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