Done many searches but can't find an answer.

For CROW setup the BVM sight says:
"NOTE: The amount of aileron “up” deflection is ¾” measured at the outboard end relative to the wingtip.
The flaps “down” is per the flap gauge supplied with this kit. The elevator trim will be close to neutral."

I'm taking this as during full flaps with TX sticks nuetral the ailerons deflect 3/4" up during CROW.
Now with TX inputs how much deflection up and down from the 3/4" point do you deflect?
A 1/4" up and down from the 3/4" point?

OR, Is the maximum deflection up during CROW supposed to be 3/4"??

THANKS, TOM

Two seperate operations.

Set the aileron throw up and down as per manual.
Then with the ail. stick neutral, setup the crow measured at the ail. tip 3/4 inch up. No other ail. measurements are needed

My problem is that in CROW the Aileron is 3/4" up and with TX stick input the up position increases to where the Pushrod hits the wing skin.
Should I just set the servo endpoint so the Pushrod doesn't hit the wing skin. I think that would give me about a 1/4" up movement when in CROW.

I want to make sure I still have enough Aileron control when in CROW. I know the Elevetor pushrod are made with a curve in them but the Aileron pushrods look straight from all th pictures I can find. Should I make the Aileron pushrods like the Elevators with the curve.

THANKS, TOM

I don't have a Kingcat but do have my Bobcat set up with crow. I set up the max deflection as per the manual and then dialled in the crow, as bcovish said.

Assuming I have done mine correctly, you do end up with significantly reduced up aileron movement (1/4" sounds about right) and this is noticeable in flight. I find it ok for approach but I know of others than find the reduced movement a bit too much of a reduction in available roll for their liking.

Having said that, it is worth using the crow as it does really help the approaches.

Does crow really help to slow down the speed of the jet or does it just make it more stable?

Tom,
If you set it up exactly as the BVM instruction manual describes, you will have plenty of aileron authority when in "Crow".
Use the plywood template for the deflections.

Make the aileron linkage exactly as the BVM instructions describe. The linkage is straight. No curve allowed.

In a few minutes, (after I finsh my lunch) I will take mine out of the trailer, install the wing panels and take some photos of the crow and flap deflections, and post them in this thread for you.

Tom

Are you using the correct servo horns and linkage attached to the correct hole in the horn?

Okay....here are some photos of my KC with the "Crow" setup.
The setup is per BVM instructions, with an added touch. Code 66, flap system, the delay is 2 seconds, allowing the flap servos to move slowly. Make no changes in servo speed in code 24.

Standard aileron set-up:
A left hand roll command produces upward deflection of the left hand aileron, and a downward deflection of the right hand aileron.
A right hand roll command produces the exact opposite deflections. Right hand up, left hand down.

Aileron deflection/movement during "Crow" operation:
Since both ailerons are already deflected upward, no additional upward deflection is required to produce the desired roll direction.
With both of the ailerons deflected upward, during a left hand roll command, the right hand aileron is deflected downward toward the neutral point, while the left aileron remains up.
A right hand roll command deflects the left hand aileron downward toward the neutral point, while the right hand aileron remains up..
My ailerons go below neutral approx. 1/8" at full stick deflection...both of my ailerons also move above the crow setting approx 1/16" in either direction at full stick deflections.
Normally, you will need no more than about 1/2 aileron stick deflection in the landing pattern. The ailerons are quirte effective while in "Crow".

Also, some up elevator deflection is needed when lowering the gear and flaps, and adding "Crow.".
The use of a "Flight Mode" is highly desirable, as the JR10X and 12X radios will remember the trim settings at each flight mode setting. Lower the gear and takeoff flap, trim the ailerons and elevator, then lower the flaps to landing configuration (including Crow), and retrim. No more trimming is necessary.
Each time you activate the flight modes, the elevators will move to the trimmed position. In code 66, my down flap and elevator positions are Flight Mode 0 Normal/Normal; Flight Mode 1 MID: 59% with elevator UP 10% Flight Mode 2 Landing Flap down 125%, with elevator UP 50% Auto Land INH.

Photo #1: Clean wing
Photo #2: Take off flap deflection
Photo #3: Landing flap with "Crow"
Photo #4: Closer view of landing flap with "Crow"
Photo #5: Right roll with "Crow"
Photo #6: Left roll with "Crow"
Photo #7: A better view of right roll
Photo 8 and 9: straight pushrod.

I use the flap switch for the flight mode activation.

Here's the photos....

Harley,

Thanks a ton for the info and pictures. I'm using the JR10X flight modes but I still must be missing something in setup.
In CROW both my ailerons still move the same unlike yours. I'll go through the BVM instructions again off the website.

THANKS, TOM

Tom,
When I was using the 10X, I used JR Matchboxes for the flaps, elevators and rudders.
On the ailerons, plug the left hand aileron servo into the aileron channel, and the right hand servo into channel 7 (Aux 2).
In code 17, inhibit the Aux 2 switch.
Go to code 51 and create a mixer Aile>Aux2. +100, +100 offset 0; on page two of the mixer, all switches should be in POS 0.; On page three of the mixer, Master is NORM, Trim is ON.
In code 52, mix #FLAP>AILE Offset 0; +0%, -0%) Page two of the mixer, F2 to POS 1
Code 53, Mix #FLAP>AUX2 OFfset 0, Pos 0 m-0%, +0% Page 2 of the moxer F2 to POS 1; Page three of the mixer MASTER to ORIG

Also, on Code 54 mixer, mix Rudd >AUX 4 and plug the nosewheel steering servo into Aux 4. You can then use the Aux 4 knob to keep the steering centered to compensate for nosewheel and main wheel tire wear. Hope this helps

Harley,

Why do use a FM? Isn't easier to use the settings in "Flap Sys" for elev position? It eliminates moving to switches during landing.

Gary,

Slows the jet considerably, adds stability but dumps lift.... really makes it nice because of predictable sink rate and allows you to manage altitude with throttle. After Icommand everything out on gear pass Ithottle up to about 1/2 to keep it flying, backing off as Iroll out on final to a few clicks then cut to idle only when ready for touchdown, Iactually begin the flare before going to idle most of the time. If there is ZERO wind Igo to idle before the flare.

Cats + Crow = great setup!

Harley,

Using Spektrum AR9000, so only 9-ch's.
The elevators are Y-harnessed together.
Matchbox on Flaps and Rudders(includes nosewheel).
Aileron channel = Left Aileron,
Aux2 = Right Aileron.

BVM's instructions are different than yours. Did you use a Flap-to-Flap mix?

BVM website .pdf
P-Mix 51 Flap-to-Flap Allows side lever to be deactivated.
P-Mix 52 Ail-to-Aux2 Slaves right aileron (Aux 2) to left aileron (ail channel)
Don’t forget – trim function on.
P-Mix 53 Flap-to-Ail Activate crow in left aileron with full flap position.
P-Mix 54 Flap-to-Aux2 Activates crow in right aileron (Aux 2) with full flap position

When I get home tonight I'll check my setup again.

THANKS, TOM

STKNRUD, The reason for using a Flight Mode is simple.
In "Flight Mode", the transmitter stores the trim settings for each Flight Mode switch position. No need to keep trimming the airplane each time you lower the gear or flaps.
Trim the airplane once in each of the three Flight Mode positions, and no more trimming is necessary.

First flight scenario as follows:
Lower the flaps for takeoff. Roll out, take off and trim the airplane for straight and level flight at landing pattern speed. (Flight Mode position 1)

Raise the flaps and gear, trim it again for a clean wing and retracted gear...normal and high speed flight. (Flight Mode position 0)

Drop the flaps and gear to "take off flap" (it is already trimmed since you trimmed it after takeoff. Flight Mode position 1)

Slow down to Full flap speed, and lower the flaps to landing position, (which adds "Crow"). Trim it again. (Flight Mode position 2). You will need to add more power to compensate for the additional flap and gear drag at this point.

No more trimming is necessary after that, as each Flight Mode position has its own trim system memory which is retained until you move the trim levers. Future trim lever changes will only affect the selected Flight Mode.

Fly the pattern and discover how the sink rate is affected by the "Crow".....you wil need to carry more power than without "Crow".
The "Crow" adds drag increasing the sink rate, which simulates a more highly loaded heavy jet. The KC is fairly lightly loaded because of its large wing. "Crow' is especially welcome in crosswind landings.
Also, the ailerons deflected upward behind the CG adds a small up elevator effect.

You only need to move two switches....the flap switch, and the landing gear switch.

To each his own but that is a lot switch movements for me especially when you are working the gear and flap sw at about the same time. How often and for how long are you actually at any stable state, i.e. straight and level. I trim it for straight and level and that is about all since the rest of the time all the flight characteristics are changing (speed, AOA, etc.) Any if you fly with and without smoke oil, you need to adj the trim anyway. Using the flap system for elevator settings at approach and full flaps eliminates the need to move a FM switch along with the flap and gear SW for approach and landing. But like I said...everyone does it differently or why would we need programable TXs? And I didn't mean to change the focus of the thread.

George

STKNRUD,
I never thought that working two switches was a big deal.
Re-read my post #8 for the code 66 flap system elevator percentages. You must have missed that part.
I use one switch (Flap) in conjunction with a programmed flight mode to lower the flaps and add elevator compensation. One switch movement lowers the flaps and adds some UP elevator. Another switch movement (LG switch) lowers the landing gear. There is no additional third switch...the Flight Mode switch is the flap switch.
No trimming is required after the intial trim flight(s).

Lessee here....
Take off, raise the gear and flaps...two switch movements.
Fly for awhile, lower the gear and flaps....two more switch movements....
No trimming involved.
Land....don't forget the brakes....on the R/H slider.

Hmmm...only two switches to move before landing.

Harley,


Thanks for taking the time to show all the super info on the crow setup for the BVM Cat. I am a Pilot 40 years of Bushpilot in Alaska Flying the Jets RC is so Cool and the New TX JR-12X has so much programing that is helpful. I use crow on my Bobcat and have over 150 flight so far.

The take off and landing have a Pattern and a flow just like Flying a Bush Plane and landing on off airport strip it become Natural.


Thanks

Pat Martin

Pat,
I am happy to be able to be of help to all those that are interested.
Thanks for the complimentary words, and I wish a "Happy Thanksgiving" to you and yours.

Harley,

Thanks for the clarification. I admit that I didn't read your setup close enough....shame on me. FMs are are new to me. I should break out of my habits and try them. Happy T-day.

George

George,
Thank you, and a Happy Thanksgiving to you and yours!!

After having flown a season on the KC, I can tell you that Crow helps alot. I flew the first several flights without it and then one day, found another KC with it, so I added crow and took out some elevator.

What I noticed when moving from the NO crow setup to Crow is that the tail drops a bit to a better landing attitude, and the pitch sensitivity is gone and aileron effectiveness is unchanged even on low rates. the plane "locks in" on final better than any plane I have ever flown with Crow.

However its mixed, you have to watch the 'additive" effect of the mixes.. Its addressed in the 12x. It wont let you go past the MAX ATV... if you set the atv to the max value, Doesn't the 10X limit you too? I never flew the 10x, so Im asking.. The 12x has a flaperon setting that makes crow a cakewalk.

Mine is set up against the Flap switch, so that at 15 deg takeoff flap I get about 1/8 inch crow, and a tad less than 3/4 inch at 35degrees landing flap. The wee little bit of crow on takeoff helps it rotate smoothly. Once I did that, it became my favorite plane instantly..

Flying the KC... IF the Nose gear ever touches first, go around or fly away and reset... crow helped this situation immensly too...

thats what I learned this last season.. I can wait for next season. Im going for 100 flights on it next season... thats alot for me but I just fell in love with the plane...

It was mentioned previously or perhaps in another thread but the Kingcat is a lightly loaded for its size.

while the crow certainly helps lock in the landing attitude you can help the a/c penetrate the wind while providing even more stability by landing the a/c heavy.

one way to do to this, as proven by BV during some UAV tests a while ago, is to add weight. I think they added up to 10lbs during tests perhaps more, Harley probably knows for sure.

however, the easiest way to land heavy is to land with more fuel in the tanks. You can purchase a Gary Mueller center fuel tank, although I think some folks use it for smoke, after 9 min of shooting touch and goes, some slow flight to full power near vertical climb outs, loops conducted into and across the prevailing wind etc etc. there's still plenty of gas. the main fuel tanks are JINORMOUS!!

if you opt to fill the Mueller center tank with fuel there is still plenty of room behind that tank in the aft section of the fuselage to stuff a 32oz tank for your smoke oil or you can simply add a centerline drop tank as Dan Avilla has done with his bird.

one last thing regarding flight modes, flight modes will be your first indicator that something could be amiss (servo, linkage, wing warping etc) since if after numerous trouble free flights you find yourself having to re-trim

cheers