More on Perpetual Motion

I was at the Lab yesterday and we did some testing of the perpetual motion machine.

Here’s Sanjay’s explanation followed by a more scientific explanation.

Practical Jokes

I like playing jokes on people. My friend Sanjay has some sort of aversion to food that is browned (or a he referes to it: “burnt”).

In fact there was a funny incident at a restaurant a while back where he attempted to return food and the server just said “That’s how we do it”. Welcome to the Royal Oak.

So I conspired with the staff of a different restaurant to make sure he got a plate of burned food. 🙂

Of course Sanjay took up the issue with the server and she said “That’s how we do it”.

The joke went off pretty good. We almost split our sides laughing.

ModLab-Ottawa aftersocial

We went to the pub to continue our business after Modlab.

I delivered some motor mounts for Marc-Andre’s hover craft project.

Also a prototype jackplate for Sanjay’s speaker project.

There were other projects of course.

We had a great time reflecting on the Modlab, coming up with new ideas. And solutions.

JackPlate V2

I made another Jackplate for my friend Sanjay.

The first one came out with the wrong dimensions for some reason.

This time I added some features to make it snap together for fun. I think this isn’t worth it for a one of like this but could sure make things go faster if you are making a log of something.

It was a lot faster to glue together.

What I did was added a “plunge” at the corners to make sure the pieces fit. There was an issue in that the phlatboyz plugin for sketchup didn’t do all the plunge holes. I’m a little puzzled. I just cut out a bit with the dremel where it missed and everything went together okay.

Pencil holder also works as a picture frame

pencil holderI am making a “jack plate” for my friend Sanjay’s speakers.

We drew it up in Sketchup and I cut the parts out of hardboard on a CNC mill.

I sort of made a mistake because I think the steps per revolution in my Mach 3 configuration was wrong and the part got scaled up slightly.

So the part doesn’t fit of course.

But we figured out what to do with it. It makes a perfect pencil holder. As you can see her it can be used for glue and other object.

It also works very well as an iPhone holder. It becomes a DIY electronic picture frame!

Bike Generator


I’m doing experiments with human power.

Here is the mounting plate design to connect a generator to my friend’s bike.

I’ve test fitted the part on the generator and here it is being test fitted on Sanjay’s bike.

Time to get a piece of aluminum to cut this out. I’m figuring 1/4 inch will be good.

We need a 3/8″ to 1/4″ direct drive coupler of some sort. I need to find that or someone with a lathe. 🙂

If I don’t find something shortly I’ll get a lathe or a 4th axis for my mill or something.

The generator is a 350W, 24V DC go cart motor. Any ideas of some interesting loads to try it with?

Mounting generator on bike

plate, covered measurement is 1 & 11/32”. That's between the two top mounting bolts.

Okay, here’s what the output of the pedal system looks like.

I think it will be easy to make a direct drive system. I suppose making a plate with holes matching the pedal system (right), then having the motor mounted on standoffs that are mounted on the same plate.

Add some sort of coupler to connect the two shafts. I guess I’ll see if a coupler is available for the two shaft sizes. If not, I suppose I’ll have to make one. I don’t have a lathe but may buy one if I need to make this sort of thing often.

I wonder if it’s easier to add an A-axis to my mill? Any comments on that?

motor plate

Here’s what the generator looks like. As you can see it has a face plate that has three mounting holes.

It also has a sprocket which I will remove. I guess I need to measure that shaft.

I need to get or make some standoffs to connect this motor to the mounting plate.

Are they available or do people make those? I suppose some 1/4″ threaded rod would do. Hmm, that sounds like a great inexpensive way to mount it. I’ll give that a whirl unless somebody gives me a better idea.

generator face plate

So the mounting plate will have 6 holes. Three for the pedal output, three for the generator. The generator will be mounted on a standoff and a direct drive coupler added. There will of course be a hole in the plate in the middle for the drive shaft.

I was able to cut the part out on my CNC mill. I used the Phlatboyz plugin to generate the g-code.

The outer holes match the generator perfectly. I will send this over to Sanjay and see if it fits his bicycle thingy.

Interestingly, the first time I generated the g-code, the straight lines at the perimeter of the piece came out as curves. I right clicked each line and expanded or exploded (can’t remember).


After generating the g-code again it seemed to behave. I find that with the phlatboyz plugin you can’t have any components, grouping and such.

I find it really important to verify the g-code before bothering to load it on my mill.

NCPlot has proven to be very nice for this. It shows the tool path in great detail and you can pan and rotate around. You can even “play” the file and see the tool path motion at whatever speed you choose.

Mounting a generator on a pedal bike


Looks like my friend Sanjay will be the first guinea pig for generating electricity from human power.

He has an exercise bike which looks great for getting some testing in on some generators.

I should have a generator in hand today if all goes as planed.

I will take a look at mounting something on the bike.

I guess we need some nice loads for the first tests.

Anybody have anything that will run on 12-24vDC or there abouts?

Any suggestions?

I’m betting we will get 12v or better since the first generator I am getting is a 24VDC motor from a go-kart application.