Equipment

Here is some of the equipment I'm using during controller development. This list is not static.

Dummy Load

A dummy load is needed for controller testing, so you don't have to spin up (and possibly damage) a real motor when testing controller designs. An inductor and a power resistor are placed in series to simulate the resistance and inductance of a large series-wound DC motor. Here's what I'm using:

Big Power Resistor

Two GE .110 ohm resistors, 750 to 6000 watts (depends on cooling). In parallel, these simulate the approximate resistance of large series-wound DC motors. The coils are going to be painted with high-temp paint, so they can be immersed in water for high power tests, since the coils are steel and will rust. Available from C & H sales: Part #RS9300, found here. About $18, each. Total cost was $46 for both, including tax & shipping. Thanks to Otmar Ebenhoech and Rich Rudman for the tip on where to find these.

Medium Power Resistor

Ten 6.6 ohm 600 watt non-inductive resistors. These will be configured in various ways to use as a load for lower-powered prototypes. Made by EBG, part #UXP6006R6J. Purchased from Skycraft Parts & Surplus. Found here. Cost: $3.00 each, $40 total including shipping.

Big Inductor

Toroidal core inductor. The core is a T650-26 from Micro Metals. This is used to simulate the inductance of a large series-wound DC motor. Approximately 25 turns of wire is wound onto this core for the correct inductance. It is 6.5" in diameter, 2" thick, and about 10 lbs. Cost: $27.92 Each, about $33 with shipping. Micro Metals is very close to me, so shipping was rather inexpensive. Thanks to Rich Rudman & Otmar Ebenhoech for tipping me off to the location and cooling (respectively) of this item.

Heat Sinks

Heat sinks. One of these is for cooling the EBG resistors, as they are designed for heat-sink mounting, and don't appear to be safely dunkable in water. The other heat sink is for cooling the MOSFETS and diodes in non-water-cooled prototypes. These were purchased from barrredboss, a seller on Ebay. They are 12" long, 5.375" wide. The base material is .375" thick, and the fins are 1.0" high, for a total thickness of 1.375". About 4.5 lbs each. Their thermal resistance is .375 C/W for the 12 foot section. This means that the temperature of the sink will go up .375 degrees centigrade (above ambient) for each watt of heat that is put into it. This can be improved by using fans. These are heavy-duty heat sinks, though they might seem a bit pricey, they're well worth the money.

Large Thermal Mass

Bucket-o-Water™. The larger GE resistors and the toroid are immersed in water for higher power tests. For lower power tests, the EBG resistors are used, and are bolted to a heat sink. While pure water is an excellent insulator, most water is not. A non-conductive bucket is required.

Miscellaneous

There are many items, too numerous to mention, that any reasonably well-stocked electronics-oriented tool box should have in it such as pliers, wire cutters, wire strippers, crimpers, wrenches, screwdrivers, etc.

There are a few useful items that I will specifically mention:

Drill press: Good for making straight holes, and for tapping holes (to keep the tap straight; do not use a tap under power). You can use a hand drill, but a drill press is much better.
Hacksaw or metal-cutting bandsaw: Sometimes you need to cut bus bars or heat sinks, or other metal items.