The Mk. II version of the rotors will feature a custom electronics board. @Georges Oates Larsen has completed the schematic and the board layout is forthcoming. We wanted to post it here to here to see if anyone had some feedback they'd like to contribute.
The Mk. II electronic board features:
ESP32 WROOM (same as Mk. I)
Primary vehicle power (supplied via brushes)
Secondary power from on-board batteries (2) 1S power packs in series (for balance)
Charges the on-board batteries from primary vehicle power
Seamlessly switch to backup power if primary power fails
The board layout should be done shortly and if all goes well, we'll have our first boards built in early 2020.
We’ve recently completed a prototype of the power transfer hardware that will be used on our next generation rotor design. Carbon brushes, held in place with a custom 3D-printed holder, transfer power to copper plates on the rotor. On-board batteries will remain, providing a backup power source.
This summer has seen a flurry of activity involving our Electric Variable Pitch Rotors. With the basic technology tested out, it was time to polish the design to get closer to a final product and a new Mk. II rotor is being designed. The Mk. II rotors feature three major upgrades.
The batteries on-board the rotor work well, but are only rated to last 20 mins. #Goliath - A Gas Powered Quadcopter and Titan are both designed to fly for an hour, so more capacity was needed. An axial flux generator was previously researched and would likely work, but would require a large design effort and several iterations. Instead brushes will be used to transfer power from the main vehicle to the rotors and the batteries will serve as a backup to the main vehicle power.
New Gear Drive
The drive system was re-geared to increase the torque from 1.67: 1 to 3:1. This increases the torque which will be needed for the new 42" rotors, increases the angular resolution and the gears are now all off the shelf, so no more custom made gears.
The previous electronics, were based around the Huzzah32, a great board, but a custom power supply and other desired capabilities led to the need for a custom board. @Georges Oates Larsen is currently designing that board which we hope to unveil sometime in September.
As the design progresses, we'll have logs which will go into the details of each aspect of the new design, so stay tuned.
Also, if you're in the Pacific Northwest, be sure to check out thePortland Maker Faire, Sept 7-8. We'll have a booth there again, showing off the EVPR, Goliath and our new prototype, Titan!