opjose
Posts: 6146
Joined: 11/26/2005
From: Poolesville,
MD, USA
Status: offline
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There are a few areas that you have to be careful about with this plane, especially if you have not flown a Bobcat type plane before...
- When setting the neutral point of the elevator control surface, align the trailing edge of the elevator with the back TOP edge of the stabilizer.
Initially I did what I would do in any normal plane. I used a straight edge along the bottom ( flat part ) of the stab, and aligned the elevator to this, assuming that this was the ideal "neutral"... boy was I wrong!
The plane would NOT lift until it was far down our paved field, then it JUMPED into the air almost straight up.
After landing the plane one of our resident "jet guys" looked it over and pointed out that I had it "forcing the nose DOWN"...
He was right... I popped out the control horns and moved them over one tick on the servo, so that the trailing edge was level with the back of the upper part of the stab...
Now the plane flew perfectly.
- You can set your radio up with FLAPERON's to help in landings... e.g. right aileron on channel 2 and left aileron on channel 6, and use the radio mixing for flaperons.
If you do this, unlike conventional planes, you want the both ailerons to come - UP - 1/4" or so when you hit the flap switch.
This will cause the plane to balloon up in flight a bit, but it will land with a beautiful nose high attitude.
- DO NOT break in a new engine on this plane! Because it is a pusher prop plane, the engine will tend to overheat on the ground.
Get your engine broken in and tuned up elsewhere, then move it to the Bobcat when it is ready.
I used a GMS .76 Ringed engine with an APC 11x7P pusher prop. This turns out to be a very nice combination. Some people are also using Graupner 11x8P props with success.
- If you purchased the retract ready version, first attempt to loosen the mounting blocks from the underlying wood support, using a screwdriver. On one wheel one was not properly glued.
I would recommend popping them up ( or off ) if possible and liberally applying epoxy to the whole area.
If they are somewhat secure, expoxy all the exposed wood areas around the gear mounts. You'll be glad you did.
Also see if you can insert a block of wood on both sides of the gear mounts, under the existing wood. Epoxy this in place.
Choose screws that will go through the existing mounts into this new piece of wood for a very secure and sturdy gear mount.
- I set up my front stearable gear using a Pull-Pull system. This worked great but I initially had problems with the wire tangling when the gear was retracted.
I solved this by letting the wire run UNDER a small metal bar that I placed at the point on the wheel well where the circular area of the wheel meets the longer area of the strut... ( pictures later ).
This prevents the wire from looping around the gear or kinking.
The pull-pull wire is strung THROUGH the plastic wheel well using a bit of tubing at the junctures.
( Edit: I was STILL not happy with the results... see subsequent posts for a much better solution! )
- I left about one degree of "reflex" ( postive or "up" aileron movement )when the ailerons are neutral.
This helped keep the nose from dropping, for hands free flight. If you use Flaperons, try it.
- As per another suggestion here, I ran my exhaust THROUGH the wing so it comes out under the plane by using a Dubro Silicon Exhaust Extender.
A great idea, now the plane stays clean.
I used grommet washer's I had on hand to strengthen the two holes I made for this... I also wicked CA onto the underlying Balsa after cutting the holes to both hold the covering and strengthen the area.
< Message edited by opjose -- 9/12/2007 8:48:50 PM >
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