Do I need Twinsync
 

Hi all,

I am new to twins, I am currently building a Twin-Air 45. The choice of power are Saito 56s.

Both have been broken in on my trusty trainer, but one engine is much stronger then the other( higher rpm).

Will this cause me problems?

If it dose will twinsync help me out and make it more enjoyable to fly with out woring about a engine out problem.

Any help would be great.

Bob(N2RYD)

RE: Do I need Twinsync
 

i have same situation with a pair of OS .52's. I run the strong one rich to get the high speed rpm " in the ball park," maybe as much as 500 rpm different. No synchronizers. Looks a little wierd with the different exhaust smoke trails, but flies just fine.

RE: Do I need Twinsync
 

Most twins you are better off keeping them simple, perfect sync is not that critical and can be adjusted with a linkage if needed. Gyros, synchronizers, flaps, retracts, complacated tanks, ect add complication that sometimes just aren't needed IMHO -

RE: Do I need Twinsync
 

I am a big fan of the TwinSync. Syncronized engine sound better to me. The big plus of a TwinSync, for me, is that when/if an engine dies, the good engine will follow it to idle. This feature stops the initate yaw factor that takes place while one engine is dying and the other is still at power. Turns your powered airplane into a heavy glider untell you reset the throttle.

RE: Do I need Twinsync
 

Surely Syncho-sound is great, but that is mostly sound effect in general.
I would think it is more critical that one has independent gyroscopes for each of the two rudders;
to react instantly there, on board, not to wait for a control input from the ground;
that might help lot more in trouble with one of the engines. Such gyros are pretty
cheap, just less than 50 USD and do not need any programming; just to be
placed between the Radio and the servo. Isn't it ?

Cheers,
Nick

RE: Do I need Twinsync
 

The right engine of my Mossie is noticeably more powerful than the left engine, 500rpm easily, maybe more. It's not a problem, and I don't use a Twinsync. The engines actually synch themselves in the air, as the more powerful engine pulls more of the load, and the weaker engine unloads more. You can hear the engines go in and out of synch as I turn, depending on how well I use the rudder.

The Twinsync would probably make take off easier, since it would keep the engines together as you throttle up. On my Mossie, I have to be very active on the rudder as the two engines will sometimes spin up at different rates (a long, slow-starting take-off roll helps here, giving the engines time to come up slowly together).

And the Twinsync could really help on an engine-out of course. I'm fairly sure the plane you're talking about is pretty docile on single engine, so it's probably not a huge deal.

That said, compared to the cost of the model, a Twinsync isn't very expensive, and if it makes you more calm while flying the model, it could be worth it for you.

RE: Do I need Twinsync
 

N2ryD,

I have a Futaba 10C radio and I mixed the throttles in the transmitter. Doing this the syncing of the engines was a piece of cake because you adjust each engine seperately. I broke both engines in on a test stand (OS25LA's) and then mounted them on the plane...a Hobbico Twinstar. Then you can adjust each engine until you get the same RPM +/-. It works great and you don't have to buy and install extra hardware. Mixing instructions for this are on Futaba's website under mixing for the 9C but it works for a variety of radios. It's fun to do!

Andy

RE: Do I need Twinsync
 

I have a Twinstar and decided to fork out the extra cash for a twinsync. I'm running 2 Magnum 4-strokes and the twinsync keeps them running very close (within ~50 rpm according to my tach). Ask any pilot who flies twins and they'll tell you that synchronized motors are much easier to deal with on takeoffs because you don't have to worry about one engine overpowering the other and fighting the rudder. But where they also really come into play is if one motor quits. The other idles and then you can regain control by bringing the throttle stick down and moving it back wherever you want. Another option I set was to have one engine speed up while making a rudder turn on the ground during taxing. And needless to say they also make your plane sound really cool when they're synched. So on my 1st twin, having a device keeping my engines always synched in my opinion is priceless...ok it's $99.

Chillybee

RE: Do I need Twinsync
 

I have been considering a Twinsync myself for a TF Cessna 310 project. I noticed that the Twinsyncs are out of stock at Troy Built Models. You guys know of anywhere else to get them?

Steve

RE: Do I need Twinsync
 

Steve,
I have one that's never been used (I've been flying twins for ~10 years and never needed it). Contact me if you are interested.
-Les-

RE: Do I need Twinsync
 

I never used a Twinsync either. I always adjusted each engine to run its happiest and if one engine was too strong, I would back it off a little on the needle valve. But I have flown the planes with more than 500 rpms different between the two engines and it only results in a little trim change.
So I never really worried about it.

RE: Do I need Twinsync
 

Been flying twins for years and never used one. Keep the engines slightly rich, and as everyone else had suggested, bring the leaner one down (rpm's) with a few clicks. You can hear the engines sync up. I ALWAYS hold the plane verticle for at least ten seconds to check fuel draw before I fly.

RE: Do I need Twinsync
 

You guys have me second guessing as to whether I really need it myself...Les, I'll send you a PM if I decide to try it out. Thanks!

RE: Do I need Twinsync
 

I have a 4 engine plane with 3 different types of .25 engines (fx, la, gp) I just set each engine to run a bit rich and away I fly. Does create some interesting effects when one engine is trying to catch up to the others though.