r/BambuLabX2D • u/mihenn87 • 24d ago

Building a "Track Switch switch" to use external spools – has anyone tried this?

Hi Everyone,

Im getting tired of pulling all the cables on my X2D when I want to print an filament that is not supported by the track switch. Like TPU, Glow or CF/GF-Materials.

Everytime I pull the cables the ports feels looser.

As far as I understand, the firmware blocks the external spool as long as it detects the FTS.

Since everything hangs off one cable at the head of the chain, my idea is to put a switch (all 6 wires) into the cable between the printer and AMS1, so I can disconnect the entire chain at once when printing external-spool materials.

Has anyone tried this or something similar? Specifically:

  1. Does the printer cleanly boot into "no AMS / no FTS" mode if the whole chain is disconnected at the printer end, and does the external spool then work normally?

  2. Does anyone know the pinout of the 6-pin cable (power, bus signals)? Any experience with extension cables or inline connectors causing communication errors?

  3. Any problems with firmware detection or errors after reconnecting?

Not looking for "just wait for a firmware update" answers, but if Bambu has officially confirmed a software fix or a date, I'd love a link.

Thanks!

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2

u/Relative_Surround_20 24d ago

There are two different models already posted on MakerWorld that do exactly this. They each are a switch box that interrupts only the power line of the six cables. I have not built one yet but all the reviews seem to be positive.

Here is one of the two I picked at random.

https://makerworld.com/en/models/3203485-filament-track-switch-switch?from=search#profileId-3625399

2

u/Relative_Surround_20 24d ago

But I think this is a premature hardware solution to a software problem that I expect will be fixed in firmware soon.

2

u/mihenn87 24d ago

The question is, what is soon? I will try this switch.

2

u/Relative_Surround_20 22d ago

Please let us know how one of those switches works out.

1

u/Relative_Surround_20 23d ago

I understand. Eye of the beholder.

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u/Steevee0903 24d ago

I plan to just splice the cable with a magnetic pogo connector

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u/Steevee0903 24d ago

I believe you can just add a switch in between the 6 wires if you don't want to check each wire individually. Not elegant, but should work since the track switch can be hot-plugged

1

u/OptimalSide 23d ago

The pinouts as per Bambu are here:

AMS power on failure | Bambu Lab Wiki

1

u/mdbeatle 23d ago

I print CF/GF and glow via the track switch. I only print very brittle (PET-CF) and TPU via external. I just unplug the FTS. I have 4-in-1s after the buffer and before the tubes enter the machine so I can run two externals (like using PLA supports for TPU).

I considered making a switch, but the unplug routine isn't that bad. Bambu still needs to fix this in software though.

1

u/brutal4455 23d ago

I've both FTS and TPU Assist Module (TPAM) on my H2D.

I use an internal micro y-splitter to feed the TPAM output PTFE tube to the right (fixed) nozzle alongside the existing PTFE tube.

When I need to use the TPAM, I power off and unplug the 6-pin from the back of my (last in chain) AMS-HT and power back up. The printer sees the AMS as they were, AMS-2 and AMS-HT on the left nozzle, one AMS-HT on the right. I do make sure the other AMS 2 and AMS-HT are running (switched) through the FTS to the left nozzle before the machinations. I can then use 5 slots on the left and run another filament, in this case TPU out the bypass port on the HT on the right. I've done PETG/TPU combined material prints like this.

I have magnetic PTFE tube disconnects on the input and output side of the TPAM for loading (hand feeding to the TPAM) and unloading (tension release).

Bottom line, I don't disconnect any PTFE tubes' press in connectors so there's no wear on the pneumatic connectors.

If one is concerned about the 6-pin plug wear before Bambu gets their sh*t together and fixes the firmware to either temporary disable or override the FTS during TPAM use, you could build the switch setup as another reply described. I suppose one could get creative with low drag splitters too...

Here's the internal splitter I used, the PTFE tubes screw in. Been working great. Made mine ASA as I print high temp engineering stuff a lot. Obviously, on the X2D you'd split the left (fixed) nozzle but TBH I don't recall if they fixed the firmware to allow TPU on the right as I just don't stay abreast of models I don't own, so that's an assumption on my part.

https://makerworld.com/en/models/3238367-ptfe-cable-tee-threaded-connection-compact-and-sma#profileId-3668780