Balancing a GEM on the fly without touching the clutches?

[DannyHarvey]

What if you checked the current going into the unit and slewed on way and then the other? Would you be able to see the difference if the scope was out of balance? (Checking each axis independently of course).

This would provide a way of balancing the scope without having to undo the clutches, and thus keep the alignment.

Does this make sense or am I talking a load of rubbish?

r.

Danny

[brantuk]

Would you be able to see the difference if the scope was out of balance?

Interesting question - I think even if you saw a different voltage pushing a heavier weight one way it still leaves the question of how do you rebalance it to compensate. You'll still need to loosen the clutch to do that. Even measuring current you'd have to somehow see where the imbalance is. It could be on one axis, or the other, or spread across both.

It's a great thought but I reckon you'd need some reasonably sophisticated software to tell you exactly where the imbalance lies - something like the mechanics and electronics used in car wheel balancing. Much cheaper and quicker to do it manually imho.

[glappkaeft]

Wouldn't be much easier just to mark the position of the scope and weights with say masking tape the first time you balance it?

[DannyHarvey]

The more current  taken (ie Amps not volts) through a motor I would expect it to be pushing a larger load - so if the scope was out of balance the currents for slewing one way vs the other would be different. Of course you would need to measure accuracy, say to a mA or so, with a max range of 2A (my CG5 takes 1.5 amps when slewing)

For the RA axis at least, you wouldn't need to touch the clutch, just move a weight one way or the other and re-check the slewing currents., you would be able to work out which way to move the weight by the larger current and the direction of slew.

Yes you could mark the axes with tape - I have indeed done this. However my bearings are quite sticky as the scope is new so there is quite a large range I can move the weights and it still feels in balance to me.

The other problem is I have numerous configurations I attach - so the lines on the tape idea get a little messy.

I might try adding an ammeter just to satisfy my curiosity..

[Astro Imp]

Wouldn't be much easier just to mark the position of the scope and weights with say masking tape the first time you balance it?

That is exactly what I have been doing from day one.

[DannyHarvey]

Well I gave it a go tonight - tried to measure the current when slewing one way then the other. So much noise in the signal that the reading flickers around too much to make sense of it, so my idea was a load of rubbish! But it doesn't hurt to faff around with the scope on yet another night in rainy England!