Fitting a ZWO EAF

[recceranger]

I was fitting my ZWO EAF to my William Optics Zenithstar 61ii yesterday and came across an issue. various YouTube tutorials showed that the EAF bracket fits absolutely flush with the EAF. But when I placed my bracket onto the focuser, there was several mm of gap, which caused the EAF to become skewed when attached to the bracket. I’ve supplied a few photos as an example. The first few shows the correct fitting of the bracket, and the next series the mm gap that I believe shouldn’t exist, followed by a final series of images showing the resulting skewing when EAF is attached to bracket. 

On looking online I can’t see that ZWO produce a specific bracket for the Z61ii? Also, my fitting of bracket is correct. 

Has anyone else with a similar setup came across this issue? 

[StevieDvd]

I have the same issue. I swapped an EAF over from my Evolux to a new WO Z61 and found the same problem.

Being a little cautious I double checked the bolts that would replace the grub screws which allow access to the focuser spindle/grub screws were correct it looked like the standard bracket would be a straight fit.  Only to find the bracket would not allow the motor to fit snugly and orthogonal. So undi it all and made sure the coupler was far in as possible both on the motor side and focuser, this helped a tiny bit but still let a few gap. Then I made sure the bracket was as far out towards the motor as needed which meant the bolt furthest from the motor was the partly covered.

As an interim fit I added a washer to that blt and fitted that end first as far over as it could go, then sorted the gap at the motor end with a washer between the motor & bracket and this gives a tight but orthogonal fit. I checked the motor & coupler worked without wobbling or making any odd noises so that solution works. But being a bit obsessive over things like this I will probably remove the bracket and lengthen the slot to give a few extra mm range and a straightforward fit of the angle bracket & motor.

Hope that helps, even to know it's not just you having that problem.

Steve

[recceranger]

1 hour ago, StevieDvd said:

I have the same issue. I swapped an EAF over from my Evolux to a new WO Z61 and found the same problem.

Being a little cautious I double checked the bolts that would replace the grub screws which allow access to the focuser spindle/grub screws were correct it looked like the standard bracket would be a straight fit.  Only to find the bracket would not allow the motor to fit snugly and orthogonal. So undi it all and made sure the coupler was far in as possible both on the motor side and focuser, this helped a tiny bit but still let a few gap. Then I made sure the bracket was as far out towards the motor as needed which meant the bolt furthest from the motor was the partly covered.

As an interim fit I added a washer to that blt and fitted that end first as far over as it could go, then sorted the gap at the motor end with a washer between the motor & bracket and this gives a tight but orthogonal fit. I checked the motor & coupler worked without wobbling or making any odd noises so that solution works. But being a bit obsessive over things like this I will probably remove the bracket and lengthen the slot to give a few extra mm range and a straightforward fit of the angle bracket & motor.

Hope that helps, even to know it's not just you having that problem.

Steve

Hi Steve,

That does help sir and TY. Great suggestion WRT extending the bolt recesses on the bracket, I never thought of that 👍. I went for same intermediate solution with the washers. Seems to be a good solution.

All looks flush

Clear skies buddy☘️

Edited November 15, 2022 by recceranger

[StevieDvd]

I looked at the youtube installations again and might try a refit first. This time I'll follow their order of assembly, it could be the coupler has different hole depths and could fit a little closer to the motor if swapped around (not that I'm aware if the coupler I used has same hole size each end!!).

Also, if the coupler can be fiited further in the focuser (but have the grub screws still accessible) that might help a bit too.

 

 

[recceranger]

19 hours ago, StevieDvd said:

I looked at the youtube installations again and might try a refit first. This time I'll follow their order of assembly, it could be the coupler has different hole depths and could fit a little closer to the motor if swapped around (not that I'm aware if the coupler I used has same hole size each end!!).

Also, if the coupler can be fiited further in the focuser (but have the grub screws still accessible) that might help a bit too.

 

 

That’s a good point Steve, and I think the coupler for the WO Z61 fit has the same diameter holes on both ends, which coincidentally are the same diameter as the EAF barrel. 👍

[StevieDvd]

I took mine off to refit last night and managed the fit without the washers. I did the following:

• Removed the bracket from the focuser and the motor and left just the coupler on the focuser.
• Loosened the coupler on the focuser spindle and made sure the grub screws were still accessible
• Loosly fitted the bracket ensuring it was out twards the motor as far as possible
• Connected the motor and aligned it with the bracket - it was better fit
• Tightened the coupler then the bracket bolts
• Tested use

It was a good job I did that as I had tightened 2 loose bolts on the first fit thinking they were just holding the focuser spindle housing to the focuser. The focuser was very stiff so I had to loosen them and adjust until the fine speed control wizzed round and the focuser travel was not too loose or tight (hopefully just right).

So it's a good thing to come out of it with my focuser 'fettled' and the bracket fitting. It was a tight fit for the bracket and I would have preferred a bit more leeway for the screws so I may return to it at a later date and file the bracket slot to give a few more mm's for peace of mind.

 

[LaurenceT]

I'd be grateful if someone could help a non-engineer with this. I have the same setup and on checking mine the gap is obvious. It doesn't seem to affect performance but is there a risk of damage to the EAF?

[knobby]

The flexible coupling 'should' prevent any damage but It will surely put extra load on the EAF.

I'd be inclined to use washers as above.

[StevieDvd]

I've just refitted mine after extending the slot on the bracket a little. As can be seen on the images below there is now a gap on the motor side between the bolt and bracket. And on the opposite end, where I drilled & filed the slot a few mm's, you can see the bolt head is a little further out too.

Now it does not seem to be overly tightened to get it orthogonal (my word of the week) and I'm happier it's not under any stress.

Steve

Edited November 16, 2022 by StevieDvd
Shrunk & aligned images

[recceranger]

3 hours ago, StevieDvd said:

I've just refitted mine after extending the slot on the bracket a little. As can be seen on the images below there is now a gap on the motor side between the bolt and bracket. And on the opposite end, where I drilled & filed the slot a few mm's, you can see the bolt head is a little further out too.

Now it does not seem to be overly tightened to get it orthogonal (my word of the week) and I'm happier it's not under any stress.

Steve

Superb job Steve. “This is the way!” 👍😃