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Roland, thanks again for your response.
Is your comment on -25 F a storage temp issue or just an operation issue? I typically leave my setup in the garage (roll it in and out) between imaging sessions for single objects. Where I am in Vermont it doesn’t go to -25 F all that often or even yearly, but it can go there. I don’t think this would be a big issue.. when the temps are in this range I’m probably not going to be leaving anything outside anyway. Single digit minus F temps are pretty frequent in the January-February timeframes. Will all of these things be defined in an operation/storage specification?
We have tested our mounts in the deep freezer (24 hours soak) where the temperature is -5F (-20C) and the mount operated perfectly. Encoders worked fine. I think if your conditions were such that you would see temps drop to -25F on a typical day/night cycle then I would definitely go for the extended range version.
To: ap-gto <ap-gto@...
Sent: Sun, Sep 8, 2019 10:13 am
Subject: RE: [ap-gto] Re: Mach2 price and specs are now on the AP website
Just an old man’s wonderings but could small heaters be used, think dew like heaters, where the encoders are installed for colder than usual times. But then again Roland did say it would diminish results but not enough to even consider not imaging. Now if you were in a climate where this was more the normal I’d think you may need a solution to make it work more often. Just saying out loud.
Sunday, September 8, 2019 9:58 AMTo: ap-gto@...Subject:
Re: [ap-gto] Re: Mach2 price and specs are now on the AP website
Since the encoders are a key feature of the Mach2GTO, it would be really nice to have them work to zero degrees as well as the rest of the mount. While zero is a bit extreme, and it’s rare to start anywhere near zero for me, it’s easy to end up there at the end of some nights in the northern climates. Most times I don’t start at temps below 15 F and pack up between 10 F and 5 F. I checked the specifications on the site and no operating temp range is listed.
I have operated the standard temp range version in my observatory down below freezing to about 10 DegF over the last 5 years on my encoder mounts (1600 and 3600 mounts). A few nights it was zeroF and below for a couple of hours during imaging sessions. I think the Renishaw specs are quite conservative. If your temps are consistently below 10 to 15 F, then maybe the extended temps are for you.
Is the minimum recommended operating temperature for the Mach2 absolute encoders 32F? (The same as the standard absolute encoders for the AP 1600.)
I currently have an AP 1600 and I purchased the “extended temp” absolute encoder upgrade kit. My club’s observing site is 4800 ft elevation (SE AZ) and the average low temp in Dec and Jan is 29 F. It can easily get down to the low 20’s. Thus, I decided spent the extra money for the extended temp option.
I was thinking of purchasing a Mach2 in a couple of years to use with my favorite scope, the AP 155 EDFS with a recent 4” focuser upgrade. My primary interest will be imaging nebula. I also plan to use the mount at local school educational events.