EQ8 RA drive hiccup

[Shiraz (Ray)]

Hi

all of a sudden, my EQ8 developed a 3 arc sec RA spike when guiding. The PE curve showed a step transition in the PE that was not there before, so something had changed. Rather than wait 4 months for Tasco to maybe fix it, I took a deep breath and disassembled the RA mechanism. The worm and wheel both looked (and felt) very good, with plenty of clean lube, but there was a tiny bit of black dirt that could have been the remains of an ant on the belt. There was also a superficial nick in the edge of the belt that could possibly have come from rough assembly and the belt was also a bit sloppier than it should have been (according to the belt manufacturer's website).

Cleaned it all up, tightened the belt a little and it now works fine again.

[rustigsmed (Russell)]

nice work Ray, i'm not sure i'd have the courage to attempt that, must've been a relief to see it all up and running as before.

cheers

[LewisM]

Had a massive and sudden spike in RA last time out that would happen every 3 minutes. Opened up the GPD2 (powered by a Skywatcher Synscan GOTO kit) and there was a dark crud in the lithium grease I use - seems some insect decided to have a look and got rather squished. I keep my mesh pretty tight, so ANY matter is going to affect it.

Cleaned it next day and all good again.

[Shiraz (Ray)]

Originally Posted by rustigsmed

nice work Ray, i'm not sure i'd have the courage to attempt that, must've been a relief to see it all up and running as before.

cheers

Thanks Russell. As far as I can tell, Tasco isn't set up to provide much support and Skywatcher seem to take the view that they will put the mount on the market and then lose all interest - so there were really no options other than DIY. Anyway, it wasn't as daunting as it looks and took under an hour all up - simpler than an EQ6 in many ways.

Originally Posted by LewisM

Had a massive and sudden spike in RA last time out that would happen every 3 minutes. Opened up the GPD2 (powered by a Skywatcher Synscan GOTO kit) and there was a dark crud in the lithium grease I use - seems some insect decided to have a look and got rather squished. I keep my mesh pretty tight, so ANY matter is going to affect it.

Cleaned it next day and all good again.

Thanks Lewis. It is surprising how little it takes to throw out a worm drive - about 1/100th the thickness of a human hair is enough to notice, so our bugs were quite sufficient.

regards ray

[Ryderscope (Rodney)]

Very good Ray, nice to see somehone having a go at some DIY maintenance on the EQ8. I have some DEC backlash in mine that I keep thinking about and then keep ignoring. Maybe one day .....

[Shiraz (Ray)]

Originally Posted by Ryderscope

Very good Ray, nice to see somehone having a go at some DIY maintenance on the EQ8. I have some DEC backlash in mine that I keep thinking about and then keep ignoring. Maybe one day .....

Hi Rodney. I wouldn't have touched it if there was a workable alternative, but it turned out to be quite straightforward. I also need to tweak the Dec, but it works fine with a little play and I don't want it to bind - as you say, maybe one day.

[Logieberra (Logan)]

Ray, great find. Did you happen to take any pics? I've always wondered what the EQ8 RA and Dec systems look like... next time?

[Shiraz (Ray)]

Originally Posted by Logieberra

Ray, great find. Did you happen to take any pics? I've always wondered what the EQ8 RA and Dec systems look like... next time?

No, I didn't Logan, but this shows it pretty well. http://www.dangl.at/ausruest/eq8/eq8_e4.htm

[Logieberra (Logan)]

Thanks Ray. That's a good resource. It will help a local mate and I service his mount in time to come. Cheers

[Shiraz (Ray)]

hi Logan. then the attachment on this may also be useful to you.
https://groups.yahoo.com/neo/groups/...s/messages/398

[Logieberra (Logan)]

Perfect. Thanks again