April 7, 2025
All this tariff nonsense made me realize that if I wanted a slew-drive now was the time to act before Chinese product prices went sky high. I checked with Paul, W2HRO at Sub-Lunar and he had stock on the 3 inch drives. Ship it!
I assembled the mount and used three M10 washers on each of the azimuth bolts as spacers to make sure nothing would bind.
As usual there was the fun of figuring out how to marry it to my Green Heron RT-21 controller. It turns out the manufacturer ships these drives with various color codes for the wire connections and even different encoder pulse counts per 360 degrees. My particular unit had a pulse count of 35962 X2 and the wires were color coded as follows:
DC Motor + Heavy Red
DC Motor - Heavy Black
Hall A pulse Blue
Ref. Voltage + Brown
Ref. Voltage Return Gray
Hall B not used Orange
Bench testing showed all was good and ready to go. However, lifting the 65 pounds (22kg) of slew-drive chest high to slip it onto the tripod mast was a full-focus challenge. Umph!
I have some shimming of the tripod to do to make it plumb and then we'll see if I can really track the moon within 0.1 degree. Thanks to Paul, W2HRO and Frank, KH6FA for sharing what I needed to know saving me hours of fiddling.
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| Getting ready to solder connectors in place and see if the motors move. |
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| Not square, level, or plumb ... yet. |
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| Telling PSTRotor the good news. |