Simple Bots: Inchworm

If you can count on only one thing, it would be a ruler. Now, don't get me wrong. I am not talking about supreme despots for life, or anything of that sort. The rulers that I am referring to are the measuring kind. After all, how can you not count on something with so many sequential numbers? That is why, when it came to deciding what the armature for Inchworm Bot should be, the only thing I could think of was my good, dependable friend, the ruler. After all, in the grand scheme of things, there is merely inches of similarity between the two.

Step 1 Go get stuff

You will need:

(x1) continuous rotation servo modified for direct drive**
(x1) 18" aluminum ruler (or longer)
(x2) small plastic container
(x2) 2" - 3" fixed casters
(x1) bic Classic pen
(x1) comb
(x10) small nuts and bolts
(x4) small washers
(x1) 2" - 3" metal standoff
(x4) zip ties
(x1) DPDT lever switch
(x1) 4 x AA battery holder
(x4) AA batteries
(x1) red and black wire
(x1) electrical tape

**Learn how to modify a servo motor for direct drive at this page.

Comments

[strider_mt2k]

I was so inspired by your work that I put an inchworm bot together out of industrial scrap at work.
The only thing that's new is the gear motor.
http://www.flickr.com/photos/strider_mt2k/sets/72157625069322244/

I look forward to building more simple bots like yours out of industrial scrap!

Thanks for getting the wheels turning in my head!

[boston09]

this was a fun project, thank you.

i might add some wheels soon

[sviswanathan]

this is the most complicated model to make...
really tough
my switch isnt being flipped
could someone help me?

[randofo]

What happens when you turn it on? Does the comb keep trying to push down on the switch? If it keeps applying force and does not reverse, then the switch is backwards. Simply, spin it around 180 degrees.

If the comb misses the switch altogether perhaps try elongating the switch by hot gluing a pen cap onto the lever.

If it is doing something else entirely, explain what is happening and I'll see if I can help.

[jmacco]

great projet, i like it and is my project for the science fair

[khobis]

it's really an awesome project.. i'm gonna build it as soon as i collect those stuff's

[zap8004]

could you use a 12' ruler

[randofo]

Sure, but you would need two of them. I used a single longer one simply because it was cheaper.

[zap8004]

do I need to change other mesurements

[bears0]

i want to use a servo driver for RC cars, it has two servos and i want to substitute a servo for a motor, i'm planning on making an electric boat and i cant use a servo to make it go, if someone could tell me how it would be greatly appreciated.

[axeman911]

what is an arduino?!!!

[randofo]

An Arduino is a small programmable micro controller (circuit board) that plugs into your computer and you can use it to read sensors or control motors, electronic switches and other things that move.

[axeman911]

thanx

[Carnavislol]

can the Tupperware be about 3" tall?

[randofo]

I don't see why not. May as well give it a try

[Carnavislol]

wait should i get the continuous rotation servo motor or t he standard one...

[randofo]

It doesn't matter. The controller is removed and it never rotates far enough where it will hit the stop.

[Carnavislol]

That so awesome! I'm gonna build it soon with my friends! Very explanatory guide!

[hyw_scott]

Nice, try to make one.

[Kiteman]

A few broom bristles, taped to the side of the boxes, angled towards the rear and projecting slightly below the boxes should encourage forward motion, especially on carpeted surfaces. (Another nice one, Randy!)

[randofo]

I considered doing something similar involving pivoting doorstops, but didn't feel like adding a few more steps. Brush bristles would give the same effect in one step and is actually a really great idea.

[muskogee]

also could you use a 9 volt instead of 4 AA's?

[randofo]

A 9V battery is 3V more which is probably a little too high for the motor.

[muskogee]

Instead of using a comb... couldn't you use another ruler? Maybe a 8 inch plastic one would work.

[matstermind]

this reminds me of the most useless machine ever

[macrumpton]

Very cool. It occurred to me that if you had a pendulum on the joint that shifted a weight over the rear leg when you are pushing the legs apart and shifted the weight over the front leg when the legs pull together, that there would be a lot less slippage. another approach would be to use some wheels with a ratchet that allowed only turning in on direction.

[masynmachien]

Nice work, great Ible. As a kit I used to have a construction kit for an inch worm "robot" with at its "feet" wheels with a ratchet blocking any backwards movement. It moved quite fast. You could ad something similar with yours. If you want to avoid wheels (to keep a more annimal like type of propulsion) you could add something else that allows forward movement and block the forward movement. Inclined bristles should work, which would give birth to a completely new type of bristlebot.

[Dr KAZ]

I agree, the ruler RULES! It can be used to (indirectly) measure mass, capacitance, resistance, magnetic flux, velocity, etc. etc. etc. and if you are very creative it can be used to measure the iron content of spinach. Trusty old ruler. Thanks for a useful, clear, fun, cheap, instructable!

[inblack]

Add some grip on the boxes and it sould run faster!

[WingDings]

Great idea on the comb! That's a really innovative idea. Good work on the clear instructions and photos, too.

Could you also drill a larger hole in the ruler attached to the servo horn (the size of the other side of the servo horn that fits onto the servo spline), in the centre of the four holes that the servo horn bolts go through?

That way you could affix the servo horn, in the same orientation, but with the servo horn arms on the other side of the ruler and the spline side passing through the ruler. That would make the ruler attached to the servo horn a bit closer to the servo bearings, perhaps reducing the side-loading on the servo bearings?

[Lindie]

I was anticipating how you made an inch worm, till I saw it. Very nice! LOL!!!

[cory.smith]

Thumbs up!

[fearme36]

"Inch"worm made out of a ruler. Bud dum tsss

[boston09]

in the pictures the servo is a standard sevro, but the list says a continuous rotation servo.. which one is needed?

[randofo]

It doesn't matter which is used as the controller is removed and it never breaks 180 degrees of rotation. I'll change the text to say a standard servo.

[Re-design]

Using the comb as a reverser was brilliant. An easy to adjust the movement.

[jam BD]

nice simple and elegant complements on the photos by the way

[shinjiyuubix]

hahahaha, simple and fun

[Patented]

awesome I love the idea !

[kcls]

I like that the switch turns back and forth reversing the motor. Ingenious!