David James replied to the topic 'Alternatives to Raspberry Pi4?' in the forum. 3 years ago

AstroNerd wrote:
Nice idea...BUT
One should never run an imaging rig with the counter weight that far down the shaft, it can cause huge loads on the motors when slewing, it’s much better to have much more weight and further up towards the mount head, there has been a lot of research done on this, the initial inertia with a weight that far down I’d bad for the mount.... :)


I can see that would become an issue with larger loads and much longer extensions, but we're talking about a weight that's still less than that of a single counterweight that comes with the mount on a mount that's designed to take at least three of them (all told there's currently less total weight being carried in payload and computer combined than the mount carried in counterweights alone for its original payload).

For comparison, here's what the counterweight loading looks like when the mount is carrying the original 10" Newtonian with a mirrorless camera attached.



The moment of inertia of all that has to exceed that of the mini computer sitting another 2" further out. It's like 3½lbs vs 30lbs.

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