please take a bit more time to read before you shoot from the hip again.
Yes, it can be detected which filament has run out. But then, how does the user remove the remaining filament strand from the printer? The present solution in the Core One is a filament sensor right next to the input side of the PTFE tube. The extruder only needs to push the filament back a few cm, and the end will come back out of the PTFE tube. This is where the user can grab and remove the filament.
A sensor in the extruder does not allow this. You would have to detach the PTFE tube from the extruder (or fro the INDX nozzle) to get hold of the filament. That issue is exactly the reason why the Core One has that second filament sensor at the input.
As you can see there is a notch where the extruder gears can grab the filament. This can also be used to get a grip of the filament and pull it out. If the filament runs out mid print, you dock the tool so that the operator can detach the dock and extract the last bit of filament through this notch.
I thought this was obvious? If you forget to notice something, then it is not me who is shooting from the hip.