Gina's DIY All Sky Camera - Mark 4 - with ZWO ASI185MC

[Gina]

Looking good - Milky Way showing nicely

 

[Gina]

Here is the saved still file cropped a bit and reduced in size in Ps for upload here and saved in PNG format.  The focus needs adjusting.  I shall arrange remote focussing later.

[Gina]

Nearly dark now.

[ChrisLX200]

Milky way is showing strongly there Gina, your site is clearly darker than mine!

ChrisH

[Gina]

Best shot I've had of the Milky Way so far   Yes, this is a very dark site - I'm very lucky here.

[Gina]

Cloud coming over now.

[Gina]

Think the clouds may be going away again.  Two aircraft trails in this view.  Exposure time 60s, normal gain, gamma at 26.  Also capturing AVI. again.

 

[Gina]

Now working on a new mast mounting and case for the ASC.  Also, looking into remote focussing.  With the current arrangement I can focus by turning the 3D printed part that holds the dome which is a sliding fit on the main casing.  I do this by hand ATM but could arrange a pair of spur gears and small servo motor.  I would keep the present dome and ring and design a new casing to take the ring with a press on spur gear for the ring.  With a 20mm flange on the mast mounting there will be room for a Raspberry Pi 3B on edge.  Design models to follow...

[Gina]

Been turning the mast fitting but the drive on the lathe has failed.  Motor's running but no drive.  Not the gearbox because it's the same in both ratios.  I was on the low ratio merrily carving off swirls of ali but I guess I overloaded it   So sometime I'll have to strip down the lathe and see what the damage is.  Goodness knows when I'll be able to finish this project.  Have to have a think - may be able to arrange a different sort of mast fitting.

[ChrisLX200]

Oh dear. Probably a little drive pin sheared or something like that. Hopefully an easy fix.

ChrisH

[Gina]

Partly dismantled lathe drive and it's the timing pulley, driven one, for the motor timing belt.  Looks like ABS plastic.  Broken around the key slot.

[Gina]

An alternative to a turned aluminium mast fitting would be a 3D printed one with an aluminium plate attached to the camera and coming out to the side with a finned heatsink screwed on or it could be attached to the mast with bent aluminium brackets.

For remote focussing I could use the current dome with ABS spider connecting the lens focus ring to the dome ring and then external spur gears to drive it OR I have a new, replacement acrylic dome which is 100mm diameter compared with the current dome of 75mm.  The 100mm dome would have room for spur gears inside with one gear on the lens focus ring.  The 100mm dome was a lot more expensive than the other domes I've used but should be much better quality as it is a replacement dome for a commercial ASC.

I already have an Arduino Nano with stepper motor driver and stepper motor that I used in the previous version of my ASC.  I would just need to print a couple of spur gears.

[Gina]

This is the lathe part that's broken :- C3-27 Pulley  as listed by Arc Euro Trade spare parts.  Cheap enough but they're out of stock   I guess everybody's breaking them!  I guess I could probably 3D print a replacement.

[Gina]

Found another supplier but at twice the price!  Think I'll try designing a replacement in SketchUp tomorrow.  Shouldn't be too difficult

[Gina]

Designed and printed gears for remote focussing.  These fit inside the 100mm acrylic dome.  I may reprint them in black ABS if their reflection can be seen in the dome.

[gentlebear76]

Hi Gina (and all the rest :-) ),

I was wondering if your camera has an internal shutter or if there is one in the lens. I'm working on something similar, although I use a qhy5 camera in mine, and I'm unsure if I can leave it outside all day in the sun without it getting damaged. I have been through all of this conversation and the previous ones about your all sky cameras and I know the Fujinon lens has a manual aperture but what about this one? Any way, it's a very impressive setup you've got. I'm looking into passivelly cooling my camera as well but finding something with an inner diameter of 1.25" or equivalent is pretty hard in Denmark :-) Trigger creativity ;-)

Clear skies :-)

[Gina]

Yes, the ZWO cameras have an internal shutter and are quite safe in full sunshine.  With the ASI185MC that I'm using and most (maybe all - I haven't checked all of them) have a minimum exposure of 32µs and both night and day imaging is fine.  I'm using the AMCap software supplied with the driver and that has auto exposure and auto gain and will automatically adjust to the full range of light levels, though you can get some blooming from unshaded sun or moon.

I thought I had a midday image with full sun but seems not.  I'm working on the ASC ATM but when I have it outside again I'll capture an image with full sun and upload it.  These show a bright evening and rising moon.

[Gina]

Cloud forecast for later tonight   After several days forecasting clear skies for several hours after dark!!!  Fairly clear ATM with just a few cumulus clouds about.

[ChrisLX200]

Forecasts for my area have been alternating between cloudy and clear throughout the day, currently saying 'partly cloudy' - I guess they couldn't make their minds up in the end   I guess I'll have to set up anyway to find out, at least rain looks unlikely.

ChrisH

[Gina]

Still without dome as I haven't yet made the new case etc. Focused by hand with camera pointing south towards the far horizon out of the window before hanging the rig on the guttering.  Both domes change the focus so remote focussing is needed with a dome on.  Guessing the focus change is not good enough.

[Gina]

Clouds seem to be going away.  Fingers crossed.

[Gina]

Clear sky ATM but will it last, I wonder...

[Gina]

Stars are starting to show.  Odd wisp of cloud.

[Gina]

Autoexposure up to 10s now.  Gradually getting dark.

[Gina]

35s exposure and Milky Way showing