sskianpour

My Feedback: (2)

Hi to all BVM F86 80" experts (Jack Diaz Sr, this means you! )

I am setting up my large Sabre. Gyro is connected to BOTH rudder and nose steering. Here are questions:

1. Is it true that I want rudder travelling in SAME direction as Yaw? i.e. if Plane yaws to the RIGHT I also want the gyro to make rudder travel to right as well?

2. Previous owner had gyro set up so that when Gear was UP, gyro would stop working. When Gear came down, Gyro would become active-so as to compensate for Dutch rolling on final approach at slow speed I presume, and also for nose steering to auto-correct any crazy landing and rollout on ground. So....

I am wondering, HOW IMPORTANT is it for gyro to be made INACTIVE during regular and high speed flight? Can I let Gyro stay active during high speed and regular flight? Is that dangerous?

Reason I ask is because the way Gyro is currently setup, the rudder AND nose steering are"Y"ed into ONE Channel (I am limited on channels with my Futaba 12Z). So If I make my Gyro INACTIVE when gear go up, I am essentially making my Rudder INACTIVE as well (something that seems awful dangerous to do as I prefer to have rudder control, not just a centered rudder that will not respond to input during gear up flight)

I would rather error on the side of caution and have NO mixes so whether my gear go up or down, the gyro remains active and helps auto-correct nose steering AND rudder. Frankly, I am not a fan of gyros on flight control surfaces at all, and would much rather just put the gyro on the nose wheel, and not worry about gyro on rudder AT ALL.

So my options are:

1. Keep gyro active for rudder for slow flight, fast flight, on ground, gear up, gear down, everywhere? [&:]

2. Make Gyro AND rudder INACTIVE during fast flight and gear up conditions, and only activate gyro AND rudder when gear are down and landing? [&:]

3. Forget the rudder, just put Gyro on nose steering and dont worry about dutch roll? [8D]

4. Figure it out, go get 2 gyros, split up the nose steering and rudder into TWO different channels and gyros and make SURE I have Gyro for slow flight and landing? []


All help from EXPERIENCED BVM F86 80" pilots is appreciated. Please, this is not the thread to post about how you have a gyro on your Rafale or Eurosport and you "love it", etc...

I am trying to ask a very narrow, specific question pertaining to THIS jet and THIS jets pilots and experiences. Thank you all.

If calling to discuss helps, please feel free:

303-482-5004

Thanks again!

Shaz

bskyinc

Ck out rcjetaddiction.com Dustin Buescher has a great video on setting up gyros. On my metal morph I have gyros on rudder and ailerons with rudder and nws connected via matchbox. The gyro ( JR370A) is between rcvr and matchbox and rudder/ nws is never inhibited. With the mixing on the stick position to gain and flap position. Lowest gain with flaps up, (higher speed more effective rudder), as stick is moved for rudder, gain is decreased so by approx 1/3 stick movemnt gyro gain is 0 and no gyro correction. Gain percentage is programmed to increase with approach flaps ( slower flight less effective rudder) and more gain with landing flaps/ the stick inputs still decease gain is the mix. Aileron is set almost the same. It is unbelievable how smooth it will fly when setup this way. I have my BVM F4, BVM 80" metal morph saber and BVM 60" EVF Sabre set up like this.

Ron Stahl

My Feedback: (12)

Shaz,
The gyro command to the servo should be opposite of the direction that plane is moving as to stabilize the axis the gyro is on: other wise it will drive it more divergent instead.

Chris Smith

My Feedback: (2)

"Throw follows displacement". Left wing [displaced]down left aileron should go down. Tail move right (nose left) rudder should move right. Steering follows rudder.

Tom Antlfinger

My Feedback: (24)

Shaz, I have owned 3 different 80" Sabres, including the one I am currently flying in the Utah scheme on the video I posted on Greg Wright's 80" Sabre thread. All have been set up the same way....N/G is mixed to Rudder.....N/G mix is on with gear down and off with gear up....I use Jack D's CG setup....a bit unusual but works perfectly......balance on the forward blade spar receptacle on the fuse with the WINGS OFF.........tanks empty, UAT full....

Gyro is on rudder, mixed to N/G with gear down, rudder with gear up, as the previous mix turns off the N/G movement with gear up...

I use the Right Front 3 position switch on my 12 X as my gyro control.....pos 1 is gyro off....pos 2 is 1/2 sensitivity.......and position 3 is full sensitivity.....on most days, unless it is very windy with some tail wagging, I don't use the gyro in the air.....no need for it....it tracks like on steel rails with no tail wag or dutch roll......as I recall, I use BV's setting for full throw of about 1/4" and about 1/8" for low throw....you can fine tune this setting.....not using the gyro on high cruise flight saves the rudder servo since with it on, it is constantly twitching with every little wind burble......having an off position also allows you to turn of the gyro in case it glitches(used to happen alot with older gyros, but less of a problem with the newer ones) or you somehow get the output reversed.....that's almost as bad as having servo's accidentally reversed.....

As far as direction, nose yaws left, correct with R Rudder and vice versa, just as you would if you were using the rudder stick.

You do need 14 channels for this setup with Speed Brake and Sliding Canopy, so you have to use Y-connectors or matchboxes on ailerons, flaps, or elevator. I am using Y connector on the ailerons and elevators, but as soon as I put it away for the season, I will be changing over from my 12X to my DX-18 and the Y connector will go. Jack D. does recommend a little landing crow, which I can't do now as the ailerons are Y'd together, but it is a major PITA to get at the RX and all the servo leads now with the huge central bypass, much like on the F-100.....

Consult your local FUT guru on specific port and mix settings for your 12 ZAP.......

TA

smchale

My Feedback: (67)

Shaz,
What did you end up settling on for your setup, if you don't mind me asking?
I'm currently building the same model and I fly with a Futaba 12FG. What gyro are you using? Servos?
I was planning on JR servos all around but think if the gyro is Futaba then the rudder servo needs to also be Futaba to communicate correctly. Feel free to answer over on RCJA, that's where I'm going to document the build, etc.
Thanks!
Sean

furloughed ual

My Feedback: (31)

Tom says "Consult your local FUT guru on specific port and mix settings for your 12 ZAP....... "

the local Futaba Guru says....

Shaz....you missed OPTION #5....Throw the gyro in the trash and fly the damn airplane!!!!

Sorry, couldn't resist.

How you doing Tom? Flying season is about done for you boys in FDLac.

Ryan.

sskianpour

My Feedback: (2)

LOL, Ryan good advice, I actually would and she was slated to fly last weekend but I still am waiting for Tam to ship me a batch of failsafes (as you know the extra one I had was on the fritz) and for JC to update my 160SX ECU to 9.9v and for Todd to get me my Check-valves so I am just whistling dixie and killing time playing around with Gyros. I actually don't trust them terribly much despite what others say about how reliable they are. All you need is one flopping loose or going haywire and your plane starts doing snap-rolls and flying like the pilot is on crack! Bad news...[&:]

Shaz

sskianpour

My Feedback: (2)

Sean,

Will hop in on your other thread on RCJA and send you the goods. I also still need to copy and email Greg Wright the World Masters Docs on this Sabre, and perhaps you and I can exchange notes on the Hunter as I am starting a build on the one I have sitting here in Box as soon as my SM Lg Hawk 100 is done!

I know, I know, I have issues....

Shaz

Jack Diaz

My Feedback: (1)

Shaz, I am looking at this thread for the first time right now (was at BITW and didn't browse the computer much). Sorry, I was not ignoring it

Every advise you have been given here is perfect.
I would just add a couple of comments:

-My rudder servo and nose gear servo are on the same channel. It goes: from the receiver - to the gyro - to a "Y" - to both servos.
-I adjust the nose gear neutral position mechanically (you only do that once).
-I leave the gyro "on" for the whole flight. A lot of gyro gain with flaps down .. less gyro with flaps up.
-The gyro gain channel is controlled by the flap switch.
-So, two channels for rudder, nose gear servo, and gyro gain.

Tom, I don't use "crow" as such. I raise the ailerons about 1/8" from the flaps up reference (in other words, I increase the wash out 1/8"), and they stay like that forever. This is very important !!!
I have both ailerons on one channel, with a matchbox for throws adjustment. Crow would require two channels, and then you won't be able to use a gyro on the ailerons if you ever wish to do that.

I will get back to this as soon as I remember something worthwhile mentioning.

Jack