Any help for details with PID robot balancing robot?

I am still working on my balancing robot program without success. It is an extension of the MakeBlock firmware balancing robot code. I am trying to add a Wii nunchuck for control. I have discovered that the firmware has a PID for speed and also a PID for angle. The PID is run on speed as an input to the angle PID. The speed PID is really just a PI but the angle PID is all three parameters. The speed PI seems like it really could use a D parameter. But, I am wondering if two consecutive PID's is considered good coding practice?

CLplaneguy:
But, I am wondering if two consecutive PID's is considered good coding practice?

Nothing wrong with it at all - should work just fine if tuned correctly.

Shameless plug: you seem to enjoy RC planes, here's a build log for my Arduino RC plane stuff in case you're interested: build log