Hi, recently I rebuilt my DIY adapter. And use carbon fibre to be the GG holder. Then I use 3 small carbon fibre pins to mount the gg holder on the "base plate". The holder is very lightweight since it is made of 2mm carbon fibre.
However. The GG doesn't vibrate properly. It doesn't vibrate in a circular pattern and the vibration is not uniform across the frame. Also, the amplitude of vibration is so small. I tried using 3 softness of the pin. The softest one I tried does not even strong enough to hold the GG in place. And I tried 1.5V and 3V. It just didn't vibrate properly. 1.5V give almost no visible vibration and 3V is even less vibration but I hear the motor whining. Seems like the motor is running too fast for the GG holder to react.. Please help.

Try to put some counterweight on oposite side to your motor, glue some piece of metal, washer or something similar. Is your wires flexible enough, those pins you are using seems very long and thin, so wires can prevent gg from moving. You are using Nikon D screen, this is heavy piece of glass in terms of gg and you are saying that this isn't moving? Is your motor OK? Can you try another one?