Can I assume there is a small gap in time, either physically due to the mechanism or electronically due to software to remove the potential for both being connected simultaneously?
This could cause a short or electronics issue in one or more connected devices.
My less developed attempt at same problem. I used 2 multi pole switches in parallel (I initially thought only 4 poles needed to be switched). I used Molex 3.0mm ready wired cables, but like the idea of using a power board.
Ultimately I would like to move the switch with a servo.
If you look closely at the 6-pin AMS cable, the ground pin extends slightly more than the rest of the pins, so ground is established before power when plugging in the cable. I need to adjust the cams on my knob to emulate the same effect when twisting the knob. e.g., engage the ground signal before the rest of the signals when switching between the AMS units. And reverse the process when switching the other direction. But I have switched it without this feature several dozen times and I haven’t seen any issues. So far…
Hi Ukdavewood, Here is the schematic that I used. However I didn’t add the termination resistors. I figured that if I signal integrity issues I could add them later. But so far I haven’t seen any. If they aren’t needed, then it could be reduced to a 6P2T switch.
I guess a custom PCB as mentioned earlier above would be the best solution ultimately, with mounting for the 3 connectors and appropriate tracks to form one half of the 6 pole switch. My biggest concern is the reliability/smoothness of the ptfe filament part of this type of switch.
Found a post with a bit more detail of my attempt if it is of any interest. I didn’t progress it any where near as far as @mcmaven
That’s exactly what I want too. And it would be really nice to support printers other than Bambu, but later…
I posted a replacement spool tray for the AMS that supports all the features of the Hydra, but where the dividers can be moved so a spool can span 2 slots and support spools up to 97mm wide.
I’ve also started working with a friend to use a single slot, 124 mm wide variant (for 2KG spools) of my current tray design, with an AMS Feeder Unit that can load or unload an External Spool via WiFi. Sort of a ‘poor man’s’ 5th spool. I will be able to load/unload it from my desk, but it won’t be able to be used for multi-color prints.
The plan is to also make a dry box enclosure for the external spool. Designing the side tray to fit all the AMS hardware was the hard part, but designing a larger enclosure that would support a single wide spool should be easy, just a LOT of printing.
Would love to see this evolve into a kit with a PCB! This may sound dumb, but with 4 AMS, this is what has prevented me from buying a second printer. If I could switch the AMS between printers, I’d grab another X1C or maybe a P1S.
Hi DruiD,
I need to put together some documentation for it, and I will post it to my MakerWorld page. It requires a small ball grinder (to cut traces and the ground plane on the AMS Power Board), a soldering iron, and a small spring and 6mm ball-bearing to act as a detent for the knob. I used my spring winder to make the spring.
Hi d_p,
I am currently using 12 micro-switches to act as a 12PDT switch. The micro-switches are arranged in groups of 3 around the knob. The weird angles of all the switches do not lend themselves to PCB, but I guess one could use a flex circuit. The problem is that I’ve never designed a flex circuit… I did print a special ‘jig’ version of the base with no sides that holds the micro-switches, AMS Power Board PCB and 6-wire AMS cable in their relative positions so they can be easily soldered. Once I have all the wires neatly cut to length and soldered, I then move the whole wiring harness over to the real base.
My long term goal is to control the switch wirelessly. This would mean adding a servo to rotate the knob between the A and B outputs, and some relays to switch the signals. Relays are much more PCB friendly. One thing that I really like about the Bambu is the fact that I only have to visit the printer once per job, i.e., to pick the parts off the build plate. If I can control my AMS switch from my desk I will be able to preserve this usage model.
A friend of mine and I are looking at how to make this into a kit, along with some other devices for filament management. Keep in touch.
I feel like there must be some clever way to use tiny magnets for the switching. You want a double-pole contact which will reliably engage either pole, and doesn’t take too much force, since there’ll need to be six of them …
Just haven’t thought of it yet.
Maybe reed switches? Do they make double throw versions?
I initially held out on buying an X1 Carbon as I had a deposit down on an XL, however, all the delays pissed me off so much that I redeemed my deposit but held out on buying the X1C and AMS as I thought it might be possible that Bambu would release a tool changer printer to compete with the XL, this never happened and so I bought the X1C combo.
I still think Bambu may release a tool changer and so I am not happy to buy a second AMS, even with calibration for wastage it still poops far more filament than I am happy with.
Nevertheless, this A/B switch is a very good thing, at first I wondered why Bambu Lab had not released one, and I came to the conclusion that it would reduce AMS sales.
Until I know what will succeed the X1C I am not thinking of buying a second.
I debated long and hard too about whether to buy a 2nd x1c. So far I haven’t regretted it - I don’t do that much printing, but it is surprising how often I find a 2nd printer useful when I am needing to do some parallel printing.
Like you I am also looking forward to the next BL printer - however I am hoping it is not a toolchanger or an idex - I am hoping it is something much more advanced - that allows for parallel printing of at least 8 colours.
I have quite a few printers including a Pro 3D V-King 400 that I built from self sourced very best quality parts so a second X1C is not really needed for my printing setup.
Whatever BL come up with to succeed the X1C I can see myself being tempted by it!
I had a MK3S with an MMU for several years, and a deposit on an XL. I had given up on the XL, and bought a P1S combo on the recommendation of several friends. Then I finally got the notice that my XL was ready to ship. I ended up buying the XL after deciding not to wait for Bambu to offer a large format printer.
I really like the large bed of the XL. And it can switch colors in under 10 seconds, so it is MUCH faster than the Bambu for multicolor prints, and the multiple heads generate almost no waste. But XL is 5 years behind in filament management. So far, that’s the most disappointing part about it. My other issues with it are:
It is limited to 5 colors.
PrusaSlicer does not support Plates or object level parameter assignment.
It doesn’t have an accelerometer, so its input shaping is far from optimal. For single color prints, the Bambu is still much faster.
The Bambu has spoiled me. My dream is to attach a filament management system to the XL and Bambu, where I can share a pool of filaments across all my printers. My AMS switch is the first step. I’m working on a modified version of it where the ground signal switches in first and out last, like the connector.
I also designed a box that mounts on the sides of the XL which uses Bambu AMS Feeder units to load and unload the XL filament. I haven’t built this because I’ve moved on to a more generalized architecture where I want to share filaments across the Bambu’s or the heads of the XL.
Really like your thinking. I too would also like a solution where I put one or two rolls of every roll I regularly use into AMS like units which can then be automatically loaded into each printer (or multiple printers).
Buying AMS units for every filament is a little too expensive - around £75 per filament roll, buying 1st stage feeders and rollers for each roll is a bit more cost effective at around £39 per roll, but still at bit expensive.
Also there is a bit of a risk buying too many AMS units in case they are not compatible with the next printer - so I have currently stopped at 4.
What I would ideally like to see in future (or homebrew) AMS units that are:
Allowing this solution to also be used on other non BL printers would also be a bonus.
I almost got an XL too - within about an hour of launch I tried to order one - but for some reason my virus checker flagged the prusa site as suspect so I didn’t end up going for the order - which I am quite glad.
That is a great idea and project. Will it work with the AMS lite as well? I wish BBL would enable the use of two AMS’s on the A1/A1mini. there are two plugs so somebody must have had the idea that one could use two AMS’s. Do you have a post on making it?
Hello, I am interested in the electronics part of this project. I am currently working on a filament switch for the AMS-lite. The two could be complementary.
Search “2 imprimantes de la serie A1 sur un seul Ams lite” on FB.
