Re: Small mount was Recent encoder discussion on CN

Christopher Erickson

High precision abs encoder on RA. For precise homing, pointing and tracking.
Lower resolution abs encoder on DEC. Much cheaper and perfectly suitable for precise homing and pointing.
Servo motors. For lowest voltage and current requirements.
Operable on 8-20VDC.
Strain wave gears with electric brakes. For zero backlash, no reverse-driving when power is lost, and size/weight savings.
Super-lightweight and compact overall.
No clutches needed. I haven't missed having clutches on my RST-135 at all.
Motor-current-measuring-based balancing function.
New, dedicated hand controller with integral GPS & Bluetooth, and optionally WiFi, serial, USB and Ethernet.
Maybe have an XBee socket or two in the hand controller. Let users pick their own wireless frequency and protocol options.
Mount setup procedure optimized and simplified for travel. OLED display good to -40F/C
Built-in base adapter to put it on a carbon-fiber Gitzo 85 (or clone 85mm head) tripod.
Optional hollow composite counterweight. Fill with water when in the field.
Lightweight counterweight shaft. I am a strong believer in counterweights for strain wave mounts, whenever possible. I don't care what Rainbow pushes in their ads.
Lightweight, telescoping, two-section, aluminum pier with 85mm socket head option for travel. More rigid than a Gitzo CF tripod.
Ability to operate in Alt-Az as well as polar mode. Alt-Az is great for visual, solar and occultation use.
Options for both electronic as well as optical polar scopes.
Give the electronics enough horsepower to add cool stuff in the future, like Slo-Mo all-sky tracker features and the like.
Bubble levels in mount and pier. Optional compass.
Multi-star alignments with software ortho compensation.
Voltage and current displayed continuously on the hand controller.
If possible, through the mount power and USB3/USB-C. Or put cable securing points on the DEC axis and base so a springy umbilical channel can be used.
Optional custom, lightweight, wheelie travel case. Maybe have a stroller or diaper bag camouflage kit for it. LOL

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii

On Fri, Feb 26, 2021 at 12:01 PM Roland Christen via <> wrote:
I guess if you need just an imaging mount with no clutches (no way to use manually without power), it can be very small and light weight.
A universal mount like the Mach2 or 10-Micron has more components than a non-clutched mount like the MYT or Rainbow mounts.
A non-clutched mount without encoders would be slightly less weight, and less cost, but will always require aggressive guiding.
A non-clutched mount with just an RA encoder to eliminate the periodic error would be medium cost and light weight.

There are a lot of permutations and possibilities, and it would depend on what you want to do with this mount. Some people just want a light weight mount that they can haul out from the basement to the driveway, put a scope on it, put an eyepiece on it and do a Moon Cruise or examine the planets. They don't need encoders or PE correction. Others want one as small as possible for airline travel and may or may not want to guide. Others want a precision universal mount that they can do anything with, but must have low weight because their back hurts. The possibilities are endless.

Low cost, medium or high cost. Medium weight low weight or ultra-low weight. Low tracking performance, medium or ultra-high performance. Clutched or non-clutched - universal or targeted. Single encoder or dual absolute encoders.

Pick any 3 out of 5.


-----Original Message-----
From: alan.dang@...
Sent: Fri, Feb 26, 2021 2:46 pm
Subject: Re: [ap-gto] Small mount was Recent encoder discussion on CN

And not just older people, but young enthusiasts who just want a lighter no-fuss mount that more easily travels when going on a group road trip where you have limited space for the Astro gear along with clothes and other travel essentials.

A real question is what is the smallest mount that would work with a AP105 and have encoders?  You might not save production cost over a mount that handles a C11 or AP130EDT — but if the mount is dramatically smaller or lighter, it could be interesting.

Roland Christen

Join { to automatically receive all group messages.