This is it: our last day before we have to pack up the Botmobile and hit the road to Motorama. We have two unfinished 'bots: the featherweight Formidable Fustigator 2.0 and the sportsman Palindrome30. The featherweight is closest to being completed, so that's where we'll concentrate today. To Hit Back after viewing an image.
We need to drill weapon transmission holes in the top and bottom panels, so we printed a 1:1 template from Rhino3D to help mark the holes, and punched them into place.
Meanwhile, Milly was off making bearing blocks for the Sportsman, in the slim chance we'll have some time to work on it too, today.
Here are the bearing blocks - they need to be cut up, but otherwise ought to be okay.
Going back over to Milly, we used the 1/8"-inch end mill to position the top panel and then used a Mach3 wizard to cut a circular hole for the bronze bushing for the transmission shaft.
And hurray - top and bottom are done. Of course this photo doesn't show the time that ticked away disassembling and then reassembling the 'bot ...
The top panel has had a coat of paint, and we've also pressed the bushing in here too. Now we just have to finish the wiring!
As we have plenty of weight to spare, we decided to cut and install a battery wall, using some 2" polycarbonate strips. Fortunately it didn't take too long to cut, drill, and tap them, and we moved on.
Now that we can actually put the 'bot together, we found ourselves with a very tight fit in the transmission bushings for the shaft, so we put the shaft in the drill press, and used a file to trim down the diameter of the ends of the shaft until it spun more freely.
Et voila. We need to trim the bronze bushings down - we only had half-inch long ones on hand, and only really needed quarter-inch, but that's a trivial task.
Here we're in the midst of aligning the gears for the weapon transmission - through the forceful application of the arbor press we were able to bring the bevel gear in alignment with the pinion, and things seemed to fit together fairly well.
We've just realized something: we thought we were being clever angling the weapon motors away from the blade path and drive motors, but in fact we've shot ourselves in the foot - now we don't have room behind the rear drive motor for the wiring to pass from one side of the 'bot to the other. Grr. We're going to have to run it over the rear DeWalt, and squish it down with the top panel.
It's gone from being late to being early again! But we press on with the assembly and wiring, doggedly determined to wrap up this build for Motorama. The weapon transmission is done, and we move on to the remaining wiring.
The battery wall has been installed, so now we can run wiring from the batteries to the power switch and common ground.
It looks a bit of a mess, but except for the weapon motor speed controllers, the wiring is all in place! We decided to use ring terminals to connect the speed controllers to the weapon motors, so they don't take very long to install in the end.
Smoke! We fired the 'bot up to test the drive wiring, and one of the Victor 883s let out the magic smoke from one half of the FETs - the motor connected to it would go forward fine, but there would be smoke, flame, and no movement in the other direction. Yet more precious time was consumed swapping out both the speed controller and the motor.
Due to our weapon motor placement gaffe, we're having to route a pair of wires across the front of the 'bot and under the path of the blade. We use wire anchors and zip ties to keep the wires taut across there.
The wiring is finally done! The mess of PWM cables has been zip-tied up, and everything checks out okay! Time to bolt the 'bot up.
Last thing to do is check weight, and we're way under - 27 out of 30 pounds allowed, so no problems there. We'd better get the Botmobile loaded - it's 4am, and we leave for Motorama in four hours!
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