About this video
This video shows how to add a bent paper clip tail to the back of a small robot named Spout to reduce friction on the ground. After trimming, bending and hot-gluing the tail between the switches, the builder tests the bot and finds it backs up a bit better, though it still sometimes needs help triggering the switches. The video ends by setting up a next step to optimize Spout further.
You'll be able to
- explain how a low-friction tail changes how a robot moves over a surface.
- fit and secure a mechanical part using bending and hot glue so it stays in position.
- test a build, identify what still needs help, and plan the next improvement.
Key words
- Friction
- The resistance between two surfaces sliding over each other, which slows a moving object.
- Drag
- The resistance a moving part meets from the surface it runs over, which the tail reduces.
- Switch trigger
- The contact point that a bumper or arm must press to make the robot change direction.
- Hot glue
- A quick-setting adhesive used here to hold the tail and wire in a fixed position.
- Optimization
- Adjusting a design step by step to improve how it performs.
Transcript
So in this video, we're going to use a paper clip to add a little tail to Spout, to help to reduce some of his friction as he's moving around on the ground. This may help improve the performance of the bot, so let's see. We're going to just take a paper clip and bend it out and then cut it with our needle nose there, with the cutting section.
And we're just going to try and get that tail the stick down, not quite as far as the motors, but further than the back of the battery holder right now. And you can sort of make yours whatever shape you like, but this basically will allow the bot to have a lot less drag on the ground.
So it works pretty well when it's running over a smooth surface. So again, once you've got it bent and it fits pretty well between the two switches, you can obviously adjust it and bend it to where it's just the right height and lines up perfectly. And then once you've got that figured out, you can take your hot glue gun and hot glue it in place.
Now we'll also use the hot glue when I glue this in place to hold that last wire, the yellow wire, in place too, because some of the hot glue will spill over onto it there. And again. There we go. Where's the hot glue gun? There it is, all right. So again, you want to make sure there's a fair amount of glue on it, and you've got to let it sit until the glue has turned opaque.
Alright, now that the glues dry, let's try it out and see if it's any better. That's a little better. A little bit more responsive. So we can see that Spout is starting to back up a little bit better on his own. He still does need a little bit of help sometimes, to get the switches to trigger so he'll back up.
Next video, we're going to see if we can optimize Spout even more, so he's more energetic and reactive, and he backs up better when he bumps into new obstacles.
Video © Khan Academy, used under CC BY-NC-SA. Watch on Khan Academy. Puzzicle is not affiliated with Khan Academy.