Damn V tails
 

I finally got a chance to try to fly my new RacerII yesterday. Unfortunately, all it did was grind the tips off of the prop as I tried to take it off. I'm guessing the V tail is not properly aligned. Today I set up the plane on my bench and leveled the wing as best I could. I got the leading and trailing edges all leveled within about .020". I measured every possible way I could think of, made several checking fixtures and alignment tools but I still check the V tail to be in line with the wing, at least within 1/2 degree. That is about the limit of accuracy I can get without considerably more fixturing.
That being said, how do the rest of you check it and how do I go about correcting it? The tail is solidly glassed to the fuse. It would take quite a bit to remove it and reset it. I thought about cutting the fuse just in front of the stab and regluing it with a corrective angle. I'd then have to glass the joint to get sufficient strength back.
any other ideas?
Thanks,,,basmntdweller

??
 

Can you describe your takeoff procedure?

I assume you give it the full throttle push off?

Damn V tails
 

Since it doesn't take much effort and I frequently fly by myself, I put my TT40 on it so I would have throttle. I just did a normal takeoff like I would any other plane. Sitting on the runway, pointed into the wind, hit full throttle while holding a little right rudder and about half up elevator.
My Predator with my Jett was easy to take off, It just needed about 1/3 right rudder and just a hair of up. This is on paved runway.
I will try it again tomorrow just to be sure I wasn't doing something stupid yesterday.
basmntdweller

Damn V tails
 

While in the building stages,,, did you use an incidence meter on the wing and a bubble on the V tail?,,, (both at zero and level)

Can you tell me how much elevator throw you have now?

where did you mount the landing gear?

CG is ???



BV

Prop Trimming?
 

I would suggest a full throttle release with full elevator to pop-it-up into the air. Then get some altitude and trim for straight and level flight. Sort out flying characteristics before any major surgery. My RII's with TT 40's don't need any rudder on takeoff, unless a cross wind is present.

Good luck

MaxQ

Damn V tails
 

I used a ruler and leveled the wing and tail when building. 1/4" up elevator throw. CG at 2 5/8" from leading edge. Landing gear mounted just like the plans show it, directly behind #1 former.
basmntdweller

Damn V tails
 

This may be a bit late for you but a while ago I posted this regarding the set up of VEE tails. Before you do any surgery you might check the alignment using the method I describe to set it in the first place.

The important thing is that you will need two incidence meters. I use the Robarts.



Here is what I do.

I have some lines drawn on my work surface to represent the fuse centreline and the the wing and tail positions. The wing and tail lines are of course square to the fuse centreline.

You will need two incidence meters

The Vee tail is finished.

I mount the wing to the fuselage in it's final position. Saddle all potted, etc, etc.

I lay this assembly on the worksurface upside down. I block up the wing (keeping the wing parallel to the worksurface) until the wing incidence is zero with the rear of the fuselage sitting on the upside down Vee tail. The second incidence meter can now be put on the tail without the tail tipping over. Some extra shimming may be required to get both meters to read zero.

So you now have the vee of the tail square to the wing and the incidence parrallel to the wing. there is one more adjustment to make. At this point the tail may not be aligned with the fuselage centre line. Giving you sort of big rudder offset. I measure from the T.E. of the wing to the hinge line of the elevator both sides of the vee. I also have marks on my bench for this purpose. The tail is now true in all three axes.

I usually set it all up roughly before applying any glue. I use a slow setting epoxy to allow time for final adjustments when the actual gluing takes place.


Ed S

Take off
 

If you are within 1/2 a degree, the plane should fly fine, with minimal trim. I would suggest having a helper give you a push at full throttle.

How about your balance? Wheres it at?