As I build this project, I thought it would be helpful to construct a bill of materials and keep track of the cost.
I have placed the Bill of Materials with costs, suppliers and part numbers in the Air Quality Sensor Project Github Repository.
As I was doing this, I started to wonder about the power of scale in lowing cost for the sensor board. To build a single board costs a fairly steep $75.48. But, many of the costs would go down as the volume went up – right?
To test this, I priced all the components for the sensor in units of 1, 100 and 1000. The cost went down to $40.06 at quantity 100 and $34.38 for quantity 1000. Obviously, this is only a superficial analysis as I did not price the move from cut tape parts to reels or consider the assembly cost which would have a huge decline as you move from hand to automated assembly. Still, it is interesting to see which parts decline in price and which do not. The so called “jelly bean parts” or common passives showed the least decline – probably because they are so cheap already. Here are the three quantities with a breakdown of cost.
Doing this work helped me appreciate the cost of building a quality product and why other Air Quality Projects such as the Air Quality Egg cost so much.