build plate free falls after moving to home axis

[entre3D]

I don't know that this is really a problem but a strange behavior for sure. If I tell my 2X to go to home axis, it does, but then the build plate just basically free falls away.

Glad to find this forum after the google group shut down!

[American 3D Printing]

Is it being driven down by the motor?

It takes quite a bit of force to manually force the plate up or down when not being driven by the motor.

[entre3D]

No. Its just slowly lowers itself free of any motor control. Silently drops. Works fine when I start a print. It's just after going to home axis or after bed leveling

[American 3D Printing]

Wow, that's really bizarre, never heard of such a thing. Normally the motor, when unpowered, has enough resistance to prevent that from happening. Since all 4 motors are identical, you might try swapping the Z motor with the X (easiest to get to) and see if that fixes it? If the problem goes away, then you know it was the motor. If it doesn't, then it is the drive circuitry on the mighty board.

[entre3D]

This all started sometime after installing aluminum Z arm upgrades. This was the 2nd of 2 printers I installed on, no issues on printer 1. I wonder if it's related. I'll try removing the threaded rod and re-installing. MB support says they've not heard of this.

[wpilgrim]

This all started sometime after installing aluminum Z arm upgrades. This was the 2nd of 2 printers I installed on, no issues on printer 1. I wonder if it's related. I'll try removing the threaded rod and re-installing. MB support says they've not heard of this.

The first thing I wondered, was if you had modified this in anyway. Imo I would think that is somehow what introduced the problem. When the build plate moves down on its own, can you tell if the rod itself is spinning, or does it appear that the threaded rod is stationary? If the rod is stationary than it must be the bearings or bushings. If the rod is spinning then it must either be the motor or the connection point between the motor and the rod.

[entre3D]

Makerbot's reply was that I needed to remove Sailfish and go back to MBI firmware, because Sailfish isn't supported in the 2X.