Thursday, March 3, 2022

60" Build Step #22

Sit on the chair and take a break, as you deserve it. Note use of ply airbridge to avoid NO-STEP zones when boarding. The grilles upped rigidity so there's barely a deflection due to my seventy-five kilos (twelve stone... shit!) and bear in mind the motors will be flexing the airframe in the opposite direction and relieving the stress on the structure, if not the pilot.

Things we might do differently? We're up to 17.5 kg (39lb) in weight and we could have attached the safety grilles with brackets instead of angle-alloy, which would be lighter, cheaper and easier. I would prefer taller skids and horns too, but then the decision to mount motors on the underside came late in the day.

There may also be the option to reduce the frame from 60" square to 54", though I am waiting on T-motor for comparative performance of 36" propellers as against 40". The rule of thumb for rotorcraft tho' is that the greater the disk-area, the lazier motors may run. This in turn reduces the size of the battery-packs, which will lighten the load accordingly in a 'virtuous circle'.

The airframe is designed around T-motor's U15II 100KV unit driving 40" propellers that ought to produce up to thirty-five kilos of thrust apiece. It's not unusual to suit the airframe to a projected power-plant at the design stage, incidentally, as there's always an element of symbiosis there. Next task ~ Rome not having being built in a day ~ is  to fit the motors along with the avionics and sub-seat battery-packs.