Rusty if you decide to build a 601 let me know as I have just started
building one along with two other guys and we did a PDX file on the plans
and had all the pieces laser cut and pre punched just like the factory kits
and could get you a file for it,   Thanks Ken, but if I go for a 601XL, I'll probably just buy the kit.
Until/unless the single rotor starts behaving better, I won't be building
one.   On that subject, I watched the Warp Drive prop on a Subaru powered gyro
today, and saw some of the same fore and aft oscillations.  It wasn't as
bad, and the guy who set them up told me a way to get the blades a bit
closer to the same pitch, which he thinks has something to do with this.
When I get the single running again, I'll make sure the blades are as close
as possible, then try it again.   Rusty