I have had endless issues with filament feeds from my two AMSs. Basically the filament is pushed almost to the extruder but not fully. I think it is related to the placement of the units relative to the printer. When I put everything outside of the cabinet on the floor with short tubes, no issues. Any suggestions? Photos attached.
Shorten the PTFE path.
Your own tests show this.
The length of the PTFE tubes cannot be long. I’ll be honest, I do not know the maximum path.
You have to remember the purpose of the PTFE tubes, they are there to route the filament from the AMS to the print head.
The longer the path, the more material needs to be moved, thus causes two issues: the weight of filament being moved and the friction of the filament be pushed. Each of these is an issue.
Each cause difficulties for the motors trying to shove things distances.
The other issue you have to consider is the system likely has a loop it traverses:
- push filament
- Is the filament there yet?
- Yes, stop
- No, go to step 1
At some point there is likely a safety check in the code (at least, that is what I would have created), is there a problem as I have been going for too long.
Shorten the path. You have multiple joins, this is an indicator they are too long.
1 Like
If your issue is getting it into the head unit like it was for me, after installing this I never had an issue again - Extruder / toolhead PTFE guide for Bambu P1 / X1 by oddsandsods MakerWorld: Download Free 3D Models
The angle of th tubing under the glass caused my issue and it looks the same in your screenshot.
Give it a try.
My buddy has the same printer and came over … He mentioned his tubing is even longer and he has no issues. I may take everything out of the box and reduce the bends…see if that helps.
As I said, my point was the two important factors, length of the PTFE tubes and the friction.
Longer tubes with friction are more likely the issue.
You are pushing a lot of weight through tight turns and expect ping the motors to just cope with it. If they were pulling, it might be easier.
If the path from the printer was straight, the friction wouldn’t be an issue as it would barely touch the sides, thus less friction, less friction increased weight is far easier than more friction with increased weight.
I didn’t say length was your issue, I said it plays a role due to the above, I also said I do not know what any maximum length would be. Only that if I wrote the software p, I would have built a safety net in to minimise the stress on the motors.
The longer the path, the longer your prints will take if you do a lot of colour changes.
The printer has to wait for the filament to return to the AMS before requesting the next colour. If the length of your filament is twice the standard one supplied, that portion of the delay is now twice as long as it would have been if the motors are running at 100% which becomes harder the longer and tighter the PTFE is connected between the printer and AMS.
PTFE, also known as Teflon, is specifically used because of its chemical inertness and very low friction. It has the property of being self lubricating. You can swallow it and it will pass through unaffected.
On a couple of my AMS units I am using longer tubes and they work just fine. The most common problem with PTFE tubes is the radiuses being too tight as you seem to be aware of.
I once had an annoying problem with filaments not feeding properly. After having completely disassembled and reassembled an AMS unit as well as the hub, it turned out that the problem was caused by a small piece of filament having broken off in the AMS hub.
I would unmount the AMS hub from the X1C and put it on direction to the hole, where the ptfe tubes comes into the cabinet. This gives you a smoother and shorter tube path with less bends. The shorter path also helps to speedup load and unloading filament.
It can’t help angles too tight to turn.
