Ad Astra Observatory

Asi I was designing Trixie, I aimed to have the balance point be at or behind “ring 2”, which is the middle
one.

I put all the actual weights of things into my balance spreadsheet and let it help me to calculate how long the tubes would be (and thus how far in front/behind the balance point, and thus how much lever-mass contribution it adds).

Then I used Data->Goal Seek to set cell I6 to 0 by changing I2 (or by changing D13). That is, I tried to find the point where the OTA balances with the photo rig, by moving either the balance point (I2) or by setting the balance point to where I wanted it and then moving the guidescope back and forth (makes a good sliding counterweight!).

Note that as I have it set up, the guidescope is only 5” from the back of the scope (it hangs over a *lot*) in order to bring the balance point to 13” (which means that the front of the plate and the front of the saddle are about even — the OTA is very nose-heavy with a 1.5# camera attached to the top).

Note that the 1.5# camera adds way more (887) to the nose balance than the much-heavier guidescope (5#) adds (620) to the tail balance. It’s all about being 36” in front of the balance point vs 7” behind it.