Re: Canard mounting
Jon Finley <finley@...>
John,toggle quoted messageShow quoted text
Sounds like I better explain myself so I don't sound like I'm dreaming up
some hair brained idea!!
My Q2 has over 400 hours. It flew almost all that time with a Revmaster. Now
flying with the Subaru. It flies pretty well. However; it does not pitch
buck. Rather, it starts downhill (mushes) at 85mph and full down elevator.
The down elevator stop is greater than the plans (first thing I tried years
ago). I must be over the numbers at 90mph and a little power if I hope to
land (otherwise there is no elevator authority). I have tufts on the
elevator (canard) and they exhibit some interesting behavior during climb.
If I use the elevator to pitch for climb the tufts start going wild (side to
side, up, and occasionally FORWARD) when deflected more than 1/4" - 3/8"
(haven't measured it exactly but it isn't much). To avoid this I have
started using my reflexor and t-tail to pitch for climb and keep the
elevator "in-trail". I don't have a VSI so I cannot accurately determine if
there is any difference in rate of climb (between the two methods of pitch
change). I am currently flying at the forward end of the CG limit but I am
within the limits. My Q1 pitch bucks normally so I am familiar with what it
feels like. This problem has never been a big deal but am becoming more
interested in at least knowing what the problem is even if I don't fix it.
I made a set of "outside" airfoil templates using the core cutting templates
(the BL 48.8 template for wing and BL50 for canard). I transferred the
water line from the template. My new templates match the airfoil pretty
well. I raised the tail until the main wing was level and then checked the
canard, it was slightly nose down. I didn't measure how much as I didn't
have a digital level and couldn't remember how without one (no need to write
up instructions - I have them, just need to dig them out). The original
intent of my question was to find out if a Q2 would even fly with a nose
down canard and if so, would it behave like mine does. Sam, mentions
needing lots of nose up trim. I don't need much but I do have a t-tail which
could be masking my problem.