Time to Build Part 2

Scoop Build

As the scoop design is a combination of materials and manufacturing techniques, this aspect was a little more complicated than first expected. The most difficult aspect was that the lower scoop sections had to be at the same angle and height. After a couple of adjustments I was happy with the result once it was mocked up on the robot.

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Really starting to come towards the end of the mechanical assembly.
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Only main aspect left to do was the install of electronics ready for final assembly (with rear armour) and paint.

Electronics
This I knew was going to be the real challenge. Not because of a limited knowledge of electronics, but due to a lack of any space inside (as usual). Despite this, I wanted to have some form of order to the main loom so I can access most of the vital components (batteries, link etc.) without taking the whole machine apart.
To help simplify the electronics as much as I could, the robot has separate low and high power circuits. The low power loom feeds the battery eliminator circuit to the RX, power lights and weapon limit switches/ low power side of the relays. The high power circuit, feeds the drive ESC's and weapon high power relay circuit directly from the battery.
The drive speed controllers are Hobbyking F80 brushless speed controllers programed for bidirectional control via SimonK. I found SimonK to be limited way of flashing ESC's, but for my first play with brushless drive it was more of a set-and-forget job that was an already tried and tested method throughout the community.
The sides of the main arm assembly are dedicated to the two 4s (1500mAh) lipo batteries and drive speed controllers. The front section houses the main fuse, main power distribution and weapon motor wires. As is seen by the image below, this meant both internal and external wire routing around the main bulkhead as the "high power" wires of the weapon drive relays and link would not fit (note that the main fuse is not in the image below). The external wires are then protected (somewhat) by the front impact panel. Changes to Mk1.5 have been applied to help better protect these wires.

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Lifting Arm limit switches
As the arm electronics are "simple" it meant that the endpoints could be controlled in the same way that a conventional linear actuator works - limit switches at either end of the desired travel. As I had made my own system, I could position these limits wherever I wanted. This however had to be completed last to test the limits in real-time and adjust accordingly.
The front limit switch is positioned under the arm scoop spacer block and moves with the weapon mechanism. When the arm is lowered, the switch contacts the front inner impact panel to stop operation in that direction. The rear limit switch is positioned above the weapon gearbox and is switched by the arm link to the leadscrew. Both systems are shown below.

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Final Assembly
After a couple of setbacks which included robot weight reduction and self-righter last minute testing, FeatherDozer was ready for it's first event - Robodojo on 26/07/2020. I will go into minor details and analysis of the event in the coming entry. For now here is the completed build of FeatherDozer Mk1.0

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