Getting closer to a rolling kart

Walle came over today, so we bled the brake fluid. Stafke helped as well. As a result, we no longer have air bubbles stuck in the hydraulics lines. With some further tweaking of the brake pads, they now retract after braking, instead of getting stuck, which they did before. Being newbies and all, we learned completely new stuff with this little job. In the following, Staf (he's 4) demonstrates how the bleeding is done.

The tires got flat over the last few days, which is kind of worrying. I got a compressor and I've inflated the tires to 2 bar.

After some more stripping down decorative and unnecessary parts we're getting closer to a bare bones kart. All we need now is a seat and the kids can pushed around on a smooth rolling kart. The following picture shows the kart in our garage, its usual position is to sit on those two little Ikea tables so we can access all parts easily.

We'll be checking out a kart shop on Tuesday to try and get a seat and brackets to install it. Maybe we can get our hands on an engine mount as well.

Walle will be getting his head wrapped around setting up the circuitry for the engine. The fact that we'll be pumping 4800 Watt through the circuit (100 Ampère at 48 Volt is the normal mode, we could get the motor up to 300A for its peak if we want) is somehow frightening to me.

My first little steps ...

I'm a complete newbie at this stuff. I haven't handled anything other than bicycles previously and even then, that's only been at the basic level of fixing flat tires. I'm doing this project to learn stuff and I'm aware that there's still many many jobs that I have never done before and have no clue how to do them. I'm probably not even aware of the majority of these details.

So today, I started off with some basic jobs, tinkering with things to try and get some extremely basic hands-on experience. I figured out how the braking pads can be adjusted, by fastening the nut on the middle bolt of the braking system. I had a go at removing a complete wheel from the rear axle and removed the pulley that was installed by a previous owner. We'll be putting in gears at the other side of the axle later on, as the motor will be placed at the other side anyways. After strategically applying some WD40 here and there, we now have a smoothly rotating rear axle, which is great. Here's the rear axle without its pulley.

Originally, I wanted to get the bubbles out of the hydraulics lines of the braking system. The process to do this is called "bleeding"; while pumping the brakes and opening/closing the outlet at the brake, you can refill the brake lines with bubble-free braking fluid, which I found for 7€ at a car maintenance store. Unfortunately I only have two hands, so I'll hold this job until I get some help from two other hands.

I've been taking a look at where the motor block will be going. The carpenter rule in the next picture roughly shows the size of how big the engine mount will have to be and where it will be located. It will have a pretty big footprint, at about 20 by 20 cm. If we don't want to get rid of the plastic boxes on the sides of the kart, we'll need to access the tube which would end up in the left-middle of the mount.

Next up: getting those bubbles out of the brake lines and finding a seat!

Alternative Motor

Found this possible alternative to the e-tek motor by Agni used to break the electric speedboat world record. The man who built this motorbike looks/talks a bit peculiar but he did make a bike with very good specs using his motors (rectangular laminations for higher heat dispercion).

Agnum motor and thundersky lithium battery gives 200 miles and range at 60mph top speed.

Here is a video.

A rudimentary to-do list

Now that we have the kart in our garage, it is time to settle on an initial plan of attack, choosing some high priority jobs. Obviously, most of the energetic discussions about the project over the last weekend have revolved around pimping the kart with lights, a boom box, shiny painting skills, and whatnot, ignoring the vital requirement of having a kart that you can actually ride around. So here's an initial plan on how to get it up and running, with some to-dos that need to be done before bringing in the pimp shizzle.

1. The kart is currently out of a seat. In order to fit in all the (large) components, such as the batteries and the electric motor, it would be wise to know how much space a seat would take up, so we can figure out where to install all the vital components. Putting in a seat is supposed to be an easy and inexpensive first task.
2. A frame will have to be constructed that allows to attach four 12V car batteries to the kart (2 batteries on either side), providing us with 48V for the motor. But in order to start constructing this part, we need to know the batteries that are to be used, and their dimensions. I think it is best to weld a rack to the kart that can hold a few batteries with tie down straps, and can then be flexibly be replaced by other battery types if this is needed later on.
3. As for our motor, we would like to use an Etek R motor, which provides us with 4800W of power, consuming 100A to deliver about 10hp or providing 15hp peak power while consuming up to 200-300A. A mount for the engine, in order to be able to attach it to the frame is needed as well. Standard kart engine mounts exist and can be bought quite expensively from kart shops, but they are probably not well suited for fitting our motor to the kart frame, so we'll be welding our own mount there as well, as in the diagram below.
4. Other parts, like the controller (we're probably going to choose an AllTrax AXE controller), a potentiometer near the gas pedal and miscellaneous wiring -- although equally vital to the construction of an electric kart -- will be a lot easier to integrate in comparison to the batteries and motor. With some wiring, we'll set up a separate motor circuit first and then integrate it when the construction of frames is ready.

If we can finish the above steps, we would have a running kart, in theory. There's probably 200 little details that are going to be in the way of the above installation procedures, but they're there to learn from.

Here's a temporary shopping list of stuff that needs to be integrated

1. A seat and brackets for its installation
   
2. 4 batteries that can deliver about 100Ah over 48V, L-shaped bars (welded into a rack) and tie down straps to mount the batteries to the frame
3. A motor and some metal plating welded and transformed into an engine mount
4. A controller, wiring and electronics to make it all work
   

Le kart est arrivé près de chez nous

Yesterday, we went to pick up our kart base. We have studied it thoroughly, had plenty of construction ideas and took it for a first test drive, pushing it down the street. During the ride, we broke the seat contraption, so we removed it to make space for a new seat, and removed other stuff (like the gas cable) that we won't need for our conversion to an all-electric kart.

Below are more pictures of the kart (without the side bumpers, and missing its broken seat) in front of my garage. Louis is demoing the steering wheel.



The kart looks like a great base for our own build. The steering and braking looks in a sufficient condition so we don't have to replace it immediately. There's plenty of space on the frame to start our upgrade, putting in new mounts for the batteries and the motor.



Two 12V car batteries will be mounted on either side of the seat, we'll install an electric motor and its drive train to the right and back of the seat, mount a potentiometer to the gas pedal, and do some wiring to get it all up and running. An extra battery will probably be added later on to provide some extra juice for a car radio, bling bling, and a boom box :) We've also had plenty ideas on the finish, and we're planning to repaint it in a shiny black, with plenty of electronics and colorful LEDs to make it look pimp shit. But the highest priorities are obviously in getting it up and running.

As the first steps, we'll have to put in a new seat, check the braking system as it doesn't seem to be perfectly aligned, and get the back axle rolling smoothly, so we'll have to disassemble its bearings, and put it all back together.

A rolling kart

I found this "rolling" kart, which has a frame, wheels, steering and braking installed. It looks pretty beat up, but it's dead cheap. The motor is missing but that is a good thing, I don't need it anyway. Here's some pictures of the kart.


Here's a close-up of the hydraulic brake on the kart:


Before even thinking about mounting new gear to such a kart, there's a first few obvious jobs that need to be done. We'll have to take apart the frame, clean it up, sand it down, repaint it, put the kart back together and fix stuff that needs fixing to get it rolling again. We'll then see what to do next.

I'll be checking it out on Friday. I hope it fits in the car, it looks like a great base to start the build from.

Can we create our own electric kart?

Electric vehicles are receiving a lot of attention, both in our minds and in many minds around the globe. Since a few months, I'm commuting with a beautiful Biketec Flyer T8 pedal-assisting bicycle, about 20 kilometers each day. As I apply force to the pedals, an electric motor provides that amount of force to the bicycle chain as well. It makes the ride lots of fun; getting to speed at stop lights and crossing bridges is lovely.

So now, I'm hungry for more. Now I want an all-electric non-human-powered vehicle. I'm not expecting affordable, great all-electric cars from our failing bunch of manufacturers, so this time we're going to build one ourselves! A small car might be somehow technically possible to conceive, but shop space is sparse, and there's no way we can ever get the car regulated so that we can actually drive it around. Instead of upgrading either a bicycle or a full car, we're trying somewhere in the middle.

A kart has a simple frame and construction. We add a bunch of frames for car batteries on the sides and an electric motor in the back. We add these components, together with a controller and some wiring, and that's that (in theory). OK, we can't get a kart regulated either, but at least a kart takes less space than a complete car and the kart can be transported (by a fuel-munching automobile) to open places -- like parking lots or industrial terrains -- to play with it. But I'm expecting the process of constructing the kart will be a whole lot more enjoyable than driving it around. The fun is in the challenge of getting it to work.

As this is supposed to be a great hack, we'll try to get it built before the Hacking At Random conference in the Netherlands this summer so we can showcase the electric kart at the event.

I'm setting up this blog to keep track of my progress. The project has a semi long term goal, of being ready by August 2009, and there will be interruptions along the line, so plenty of bursts of ideas in the middle of long silences on this blog may occur.