Construction Notes

13      Construction Notes

In building these controllers you can choose from a variety of materials and make a great many modifications to suit your requirements. We have put together prototypes of all the designs; when we made more than one prototype the units were never exactly alike. We used scrap materials extensively and often adjusted the plans to take advantage of available materials. If you can't find a specified part or material, substitute something else that you can find.

The illustrations in this book are not the kind of mechanical drawings that a professional machine designer would produce. They were done as illustrations of how the projects were put together and could not be sent to a machine shop for professional fabrication. They do include all the necessary information and dimensions, and the text gives you the steps to follow for constructing the units.
     Where they are omitted, the dimensions are not critical and you should adjust them for available materials or for your physical size. (Do not attempt to make up a limerick here-a classic already exists.) For items like pot mounts you should first purchase the specified part and then adjust the dimensions of the mounting holes to fit that part.
     Don't be afraid to adjust the dimensions of the device to suit your needs and materials. The worst that can happen is that you have to build a second or third unit before you get exactly what you want. Your early attempts will sometimes make nice gifts for your friends (of various dimensions). The entire process is an important experience in working out man/machine interactions.

You can build all the controllers in this manual with common hand tools. Many of them are even easier to construct if you have access to a radial arm or table saw. As noted in the introduction, most of these designs make excellent projects for school wood, metal, or electronics shops. The following tools are best for constructing the units:

(1)    A radial arm or table saw with a plywood blade
(2)    A 3/8-inch variable speed drill with twist drills, screwmate drills, and a counter-sink
(3)    Vise grip pliers (one of the all-time great tools)
(4)    Drill and taps for common bolt sizes (#8-32 and #6-32)
(5)    Pop rivet gun and small pop rivets
(6)    Bench vise with wooden jaw inserts
(7)    Orbital sander and sand paper
(8)    Miscellaneous hand tools: screwdrivers, hacksaw, sheet metal shears, etc.

The following tools are not required, but if they are available you can do more advanced work on some of the projects:

(9)    A drill press or holder for the electric drill
(10)  Mandrel and hole saws for the drill
(11)  A metal lathe with milling attachment

If a particular tool is not available there is almost always some way around the the problem. The text makes many suggestions for alternatives you can try.

Many of the materials for these controllers were salvaged or scrap. The parts list for each project gives the materials actually used for the prototypes, but don't be afraid to experiment with alternatives. Here are some suggestions on what to use and where to get it.

Lumber. The hardwood lumber for many of the prototypes was scrap from furniture projects. Clear softwood is also suitable, except for those parts that must have holes drilled and tapped into the wood. Just remember that the hardwoods can be finished more attractively than the softwoods.

Plywood. We salvaged much of the hardwood plywood for the prototypes from a pair of old kitchen cabinet doors. Many hardware stores sell small pieces of hardwood plywood. Maple is probably the best for these projects since it is extremely hard and doesn't splinter easily. Common fir plywood can be substituted and will look just fine if carefully finished.

Plastic. In constructing many of these devices you could replace plywood and metal parts with plexiglass with striking results. You can often purchase scrap plexiglass in pieces large and thick enough for the units from local suppliers of industrial plastics. The scrap, sold by the pound, is about as expensive as hardwood plywood. You can , successfully work plexiglass with woodworking tools once you are accustomed to its peculiarities. Sand the sawcut edges with increasingly fine sandpaper until the saw marks are completely removed. Then you can polish the edges with Crest toothpaste or a polishing compound from the plastics supplier.
Many of the projects specify plastic washers cut from coffee can lids. This plastic is polyethylene; it has a soapy feel and serves as a lubricant between wood parts. You can cut it with household scissors.

Metals. The one controller prototype that requires machining, the Super Stick, was made from machinist's aluminum. The machined parts could also be cut from brass, steel, stainless steel, or machinable plastic, depending on available scrap and the desired final appearance. The sheet metal we used was either 1/16-inch soft aluminum from an old cookie sheet or galvanized steel scrap from heavy heating ductwork. The sheet metal must be stiff enough to hold its shape but light enough to be worked with sheet metal shears.

Glues. Wood parts were glued with Elmer's Carpenter's Wood Glue, a tan liquid, and felt pieces were attached with Elmer's Cabinetmaker's Contact Cement. The latter can be cleaned up with water, a nice feature for the home craftsman. No lockwashers were used: all bolts were secured with thread sealant on final assembly. The bolt threads must be oil-free for this to work properly. You can substitute Super Glue or fingernail polish for the sealant.
     Wherever rubbery adhesion was needed, we used G. E. Silicone Glue and Sealant. Also known as RTV (room temperature vulcanizing), this was used to form strain reliefs for cables and for insulation over electrical connections. Don't use an excessive amount of RTV in any application since it can ooze out and look very sloppy. Clear sealant is the least messy to work with. You should also note that this material contains an acid catalyst and can cause eye and skin irritation if handled carelessly.

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