Dennis Havlena is a DIY musical instrument builder based in Norther Michigan who makes guides to building inexpensive musical instruments. He has released over 100 guides o how to build and modify various musical instruments. The majority of the materials he uses are available from ordinary hardware stores and there a great deal of resourcefulness to his methodology in construction. There is a focus on low tech solutions and careful consideration about the materials that are suggested for use.
Website 1)
Youtube channel 2)
Feature on Oddmusic- 3)
Second feature on Oddmusic- 4)
There should be further discussion about how far and wide the designs that Havlena has made have spread, as a number of other DIY instruments seen online seem to derive a large amount of the ingenuity from these original designs (without ever referencing Dennis Havlena).
There is an amazing amount of respect I have to give to the aspect that all of these meticulously made designs have been given out for free on Havlena's website. I think there should be a great deal more written about the generosity that is seen in DIY instrument groups that makes communities like this possible.