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Selecting parts

Finding the right parts for the project is one of the most overlooked and challenging aspects of building this kind of art and inventions. First you often need a design that integrates your ideas with what is available and this can be difficult if you do not know what is out there.

When purchasing your parts you should be considering:

  1. Is the part in stock? This may seem trivial but when you need to make a deadline you must really consider if you are going to get your parts in time. Suppliers are notorious for saying parts will be available in a week or two but they may be holding you off from going to another supplier. If you cannot find your parts in a timely basis than many of the suppliers carry parts that others have so I recommend going to these other sources.
  2. Is it surplus? Many love surplus parts and some of you only have budgets to work with surplus, however I have had some bad experiences working with surplus for a number of reasons. First, surplus parts may be old and already worn out and therefore can breakdown. Another challenge with surplus parts is that they generally do not come with data sheets and this can be very challenging for beginners who do not want to hack into something they are depending on. The up side to surplus is that it is environmentally correct and therefore you are doing a good deed, recycling rather than letting stuff go to waste. 

One of my favorite new parts suppliers is Jameco and I recommend them simply because they have clear pictures which help the beginner to understand what they are purchasing. Other great suppliers are Digikey and MCM Electronics for general electronics though their catalogs can be a bit complex for the beginner. 

Supercircuits is a great supplier of mini video cameras and wireless cameras.

Small Parts Inc has small tubing that is difficult to find with other small parts for building prototypes.

Grainger nationwide are important suppliers of hard to find mechanical parts and you may need to be a part of a company to have access to their competitive pricing. 

Check your llocal hardware store, Lowe's or Radio Shack and Hobby stores are also excellent sources of electronic parts and mechanical findings. Sometimes train type hobby stores will have hard to find small parts or are great sources for parts you may use to improvise.

McMaster Carr has one of the best websites for finding mechanical parts quickly and their delivery is excellent.

When selecting electronic and mechanical parts from suppliers pay special attention to:

  • What voltage is the part good to? (remeber to over design by finding parts with good voltage clearances)
  • What are the absolute maximum ratings for the part?
  • What amperage is the part rated for?
  • What are the dimensions of the part? Will they fit your project space?
  • Are the parts up to your aesthetic standards? (many use the open electronic aesthetic where this is a consideration)
  • Are the dimensions in millimeters, inches, meters etc. Use an online conversion service to translate one into the other if you need. http://www.sciencemadesimple.com/conversions.html
  • Will it fit in your project?
  • Is the part going to be seen and if so will it work for your aesthetic sensibilities?
  • Is the part military or civilian? Military parts are generally more robust and can stand more heat or cold extremes.
  • What is the package style and will it fit your circuit board or project? (careful or you may end up with surface mount parts as opposed to parts which you can handle with your fingers)