Hi Sverre,

I have attached a picture of the SG6042 blade profile. For a 5 to 7 lb. gyro I use about a 25" long by 2.5" wide blade. You can make the blades from either 3/16" thick or 1/4" thick material and should be about right. If your blades are lite, 50g to 80g they will spin up real fast with just a little pre-spin. Most of my blades are slightly over 100 g and I pre-spin them with an electric drill. By pre spinning them if everything else is set up correctly your chance of success is much better. If you make the blades from balsa, add a little weight at the tips and you will have more stability.

Good luck, Attach a picture. Best taken before you fly.

Phil