Why does my EAF grind when moving focus

ricklkiwi

Can someone tell me why there is a grinding sound coming from my EAF when I am moving the focuser? I have attached a link to the video of the noise the EAF makes. Please help. https://youtu.be/Kk3503iqioA

Thank you.

Rick

Tech@ZWO

ricklkiwi It looks like the jackscrew didn't fix will, please refer to this picture to check.

pace

I have exactly the same issue with my new ZWO EAF 5v (not fixed to my telescope, so this is not a jackscrew issue or a backlash from the scope focuser).

Each time I move IN or OUT, there is the weird grinding sound and then after around 1 second the axis starts to move. The issue is always here, even if I move IN only and regardless of the number of steps.

Should I send my EAF for RMA ?

w7ay

pace there is the weird grinding sound and then after around 1 second the axis starts to move.

Probably just a rougher stepper motor rate to get the additional torque when starting movement. And then it goes into the regular slower rate (so sounds smoother). I think ZWO uses microstepping (check on Google if you are not familiar with microstepping the stepper motors) for regular motion, but uses full stepping for the initial 1/2 or so second to get more torque.

Remove the EAF entirely from your focuser -- you should hear that same noise.

Chen

pace

w7ay

Thank you for your reply. Indeed the sound comes from the stepper motor (not even the gears). It is definitely related to the low speed of the motor and then it disappears when the speed is greater.

I have found another video of a user with the same issue:
https://www.youtube.com/shorts/qEt4a9X5kbE

So my questions is the following: it is normal (i.e. all EAF have this) or is it an issue which must be repaired?

Note that my EAF 12V does not have this issue.

w7ay

pace is it an issue which must be repaired?

Doubt it. I have one on my desk not bolted to anything, just sitting on the desk (to test with INDIGO), and you can definitely hear the start-up ramp. You can really hear the reverberation from the desk. The good thing when testing is that I don't even have to look at it, I can just listen for it :-).

The torque issue had always been a concern to me, to the point that I went out and bought a 12V one (with specific instructions to my dealer) when ZWO announced the 5V replacement; just so that I have a 12V spare.

For what its worth, none of my subsequent 5V ones have fail so far; but I don't load it much -- I do use large filter wheels, but not OAGs.

Chen

pace

w7ay
Many thanks for your message. I have found another video where you can (slightly) hear the same start-up ramp noise:
https://www.youtube.com/watch?v=LZX3gvv_E4g&t=737s

I am afraid that this may induce vibration, but I guess it is a design issue. If someone from ZWO or other users can also confirm this start-up ramp noise that would be helpful.

Tech@ZWO

pace Did you update to the latest version EAF firmware to try? Choose FW Update.
https://astronomy-imaging-camera.com/software-drivers