A 3-lb combat robot, really just an update to upChukk with the following mods:
I've had some trouble with the Fingertech Gold Spark motors -- one of the original three I ordered last year stripped its gearbox, so I ordered a spare set of the Fingertech Silver motors in the same gear ratio. The description says they have beefier gears, so here's hoping. I may or may not install them prior to the competition, but I'll have them in just in case.
Also ordered a spare set of wheels, since in the new design they are more exposed -- and more vulnerable to spinner weapons.
At one point while building upChukk, I toyed with using a hard disk platter motor to power a horizontal spinner weapon (e.g., small saw blade). It had a lot to recommend it -- low amps, flat profile, and a arbor that perfectly fit the jamb saw blade I bought at Home Depot. At the time, though, I knew nothing about brushless motors and eventually gave up on that line of inquiry.
I've come back to it now after learning enough to be dangerous. I managed to accidentally buy a brushless ESC (I forgot to check its ampere rating before buying and it turned out to be too low for the particular motor I intended) a while back and realized it would probably drive the hard disk motor. So behold my experimental setup:
Using this setup I was able to control the motor speed with the transmitter.
The biggest question mark was that the motor had four solder pads (see next pic) -- but a brushless motor only needs three for signal. One of the reasons I used a terminal block to connect the ESC and motor was I needed a quick way to test out which pads were the correct ones. The terminal block would let me re-arrange connections easily until I found the right combination. Ironically I hit it on the first try. :)
(My best guess as to the fourth solder pad is that it's for bleeding off static that builds up as the platters spin. Static and hard disks are bad, mmm-kay...)
Finally, a pic with the saw blade attached:
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