oldtyme

OK.........I'm really wanting to mix my throttles on my twins in my 9C. I've made a stab at it and got it about half right but I really need some help here. I went to Futaba FAQ's and they had one version which is a bit different than I understand it. I also looked in the instruction manual for the radio and it's very ambiguous. Also looked in the instruction manual for Top Flite's DC3 and it still leaves me in a quandry. No one at our field plays with twins and the one guy that tried just Y-harnessed his throttle servos. Here's what I've done.......I have the right throttle servo in channel 3, the left servo in channel 7. Now I want to mix them such that switch C on the radio functions so that right engine is used in the center/down position and the center position........then the left engine is used in the center/up position and up position.......that should give me both engines in center position, left in the up position and right in down position.........three mixes. Then I think I adjust the end travel individually for channel's 3 and 7.
Then I think I have to have a fourth mix for throttle cut to affect both channel's 3 and 7.

OK that's how I understand what I have to do. Anyone with programming experience for this function that would care to lend a hand.....it would be really appreciated.........the more verbose the better. If you would prefer to contact me via my email, it's [email protected].

I'm presently trying to set up a Twinstar with twin OS25LA's and right behind that is going to be a Dual Ace with twin ST45's.

Thanks to any and all help I can get,
Andy

Super Hot

Hi Oldtyme

The best mix is "Throtle Needle" function with chanel 3 & 8.
Make shure the chanel 8 is null in "Auxilary-Chanel" program.
With "Throtle Needle" function, the "Throtle-Cut" is automatically programed on chanel 8, and you can use the "Thr-Needle Curve" for a perfect synchronisation of ch 8 engine with the ch 3 engine.
If you want control with sw g, use program mix 1, thr, thr, trim off, sw g, down, -100%, -100%, ofset 0%, and program mix 2, thr, aux2, link off, trim off, sw g, up, -100%, -100%, ofset 0%. but if the sw g is programed, you must use end point 3 & 8 to trim your idle,

Have good fly.

Jean-Jacques
Sorry for my english.

oldtyme

Jean-Jaques,

Would you mind sending an email and not using so many abbreviations? I really need this help.
Does it matter if I use switch g or c? Also, on the receiver that I have, it only goes to channel 7 which is why I'm using that one. Once again, my personal email is [email protected] and thanks so much for responding.

Andy

Super Hot

Oldtyme

With 7 chanel receiver, you need made 6 or 7 mix.

1- make shure the chanel 7 is null in "Auxilary-Chanel" program.
2- Set throtle-cut : mix=on, rate=40%, sw=f, position=down. This mix stop engine on ch-3 when you flip the sw f
3- Prog-mix1 : mix=on, master=throtle, slave=throtle, link=off, trim=off, sw=c, posi=down, rate= -100%/-100%, offset=0%. This mix keep throtle ch 3 idle when the sw-c is down.
4- Prog-mix2 : mix=on, master=offset, slave=aux1 (ch7), link=off, sw=c, posi=up, rate=+75%. This mix keep throtle ch 7 (aux1) idle when the sw-c is up.
5- Prog-mix3 : mix=on, master=offset, slave=aux1 (ch7), link=off, sw=f, posi=down, rate=+40%. This mix stop engine on ch-7 when you flip the sw f.
6- Prog-mix4 : mix=on, master=throtle, slave=aux1 (ch7), link=off, trim=off, sw=c, posi=center & down, rate= +100%/+100%, offset=50%. This mix run throtle ch-7 (aux1) when the sw-c is center & down.

Note: You can not turn on the trim in program-mix4 because when you use the sw-c you will slower or raise the engine on ch-7. To trim the idle on ch-7, you must use the end point or made an other mix :
7- Prog-mix 5 : Mix=on, master=vrb, slave=aux1 (ch7), link=off, sw=c, posi=null, rate= +25%. This mix is the idle trim for engine on ch-7.

If you want synchronise your engine on ch-7 with engine on ch-3, you can made a throtle curve with the prog- mix6:
First - inhibit the program-mix4.
Second - Prog-mix6 : mix=on, master=throtle, slave=aux1 (ch7), link=off, sw=c, posi=center & down, 1= -100%, 2= -50%, 3= 0%, 4= +50%, 5= +100%. You will fine set the rate of throtle ch-7 to compare the rpm between the engine.

Have Good Fun

Jean-Jacques

oldtyme

Jean-Jaques,

Thanks so much for the info. I hope I get to try some of this by this weekend. Again, thanks..Andy

Milcent

Hello Oldtime,

i built a twin engine this winter. It is not a ward bird or something else, but a SPAD. Not very expensive to build and is running 2 OS46LA.
I also have a FF9 and was looking for a way as you to manage both engine on 2 ways. I followed exactly what is explained in the FAQ of the futaba web site ([link=http://www.futaba-rc.com/faq/faq-9c-q511.html]Twin engine FF9 configuration[/link].
I also was able to use an additional mix to have throttle cut for both engine with one switch.
And i still have 2 mix for flaps and a flap to elevator.

This radio is what i needed for all this stuff.
You can see my plane on a video here : [link=http://www.rcuniverse.com/mvp/videolink.cfm?postid=3318]Twin DPS on RCUVideo[/link].

If you need any advise let me know, but i believe that Jean Jacques, de notre belle province, said also what you need to know.
Pierre.

oldtyme

Milcent,

Thanks for the additional info. I have that instruction that you mentioned.......probably just
need to go back and compare it to what Jean-Jaques explained........thanks to you both.

Andy

oldtyme

Just bumping this to the top to see if there are anymore takers on advice.

oldtyme

Just bumping this up one more time.

bruce_c

Jean-Jacques
what a very good idea to use the throttle-needle mix

I had just done the mix described in the futaba FAQ, with the 2nd throttle on a 5point curve too - but this used several mixes to acomplish (along with extra ones for cut)

Using the preset thro-needle mix is so much simpler and still retains the fine tuning of a 5point curve!!

I also think it is a bit safer - i was wondering how likely it would be to flick the wrong switch at the wrong time in the air and cut one to idle
I cant really see there being much need for individual engine control like described in the futaba FAQ