ir8prim8

Hi there,

I read in a post on here about hooking a gyro up to a rudder in a twin engine setup to help aid an engine out situation

I am building a Nossen 310 and would like some more information on this.. ive never delt with choppers before so i know very little about gyros or how to incorperate them into a plane / rudder set up. I was wondering if anyone can suggest a simple gyro, some of the posts have warned about a certian kind. HOpefully this "special" kind is the more expensive of the gyros.... or how they work or how to hook them up to the rudder. I understand that this will not solve a flame out situation but it may lessen the effects. I have alreay spent the extra money on 2 McDaniel onboard glo-drivers so hopfully my knowledge of engines mixed with these onboard drivers will keep a flame out from happeing... however im already pushing $4000 for this project and want to take every precaution to keep it in one piece. is there any programming options that come with todays futaba comp radios that can increase the user friendlyness of a twin? i.e. throttle rudder mix ect. I have flown twins before but this will be my first computer radio ive used. Ive really only messed with the exponential settings.

BillS

I have never used a gyro. In the beginning when an engine went out I simply treated it as a dead stick.

Now I practice engine out by a switch on the transmitter that drops the engine to idle. Actually 5000 RPM or it will flame out if left too long.

Bill

Edwin

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Go to warbirds.com in the techniques section and look for twinmans reports. He talks about gyros in his third section I think. If you serch on twinman here you might find a thread that explains how he did it. I believe on one of his twins he used a gyro on rudder and another gyro on ailerons. Think it was the P-38. In a nutshell, all it does is give you more time to react in a worst case scenario. Which CAN make the difference.
Edwin

Edwin

My Feedback: (2)

Oh, another thing. Might get him to respond if you post this in the twins forum.
Edwin

Ed_Moorman

My Feedback: (1)

In that 4 thousand bucks, I hope you bought a good rudder servo. I use a digital on all my twins. The Nosen is big, but is easy to fly. Just make sure you have a powerful servo on rudder and the pushrod is stiff. Hold full rudder and try to straighten the rudder out. If anything bends, you need to fix it. I use 8 degrees of out thrust on my sport planes, but on a scale plane it doesn't look scale, so you have to know how to use the rudder.

In my opinion, most twins that have trouble, start on the ground. The owner cranks the needle in so the engine really screams and it flames out after a few minutes. If you are running glow, you need to see a smoke trail in the air after take off.

If you are going to fly around at partial power, get engines that have good mid ranges. Or run gas. I would not run an inverted 4-stroke, or anything else inverted besides gas in a multi. Too many reliability problems. If you have to adjust the needle every time you fly, get some other engines for your twin. You problems don't double with a twin, they quadruple. I would also not run new engines in a twin. Get a Stick or something easy and run them in before putting them in a multi.

You have a lot of money in your twin, don't go cheap on good reliable engines or on a good rudder servo. I know what you mean about twin cost. The cost adds up quickly. I have a twin fuselage bash of a World Models Sky Raider Mach II. The kits cost $53 each at my local dealer. Counting engines (2 .46), radio and the extra wing extension, I have nearly $1000 in the plane. I was open mouthed after I added it up since I thought it was going to be a cheap twin.

JohnBuckner

My Feedback: (1)

Rudder gyros definately can be beneficial in some airplanes and not so important in others. I use three of these: http://www2.towerhobbies.com/cgi-bin...?&I=LXL313&P=7 in a four engine Kaydet Senior and in two Wing P-38's These have received benefits from its use in several ways: With the quad the chief benefit is better throttle up t/o's due to the additional directional stability as the four engines tend to come up unevenly in many cases. Of course the big advantage with the 38's is the few extra seconds it buys you to "identify and react' with the appropriate rudder response which is always rudder into the good engine, not aileron. There are other actions such as power reductions depending on your configuration and position but the big airplane survival tool is 'Rudder not aileron into the good engine'.

Good examples of airplanes that it would be a good idea are any fairly heavy wing loaded airplanes such as that nice 310/320 you got there. I,ve done a number of twins that are fairly benign and fly just fine all day on one with just a little rudder imput such as a Seniorita with a pair of 30 FS's I put together for helping folks with learning the technique.

If this is your first multi then please consider doing a more benign type first such as a Twin Star or a Twin Air. Its always good advice to get with someone who truly understands the technique to serve as a mentor rather than someone who has just survived twins because they never had an engine out and idea of survival is to cut power and land wherever you may be.

If you use a gyro then the simplest form is all that is needed, expensive rotor gyros with adjustable gain from the ground and ability to switch on/off from the ground is total overkill for our application. There is never a need to turn it off it will not fight your manual rudder use. The unit linked above has worked well for me and the rudder is mearly plugged into it and the pigtail is plugged to the Rx. and it is mounted with its axis vertical somewhere near the CG thats it. There are to adjustments: a centering adjustment and the gain. Usually start at fifty percent and thats all that is needed.

John

ir8prim8

Yeah going bigger gets costly quick. i cant believe some of the numbers ive added up. when i decided to fiberglass it instead of just covering it i tacked on another grand in fiberglass supplies and acrylic enamel paint.

FYI WWW.PAINTFORCARS.COM has automotive acrylic enamel and acrylic lacquer for a fraction of anywhere ive found. they only sell the paint by the Gal. and they only have 20 or so colors but they charge $30-$42 (depending on color or metalic) THATS GAL PRICE guys @!@!!@!@!@!. 3/4 a gal of the same paint sells at my local store for $181.00.

not that this process is right for most modelers. I think having a toy with a better paint job then my car just isnt right ... =) but then again if my car had wings maybe i would give it more of my attention =)

I got 2 dark base colors and a pint of white from the local auto supply store. use the white to mix up your own paint. mixing wastes alot cus you dont want to under mix and not have enuf to cover and matching is impossible... but let me say that again $30 a GALLON =) needless to say i will have enough left over to do many more models. (uggg more fiberglass sanding)

I have a pull pull 18 guage wire and a 150gram high torque servo for the rudder i didnt go with the digital simply for the cost factor. Ive got a standard servo on each side for flaps, standards for throttle and 130gram torque for the rest. I will be putting 2 Saito 150's in it they are both good runners and have been in other planes reliably. one is the GK version but that is only the color... LOL ironicaly i paid less for the GK then the standard. for realism i will be using 3-blade 16x8. the saito's mount beautifully under the cowl with no need to cut holes (except for normal air passage over the head and out the bottom). the only ugly part is that the plane i have is a old kit it was sitting in my grandfathers garage forever. on the plans they show the nacels square. the replacement cowls i got from Fiberglass Specialists had rounded corners. AKK of course i didnt get the cowls untill after i had everything final sanded and primed. i would have had to rebuild the entire nacel or round down the corners of the firewall (making the firewall structualy flawed) so i decided to give my rounded cowl square corners. the end result isnt the best as fiberglass does not adhere very well to gellcoat it will pass just dont look too close hehehe

It should come in around 20lb empty. I plan to add about 15lb dead weight to it bringing it to a takeoff weight of around 35. Thus the need for the 150's i need that extra climb power so i dont have to screem the engines just to reach flying speed.

I was wondering if anyone had any input on the weight distrabution of the dead weight.
To be more specific. this plane is the ONE WAY EXPRESS for 4 R/C Skydivers. each jumper has a real parafoil thats aporx 5'x1.75' and the jumper is about 14" tall. Its great fun to take a can of spray paint make a 20' bullseye in the grass and see who can fly there jumper closest to the target. I had a chance to fly one last summer and i was hooked. the one i used was a single jump setup (1 jumper). I think it will be much more fun for everyone at the field (including kids) to compete with 4.

Heres the question. should I mount them all under the fusalage or spread them out over the wing. I know they need to be at the CG thats the easy part. which would be a more stable flight. Each jumper weights in around 3.75lb Im not talking about wanting to do anything but climb and pattern fly up to drop altitude. My guess is that i should have all the extra weight centralized as much as possible. but ive never done anything like this set up before. LOL YOU SAID WHAT.... YOU WANT TO ADD 75% OF THE PLANES GROSS WEIGHT IN CARGO???? Spoken like a true jumpmaster. =)

ir8prim8

actually i was off on the weight. they are 3 lb each.

Left_Seat

An answer to the original question...

You need a [link=http://www.rcgroups.com/forums/showthread.php?t=354497]Hamster[/link]. Automatic yaw correction.