The Beast has landed

What diameter is the counterweight shaft?
What diameter and length are your existing counterweights?

Shaft is 40mm. 3 x 10kg weights are 150mm diameter and 84mm thick. 1 x 5kg 42mm thick.

Kieran,
When I had the Gemini G41, I had the same issue. I bought the cast iron counterweights in Argos.
www.argos.co.uk/static/Product/partNumber/9003194.htm
They usually come with a 25mm hole in the centre. You will need to get someone to core out a larger hole of 41mm diameter. Not easy to find someone to do that - cast iron is a very hard material and it's easier to core a hole into a solid piece of metal than one which already has a hole.
The counterweights are approx 270mm diameter and 30mm thick. This gives much better ballast at the bottom end of the bar than standard counterweights and should do the trick. Just make sure that the counterweight directly above is well secured and that should prevent an slippage or sliding on the bar.
Hope this helps.

I got a 10kg weight dispatched at 3pm from Modern Astronomy. Should be here tomorrow/Wed and possible clear sky Wed night. Tomorrow I'm off so should be able to get the Robofocus on and Kendrick connected and attached. Then need to do some cable tidies, rebalance with ccd/filter wheel extension tubes etc then check collimation. Think I'll skip putting the Apo on for the moment till I get a feel for how this beast performs. Apo will add another 4.5kg.

Got the scope balanced. Took 46kg to do it! Got the ccd on then had to re-balance and couldn't resist taking a test shot of M33.



There is a light gradient in the image either due to the laptop screen in the observatory or the fact that the security light was on. Also I didn't check the filter wheel till after shut down and found it was on the green filter. Still have to calibrate robofocus which still has a microstep size set for an sct which is too coarse for a crayford. Back to the manual

Great to see first light.
Looks to be tracking well.
Was that auto guided?
What exposure time did you use?