Stub Mandrel

I was amazed when I saw M17 through a 250mm dob last week. The 'swan' part was very obvious, especially the 'eye'.

Certainly should. It will also give you much better z-axis resolution and precision and load the motors much less, at the expense of speed.

I can see dropping being a PITA, perhaps a counterweight on a wire/string over a pulley? Works very well for milling machines and unlike various combinations of springs and levers it gives a constant force (just doesn't feel as high-tech...).

If you fit ballscrews it will drop right down with the power off, on machine tools they are generally only used for CNC where a motor gold the position. Anti-backlash would be pretty pointless as the weight you have will take up any backlash (TBH they are pointless on any 3D printer as the carriage only moves one way...) A few 3D printer things are snake oil, like bearings on top of z-axis screws, although I fitted a pair just to look neat...

Seems a fair deal to me. Might do it for the 76mm newt I rescued from a mate's skip, just because I can!

I looked up the cost for 38mm to and the price rockets. I assume you went uncoated? Still I can't see any reflection issues in your images.

Looks smashing Dave.

Unless you have your camera in exactly the same alignment to the scope every night, you need a new set of flats for each run. I get around this by sighting across the flat bottom of the camera to the flat edge of the focuser to make sure they are almost exactly aligned. you should be able to get an alignment of better than 0.1 degree this way which is enough.

It's surprising, that screen really isn't as bright as it looks, here's a screen shot; The other evening, I stuck a red A3 plastic wallet over the screen though and it seemed to make quite a difference, although using it knocked out my dark adaptation for about five minutes. I also made sure it was pointing in a sensible direction. The various red LEDs and small green display don't seem to cause any problems.

LOL! print yourself some accessories and get an excuse to combine the two interests.

These are mine from Saturday Night. Had a lot of problems. Imaging is harder in the 'real' dark, so only 11 subs each! Heart Nebula: NGC1023 & IC239:

@tekkydave I noticed this in your sig: DIY Bahtinov mask (Cardboard based ° ) Try printing this for your Nexstar, you'll need two M6 nylon screws to poke through it as supports. 130P-DS mask.STL

Blackeye galaxy?

Someone suggested he looks at this thread...

My plan for last night was to get this, I saw it visually in a dob, but I couldn't find it for imaging

Hello Steve, Drop Andy a PM (hover over his user name and click message) .

Hello Andy, PM sent!

Is anyone up for tonight? Forecast looks like it could go either way but improving after midnight, better in Staffs than Shropshire at the moment...

We appreciate your sacrifice

Thanks, no there was less noise = less noise removal = less mottle. With the cooled DSLR (well below zero) Ha seems to benefit from darks but ordinary images don't, probably an issue of temperature matching, but the noise really is very low.

I've put another note up on the forum because I don't think this thread gets much traffic and folk from across the west mids might be interested.

Lets keep in touch and decide tomorrow afternoon?

Fair enough! Parsley Hay in the Peak District is good but a bit far from the BC, but I'm happy to travel further your way to a decent, safe site, as far as Shropshire. Saturday was looking good but it's gone red on clear outside, still looks good on the met office forecast...

At the risk of clogging things up, here's a version done without any darks.

Cannock Chase on Saturday night? We need sufficient cars to deter any doggers... The Glacial Boulder car park is (possibly) small enough and far enough away from the road?