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So I am quickly coming up on my first winter....in this hobby, and I think a little more thought needed to go into the temperature limits. This mainly covers the mount, but I would like advise on other components as well if possible. My setup is GM811, WO 91MM, ZWO 2600MM, Pegasus Pocket powerbox, Beelink mini-PC. I have the mini-PC in a Home Depot storage tub I have the cover on during the night. Out of the Pegasus I have 2x RCA jack dew straps on scope & guide scope. But also use my older 5.5mm dew straps, one extra on the scope and another wrapped around the mini-PC. A 3rd dew strap I got off Amazon years ago has USB end which I plug into the 5v USB port and wrap around the Gemini close to the ethernet port. This is ultimately what worked well for me, and did resolve a lot of issues I had dealing with early morning dew.?
So now it is getting colder I need to know my limits. As I am not just dealing with electronics, but also mechanical aspect of the mount itself. If I want to play it safe, at least for this winter, what temperature limit should I set for myself where setting up risks damage to mount, camera, or telescope??
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I am interested in monitoring this topic.Living in Washington DC region. ?Been using the Telegizmo 365 cover set for a few about a month. The mount is setup on a large deck, exposed to environment.
The 365 cover set kept dew from forming on the mount and attached equipment. The 365 cover set has also handled the frost so far and lots of rain. I plan to test it down to 25 deg F. Below that, I plan to disconnect all and bring the pieces into a shed.?
For now, my all-one/pc/desk is in the shed and I run cables between shed and deck. I bring the all-in-one PC inside the house when temps approach 40 deg.?
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Hi Sean
this is a great topic. There are several different?risks you mention: moisture and temperature specifically
Regarding temperature, the mounts can perform to very low temperatures. The lubricant we use (arctic lube) is rated down to about -40C. The Gemini unit and hand controller are electronics so they are a more sensitive to temperature: keeping them warm through covering them, disconnecting hand controller (Gemini operates fine without the hand controller, and you can connect/disconnect pretty much any time) and keeping warm, and as you mentioned keeping some warmth around the Gemini all help
Regarding moisture, that's something you want to be more?aware of.?
I have telegizmo 365 covers on two telescope setups. We recently had 8" of rain in a 24 hour period (crazy!). While the covers did great, I had a problem with dew forming beneath the covers. I solved this by using a gun safe warmer (basically a low wattage heater) attached to my tripod. Here's an example of one:?
Keeping warm air beneath the covers made all the difference for minimizing/eliminating dew. If i were thoughtful i would probably bring in my telescope setup (with telescope-top nuc-style computer, router, powerbox, etc.) but I don't
Which brings me to my additional experiences: I pretty much leave everything outside 24/7/365 under telegizmos cover. I've had summers at 118F and winters at 20F. 8" of rain, dry spells, etc.?
So far, 12 years later, I haven't had any issues to speak of. I do try to keep things in the shade (umbrella or radiant shield barrier) when it's super hot, and use dew mitigation for when it's rainy. I check and adjust the gear mesh 2x per year, once in summer and once in winter. otherwise that's about it.?
If I have time and available effort, I would probably bring in my gear more often, but I don't.?
I'm not suggesting that anyone do what I do, but things are surprisingly sturdy?
Brian
On Tue, Nov 9, 2021 at 4:51 AM Sean < ssa2207@...> wrote: So I am quickly coming up on my first winter....in this hobby, and I think a little more thought needed to go into the temperature limits. This mainly covers the mount, but I would like advise on other components as well if possible. My setup is GM811, WO 91MM, ZWO 2600MM, Pegasus Pocket powerbox, Beelink mini-PC. I have the mini-PC in a Home Depot storage tub I have the cover on during the night. Out of the Pegasus I have 2x RCA jack dew straps on scope & guide scope. But also use my older 5.5mm dew straps, one extra on the scope and another wrapped around the mini-PC. A 3rd dew strap I got off Amazon years ago has USB end which I plug into the 5v USB port and wrap around the Gemini close to the ethernet port. This is ultimately what worked well for me, and did resolve a lot of issues I had dealing with early morning dew.?
So now it is getting colder I need to know my limits. As I am not just dealing with electronics, but also mechanical aspect of the mount itself. If I want to play it safe, at least for this winter, what temperature limit should I set for myself where setting up risks damage to mount, camera, or telescope??
-- Brian?
Brian Valente portfolio
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Interesting topic for me also. Live in Washington DC region. Currently setting up GM8/80mm refractor or 200mm RC imaging system on a deck and controlling from a nearby shed. Primary interest is photometry since living in heavy light polluted region.
For about a month, testing whether the Telegizmo 365 cover set allows me close to 365 day protection. So far the cover set (for mount/80 mm refractor, camera, etc) has handled dew, frost and lots of rain. Will test down to 25deg F. Below that, will put mount/system in shed.
Do not plan to leave the all in one pc in shed if temp is approaching 40deg F.
Kevin Hannon
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In very low temperatures, around 25F or less, the RA and Dec cables start getting a bit stiffer. They still bend but are a bit resistant, like an extension cord or garden hose left out in winter. Periodically it is good to check if they are well seated in their sockets, the Dec motor side wiggled loose on me once and my slews started failing. I also use a small dab of dielectric grease, the same stuff used on auto battery cables, to keep the connections working well. Have used my G11 down to 15F, but that is also my personal limit for being outside at night :).
Also using rubber dust plugs on all the unused Gemini cable ports is a good measure year round, to keep out moisture and frost, etc:
One example:
?
These don't hurt on the PC side of things as well.
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curious about this as well. I'm in New Hampshire and was imaging last year a few nights in a negatives, granted with a simple alt az mount and dslr. The frost has begun to set in pretty consistently, and I have yet to find any forming on any of my electronics, meanwhile, everything else is covered, but I set up every night so I always let the mount dry out before it goes in the pelican case. I have an extra dew strap (became an extra today when I realized it was too small..) if i find any frost forming or am having any issue this winter I'll try that on the nuc and look for a usb strap for the gemini.?
Curious if anyone has experienced trouble imaging at temps bellow those listed by our southern boys here (not sure where you are John but it doesn't sound like the south)? Personal wellbeing aside, would below zero be discouraged? I pray each night to the seven sisters for such temps to be a rare occurrence this winter... but some of the most bitter nights last year were the most beautiful.
-Cole
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>>>
Also using rubber dust plugs on all the unused Gemini cable ports is a good measure year round, to keep out moisture and frost, etc:
i can't say enough good things about using something like those to plug your unused ports. that was a past podcast topic as well?
In very low temperatures, around 25F or less, the RA and Dec cables start getting a bit stiffer. They still bend but are a bit resistant, like an extension cord or garden hose left out in winter. Periodically it is good to check if they are well seated in their sockets, the Dec motor side wiggled loose on me once and my slews started failing. I also use a small dab of dielectric grease, the same stuff used on auto battery cables, to keep the connections working well. Have used my G11 down to 15F, but that is also my personal limit for being outside at night :).
Also using rubber dust plugs on all the unused Gemini cable ports is a good measure year round, to keep out moisture and frost, etc:
One example:
?
These don't hurt on the PC side of things as well.
-- Brian?
Brian Valente portfolio
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In Minnesota here, and looking at the average historical temps come mid December I will be getting 10F during the night. Come January/February it will drop more to single digits. I hope to have Skyshed or Nexdome on order, but that probably wont even get ordered until January so for this winter it will be setting up if sky is clear and temp is tolerable.?
Besides the mount, do low temperatures from 0F to 10F risk damage to telescopes, cameras, or filter wheels??
Thanks for the Amazon link for the dust plugs, I got those added to my list to get on order. Now I am thinking maybe to add a powered USB port + USB dew heaters, or even another Pegasus pocket powerbox and getting more dew heaters to wrap around equipment. Problem there is this also will create a mess of cables that can get snagged. I wish I had my dome already.
?
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I had encountered an issue the other night with Apple iPad whereby temps dropped to 35 deg. iPad shutoff and I could not turn it back on. Power was about 90% at the time. Thus halted my mount control, Planetarium etc.
Had to return to the Gemini hand controller.
Warmed up the iPad and it returned to full functionality and at 90% power.
turns out the spec is 32 deg and Apple warns it will shutoff.
may have to rubber band hand warmers onto the back of the iPad.
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I have been through a couple of winters here in eastern Ontario with my Skyshedpod and GM8. In general, the equipment functions better at low temperatures than I do. Any lubricants are low temperature rated. But an electrically headed vest and gloves make it much more endurable for me. But when it gets cold running things by remote control (gigabit network) from the house is much more fun. No problems with equipment or computers -- everything stays in the dome. The monitor and computer puts out plenty of heat when running -- but the trackball gets slippery with gloves. I do cover my scope and equipment cluster with a big aluminized scope cover I bought from Scopestuff. In the winter there is a timer controlled Davis heater that puts a small flow of warm air up under the cover. Reduces condensation and frost. All optics are capped, though this doesnt keep the spiders out of my RC. Having house power to the dome makes it all easier -- cannot imagine doing this with batteries.
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Besides the mount, do low temperatures from 0F to 10F risk damage to telescopes, cameras, or filter wheels??
Im still pretty green with all this, but I haven’t heard of any damage. The only trouble I’ve heard of is the cold “pinching the optics”, at least that’s what I think it’s called. If the metal tube of the OTA contracts enough it can distort the glass and cause stars to appear hexagonal and other symmetrical shapes depending on how many screws are holding the glass in place. The example images I’ve seen with this are still beautiful so I don’t think I would have noticed had I not read about this, so I’m not too concerned about it. I also don’t think this damages the optics in any way as it’s just a temporary effect brought on by really low temps. Hopefully someone will correct me if I’m wrong here.?
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Another winter issue for me was the battery on my Dell Inspiron laptop would start discharging at about 25F or below, even while plugged in. After a whole night it would get down to 25% charge or less. Just not built for outside. Now I have a dedicated HP Envy tower out in the roll off, and no issues with that, though I do keep the keyboard covered with a towel to stop dew from getting under the keys. Trevor Jones at AstroBackyard?in Canada?recommends an Acer Enduro for outdoors, specially made for harsh weather:
My temps swing from over 100F in summer to below 0F sometimes in winter at 40N 75W. One good thing is the websites and magazines always publish sky charts for 40N, right on the money for me.
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As said by others, the mechanics of the mount should be fine. I've used my G11 many nights (sans observatory) down to -10F or lower. Cables, as said, can sometimes be another matter but having coiled cables that aren't too bulky helps. As suggested, plugs are a good idea for unused ports to keep dust, spiders (who will happily plant silk egg sacks in the recesses - great insulation), and moisture off the contacts.
My sole suggestion is to get a silicon keyboard skin for the keyboard. On really dewy/frosty nights even having the (laptop probably) in a tub (tipped over on its side) won't always keep the moisture off the keyboard. From there it can find its way into the laptop. I once lost a (very old and blessedly already at end of life) computer that way - the motherboard corroded. Also, the power switch is usually recessed on laptops (so dew or melted frost can accumulate there) and often isn't covered by the keyboard skins. So a bit of flexible tape over it will help keep moisture out of that entry point.
Regards,
Mark Christensen
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For our RA & DEC cables, can we find longer/coiled or even one rated for lower temperatures?
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Sean,
First, do you even know you have a problem at low temps with your existing cables or are you just worried? Temperatures like 0F to 10F are viewed with relief sometimes in Jan-Feb here in Northern Illinois.
If you really do have a low temp issue then there is really only two alternatives that come to mind: Buy some special low temp (down to -50C) cable from an AlphaWire distributor. It comes in a variety of number of conductors. One family of their low-temp cable is called 'Xtra Guard 4'.?This will run you upwards of $5 or more per foot and you may have to buy 100 feet of it. Gulp - such is the difference between the consumer and industrial markets.
Then you'll need to make up the cables or have somebody do it. Not something I'd do casually. Xtra Guard 4 is marketed as having four times the flexibility at low temperature compared to conventional PVC cabling. But do you need it? And it won't be coiled if you want that.
To get coiled cables the only reasonable option I am aware of is to buy conventional PVC coiled cable assemblies made up with connectors and then cut them off (if you don't want RJ45s) and solder on your own. An 8 conductor, 5 to 10 foot coiled (flat) cable will run you between $8 to $15 at DigiKey or Mouser. And you'll have to be content with the wire gauge they come with which is 26AWG. When I did my G11 492 to OnStep conversion I bought RJ45 coiled cables and paired up the conductors so it could handle the higher current (over 1.5 amp per winding) of the bipolar steppers I used - the system only need four wires per motor assembly having no encoders. Servos draw much less current.
For reference, according to the AWG calculator, a single 26 gauge conductor on a10 foot round trip at 1 amp will only drop 0.4V - the single conductor resistance is 0.04 ohm per foot with copper.
But again, are you just worrying or do you know you have a problem?
Mark C
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In some cases when the temps are very low, I will just coil a rubber band around the far ends of the cables and hook the last loop around the motor housing. The Dec cable is the one to watch as the RA cable gets very liitle movement. But as I first mentioned, the cables get stiff, not inflexible. Keeping them in their sockets by periodically checking or securing with a band of some type should keep all connected.
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On Fri, Nov 12, 2021 at 02:01 PM, Mark Christensen wrote:
Mark C
Mark, you are correct, I think because this is the first winter I will be taking equipment out I am just a little worried.? So do people use regular power extension cable or should I look at picking up a 'cold-weather' cable from Home Depot?
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Taking your Dec cable and throwing in your kitchen freezer overnight should be a good test of what you may experience in winter months.
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As someone pointed out, where one lives is a factor. I live in the DC area.
For the equipment on the deck, I use an outdoor rated power outlet box that comes with a 15-20 foot cord. In the shed, I use an indoor rated outlet box with a long cord for computer, fan, etc. I connect the indoor outlet box to the outdoor box. However, I keep the outdoor outlet box in the shed when not in use.
I put Ethernet cable/conduit in the backyard natural gas line trench when we had pool installed. So, using SkyX, I have the option of total Ethernet/USB communications/control from shed or controlling the shed computer from home basement via home network. Protecting the body from the environment is more important than protecting the equipment.
At the end of January, I may be able to have a view on whether the Telegizmo 365 cover works well in my area. The cover is protecting scopes, mount, focuser controller, dew heater controller/cables, cameras, Rigel finder, and power/communication cables.
Kevin Hannon
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So it’s three years later(3 winters 2021-2023). The Telegizmo 365 covers worked as advertised. Setup is currently indoors being modernized with power box/usb hub, micro router, and mini pc. Let’s see if the added gear can hold up under winter/telegizmo 365 cover. The added gear is on two carbon fiber dovetail clamps, so can be easily removed if desired.
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Red rails are made of aluminum. Aluminum rails, carbon fiber dovetail clamps and carbon fiber rings are from Rouz Astro. ?I used Stellarvue metal risers. Had to replace the Stellarvue riser long bolts with 90mm bolts from Amazon to get the Stellarvue risers and Rouz Astro rings/lower aluminum rail to securely join.?
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Kevin Hannon