david_taurus83

1 hour ago, cuivenion said:

Hi David, what are exif tempreatures like compared to the coolbox temps?

In the hour I had last night my subs were coming in around 11/12° but I was doing 10 minute subs. If I was to image with no cooling the temps would easily be 25°+. I checked some of the subs I done last week when it was cold out at 2° and they are the same, around 11°. Next session I will leave it out an hour before I start and see how low the camera temp gets. Overall I'm pleased with the performance considering the cheap parts I've used.

I have had that Recording Remaining Images message on my 6D sometimes after a session in NINA. I ignore it and cut power as there is no SD card in the camera anyway!

A bit more testing indoors today. It's about 26° inside here and the box is currently at 4.3° after about half an hour of running. That's a significant drop considering the warm weather and it's about what I was hoping for. I've added a few more velcro latches to the top of the lid as it came a bit loose last night. Another issue I'm facing is there is no way I can point to the zenith without the box hitting the tripod so I will have to look at a pier extension at some point. Currently ok looking at Cepheus and Cygnus though.

I finished the box this afternoon but then family duties took me away from my mess on the dining table workspace.

It weighs 760g which isn't too bad. I used some industrial strength Velcro for hinges and it flips open at the bottom.

I lined inside as much as I could and put an extra layer on the lid so it's nice and snug with the camera. Put in a connection for the cameras dummy battery and a male to female mini USB lead to once the camera is in place I can connect from outside the box. Only need to open the lid and switch on and off.

There was then a mad dash tonight while it was getting dark. I had to alter the focuser bracket to allow to rotate upwards so power and usb for the focuser didnt clash with the box. I also had to redrill the dovetail bar and reposition that also so it didnt clash. Then some configuring of pipes. I got a 5m length of 6mm silicone tubing off Amazon for a tenner and a couple of metres of 8mm and some reducers off ebay for another tenner I think. Didnt fancy running 8mm piping throughout as it's fairly heavy when full of water. Also rolled some of the insulation around the tripod leg and taped the pump to that. Noise and vibrations have now been reduced to almost nothing.

Almost didnt get off to a start then. I realised that I didnt have a cable to connect from buck converter to the camera as the dummy battery and connector are in the box! Had to switch out to a battery for tonight so once that's dead I'll be packing up! Also, once I was happy the pump was working fine and no leaks anywhere I switched on the peltier device and noted the starting ambient temperature of 18.3 degrees. I stared at the readout for quite some time and was starting to get annoyed as it didnt seem to be cooling. It even went up to 18.6 after about 10 minutes! I was starting to think that I'd just wasted time and money when I realised that during the switch out of dummy battery to normal battery, the temperature probe had fallen out of the box and I'd closed the lid with the probe stuck outside! Sorted that and all was well when it started to drop. Last check 20 minutes ago and the box was nice and chilly at 0.3° with an ambient of 18° outside.

Sweet 🥶🙂

Trimmed

Need to crack on with this. Missed a clear ish spell last night. The self adhesive foam was 15 quid off Ebay for a 2m x 0.5m roll btw.

A quick marry up to the 70mm quad and as thought, the dovetail needs to be moved further up. Also, the rotator needs to sit flush just above the actual box so need to trim a bit more off on the outside.

On 16/05/2020 at 18:17, Kathie said:

That's a good assessment.  I hadn't thought about it like that, I guess it would make me a beta-beta tester. : )   I hope they get these things resolved before you get yours also.  I wonder if my focus issues are an anomaly or if there are others with similar results.  I've taken many screen shots while collimating and measured to be sure my cross is exactly centered. I'm tempted to collimate off center to see if it would change anything. Sorry about the colored dots, I had to learn about dark frames. The focus wheel will unfocus further but not bring more clarity.

 

I'd be sending it back for a replacement.

From experience, the WO GT71 will not provide full frame correction. With the Flat6A II anyway, which is now discontinued. Not sure about the newer Flat 6A III. Anyway, I sold mine and bought an Altair Starwave 70 EDQ-R 346mm focal length. Very good correction on a full frame 6D and no vignetting whatsoever. Very close to your budget. Variants include the WO Star 71 (more expensive) and the TSQ-71ED. All with FPL53 glass.

Checked the pump, all ok. I tried reversing polarity and it wont run at all so its wired up correctly. Will have to look at dampening the vibrations from it.

Lid and controller are done. Might change those reducers to 90° elbows though.

Well I was up into the wee hours last night with this, fashioning cables and figuring out power source. A few issues to overcome. With my 70mm quad I will have to move it down the dovetail an inch or so otherwise the box will catch the bottom of the dovetail. The autofocuser cables attach from the camera side as well so theres not enough clearance for the box there either. Will need to alter the bracket and see if I can turn the housing 90° upwards. The pump is quite noisy and very turbulent so I'm wondering if I've wired it in reverse though its pumping from reservoir through the outlet on the pump? Will try and cross the connection and see if it's the case though what do you expect from the cheapest on ebay?! Still need to sort pipe routing and insulate the box, general tidy up but it works with no leaks. A quick 15 minute test indoors and the box lowered from 25° on start to 18°. Before switching off I put the thermometer probe into the cold heatsink and it registered 3° so there is promise with the idea.

Cheap water pump with reservoir £27 ebay special

Hopefully Adam, if it works!

The safety grills were £3 each.

Hoping get some testing in tonight and start fitting out the scope. 240mm radiator was £20 and the 120mm fans were £11.

This lid has taken me some significant time to grind flat inside and out. Would have been much easier to just find a flat bit of perspex or something. Oh, and I cut out the peltier hole in the wrong place first time round 🙈

I have some self adhesive insulating foam to go both sides so shouldn't be an issue.

Yes I have a couple of the fan types and they add a lot of weight with the heatsink. Hopefully with this it will only add a few hundred grams. This will have radiator, fans and water pump and reservoir hanging below the tripod!

Lid marked up, cut and filed down to size.

Fits relatively snug. Might not be 100% airtight but it will do I think.

You have the cool version so should have this?

Just looked at that other thread and you do seem to be having a bit of a mare with it currently! FWIW, my AZEQ6 developed a bit of rocking/backlash in the Dec axis after 6 months from new. I followed the AB guide on adjusting with the 2 work screws and it fixed it so the guide is not all that bad. Just need to use a bit of common sense when tightening things.

BTW, what is your pixel scale at 1.6m focal length?

Sorry, I looked at the total RMS error. The peaks look very bad and your sub says it all as well.

Looks like periodic error. The spike could be a bit of dirt or damage on the worm. Apart from the spike it appears to guide quite well?

I dont think anyone bothers now given the availability of all the dedicated astro cams with tec cooling. That said, I'm sticking with my 6D for a bit and I fancy a go at making something. Not looking for sub zero chip temperatures but I would like to emulate a winter environment for the camera body with the aim of keeping the box below 10°C if possible. I first though about a fan and heatsink cooled option but from experience this isn't very efficient and typically only cools to a few degrees below ambient and I also dont want a fan to induce vibrations around the camera. So I am going for a water based cooler similar to those in custom built PCs. Mine however will be as cheap as possible! I think I've got all the parts now so today I started on the box itself. This will be a work in progress and I'm kinda winging it as I go along. It'll either be a rip roaring success or a damp squib!

I got a junction box off Ebay for £13.

The camera body is a snug fit between the internal corners

After careful measuring I lined up a hole with the cameras mounting socket underneath. The box will be secured to the camera with a small screw.

I then used some of the others halfs eye shadow to 'paint' an adapter on the T ring to leave a mark inside the box. I have a 52mm coring bit that I used to drill out the front hole.

It lines up pretty well initially.

I need to make the hole about 60mm so my flattener fits inside the box itself as with a DSLR I obviously have no play with spacers so flattener needs to mate up flat to the T ring. So out with the dremel for some tidying up.

Test fit and looking good.

Tomorrow I'll tackle the lid. It's too deep for my liking so I think I'll whizz the top off and have it near flush with the opening so theres less volume to cool around the camera. I should have enough room to the top right of the camera to insert the small cold heat sink of the peltier.

I'm not sure about the filters in the Canon body but I know the CCD type have IR/UV cut so if your sure the filters left in place have adequate IR/UV blocking then you should be fine with the CLS. Personally I'd opt for the CCD version regardless.

Do you mean you want it to display the sensor size in CdC?

I bought a Petzal Tikka when I started this hobby. The red always comes on first and you have to long press the button to change to white. It also can swivel downwards so if you are looking around it's not shining in people's faces. Maybe a bit too bright still for a star party.