Jessun

Here it is seen with an iOptron mount and an Orion 8" RC. The design allows me even with this load to sit on the mount plate adding another 80kgs still lifting and tilting it by the flick of a switch. It is naturally far from ideal in terms of pier design but it's the best I could come up with for my particular problem - limited balcony space.

Sure Nibor, when it all comes together... I'm just preparing for the future with this build.

I am stuck with the limits of my balcony measuring a bit under 3*3" so waiting for the AP1600 mount I quickly realized that it wouldn't even fit out there without any OTA hitting the wall or doors...

A few solutions:

Build a bigger balcony.

Move the wall.

Don't bother with the mount.

Something else.

So I decided on Something else and set out to build my own mobile pier/tripod. Armed with a welder, some stuff from the local DIY store, a few cans of spray paint and a roll of very deer Kapton tape I designed this thing, that I just had to call Sky Crane inspired by the success of the Curiosity team. I even gave it a suitable space look .

The most tricky aspect of the build was that it had to be done on that same balcony - so the welding proved difficult on the limited space but I got there in the end. The frame weighs 52 kgs, fully equipped it's at 80kgs and it also carries up to 50kgs ballast at the back totalling 130kgs. The bars that will extend over the rail of the balcony to give me those vital extra 10 inches have a cross section metal content corresponding to a quarter of what is used to mount a B747 RR Trent engine to the wing - and that thing delivers 68000lbs of thrust too... Clearly they use far superior metal in their bolts but this design is just designed to carry a 52kg mount plus up to a 50kg (400mm) telescope plus CW, so I am convinced they won't snap.

Such a big telescope load would be tricky to polar align being a moving setup, hanging over the edge of a balcony so I built in three half tonne actuators that jack up the whole thing using the switch box mounted on the left. I can easily move each jack half a millimetre at a time. There's a fourth switch not yet in use dedicated to a future powered AZ adjustment meaning that I'll be able to polar align to an acceptable accuracy using just the switches. To aid this the top box features an LED screen connected to a sensitive camera that fits onto the polar scope so I won't even have to lean over the edge to have a look.

It has a 220V power supply with a 26AH battery backup with the goal to move towards a UPS system for any eventuality. When finished it will also incoporate an industrial USB hub - that uses 12V as a source to power whatever needs powering. On the right you'll see a clever zippered sleeve riveted to the frame that will hold all the cables for a tangle free setup. Best solution I've seen for cable management maintaining instant access to each cable.

The business end has a 10mm aluminium mounting plate seen in the picture with the Astro Physics 1600 10" mounting ring. Depending on scope/camere setup I may have to put a section in between there to lift it to the right height.

When looking at this design you have to bear in mind that since I can't flip it's in this configuration only suited to image east or west. Pointing at Polaris the counter weights will extend below the balcony rail, but with limits preset they should never crash into it hopefully!

PM sent Davey-T.

The iOptron that I use as mobile setup has a built in GPS, and I find it to be great. It takes a few minutes at most to power up but you can turn it on the first thing you do, so when you're finished setting up it's up and running, ready for polaris.

All it really does though is increase your chances of having the first alignment star close to the cross hairs. For some reason when I use my HEQ5 I'm sometimes off by 30 degrees... Obviously something I do wrong.

Pay extra for one? Hmm, naa I'd have a look in the Tomtom in the car and scribble that down.

I'm with Olly on this one. Imaging is all about S/N ratio so why even bother with 30 min subs Sara? The atmosphere will inevitably increase the size of the Airy disc on any star or source of photons and the gain is well I don't really know. Unless you take 20 of them? (Airy has nothing to do with air btw...)

As to perfect alignment, I believe that it can all be guided out for any reasonable sub length and if backlash is a major player with your particular mount then why not 'misalign' and 'unbalance' to keep the adjustments going in one direction using a slowish guide speed so as not to induce that pesky gear wobble?

Then dither and sigma stack and do loads of subs and that's it!

Sub length is like Watts on a car stereo IMHO...

I have used and compared many mounting systems - I'm talking about pucks, dove tails, dual bars etc - ranging from standard Skywatcher and iOptron to Vixen, Geoptics, William Optics and Altair Astro and in my view Altair Astro beats all competition when it comes to fit and function and versatility. Put on gloves and get out in the dark and AA does the job better! Look at surface to surface contact on the various plates - just by looking along two connected plates for instance against a bright background and you'll find that some systems grab on by a knife's edge while AA pretty much block the light - their plates be that Vixen style or Losmandy fit like no other.

And as to service I recently received and item that had been damaged during shipping and all it took was one e-mail. The reply came within the hour and with no question asked a replacement item was sent that same day. Not even a mention on how and when to return the damaged item. Outstanding!

I would not go on here to name and shame any company - I think everyone can have an accidental bad day. But you don't accidently have good days over and over again so Altair Astro deserves a Thank You for consistent fab service and again the mounting products are just phenomenal.

If it's anodized blue it's gonna work!

Ok, the official SX answer is this: a warm pixel in the vertical register, which is a readout issue, and the cure is BIAS as pointed out by you guys. Very common too, and within specs.

I am happy with the reply, and can forget about it now. A few BIAS is no biggie, useful in any case I reckon. I can't wait for some clear nights...

Thanks again for the input on this guys!

Here's a BIAS stack, 20 of them. The line is dotted up and more solid down. Does that give a clue?

Flavour 1 confirmed Steve! We're a day early on the continent! Excellent!

Harry, this pixel and associated line is not completely hot. It seems to feed a bit on light, but visible to certain degrees in Lights, Darks and Biases. After tinkering around with a few exposures before the clouds drifted in it is pretty clear - as you guys pointed out - that it does not pose a problem. As Olly points out this will even easily dither away with a stack.

Not heard from SX, but if they want to take this camera from me they will have to send a SWAT team to get it! My initial play around is very promising.

I ran the Lodestar through its first run too and it too performed really well. The only problem was to bring it in focus during daytime to get all spacers right. I was down to 0.0001 second exposure in Nebulosity (can it do that??) with centre dust cap off only - and still it over exposed like crazy! Sensitive little thing!

Thanks for all your help with this 'issue'.

FLO are often featured here with good comments, and they sure deserve it. I made an small order to ship to France a few days before Christmas and it's all delivered.

When moving abroad, it's great to have good support from Blighty!

Thanks for the info Steve! As of yet I have heard nothing from SX, so I am not sure of a) what this is - as specified by SX - and if it is covered, so I'll leave it there for now.

I can always return the camera anyways to the dealer if I wish - German consumer law I'm guessing...

I was hoping not to have to take darks so that is good news. Darks in the wrong hands just make matters worse and I need to develop my skills more...

At least a BIAS is quick! It would be great if it was such a simple cure for this CCD too! I'll give it a crack asap.

On another note what size is your book? I am trying to work out some flat packages under the Xmas tree...

Thanks Gordon, yeah wait and see. ATIK for example clearly state that they use grade two CCDs unless specified and that the odd bad column can be present BUT that they assume that darks will be used anyways. SX say no bad columns and that no darks necessary for 'most deep sky objects'. As for SBIG... well I saw 9000 dollars for a full frame OSC and quietly left that website...

I do not know for sure if this is a bad column per definition or something else - I am no CCD engineer. My line goes all the way, only dotted and weaker 'up' so takes a bit of effort to see it. Perhaps it falls under single pixel error too.

I have run some trials with Nebulosity's Bad Pixel Mapping which is an very interesting alternative to darks but this does not cure it in the result. Darks do and I have played with flats as well and that seems to cure it too. (Still puzzled by that btw considering I did a 3*3 median blur on the flat and Nebulosity does another blur on top of that...)

I got the SX based on the 'no darks required'.

Anyways, the jury is out on this and I don't mean to discredit SX in any way with this thread. I just seek to get the facts right. Apart from that one gremlin, the camera is an absolute joy to work with - Nebulosity does the best job so far as AstroArt is a hit and miss still if it downloads a useful image or not. That's another story though...

Cheers

Thanks Andrew, I sent the question to the guys, and know they'll be quick to answer as they helped me out before. It's weekend now close to Christmas but it wouldn't surprise me if I had an answer in the morning.

It's pretty clouded here now so I can't do much more yet...

Hello all,

This is a 10 second dark with a newly delivered SXVR-M25C. Specs state less than 50 hot pixels in 10 seconds which this one passes - just.

But this annoying green line? Is that in fact a 'bad column'? Specs state there should be none for a grade 1 CCD.

The line appears regardless of exposure time...

CCD temp is -10°

Thanks in advance

This is a very reliable shop and their service is lightning fast!

Example: Bought a telescope from a large UK supplier, I was sent a demo and a part was missing but I thought it wasn't a big deal. I asked this shop to send the missing part and also for info about accessories that I might need, and sent the same question to Teleskop Service...

Teleskop Service answered, sourced, packed, shipped and DELIVERED before the UK company even replied...

I am still waiting for the missing part...

I am delighted to deal with Teleskop Service and it's obvious that they will have my future business!

/Jessun