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1 4oz. Bag |
2 4oz. Bags |
No Bags |
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During Balancing |
For Pointing East |
For Pointing West |
Unbalance to Load the Worm
UNBALANCE - On purpose? Yes! At least for me. Ever since I had a motored telescope, the general consensus has been to put some weight in the east arm of a forked telescope and on the counterweight shaft of a GEM when pointing to the east. I would guess that when pointing to the west you could take the weight off of the counterweight shaft and add it to the OTA end. Right? Sort of. Let's say you wanted to put 4oz. on the counterbalance shaft after you balanced the entire setup so as to load the worm. Now, when you cross the meridian and take the 4oz. off, where you put it on the OTA end makes a difference. The torque created by the 4oz. is comprised of the 4oz. AND it's distance from the axis of rotation. So when you move it to the OTA end, you will need to put it at the same distance from the axis. This is not practical so you change the amount of weight such that it gives the same worm load. Another problem is that you will very easily upset the Dec balance and load the Dec worm. This could be bad. But cheer up.
I thought a very easy way to load the Ra worm for pointing in the east and west.
Look at Fig.1....
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1 4oz. Bag |
2 4oz. Bags |
No Bags |
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During Balancing |
For Pointing East |
For Pointing West |
Fig.1
Here's how it works. Let's assume you want to load the worm with 4oz. of weight. When you balance the Ra axis, include a bag containing 4oz. See left frame in Fig.1
So now the Ra is balanced and it does have that 4oz. hanging there. Now, when pointing East, add a second bag of 4oz. See center frame in Fig.1. Now the worm is loaded with 4oz. and is pointing East. So now we do a meridian flip and remove BOTH bags. Now the OTA end is heavier by 4oz. and so loads the worm again by 4oz.
Something to be aware of is the fact that that when the counterbalance shaft is in a horizontal position and you load it with say 4oz., as the mount rotates in Ra, the effective load imposed by the 4oz. diminishes to the point that when the shaft is vertical, there is zero load applied.
