I was thinking that was the lift servo here Because it seems so shallow compared to even the extruder stepper. I think people are confusing closed loop steppers with servos. With gears this tiny, you wouldnt want sensorless end stops Bang bang. You would want precision by setting digital end points. The encoder will give the feedback needed. This will also enable the printer to stop and error out if theres something blocking the nozzles movement, instead of trying until the servo over amps or stopping before ghe full motion is done.
Plus, it doesnt have enough poles/steps to be a stepper. I count 12. and
"
Servo motors typically have a low pole count, generally between 4 and 12 poles, unlike stepper motors which have a higher pole count, often 50 or 100"
âServoâ in the context of a 3D printer or similar machine refers to a positioning mechanism that uses feedback (to detect position or velocity or both) as part of the control system. Servos can take many, many physical forms.
The current batch of BBL printers donât have servos. Just plain old stepper motors. Steppers do pretty much what youâd expect. Where a normal motor rotates continually when you apply a voltage, a stepper rotates a fixed amount and then stops. But if something keeps the motor from being able to move, the system cannot detect that.
If one of the XY steppers on your printer misses a few steps, youâll get a layer shift in your print.
Stepper motors with encoders can detect these events and correct for them.
But steppers with encoders arenât really servos.
Also, stepper motors are like normal motors in one regard, the faster they go the less torque they produce. And asking a stepper to step to fast is another way steps can get lost. With an encoder, the stepper motor can be run faster/harder because the system will know if a step is missed and simply add an extra step to compensate.
This is a big problem with my CNC mill. If Iâm machining hard material like steel, even though my end mill can spin fast enough for a higher X/Y speed (the cutterâs rotational speed is one constraint in how fast the mill can run), I have to run slower because otherwise the steppers donât have enough torque to push the end mill through the stock. Iâd have upgraded my machine to servo steppers except I really donât machine hard materials very often.
A servo for the nozzle positioning system doesnât make sense. Iâd be surprised if thatâs how they did it. The nozzles can simply be driven open-loop until they hit a mechanical end stop. Precision positioning with a servo mechanism shouldnât be necessary. Stepper, though, yes.
I count 12 poles.
" Servo motors typically have a low pole count, generally between 4 and 12 poles, unlike stepper motors which have a higher pole count, often 50 or 100"
The forum is so fun right now. This is awesome
why does your says âMake and appointment nowâ mine just says the realease date 
Because Bambu proposes a blind date⌠and one could only hope the first date goes wellâŚwithout having to break oneâs bank account paying for the âfoodâ⌠
is it direct drive extruder
Most likely, same as all other Bambu printers.
Dual hotends, Dual filament inlets, Dual extruder gears sharing the same central gear? Also servos. Its like the inner working of a watch or clock.
Also people are talking about the servo like its for the extruderâŚit may not be. It may actually be for closing off the nozzle to prevent oozing when switching between the two hotends. This is how ratrig does it on the vcore4 idex. Not exactly- no servo but the toolhead is moved to a drip plate that butts up against the nozzle tip. BL has built this into the toolhead itself and so some kind of motor is needed to move it.
Iâm pretty sure @StreetSports mentioned that.
i think your point about the servo is 10/10, given that the mounting holes look very similar to the ones in the teaser
He made this picture from google translate, source by my post. It is common google translate mistake to fix the miss written word even itâs an private name like we saw in this example.
You can check the original Chinese picture from here: âThe Beauty of Mechanics - #53 by Mad_Scientistâ
I wonder if there will be a print + iron at the same time function where one nozzle prints and the other irons.
they are on different positions.
how should this work ?
You would have to have 2 spools of the same filament and it wouldnât work anyway because the nozzles are in different places.
That is not exactly true, depending on the driver used, the change in current due to a stall can be detected and accounted for. Some designs use this characteristic rather than using a limit switch at end of a deviceâs travel.
I should have been more specific. The system can tell if itâs missed a step because of the motor current (or more specifically, the back EMF generated when the motor rotates, or in the case of a missed step, doesnât rotate). But it generally canât tell how many steps itâs missed. These systems are imperfect because thereâs not a lot of margin between the motor moving slowly because of a high load, or not moving at all.
The X1C detects lost steps just this way, but it canât just ârecoverâ, it has to re-home the printhead to resume printing. And the homing operation itself is not going to be completely repeatable each time, so rehoming might result in a small layer shift.
A stepper with an encoder (or in the case of the H2D a build plate that can provide accurate position feedback data) can recover from exactly as many steps as it missed, on the fly without rehoming.
The mechanics are beautiful, but dual extrusion is useless unless itâs 2 independently suspended heads working asynchronously.
I came from a dual extruder 3d printer I modified the heck out of, to the X1C+AMS. Iâll never consider another dual extrusion setup again that doesnât work in unison because of the added problems of achieving accuracy. (which probably wonât happen in my lifetime)
What mods did you do to your AMS and X1C?