I have actually built 3 separate versions now. The goal was to be cheap as possible.
My first dome I built in 2010/2011, featured a 18" diameter dome with a 3 stacks of 3/4" plywood for a frame. Build cost was between $300-500 from what I remember. I used a Bescor MP-101 that I modded to do 360 degrees for the mount. I bought a Canon HD HF100 to use in there. The Bescor allowed me to rotate the the camera around and had a 15 degree pitch available. I could zoom the camera, but it required me to stick the remote outside the car to get line-of-sight. I think some Sony cameras allow you to control their cameras through a cable. I quit using it after I bought a vehicle without a roof rack and got tired of the hassle. It was very large, so it took up way too much space in the vehicle and added a lot of drag. Couple MPG per trip.
https://www.facebook.com/media/set/?set=a.945440851887.2558611.9609344&type=1&l=6346031130
Dome design #2 from last year, that James linked, featured a 8" diameter dome with a Foscam IP camera. I actually preferred to use a non-HD camera in that setup as it operated more smoothly and was less troublesome. Downside is was not HD and still a bit of a pain to maintain. Perks to it though, it was very small and lightweight. Only took a couple minutes to setup and since it sat behind my fairing on my roof rack the drag was not noticeable. It was also quite stealth, at least compared to the monster I built before.
https://www.facebook.com/media/set/?set=a.10102865628155097.1073741872.9609344&type=1&l=f867009ad4
I have redesigned dome #2 for this year and changing out what camera is in there. I am using the same 8" dome but built a brand new box with a couple extra inches of room to house the Bescor mount again. I am mounting a JVC Adixxion GC-XA2 (like a GoPro, but cheaper) alongside a HD webcam (Microsoft 5001). The JVC is so I can record HD from the dome. Had it on the windshield last year, but I hate not having an HD camera not pointed at the storm at all times. The webcam is so I can see where the cameras are pointed and what the storm looks like at all times.
https://www.facebook.com/media/set/?set=a.10103631676488097.1073741913.9609344&type=1&l=8bcb8da6fe
There are other options out there like MesoDome (
http://www.mesodome.com/), but cost are a big factor. My designs are as cheap as you are going to find when it comes to domes.
Some costs to consider:
Dome - 18" was $120 with shipping, 8" was $45
Bescor - $80-$130, mod is free
Foscam - $20-$100 depending on model, Other HD cameras can cost $50 to $300
Plywood - $10-$25
Various parts for box - $10-$50
other costs include programs and other stuff like that
Size comparison between dome sizes -
If anyone wants to buy my old 18" dome with the box from the first build I will sell it, though it has to be picked up in Amarillo. Just collecting dust at this point.