I've tried hard with all the designs to reduce as much as possible the range of tools needed to build the karts and vehicles.  This is reflected in the designs - in the types of mechanical assemblies I've made and the components and materials used. The best way to understand the tooling required to build the vehicles is to study the plans and understand the component shapes you would need to make - you can do this for some of the designs with the free plans.

Here's a general overview of the types of hand and power tools that are likely to prove useful when building your own kart or buggy.

The types of timber used are predominantly planed softwood sections and general purpose plywoods. On occasion hardwood blocks may be suggested for bearing housings. For the woodwork then the usual range of DIY saws, rasps etc will be needed. A powered jig saw will help greatly with the profile cutouts in plywood that make up the vehicle shaped panels. A bench mounted circular saw will help in the important job of cutting straight edged lengths of plywood for the gearbox casings and other vehicle structures. A manual mitre saw is a great though inexpensive way of cutting clean square ends on timber lengths - important for screwed and/or glued abutting faces.

A good powered drill is certainly needed for the metal parts (see below) but is also needed for drilling accurately the timber parts, a selection of flat tipped wood drills is needed to drill accurate holes such as those used for bearing housings.

The metal parts of the vehicles have also been designed to reduce as far as possible the metal working required - this varies between designs, some need more metalworking than others.. However you will still need a good hacksaw (with sharp blades), flat and circular section files are always useful and a good powered drill should be to hand - preferably a proper bench drill (drill-press), but failing that a powered hand drill mounted in a bench drill stand.

Get a small vice to hold the metal workpiece when drilling - drilling accurately positioned and sized holes in steel is simply not a job for a hand held drill! You will need a selection of centre and properly sharpened (best new) HSS twist drill bits for the hole sizes in the parts shown in the drawings. Consider learning how to sharpen your twist drill bits - sharp bits make life a lot easier.

Several of the gearbox and steering shafts need flats ground on them for torque transfer; you could, with effort, do this with a hand file but far better to use a grinding wheel attachment for your stand mounted drill or, even better still, a proper bench mounted grinder - these days they are not expensive.

I have for some time used a small model engineering size lathe for metal turning work on the more advanced projects. I try to reduce the need for this as much as possible however a lathe does allow you to do some jobs at home that you might not otherwise be able to. Boring larger diameter holes in gears or chain sprockets or in support plates, turning down round bar prior to threading are some in addition to the usual shaft turning. They are also the best tool for drilling straight and accurately centred holes in gears and sprockets.

Aside from the working tools you should give some thought to measuring, marking off and checking your work. A good centre punch, scribe and accurate measuring tools will help, buy yourself some decent vernier callipers; you can then check accurately the shaft and hole sizes. A draftsman scale rule helps as does a good tape measure.

Finally, other than the usual screw drivers, spanners etc you will need to be able to drill and tap smallish  diameter screw threads - so a set of taps and dies will be helpful but particularly M6 and M8 (1/4" - 3/8") sizes. I've almost forgotten to mention that a good quality bench vice mounted on a sturdy work bench will help greatly, "workmate" type benches are also useful.

Finally for the electrical work there are a few items that will help. Crimping tools to suit the cable connectors you chose, a soldering iron will be invaluable and invest in a decent multimeter - you may  need it to check out the wiring if (when) it doesn't work first time and to build up your understanding of how the electrical circuits work!

It should go without saying that the necessary safety precautions should be taken when working with power tools - look after your eyes & fingers especially, they are much more important than any kart you make.