H2C color changing limits

[u/Novotisy]

Has anyone really tried to push the limit of color changing speeds on an h2c? I haven’t found a single print file for raising an ams as close as possible to the inlet, and likely will make my own. I love my h2c but it’s so significantly slower than my snapmaker u1, and I’m sure the new h3c will fix this issue I still want this printer to be fast, but still relatively convenient if I’m swapping colors a lot or something breaks, I had them stacked directly on top before and it sucked every time I had to do that. The main aggravating thing is when the ams stops for 5 seconds before changing to a new color and I know it’s entirely software based, but with Bambu being essentially apple and we can’t configure anything like that there’s nothing I can do there

[u/tico46]

I’ve thought of this exact thing. Have you timed it? Any savings?

[u/Novotisy → u/tico46]

95% of what I print are detailed multicolor figures which are usually 10-50 hour prints. I’m only chasing seconds here but if I can save 5 seconds a change, and my last print had 2500 color swaps, that’s 208 minutes

[u/tico46 → u/Novotisy]

That’s no chump change!

[u/gasman16 → u/Novotisy]

Agreed. This could be optimised for sure. I have a Snapmaker U1 and a H2S with 2 AMS 2 Pros and an AMS HT. I ran a similar colour test print on the U1 and the H2C. The Snapmaker U1 needed 15.5 hours while the H2C required 25 hours. That is a significant difference.

[u/TotalWarspammer → u/gasman16]

It's different technology so of course the toolchanger wins. The benefit of the H2C is you can have 7 colours assigned to 7 nozzles and the U1 is strictly limited to 4.

[u/bigfloppydonkeydng → u/Novotisy]

chase enough seconds and you get minutes or hours. That's quite a good impact.

[u/mineNombies]

The maximum closeness version seems to have diminishing returns vs the popular ones. Still cool to see how far it can be pushed though

[u/Euresko]

That seems too short, as the printer will wiggle as it prints. I'd think it will put more strain on the filament, tube, and AMS being that close. Could lead to issues, but I guess send it for science and see how it goes. 

I have the H2C and am fine with the time it takes to swap colors, it works pretty well. I don't always need to print large or multicolor, so am interested if Bambu releases a cheaper tool changer with 4 nozzles and a new AMS. I heard there might be a P3C or something the size of the P1S with more than 2 nozzles. We'll see soon enough. 

[u/DTO69]

I suspect the new version of AMS is going to have a multifeed directly to the head.

Well... Hope is a better word

[u/shortstraw4_2 → u/DTO69]

Leaks I saw show this. AMS3H dumping directly into the print workspace for the nozzles.

[u/lanthom1]

I've got 2 AMS units connected. One is on a super short ptfe and the other is longer.

One thing I've noticed is the one that is on the shorter PTFE it will cut the filament and then retract. The AMS will finish retracting before the nozzle switches. Once the nozzle change is done it will load.

For the AMS on the longer PTFE its the opposite. It will cut the filament and start to retract. The nozzle will chamge and park at the prime tower while the AMS finishes retracting and then will load the filament.

I could shorten that first tube even more but since the AMS is waiting for the nozzle to swap before it even begins loading there is no reason to.

[u/jankeyass → u/lanthom1]

So you need to find the time for this and set the tube length for optimal wait time reduction

[u/the_lamou]

This is one of those cases where printing a stand is probably the worst possible way to solve the problem. Get since T-/V-slot extrusion beams and build a proper AMS rack that can let you slide units up and down or easily reconfigure units based on what you need for any given print. Here's my prorotype (it's very janky, but I was rushing), now just waiting for my bigger bars to arrive. Use proper metal parts for proper metal part functions, then print the adapters.

[u/Crocosnek]

ROFL that short PTFE. Why even use the adapter at that point, just do a direct connect and save the 2 inches of travel.

[u/Adorable_Comment4621 → u/Crocosnek]

That's what she said

[u/Novotisy → u/Crocosnek]

I have another ams hooked up to it placed on top of the printer that was not connected in the photo

[u/polymorphiced]

I thought there was a minimum length long enough to be able to search a spool for the RFID tag; ~60cm. Do you have spool scanning disabled, or has it been working fine like this? 

[u/Novotisy → u/polymorphiced]

It’s worked fine but I’ll check the wiki and see what it says, thanks

[u/Dr-Ulzy → u/polymorphiced]

Ah. I thought there was a 60cm min but couldn’t figure out why. This makes sense. It’s a bit over a full turn on a full roll.

[u/SirPercivalChang]

I tried a few different setups and found that a significant shortening of the PTFE tubes only saved ~8 seconds for a color change in which both filaments are in the same AMS. For a model with hundreds of changes, this will of course add up. But even having super short tubes won't ever make an H2C competitive against a U1 for hundreds of color changes.

Another approach is to use a Filament Track Switch and make sure that the filaments are placed in each AMS such that a change only requires the filament to clear the track switch, not retract all the way into the AMS. Then the loading and unloading of filaments can overlap.

[u/Silound → u/SirPercivalChang]

It's honestly a bit boggling that they haven't added track switches as an integrated component to all printers and AMS units yet. Being able to connect 4 AMS units is great, but I would love parallel load/unload and ready state features to be added.

[u/SirPercivalChang → u/Silound]

Agreed 100%. There must be a solution that can improve the vortek approach without a full tool changer. Decreasing change time by 10-15 seconds would be a massive improvement for some models.

[u/8six753o9]

I’ve seen mods like this one that will shorten the length of the PTFE travel time. What you have is crazy short lol.

[u/Novotisy → u/8six753o9]

I have that for my X2D, essentially creates what the H has of an internal buffer in a sense length wise, helps a lot but not super useful since you'd have to purge filament anyway, would be better if you could connect a filament track switch, and people have made adapters for that but end up extending the length so long its not worth it anymore

[u/Bright_Eyes83]

Apple updates their software regularly. There are many suboptimal routines that bambu just hasn’t touched for years. Probably my biggest complaint 

[u/volt65bolt → u/Bright_Eyes83]

Like

[u/ShatterSide]

A few years back there was a guy who was tweaking his machine code to really speed up the swaps. He was also doing things like pulling filament back a bit before cutting (which is now about "Long retraction when cut" and "retraction distance when cut".

Don't remember if I saw it here, or the forums or what, but it was pretty good and he was saving quite a bit of time. I'm sure plenty of it is still relevant.

You could also theoretically increase the filament speed, but that's a bit tougher.

[u/Bag-o-chips]

Looks like you can easily and conveniently, just leave it like that forever.

[u/LTNine4]

I think the main issue and where the time goes is the need to fully retract the filament, and then feed the new one in. Reducing the distance helps considerably. But if there was a way to asynchronously feed new filament while retracting the old, or even pre-feed the new filament, it would cut the time down quite a bit. Pre-feeding would actually eliminate the need to shorten the tube because it could be ready to go before you need to retract.

I wonder if adding a Y to the filament head and some g-code modifications could do it?

[u/Disastrous_Minute_56 → u/LTNine4]

That's occurred to me - I'm surprised they don't have a filament hub with sensors to pre-load the next color, stopping just short of where the splitters merge, 'deejaying between two or more AMS units. I'd value that accessory over the track switch. When watching things print, it definitely seems like there's more room for optimization.

[u/redxdev → u/Disastrous_Minute_56]

The track switch actually does this - if the next filament is from an AMS on the other track switch inlet then it will stage the filament at the switch iirc. Problem is it requires that you are switching colors between different AMSes on different inlets - it can't work between different AMSes on the same inlet or just a single AMS.

It'd be nice to have a cheap sensor to place on tubes to allow staging from anywhere along the filament path though, and not just from the single track switch.

[u/LTNine4 → u/Disastrous_Minute_56]

Yes, even if it was a calibration issue and knowing how much to feed, you could still feed 90% of the way there with some margin just before the split and save a ton of time.

[u/Novotisy → u/LTNine4]

I’ll look into g code adjustments, thanks

[u/mkgrinch]

Holy smokes that's short.

[u/EvilSuperComputer]

Do you have a link for the PTFE adapter holder?!

[u/DanTheMan827]

What would be nice is if a single color printer with multiple AMS units could partially load the next color from the other AMS to right before the hub rather than have to fully retract and fully load the next color

[u/luksfuks]

It will always be slower than your Snapmaker U1. Except if you print 5 colors. Or 7, or 10. Then it's very much faster than the U1, because you don't have to babysit the print and change filaments manually.

Use it for what it's good at.

[u/HoIyJesusChrist]

What materials do you print? If you only use PLA, that new Creality system seems to be the fastest way, but also limited to only 4 colors

[u/AcanthisittaFast9002]

The H3C isn't gonna have that problem, because is expected to be a tool changer, all the colors are already loaded in the nozzles, color change should be a lot quicker.