| To make a go kart that corners on rails like a Porche, | | | | old lawnmower wheels if they have bushings in them. |
| looks like a Ferrari and turns all your neighbor's heads | | | | They work great for acting as bearings. Grease snot |
| we need to back up the truck and go to the | | | | out of the axel-hub interface and away you go. Be |
| beginnings. | | | | sure to retain the wheel with a cross bolt that is at |
| In short hand, there are five steps to making a simple | | | | least grade 5. |
| frame. First of all the following steps are: | | | | 3. Steering System |
| 1. Engine And Passenger Layout | | | | So after having mounted the rear axle (with brake disc |
| 2. Drive Train System | | | | (or brake drum) and sprocket), and having placed the |
| 3. Steering System | | | | engine and chain system in place, proceed to mounting |
| 4. Brake System | | | | the front steering system. |
| 5. Throttle System | | | | Before we did some measurements of the person |
| Let's get into it now.... | | | | sitting in the comfortable position, make sure you |
| 1. Engine And Passenger Layout | | | | remember the measurement (relative to the go kart |
| First of all the assumption, whether this go-kart is made | | | | frame) of the steering wheel. That is the target point |
| out of wood or is made out of steel is that you have | | | | for the steering wheel. |
| some sort of layout in mind. Typically the engine is | | | | The actual position of the front wheels is a bit more |
| behind, and the person sits in front of the engine. A | | | | involved though. You will need a scale. Place the scale |
| good safe layout is to have a seat protect the | | | | first of all under the rear wheels. I typically use a board |
| passenger from the engine. | | | | placed across the rear frame rails underneath the |
| So a structure of some sort is needed to hold the | | | | wheel area. Have someone sit in the go kart. (Be sure |
| seat in place. You can use a seat off of a chair, but a | | | | to a have the front wheels, steering wheel and |
| more protective seat is a ½ piece of plywood | | | | steering structure on the go kart when you weigh it) |
| angled back and supported. Covering the piece of | | | | Now proceed to the front of the go kart and place the |
| wood is optional, but it is more comfortable with | | | | board in the general area that you want the steering |
| basically a piece of heavy cloth covering a cushion. | | | | system. Again weigh the go kart. |
| The cloth is stapled typically into the board (on the | | | | Take the two weights and add them together. That is |
| backside). | | | | the total weight. The front weight ideally should be |
| The structure supporting the seat can be wood, or | | | | with-in 5 to ten pounds of the rear weight. This is called |
| steel. | | | | 50/50 weight distribution. The more weight you have |
| The frame work can be wood or steel as well. If using | | | | on the rear, the more the go kart will under-steer. |
| wood, use two by fours placed vertically, so that the | | | | Meaning, when you turn the wheel the go kart will tend |
| strength of the wood is optimized. | | | | to keep going straight. The more weight you have on |
| If you are using steel for the frame, use a tubing that is | | | | the front wheels, the more the go kart will over steer. |
| at least .070 wall or thicker. The length of the frame is | | | | Most drivers are used to under-steer, it is easier to |
| really dictated by how big the person is. Have a | | | | recover from. |
| person sit comfortably in the leaned back position with | | | | But I digress... |
| a steering wheel in their hands. That is the person | | | | Once you have placed the front wheels in place then |
| compartment. Measure this length. | | | | fix the front steering system in place there. I typically |
| Add the engine drive section and the person | | | | use plates, so that I can move the steering system |
| compartment lengths together and that is the length of | | | | back or forward. So I weld mating plates on the frame |
| the gokart. Cut your frame tubes (or tack tubes | | | | and the steering system, then bolt them together. |
| together) to this length. You will need at least two | | | | For wood go karts, you can actually design a very |
| parallel lengths of tubing. | | | | stable wood go kart using the carriage style steering |
| Space the tubes apart the width of the seat you | | | | as long as the steering is supported an not aloud to |
| made (20 inches is a good width). | | | | twist. |
| Cut at least four (4) tubes to the 20 inch length. Lay all | | | | A word on steering systems: You can purchase from |
| the pieces on the floor. Place the 20 inchers at the | | | | the store steering assemblies that you tack onto tubes. |
| following locations: Engine Plate area, seat back | | | | These work real well, with one exception, they typically |
| section, seat forward section, front main bumper tube, | | | | come in .750 inch diameter shafts, where most high |
| and rear main bumper tube. (The bumper tubes can | | | | speed bearings use .625 diameter shafts. The shafts |
| be wider than the frame by 12 inches (6 inches per | | | | may need replacement. Look for .625 shafts... |
| side).) | | | | Additionally, there are ways to make the steering |
| Tack the tubes in place using a welder. If you do not | | | | more tractable and more user friendly, these involve |
| have a welder, then you can fasten them together | | | | geometric relationships such as camber, caster, |
| using plates and bolts. (Trust me, buy a $100 welder | | | | Ackerman and so forth. |
| and save yourself wood chips and drill bits, busted | | | | 4. Brake System |
| knuckles and exasperation!) | | | | Now that you have the steering system in position, you |
| What you have put together now is what I term a | | | | can button up the hole project by covering the bottom |
| "flat-go kart." You will soon find out that flat gokart | | | | of the go kart. Sheet metal (like furnace guys use) is |
| frames are weak and require extra stiffening. You | | | | the best option. Buy some tech screws (the ones with |
| may want to put some struts into the system to | | | | drills on their ends) and zip through the sheet metal into |
| bolster the frame design. Typically what I use is the | | | | the tubing. Once you have that in place, you don't have |
| seat back as reference. This works very well as an | | | | to worry about your feet hitting the ground! |
| integral frame support, side seat holder, and engine | | | | Now it is time to place the brake system. You notice |
| protector. | | | | we placed the brakes in place on the live axle, now |
| 2. Drive Train System | | | | the actual braking mechanism needs to be mounted to |
| The next sequence is to place your engine and drive | | | | the frame work. You can either weld it, or bolt it to the |
| train system in place. At the same time put your seat | | | | frame. I prefer bolting, it is more forgiving and easier to |
| in position to make sure the seat and engine are not | | | | repair. |
| hitting each other. Be sure to make the seat | | | | A word on brake float: The brake system should float. |
| removable so that you can actually work on the | | | | What that means is that the disc either needs to be |
| engine system when needed. | | | | mounted freely on the shaft, or the brake caliper |
| When placing your engine typically a plate is needed to | | | | needs to float. If the neither is floating, you will get a |
| hold the engine onto the frame. Some designers use | | | | binding, and prematurely worn out brakes, and fast! So |
| tubes with holes drilled in them for engine placement. I | | | | keep that in mind. Something has to float, the disc or |
| prefer the plate option, because it gives me greater | | | | the brake caliper (1 of the 5!) |
| options as far as engine choices in the future. | | | | For your brakes it is important to have the brake off |
| For example on the Phi-Alpha-10 and the Phi-Alpha-9 | | | | while driving. A good spring is needed to keep the |
| (go karts I designed) the engine plate served well in | | | | pedal back when the brake is not being used. |
| allowing me to use different engines, whether Briggs | | | | On a wood go kart be sure to use the same thought |
| and Stratton, Tecumseh or even Honda. All engine | | | | into the brake system. A lot of force is going into the |
| types could be easily mounted just by drilling the holes | | | | brake boards so be sure to account for this in the |
| in the motor mount plate. | | | | brake mechanism which usually involves force multiplier |
| Most go karts use a slot system to keep the chain | | | | linkages. |
| tight. In other words, the engine is mounted not using | | | | 5. Throttle System |
| holes but slots. That works, but honestly, drilling slots is | | | | This seems like the most inane or over looked system |
| intensive works and requires some patience and | | | | on the go kart. It shouldn't be though. A good |
| thought. So I prefer tensioning the chain, it works better | | | | connection between the throttle and the pedal is |
| on multiple fronts. (I can go on and on about engines, | | | | needed and a good range of motion is needed too. |
| drive trains and such...but we have got to keep moving | | | | Most pedals give you different holes to work with, |
| here...) | | | | allowing your several options in throttle actuation. |
| A word about drive systems: A live axle system is | | | | Again, like the brake, a good spring is needed. Do not |
| really the way to go. All you have to do is mount two | | | | use a spring on the carburetor, but use the spring in the |
| bearing brackets and away you go. On a one wheel | | | | pedal, or pedal system. |
| drive system, you need to have special rims that | | | | A word about throttles: most engines come with |
| contain bearings, special drive sprockets that connect | | | | governors. It is a good idea to use the governor |
| to the tires, and the axle if it gets bent, you have to cut | | | | system, because it helps keep the engine at even |
| it out of the frame and start over....so use a live axle... | | | | speeds and from over revving. |
| But, that is not all true. You can get away with using | | | | |