Hey everyone, Jason here. A couple of months ago I posted a video of my Robot
Dreams GBC module in action and today we're gonna take a closer look at how it
works and discuss some of the design aspects of it.
Probably the biggest design feature that wasn't really apparent in
that video is that it is completely modular. On the front end we have the
power unit, which right now has an L-Motor and rechargeable battery box, but
pretty much any motor and power source can be used. Obviously, in a show
environment I'll be running it off of a nine volt regulator. We also have the
intake unit which is just a variation of a pretty standard GBC intake design.
In the middle there can theoretically be any number of robots and the transfer
pedestal units between them, and at the end we have an exit unit which feeds the
balls to the intake of the next GPC module in the line. Even though the number
of robots is theoretically unlimited, practically of course there's a limit to
how many a motor will be able to drive. As more robots are added there is
obviously more friction in the system and more work that needs to be done to
pick up and move the balls. The robots themselves are just mounted on a
turntable, so they can rotate from side to side, and their arms are attached to
an axle running through the shoulders, so they can move up and down. This design
allows for single control rod mounted on that shoulder axle to be able to both
rotate the robots and raise and lower the arms. By connecting this rod to the
end of a crank, we can see that rotating the crank does double duty to do both of
those. Essentially, the horizontal component of the cranks movement
translates to the rotation of the robot and the vertical component of that
movement translates to moving the arms, and we can oscillate that crank back and
forth by driving it from this reciprocating arm coming out of the
power unit. And, as you can see that arm is segmented so that it can be extended
to accommodate however many robots are in the system. A lot of people commented
on the relatively new splat gears that I'm using to transfer power to the
control crank and there's a very specific reason I use these gears
instead of normal Technic gears. That is because they have
the cool property where is if you have two of them meshed together you can
perfectly mirror the movement of two arms attached to those gears. This is
actually impossible to do with any pair of modern Technic gears. One of those
arms will always be offset by little from being perfectly mirrored. You can
also see that I've doubled them up. Since their teeth aren't primarily designed
for mechanical performance, this just really locks them together so the gears
don't slip. Now, let's take a look at how the robots actually pick up and release
the balls. I really wanted to keep it as simple as possible so I came up with
this passive system using these soft rubber Technic connectors mounted on the
ends of two axles. These axles are free to rotate so the grips can open and
close, and I'm using a rubber band to constantly pull them to the closed
position. There is a Technic connector in the middle with a couple of half pins
jutting out on either side, which keeps the closed position just a little bit
smaller than the diameter of one of these balls. So that when the gripper is
placed over a ball the ball fits nicely inside and the elastic keeps enough
tension to hold the ball. To release the ball I just added a bar to one of the
grip axles so that as the entire robot moves to the left, that bar will hit a
stanchion on the pedestal unit which opens the grip and drops the ball into
the pedestal. The pedestals are designed with a small piston inside. When the balls are
released the piston is in the down position, leaving a nice hole for the
balls to drop into. When the balls are picked up, the piston comes up and pushes
the balls into the gripper. Power for each of those pistons is drawn off this
line axle in the back that runs the length of the model and just like the
reciprocating arm each pedestal unit extends it to drive the next one.
And, when we put all of that together, this is what we get. I have received a few
requests for instructions for this and I might put some together at some point.
I would actually like to test it running at a show first to see if it needs any
design tweaks, so that might actually take a while and that's about all I
wanted to talk about in this video. As always thanks for watching, keep on
building, and I'll see you in the next one.