Hi all
Has anybody tried controlling the Gripper with a Thruster Commander ? Is there any reason this wouldn’t work? My long history of frying electronics makes me wary of trying without more understanding. Any input gratefully received.
Hi @johng,
The PWM output signal is in the correct range so it should work fine, but controlling a device that only registers three kinds of signal (open/stop/close) with a smoothly rotating potentiometer might feel a bit unintuitive.
You might want to consider using a three position switch with two poles and a disconnected option (e.g. LOW/NC/HIGH) instead of the potentiometer, just so it’s more obvious what the gripper is actually doing for a given input 
If you go that route it will likely be necessary to bias the signal to half the voltage (e.g. with a pair ~5k resistors) so it still has a voltage to measure when the switch is disconnected:
Thanks for the suggestions Eliot. I will post my results when I get a chance to try the options.
John
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Hi all
I set the Gripper up with the Thruster Commander and no control but it appears that the problem lies with the Gripper rather than the means of control. I have no problem controlling a number of other servos I tested. with the Thruster Commander.
I had tried using the Gripper with the Navigator but it opened once and has frozen in that place since then. To be fair, although this Gripper was straight out of its packaging, I had actually purchased it over three years ago.
Hi @johng -
The gripper may be stuck - you can reference this repair guide. Simply unscrewing the two halves and re-assembling them should correct the issue!
@johng - If that doesn’t do the trick, your gripper may be from before April of 2021?
You can follow the repair guide to order a replacement motor/pcb for the one that may be burnt out…
Hi Tony
I appreciate you following this up. Yes, the Gripper was purchased March '21. I know that Grippers I bought in the years preceding that date had issues with the servos burning out? or something of that nature.
I will pull it apart in the next 24 hours to see if there is anything obvious.
cheers
John Griffiths