Just stumbled upon this video (the title is misleading) that shows a creative way to “counter weight” the Y-axis: Cetus ZAxis balancer - YouTube
Was wondering, has anyone tried this? If anything it’s an interesting approach to fight gravity for the Y-axis.
When reading the text you’d think there is an actual counter weight and a simple pulley which would work well and allow you to match the weight of the Y axis. This isn’t likely to be linear as it would presumably be spring based, and matching the exact force needed may be an issue.
Although I’m not sure what problem it is trying to solve, seems like it would just reduce the effective mass the Z motor has to lift, and there is no real need for super fast acceleration or movement on the Z axis?
If an actual weight had been placed on the axis and countered the weight of the extruder then I could see some value in fighting deflection, but the added mass would probably just add to other problems.
Nvm, the goal is to prevent z axis shifting in case of power loss.
Yup that was the advertised goal, I just wondered if it would be beneficial beyond that. But as you mentioned the z-axis movement is not an issue really. Or maybe a bit, since the brake mechanism for the y-axis is a force the stepper has to overcome moving down from a retract.
Furthermore at least mine became noisy (almost a rattling noise) and when I adjust the screw it’s either silent or properly brakes the y-axis from falling, but never both at the same time. But in any case, an actual counter-weight might be better suited than the spring, except for the weight part posing potential new issues. Oh well…
This mod looks like the best alternative to the z-axis one-way bearing used as the brake system. I’d like to know if this solution will allow the z-axis less resistance when calibrating the nozzle height. I’m not using the z-axis one-way bearing because after running many tests, and even after setting the bearing properly, the z-axis movement downward failed to move the required/specified distance…90% failure to move the full .10mm within the calibration procedure! And yes, my retractions are far more precise.
I don’t understand why loss of physical z position is a problem, if the firmware knows where to resume it should be possible to home the machine and move to the correct z height and resume no?
(Of course the machine needs to home the axis to the direction that the print head moves away from the bed, and not be reliant on probing the bed surface to set an accurate z height)
Which post are you asking the question?
@techsalad Right, you mentioned before, that the one-way bearing brake is problematic. How do you keep the y-axis in place? I saw some mods to solve the problem, but didn’t try any of them:
@superhans I’m using an extremely high-tech method 
, the excess styrofoam packing material from a past shipment. Blocks of varying height to aid in positioning the y-axis while I work on various prototypes… 
Yup, the first 3 or so power-offs resulted in the nozzle-nose-dive into the optical mirror I use as the print-bed. Surprisingly, no damage to the mirror and a quick check of the nozzle tip and back in business. Not recommended, two-thumbs down, unless you love to check the alignments of xy and z after each event.
I’m going to design a small device that is powered from a capacitor with just-enough juice to engage a solenoid. A sensor will detect loss-of-power and engage the solenoid using the accumulated power in the capacitor, and when power returns, disengages the solenoid. A short algorithm on a cheap micro-controller will decide the position of the solenoid. A project for another day, although if I fall-into that rabbit-hole maybe sooner 
cheers!
It’s not what the title says, basically it simply prevents the Y linear module from free falling on its Z axis. MK3 already has adjustable grip to prevent the nozzle from falling freely when power is cut.
The point I’m trying to make, is when using the grip (one-way bearing), and even after adjusting properly, the stepper moves against the grip do not always move the full .10mm when calibrating the nozzle-height and bed-level.
@techsalad That sounds super high-tech! 
But at least it’s obvious that you have to remove the foam bits before printing. I fear with the security hook for example, you’ll forget sometimes and it’ll lead to some nasty moments. Ah yeah and brass hitting glass, not exactly a sound you’ll want to hear to often from your printer setup.
The foam works for now, at least until I’ve published the mod-pack and have the time to focus on other projects. The security hook doesn’t allow for parking the y-axis at differing heights without some manual adjustments. I really like the counterweight method, but for me, I would also have to lock the movement somehow. The solenoid idea would provide the y-axis lock, but would require some extra logic and a few more components to allow for easy adjustment when working on the y-axis. Another solution might be using a tapered-gear where the grip exists and have the grip engage via solenoid when no power is flowing to the stepper…so many fun rabbit-holes to explore…better stop this flirting or I’ll fall into the rabbit-hole further delaying the mod-pack!
cheers!
The idea is interesting, so cool. The guy says that he works perfectly, we will believe him. I want to use it!
In general, I believe that 3D Printer is very profitable, and each of us can allow it. It’s a shame that few people know about him, because his quality is very high. I adore my printer!
realized the same issue long time ago. the bearing z-axis brake works well but causes layer shifts within prints which results in bad layer adhesion. I was already in contact with a chinese company which produces retractors as I wanted a solution for the cetus but didn´t find a suitable solution for now. My last Idea was a tiny electrical triggered magnet. In case the motors are mounted I want to activate it so the axis is free. in case the motors are off the spring energized magnet releases and blocks the axis. But even at this it is hard to get a safe solution with the stock printer due to less options in the software.