Some added information about Celestron’s encoders for the Advanced GT mount. Upon receiving some donated motors salvaged from another Advanced GT mount, it was found that at some point during the manufacturing of these Celestron Advanced GT mount models, Celestron changed encoders. The donated motors I received have US Digital encoders and the encoders on the mount were a little larger and no label of who manufactured them. It was later brought to my attention that the larger encoders cannot be found anymore. I changed out the motors to use the donated motors, having the US Digital label on them, since they were good motors and their encoders worked. I had ordered two replacement encoders and two cables/plug from US Digital prior to receiving the donated motors. Upon arrival of the new encoders, I discovered that the donated motor’s plug at the encoder matched exactly to the new cable/plug from US Digital. I had previously worked on those donated motors several years ago which had broken wires right at the plug. Even after fixing the broken wire the owner elected to seek used motors, which I installed, and he kept the removed motors. It was very nice to find that the new cable/plug would replace the fix I did. Wish I had known about US Digital’s cables back then because that would have saved the owner some money. All I had to do now was splice in the new cable’s wires to the existing wiring and plug into the donated motor’s encoder. The new encoders, not currently used, can be made to work on the older larger encode by just enlarging the base hole that slides over the collar of the motor’s shaft. You cannot see that in the video because the encoder’s disc is over the base. The collar is 10mm in diameter on the larger encoder and the US Digital hole that fits over the collar is smaller. I calculated that the US Digital hole, if enlarged to fit over the larger encoder’s collar, would only leave 0.62mm of thickness of its collar ring. It would work. The club now has spare encoders for the donated motors and two spare motors with the larger encoder, which has one encoder that is bad. Both motors are good.
Some added information about Celestron’s encoders for the Advanced GT mount. Upon receiving some donated motors salvaged from another Advanced GT mount, it was found that at some point during the manufacturing of these Celestron Advanced GT mount models, Celestron changed encoders. The donated motors I received have US Digital encoders and the encoders on the mount were a little larger and no label of who manufactured them. It was later brought to my attention that the larger encoders cannot be found anymore. I changed out the motors to use the donated motors, having the US Digital label on them, since they were good motors and their encoders worked. I had ordered two replacement encoders and two cables/plug from US Digital prior to receiving the donated motors. Upon arrival of the new encoders, I discovered that the donated motor’s plug at the encoder matched exactly to the new cable/plug from US Digital. I had previously worked on those donated motors several years ago which had broken wires right at the plug. Even after fixing the broken wire the owner elected to seek used motors, which I installed, and he kept the removed motors. It was very nice to find that the new cable/plug would replace the fix I did. Wish I had known about US Digital’s cables back then because that would have saved the owner some money. All I had to do now was splice in the new cable’s wires to the existing wiring and plug into the donated motor’s encoder.
The new encoders, not currently used, can be made to work on the older larger encode by just enlarging the base hole that slides over the collar of the motor’s shaft. You cannot see that in the video because the encoder’s disc is over the base. The collar is 10mm in diameter on the larger encoder and the US Digital hole that fits over the collar is smaller. I calculated that the US Digital hole, if enlarged to fit over the larger encoder’s collar, would only leave 0.62mm of thickness of its collar ring. It would work. The club now has spare encoders for the donated motors and two spare motors with the larger encoder, which has one encoder that is bad. Both motors are good.