cuivenion

Cheers Roland, I'll add some more subs tonight.

Cheers Roland I'm cooling with a peltier:

The sensor was stable at -5c. The image is still noisy because I was using high gain 30s subs and you generally need a lot more subs using that method. Unfortunately it was quite windy as well so longer exposures were out. Hopefully I'll get better results in calmer weather.

Well the cooler works really well. The sensor temp stays very stable. There was only 0.1c variance in temperature between lights. The only problem I've encountered is the cold travelling up the imaging train and misting up the coma corrector outer lens in the focuser tube. I'm hoping that a dew band on the outside of the focuser tube will sort that out. If not it's time for a diy dew band and drilling a hole in the dovetail-m42 adapter.

Did an M51 with my 130pds last night. I was testing out my new cooling system for my ASI224. The near full moon has washed it out quite a lot but I'm still quite happy with it for 2 hours exposure.

9 minutes ago, Gina said:

Looking good

Cheers Gina, thanks for the advice too.

Haha, it might wake up airport security a bit thats for sure. It's not as big as it looks in the images and probably weighs about as much as a DSLR. Dread to think how it looks on an x-ray though.

Cheers Craney, one of my favourite movie's.

This has been a fun project to pass the time. I've sorted out a much needed cooler for my ASI224 camera, just in time for summer.

Testing in a warm house about 20c ambient Ive had the sensor down to -4c. Fortunately you can get a temperature readout in Sharpcap. The temperature probe is on the side of the camera casing and was showing -10c with the external thermostat. Just need the desiccant to arrive today and I'm ready for first light tonight.

Here's a comparison of two 30 second darks, the left one is at 30c, the right one at -4c. Looking good.

Thanks Gina, I need the screw in wire sockets because I don't have a soldering iron at the moment. I'm not bothered about the dc or usb port though. The project's coming together nicely, just waiting for the dessicant to arrive so I can give it a proper test.

6 minutes ago, Davehux said:

Being a tightwad, I wasn’t going to spend £30 on two bolts, so I bought these for 10 quid. 

Work perfectly and don’t foul the polar cap on my HEQ5. 

I gave them a spray of WD40 and greased the threads to stop corrosion.

https://www.ebay.co.uk/itm/183147383975

Only problem with that is that the bolt doesn't have a rounded end, so it might dig in and damage the mount eventually. I've tried looking for a hardened steel bolt with a rounded end to fit in one of them clamps but I can't find one anywhere. I'm at 54 degrees north and I need a longer bolt but the usual one just bends.

After doing a test with the peltier and the thermostat i was getting the peltier down to nearly -30c with an ambient temperature of about 20c. This is running the fan at 5v. Running the fan at 12v full speed made no difference to the temperature that could be reached, so I'm definitely better off running it slower at 5v.

If I'm just running it at one voltage would I be OK using something like this:

https://www.amazon.co.uk/Power-Module-DC-DC-Supply-Converter/dp/B071ZRXKJY/ref=sr_1_146?dchild=1&keywords=12v+to+5v&qid=1588349702&refinements=p_76%3A419158031%2Cp_72%3A419153031&rnid=419152031&rps=1&sr=8-146

The is the heatsink and fan I'm using:

https://www.amazon.co.uk/Zalman-CNPS5X-Performa-1155-Sockets/dp/B006344OMM

There seems to be a lot of contradictory info on the net about powering fans. I don't want to damage the fan as getting another to fit will be difficult, If anyone has any advice that would be great.

Hi, it's quite loud at max rpm. Also having it at about 1/2 power cuts down on vibrations and the peltier still seems to work fine.

Hi, I'm currently putting together a cooling project for my ZWO ASI224. I've experimented with controlling the fan from a power bank where I can switch the voltage from 3.7v-12v and this seems to work fine for controlling the fan speed. The fan is a brushless CPU 4 pin PWM fan that I've connected to the DC using just the positive and negative (red/black) wires.

What I want to do is have a control box where I control both the pelter and the fan and I'm trying to find a suitable fan controller. I've been looking at this:

https://www.amazon.co.uk/DollaTek-Controller-Regulator-Switching-Indicator/dp/B07DJ5564D/ref=sr_1_5?dchild=1&keywords=motor+control+12v+dc&qid=1588179441&refinements=p_76%3A419158031&rnid=419157031&rps=1&sr=8-5

The problem is that the pwm frequency is not correct and I can't seem to find a budget similer item. There are other items like this but either the frequency is wrong or just not mentioned. If anyone can point out the correct part that would be great.

I'm also a bit at sea about the wiring. Can I just connect with positive and negative and still get PWM control?

Cheers Gina.

I was planning on using insulation material around the camera, if I put the sachets inside the material do you think that would work? I'm wondering how you held  the desiccant to the camera body. Did you just tape it?

Thanks Gina. How do you desiccate around the whole camera?

I'm doing a peltier cooling project for my ASI224 and I'm wondering if it's safe to put silica gel beads into the sensor chamber:

I want to make sure the beads or other dissicant won't damage the pcbs or sensor in any way. If anyone has good budget suggestions for dissicant please let me know. The ZWO dessicant is a bit pricey.

Hi. If you already have a way of attaching the heatsink to the camera it might be a pain to change it. You could try unscrewing the fan from the heatsink, putting pieces of rubber at the corners/sides between the fan and the heatsink and then attaching the fan to the heatsink with strong elastic bands. I tried it with my Zalman fan and it seemed to work great by feel. You will have to remove the plastic fan heatsink attachments for it to work.

Actually did a quick test with the ASI224 attaached to the heatsink/peltier with an elastic band. 8 second exposures at 135 gain the camera was at 27.5c, atfer about 10 minutes of cooling it was down to about 8c! That was without any thermal compound between the camera and the peltier.

I was going to try and figure out a cold finger design but this seems to do the job just fine.

Hi, I am working on something like that for my ASI224.  I also have a baader modded 600d and to be honest I really don't want to try peltier cooling that. The Martin Pyott method may work for the 600d and I might get around to that, but I would like some options to cool the 600d while I'm working on the 224.

Hi, on my last imaging session I noticed a big jump in temperature and noise in my uncooled camera. I was thinking of using freezer packs of some sort with a home made neoprene fitting for the camera. I'm looking for lightweight and as long lasting as possible freezer/gel packs. If you have any suggestions please let me know. I wouldn't know a good example of this type of stuff if it hit me in the face

Cheers. Unity gain is 135 at 12 bit with the ASI224. It can be a struggle if there are bright stars in the FOV because the full well isn't massive. I'll probably use gain 61 from now on as thats where HCG mode starts and gives better dynamic range with only a little more read noise.

I may also do some shorter exposures on some of my images and do some HDR processing.

Very good image, sorry for your loss mate.

As I'm using the AS224 to image I can only go after one of the Leo triplet at a time. This M66 with about 6 hours of 1 minute lights at unity gain. Unfortunately every night on this was a bit breezy so I had to throw out a lot of subs.

Mount: Skywatcher HEQ5

Imaging Camera: ZWO ASI224

Guiding: Altair GPCAM with FinderGuider

Imaged with Sharpcap 3.2 and PHD2. Processed with DeepSkyStacker and Pixinsight

Any comments or criticisms welcome as ever.

Great stuff, that Croc's eye is especially good!