Slewing sounds unhealthy when driver started

mfender

Hi,

when slewing my AM-5 with high speed there is a clear difference in sound (or noise) depending on wheter the driver is started (connected) or not. Without the driver the sound is smooth. With the driver started there are perodic clicks and crackles in the noise the mount makes.
Listen to the two soundfiles I recorded and linked below..
They were recorded exactly in the same manner, the only difference is the started/closed driver. The slews were performed with the handcontroller with max speed. Both axes are moving at the same time.

https://soundcloud.com/mfender-244028682/am5-ascom-disconnected

https://soundcloud.com/mfender-244028682/am5-ascom-connected

Could other users of the mount tell me if this is normal?

Could someone from ZWO tell me what is going on here? It is VERY uncommon that the connection between a driver and a mount has an influence on the sound the mount makes when slewing. To me this sounds like a mechanical problem, not like normal operation.

enaiman

Mine is doing a similar thing - not the same noise pattern but I have noticed it recently when moving the mount in AsiAir.
Using the hand controller doesn't generate any additional noises.

Ceat

This sound is apparently correlated with the moments of sending commands/inquires to mount. It is also possible, that guiding problems (spikes) may be caused by this effect. This is obvious problem of firmware.

mfender

Thanks enaiman and Ceat for your responses!

Ceat It is also possible, that guiding problems (spikes) may be caused by this effect. This is obvious problem of firmware.

This is exactly what I fear.
I did send this to support two days ago, but have no response until now.
I also wish someone from ZWO would comment on this in this forum.
(Why are they so silent about this?)

I might send it to the support for a second time today.
If this gets not sorted out, I will simply return the mount.
Without good software (driver/firmware) a mount is not much use.

Matt

enaiman

mfender I wouldn't go that far.
The sound is obvious when slewing not in the guiding phase - when guiding the impulses sent are of a very short duration and personally I can't hear anything.
A fix will probably be implemented at some point.

mfender

enaiman The sound is obvious when slewing not in the guiding phase - when guiding the impulses sent are of a very short duration and personally I can't hear anything.

It is not what I hear that worries me, but the idea that tracking / guiding might be affected.
The fact that one can hear the communication between ascom driver and electronic board as interruptions or stumbles / disturbances (or simply "events") in the slews of the mount is very odd and strange. These are two areas that should be decoupled.
Of course, these interferences are particularly noticeable at high speeds, which does not mean that they are not present at low speeds. There may be small disturbances in tracking that you do not hear at all.

I wish ZWO would give an explanation or comment on this. They should exactly know what is going on here, shouldn't they?

Matt

Ceat

I've just tested guiding by PHD2 in circumstances of heavy bombing with requests (approx. 30 queries per second, through my own ASCOM driver, each query takes 15 ask-response communications, about 2ms per one). PHD2 did NOT show disturbances in guiding, so I assume there is NO problem.

mfender

Ceat I've just tested guiding by PHD2 in circumstances of heavy bombing with requests (approx. 30 queries per second, through my own ASCOM driver, each query takes 15 ask-response communications, about 2ms per one). PHD2 did NOT show disturbances in guiding, so I assume there is NO problem.

This is very useful, exactly the kind of information I was looking for. Very encouraging. Thank you for that, Ceat!
And thanks to enaiman for your contribution, too!
In the meantime ZWO support responded to me. They also said it's without impact on the use of the mount
and announced a fix in the next firmware release.

Matt

kaiyung

mfender can you let know know what the tech support said was the reason for these sound?

kaiyung

@ASIMount@ZWO can you elaborate why the new ASCOM driver would cause these sound and that it would not cause any damage to the mount itself from a large movement? I need to use the new ASCOM driver to fix the known bugs but am afraid of this new issue.

ASIMount@ZWO

kaiyung Confirming with the team.

ASIMount@ZWO

kaiyung It is due to the upper computer regularly reading the info of the mount while slewing, which leads to some differences during the rotation. Will fix this in the next version of the firmware.

mfender

kaiyung can you let know know what the tech support said was the reason for these sound?

Support desk did not name a specific cause.
Here, the phenomena also occurred with version 6.5.11, albeit to a lesser extent.
I'm using firmware 1.1.2.

Matt
Edit: I see that ZWO responded to your question... the repeated polling is the cause.
But could it cause a damage? Should we avoid slews with max speed at the moment?

ASIMount@ZWO

mfender But could it cause a damage? Should we avoid slews with max speed at the moment?

No need to worry.🙂

kaiyung

@ASIMount@ZWO#60768 can the ASCOM team release a quick fix for this bug since it is isolated during a slewing operation?

Ceat

kaiyung This is firmware issue, not ASCOM driver failure. Disturbances are obvious, but stepper motors do not fall out of sync, so I would not worry about it.

mfender

Does the new Firmware 1.2.1 solve this issue?

Matt

mfender

mfender Does the new Firmware 1.2.1 solve this issue?

Any comment from ZWO?

Matt

Sam@ZWO

mfender yes, please try the new firmware
https://bbs.astronomy-imaging-camera.com/d/15540-am5-multi-star-alignment-firmware-beta-version-released-for-test

mfender

Sam@ZWO
Thanks, I will try it!