As mentioned previously in this thread, I decided sometime back, to investigate adding a "digital setting circles" aiming system to the APM Big Binocular Fork Mount presently holding the APM 150 BT.
First choice to contact concerning availability or development of a kit for this mount was Serge at Astro Devices in Australia. Shortly after sending an email to Serge, I received a phone call from him indicating that the could put together a kit for me that would fit my mount. He requested that I provide some measurements of critical components of the mount so he could make the necessary parts to the dimensions needed to fit properly, as he did not have access to a copy of the mount.
After several communications back and forth by phone and email, providing additional measurements needed and detailed photos of the mount and critical parts, I received very complete kit, very well packaged, in the mail.
The kit consisted of the Nexus keyboard/display/computer unit; a mounting plate to hold this unit; a shoulder bolt replacing one of the bolts holding the fixed upright arm of the mount to the base plate of the mount, to support the mounting plate for the Nexus unit; digital magnetic rings for altitude and azimuth readings; plastic housings containing readers to read the magnetic circles; one tiny metal bar with threaded screw holes and screws to mount the plastic housing for the azimuth reader to the channelled slot in the bottom of the mount base bar, (the altitude reader housing slips snugly into the wide slot in the fixed upright arm of the mount, and is held securely in place by two-sided tape under the wings of the housing); two sets of "Y" cables to go from the readers to the Nexus unit; several stick-on plastic cable clips; a battery charger with charging cable; and two instruction books, one a quick-view and the other a complete instruction book.
The two magnetic circles were mounted snugly in plastic rings sized to fit over the round support pedestal of the mount, for the azimuth circle, and over the round bearing block at the top of the fixed arm of the mount, for the altitude circle. Unfortunately, the altitude circle plastic ring was a bit loose in its fit to the round block, and also had to be slid out so much that it was overhanging the outer edge of the block to line up with the reader well enough to get a reliable accurate reading.
More communications with Serge resulted in him voluntarily agreeing to re-make the elevation circle mounting ring to slightly smaller tolerances. I was able to get the original ring to fit snugly enough by wrapping one layer of plastic electrical tape around the altitude bearing block, but Serge thought it was better to make a new mounting ring. He also made a new mounting block for the altitude reader to move the reader closer to the center of the magnetic ring without overhang.
These new parts fit very well and I completed assembly and testing of the system successfully.
The whole process from my first email until completion took several months. Due to the corona virus pandemic during this time, causing an increase in orders for products from Astro Devices, Serge had gotten very busy. I'm sure that without the virus, the process would have gone much more quickly. Astro Devices and Serge have been very good to do business with, and the cost to me for this was similar to comparable kits already developed and ready to sell at Astro Devices. I highly recommend them and their products.
So far my use of this system has been very limited, but preliminary indications are that it will be a very useful tool for me. It will allow me to find difficult targets in the night sky, plus help identify other interesting objects that I stumble upon while scanning the sky. There will be a learning curve for me to be able to get the most out of this system, but that will have to wait until warmer weather and clear skies.
Here are some photos of the system installed.
Here you can see the shoulder bolt that attaches the Nexus base to the mount.
This shows the Nexus unit, altitude ring and reader.
This one shows the altitude ring, reader, cabling, Nexus mount, and Nexus DSC.
Edited by oldmanrick, 28 December 2020 - 04:54 PM.