AirBourn wrote: Now that the seasons are changing and temps are falling, is there a minimum temperature I need to worry about when operating StellarMate outside in the cold?
Lol, absolutely not, it generates far too much heat of its own for cold weather to be a problem....as long as damp can’t get in you will be fine...
Stellarmate OS on Raspberry pi4b
Skywatcher EQ8 pro, on steel pier
Takahashi FSQ85 & Meade 8” SCT (de-forked)
Starlight Xpress SXVR H18, SXVR M25c, Lodestar x2 Guide Camera
Pegasus Ultimate Hub V2 for all USB & Power
Pegasus focus motors on both scopes
What about other equipment? Do any of you have experience with cold temperatures and have a personal minimum temperature for your gear? I'm in Minnesota, and this is always a consideration for any kind of equipment. I'm thinking about filter wheels, rotators, mount motors, circuit boards, cables, etc. Anyone in a cold weather climate have opinions there?
Not from experience, but a few things I would consider:
- cables are less flexible, maybe even brittle.
- mechanical adjustment of for example worm gear play could get too little.
- grease between the worm and worm gear gets a bit thicker.
And just try it, it will probably be fine
15 cm wavefront condensor | Earth rotation undo-er | Few photon discriminator plates | Photons to electrons transmogrifier | Stellarmate
I live in Finland and have had an automated remote observatory for three winters now (and one winter I imaged from my backyard) with temperature routinely under -15C. My observatory is not insulated (glass fiber dome and walls) and not heated apart from the equipment itself (only the control computer and IP-power switch are powered all the time, but don't have extra heating in a cabinet) and for the most part everything has worked just fine regardless of the temperature.
The specifically cold related things I've done are:
- using silicone cabling for power and USB (I have only one each going to the OTA with power and USB hubs mounted on top, so most cables don't move) as they don't get stiff in cold
- changing lubrication in my previous HEQ5 mount (though I did run the first two years and my current EQ8 with originals so far)
- tuning mount gear meshing in the cold and not during summer
The observatory is a bit warmer than the environment as it shields everything from wind and so on so dew and frosting hasn't really been an issue at all, though my open RC OTA is easier than SCT or refractor in that regards. I don't even have dew heaters installed even though I have them as haven't had the need.
The problems I've had related to cold are:
- some guiding issues probably from stiff cables at first before changing them, haven't had those since, though I also improved the cable management at the same time
- had some largeish backlash issues with the mount at first, possibly related to the lubrication and worm gear meshing as they disappeared after changing those
- my first remote controllable power switch just couldn't keep its relay on if it was cold enough and just turned everything off
- my dome closed switch stuck to closed position due to some powder snow having found its way just inside the shutter and melting there, dripping over the switch and freezing there
So all in all things work surprisingly well in cold as well with some caveats.
Very good input and insight - thank you! I'm particularly concerned about the mount handset and its LCD. I find it interesting that you don't use dew heaters. Do you think actually using them is a mistake? Differential heating or expansion issues - anything like that?
Can't comment on the handset as I haven't really used one, just EQDir cable. LCD screens might get very slow in cold but haven't seen any break so far. As for dew heaters it's most down to pure laziness, I originally didn't install them, noticed I didn't seem to need them in the observatory so to save weight on the HEQ5 I left them off. Now with EQ8 weight isn't an issue anymore, but haven't bothered. With refractor, SCT or similar closed OTA or without shelter the case would probably be different. Then again the worst humidity issues I've had have been not in properly cold weather but just above freezing in the autumn.
I ran unattended all night last night. Low temp was about 17F. I do have heater strips on main scope and guide scope. Everything worked fine outside as far as I could tell, but I did notice some light frost on some of the plastic parts of the mount and HC. Also, somewhat more concerning, I saw some light condensation on the metal parts when I brought it back into the shop (as would be expected). I left the heaters on until the condensation dissipated, but I sure didn't like seeing the visible moisture on the gear - and probably unavoidable.