EAF - Backlash? - ZWO User Forum

EAF - Backlash?

raptronix

Hiya. I've had problems for a little while where changing focus had little impact on the image, that I now realise is excessive backlash.

I was wondering what kind of backlash people are finding their EAF exhibits? I have measured mine half a dozen times and repeatedly find that it is 220, which seems huge?

So huge in fact that the capture program will not let me enter it as the field seems to top out at two digits, not three. I have not checked if I can enter such a large backlash amount into the ASIair yet as I've packed it to send it back to trade for the ASIair pro. (Does anyone know?)

Do you have any advice how to reduce this? I have checked that the lock screen onto the motor is tight.

This is the EAF connected to the SkyWatcher Esprit 100.

Cheers

Nick

james474789

I have used my EAF on a ZS73 and Skywatcher 200pds. My measured backlash on the ZS73 was approx 50 and on the 200pds it is 130. 200 seems high but plausible?

You could enter backlash data into the ascom driver?

wvreeven

I use an EAF on a SkyWatcher Esprit 80ED and virtually encounter no backlash at all. Did you use the Takahashi Scope bracket or the original one? I use the Takahashi bracket and the EAF is attached rock solid.

HTH, Wouter

raptronix

Thanks guys. I am using the original bracket as that was the only one I could find a way of attaching, albeit with only a single screw. I do have the Takashi/Esprit bracket ZWO do as well, but couldn't find a way of attaching it?

wvreeven

Remove the two bolts to the far end of the bottom plate of the focuser and attach the Takahashi mounting plate with two long Alan bolts. I can take some pics of my setup later today if you want.

Wouter

raptronix

I'd appreciate that, thankyou.

I've posted a short video on facebook in the ZWO cameras group, asking about the play people have in the spindle. Does yours have any?

https://www.facebook.com/groups/zwoasiusers/permalink/1038740573151657/

wvreeven

There is a little play but it is very small.

This is how I connected the EAF to my Esprit:

A96F5A1D-C87F-4CA7-A5F0-C0A4A3847F3D.jpeg

raptronix

Interesting thankyou. I placed that bracket against those holes and they don't look like they line up. We have different focusers.

IMG_5595 copy.jpg

wvreeven

We do indeed. The little block with the clamp to tighten the focuser in my case sticks out and in your case it doesn’t.

galactique

Raptronix,

Did you solve this ??

I just bought an EAF for my Esprit 100, which has the same focusser as your image.

I held off buying the EAF until ZWO declared they had a bracket suitable (the Taka mount), which I bought in good faith, but this just leads to the same issue you have.

It seems it can only be secured with one bolt, which is no good at all.

Have you fixed it ? can you post another image if you have pleased.

raptronix

Hi Galactique

I did the same as you, and I'm afraid I don't have a different solution. The one screw approach does work and is surprisingly firm for what it is, but its not ideal for sure.

It looks like the focuser on the Esprit has changed and so the Tak bracket no longer fits.

Cheers

Nick

galactique

Hi Nick

Thanks for the prompt response.

You confirm the worst, I shall have to go ahead and bodge it up and put the second bracket in 'storage'....

cheers

galactique

I installed the EAF onto my Esprit 100 and it works.

But it hangs a little off centre clamped by a single bolt, using the extra (not cheap) Taka bracket, which is not a good fit.

Backlash ?? Lash up, I am sorry to say !!

raptronix

I don't use the Taka bracket - I use the standard one, screwing (only one screw) right up by the focus 'arm'. It is all straight doing that, but i am not happy with the one small screw approach.

robomort

Have you considered mounting the EAF to the dovetail plate? you tube user James Lamb has a video showing how he mounted a Pegasus focuser to the dovetail plate of his ES102. You could use a similar solution for the EAF.

https://www.youtube.com/watch?v=CtCZGysgJgs

raptronix

I’ll take a look - thankyou!