Wednesday 5 November 2014

Radjet with Big Battery

...and a servo upgrade

Following my conversion of the 
Radjet to give it a battery hatch for easier insertion of the chubbier 4S batteries, I was playing around the other day and discovered I could actually get an 1800mAh battery in without much effort. This was rather remarkable and something I had thought of doing before but never taken much further as I thought it unfeasible.

My concerns are that the sustained current supply from the larger battery might overwhelm the stock ESC, and the other that the additional weight might cause issues with the Radjet, especially on launch. Regarding the former, the 1800 is a 40C while the little 850 is a 45-90C, so I don't think there should be too much difference, except for duration. To hopefully reduce the heat-load, I have installed an extra cooling port (slurpee straw) directed straight onto the ESC and of course the Radjet runs without a canopy these days.



In the case of the latter, I think the Radjet should be OK with the mass, considering the Stinger runs with this battery on a smaller wing area and with a heavier body.

I've also replaced the original wing servos with Turnigy TG9z's due to these stripping when I pancaked the Radjet on its most recent flight. I'd bought these servos as the HXT 900's were out of stock and, while expecting much the same, I was amazed when first powering these up at how quiet they were in comparison. I gather these are not quite as strong as the HXT's, however they should are well rated and sound super-smooth!


So, since today was just way too windy from start to finish, I'm hoping that I might be able to get the Radjet into the air tomorrow and see how it goes...

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