EAF backlash amount tolerances

Focusers, Filters, Barlows etc..

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herpmcderpington
Posts: 5
Joined: Sun Dec 29, 2019 2:02 am

EAF backlash amount tolerances

Post by herpmcderpington » Wed Apr 22, 2020 9:19 pm

Hi,
My EAF has a measure backlash of around 115 steps. If I detach the coupling from the telescope focuser, I can move the coupling a few millimeters freely, which I assume is the cause of backlash. I have double checked and made sure all the connections to the coupling are tight, so the backlash must be coming from the stepper motor itself. Is this amount of backlash normal? Even with backlash compensation on the ASIAIR, it's quite difficult to make precise focus adjustments.

Moson
Posts: 205
Joined: Wed Apr 01, 2020 8:28 am

Re: EAF backlash amount tolerances

Post by Moson » Thu Apr 23, 2020 8:40 am

You could check if the load of the coupling is too heavy, or the firmware is updated.

Then confirm the amount of backlash in the software.

herpmcderpington
Posts: 5
Joined: Sun Dec 29, 2019 2:02 am

Re: EAF backlash amount tolerances

Post by herpmcderpington » Thu Apr 23, 2020 11:15 pm

I am well under the 5kg payload (no more than 2 kg). Updated the firmware to the latest version prior to testing. I'm still getting 115 steps. I'm just confused because usually stepper motors do not have gears, so why would it have such a large backlash? is it a defective unit?

Moson
Posts: 205
Joined: Wed Apr 01, 2020 8:28 am

Re: EAF backlash amount tolerances

Post by Moson » Fri Apr 24, 2020 7:42 am

Maybe you could check if the motor shaft is worn.

herpmcderpington
Posts: 5
Joined: Sun Dec 29, 2019 2:02 am

Re: EAF backlash amount tolerances

Post by herpmcderpington » Fri Apr 24, 2020 7:17 pm

There are dents in the motor shaft because I originally installed the EAF too lose, so it was slipping, and the set screw caused dents in the shaft. But now everything is very tight, shouldn't be an issue.

herpmcderpington
Posts: 5
Joined: Sun Dec 29, 2019 2:02 am

Re: EAF backlash amount tolerances

Post by herpmcderpington » Sat Apr 25, 2020 9:10 pm

Any chance you could send me a new unit to try? I bought mine less than a month ago, should be well within warranty.

Moson
Posts: 205
Joined: Wed Apr 01, 2020 8:28 am

Re: EAF backlash amount tolerances

Post by Moson » Sun Apr 26, 2020 9:15 am

We have confirmed with our devs, it is normal the backlash of EAF has 115 steps.
You don't need to repair it or change a new one.

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