EAF backlash amount tolerances

herpmcderpington

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

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

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

Maybe you could check if the motor shaft is worn.

herpmcderpington

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

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

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.

joe3

moson Hi my EAF has backlash of around 1100 steps. Is this normal? I have it installed on a skywatcher Esprit 120ED. Using the ASIAIR pro, the max backlash compensation is only 200. How do I fix this?
I have checked the focuser on the telescope and everything looks to be correctly and all bolts are properly tightened.

what could be causing such a big backlash?

beachbum

joe3

Thank you for that answer...! I was wondering as well what the average backlash was on a new EAF. I measures about 100 steps on mine.

Swizerlan

Im not sure how toi adjust the asi air backlash, is it preventing you from good focus? In reading this thread I am thinking that there is mechanical backlash in your focusers contributing to the value.

Tech@ZWO

Swizerlan
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