Finder dew shied+illuminator/manual fine focuser

[asimov (John)]

Hi guys.

I know I have threads on these objects somewhere on this site, but I can't find them!

Anyway, This handy little item for fine focusing is for those that can't afford an electric fine focuser. Before I took up astrophotography it was real handy, & now even more so since astrophotography! It does take some time to get good focus before capturing but the results are well worth it. (seeing conditions a factor here)

My rough N' ready dew sheild & cross hair illuminator has been a real blessing! The illuminator is out of my EQ5 polar alignment scope. The shield is just a bit of thick plastic rolled up.

The other night I was out imaging & my illuminator batteries ran out of juice. There was a very dull glow but not enough to see the cross-hairs so I was some-what stuffed for getting mars on my laptop. No access to new batteries at 3am...so what do you do??.....I cut a 1cm square of alfoil & glued it on the inside of the dew-shield directly opposite the globe of the illuminator & PRESTO!! Could see the cross-hairs no problem!.....Still haven't replaced the batteries & that was over a week ago!

[rmcpb (Rob)]

I do like the fine focuser. How do you attach it, some sort of clutch?

[davidpretorius]

you have a red led in there for illumination from memory???

[asimov (John)]

Hi Rob. Sorry about the delay, but I had to head to the 'big smoke' for a few hours. On my focuser, the shaft the knobs attach to is stepped..ie: the actual shaft is slightly bigger diameter than the threaded ends of the shaft, so after making the arm (2mm aluminium sheet) I drilled the hole exactly the same size as the threaded part. A slight bit of filing so the arm slipped over the thread fairly snugly, but not too big so it slips over the bigger diameter un-threaded part. Place the arm on & just screw the focuser knob back on.

When I'm out viewing, I undo the focuser knob slightly to allow the arm to hang free, course focus on the object using the other knob, tighten the knob on the arm side to lock the knob, then fine focus! So in essence, the arm gets sandwiched in between the knob & the bigger diameter shaft, which locks the arm solid.

Hope I've explained this well enough.

Dave, yes it's just a little red globe mate. The beauty of it is it comes standard with most EQ mounts these days. The little variable brightness light that I'm using actually is part of the low power scope built in to the mount to polar align it. I just don't bother to polar align it this way so I unscrewed the light from it.