Gina

Will see about support. Let's see if it can cope with those bridges ?

Yes, fine if you're making tiny parts. I get through a lot of filament with my FDM 3D printing. But then, I tend to print big things like brackets for astro, giant wall clocks, etc.

Decided to try it this way - the side slots match up with the cooling fins in the camera.

Yes!

How about this orientation, Chris?

Trouble is, to avoid relying on inter-layer bonding it will need 90-100mm long bolts.

I see what you're saying - it's relying on good inter-layer bonding which PETG is famous for but...

The total weight of the rig is less than a Kilogram and PETG is strong - particularly this thick, so I think the bracket is strong enough. Anyone else have an opinion on this? OTOH I guess over-engineering is not such a bad idea in view of the cost of the camera.

Model of brackets for camera and focus motor. Found covers for the fuses so I see no point in designing and printing a new electronics box.

Hold on, I'm just designing it now...

A suitable choke is what's needed to do that. The result would be the same as you have on order ?

Bang???

I have considerable investment in FDM so that's what I'm sticking with for the moment.

I have decided to get the ZWO ASI 120MC-S from FLO. I feel a bit "lost" without the ASC image to look at! If this camera turns out not right for my ASC I can use it for planetary imaging later as I have in mind. My standard widefield imaging rig is taking priority though.

Useful link Louise, thank you. In my all sky camera system I used just two preset levels of cooling with a Peltier TEC. A low level for daytime use just to take away the thermal heating and a high level for night-time to cool the camera and reduce noise. These are simply 5v and 12v on a 15v TEC. Instead of PWM I simply switch one or other supply to the TEC using power MOSFETs. These are controlled by an output data line from a Raspberry Pi.

A couple of photos that show how I'm planning to mount the parts on the dovetail bar. Just roughly placed. Having the focus gear beyond the end means that the focus motor can be mounted further down on a shorter bracket, with the gear going below the dovetail bar. This is just a mock-up, I'm still planning to make all the brackets in one print.

I've read that Peltier TECs don't like being run from PWM.

ZWO ASI 185MC or 385MC have a coverage of 7.26mm x 4.11mm. ASI 120MC has a coverage of 4.8mm x 3.6mm. That is 87.6% of the height of the 185/385. This is not as bad as the diagonal sizes would indicate as the 120 has a narrower X to Y ratio. Here are a couple of screenshots of the two image sizes. First is the image from the ASI 185MC and the second the same image cropped to the size of the ASI 120 image sensor with the original size (185 camera) shown as a dashed box. The loss of coverage is far less that I anticipated and seems acceptable

I might make a combined print for holding camera, focus motor and electronics. That would want just four screws to attach it to the dovetail bar.

New test model for camera bracket.

Indeed it has!

Old eyes are a distinct nuisance! Since I'm mainly short-sighted, I take my glasses off for close stuff, put them down somewhere and then can't find them. Drives me up the wall. OTOH things could be a lot worse...

Printing finished and I've tied it out on the camera and dovetail. I'm not satisfied either with the camera bracket or the placing on the dovetail. The electronics box really wants to go nearer the end so that the whole camera+EFW+lens unit is within the dovetail. Hence I shall design a new electronics box with more suitable fixing holes. At the same time I can fit the fuses inside the box where they are safer from damage. The camera bracket I printed in PLA but I think it needs PETG for better flexibility, robustness and interlayer adhesion. Yes, I succeeded in breaking it!

A bit later...

Printing the camera bracket on my Concorde 3D printer.