LeeHunt

Hi to all
I have just purchased the WH 35% sukhoi, just can't keep away from them. Question is there a forum similar to this for that plane??????
Lee Hunt

exciter900rr

http://www.rcuniverse.com/forum/m_7184368/tm.htm


Have fun!!

Tired Old Man

My Feedback: (1)

And this one: [link]http://www.rcuniverse.com/forum/m_4613960/tm.htm[/link]

You'll REALLY like the 35% version.

JPal101

My Feedback: (32)

I have a quick question for anyone, has anyone closed up the wide open cowl in order to direct airflow over the fins of the engine? To me it seems like quite a lot of wide open area up front.

thevirginian

Yes, I did. And it is of utmost importance to do this, if your care for your twin. If you look into the Sukhoi 35% thread you should find pictures posted of that baffled cowl.

roboto65

My Feedback: (30)

I have the 50cc version and I did not block my cowl but did open the rear up to allow flow thru the cowl have not had a problem yet with cooling. On a twin I think it is more critical !!!!

LeeHunt

I have a DA50R on mine and have about 350 flights, I live in the tropical noth of Australia and have had no problems with overheating that I can see, having said that I did open up the bottom of the cowl a fair bit, and I run a canister.
Lee

thevirginian

I opend up all the louvres on both, my 50cc and the big 35%. Helps a lot and looks so cool[8D]

LeeHunt

virginian
Have you baffled the 35% and if you did what method did you use, Iam hoping for a DL100 motor.
Lee Hunt

LeeHunt

Oh yeah, I opened up the louvres on mine with a dremel, you can really feel the hot air coming out, Plus it looks cool

thevirginian

See, didn't I tell you? Like I mentioned before, I baffled both, the 50ccand the 35% by using thin, lightweight ply and balsa. I shaped the balsa to creat nice and round edges where the air enters the cowl. Just like a funnel. The difference in temperatur is significant.

JPal101

My Feedback: (32)

any pics of your baffeling, I want to use on the 50cc Sukhoi

thevirginian

JPal,
check the 50cc Sukhette thread. I posted some pictures of my baffeling job not too long ago.

exciter900rr

Pics from a couple of us on page 60.

You'll have to play around a bit to get the crankshaft through the opening in the front without making it too large though. It will come off as a pain at first, but easily achievable with a few trial fits and trims.... I have noticed a significant drop in temp, even though I don't use a temp gun- I just use the "hold a finger on it til you can't anymore, and count while you're doing it" technique. lol...

thevirginian

I guess one second it too hot, two seconds is just right

LeeHunt

Come on Goldylocks????? LOL
Lee

exciter900rr

Ha ha ha! Yeah- "just right"... Actually, if I can hold the pad of my index finger on the front of the fins for 3 or so seconds, the it's "just right"- We really aren't looking for any "grill marks" or anything- just not so hot as to burn ya- not too scientific, but it's just the way I like it.....

boosted180

My Feedback: (8)

i've had my sukhoi for a few months and overall am very happy with it. the only "issue" i have is more pitch coupling than i'd like when i'm on the rudder (especially at extreme deflection). with small rudder movement, i have to mix in about 8-10% of up elevator to prevent it from pitching to the belly. but at extreme defelctions (like when doing a hammer-head turn, it pitches really badly to the belly, and the 10% mixing is no where near enough to get it straight. i also like to do "knife-edge harriers", which require 100% rudder and it's very hard to do on this plane b/c it pitches so badly to the belly.

anyone have this problem and/ or suggestions on how to correct it (other than using radio mixing). is there something i can physically change on the plane to compensate for this coupling?

one other thing is noticed is that i cant get it to roll quite as fast as i'd like. on high rates, it rolls just as fast as low rates, which is about 70% of high rates. in other words, there is a limit to how much aileron deflection i have and how fast it will roll. right now 30 degrees on the alerons is about as much as i can go to increase the roll rate. (when i increase the travel to 45%, it does not make it roll faster). i'm thinking about putting on some home made "side force generators" on the tips of the wings to "trap" in the air flowing ove rthe wings and maybe this will help make the ailerons more effective??

any comments/ suggestions?

Obee

Hello,
I live in Wa. and we have 10% Ethanol fuel showing up everywhere. If my memory serves me correctly this is bad news for may small engine(TOC 53) what is the skinny on this? Where may I find approved fuel, what are the risks of using ethanol? I would gladly pay a bit more to prevent damaging my investment.
Obee.

Tired Old Man

My Feedback: (1)

No problems with your gas. The TOC 53 uses a Walbro carb that more than likely was made in the last three years. Those that have contain ethanol resistant components. Don't get caugt up in all the ethanol/methanol bru ha ha. I've been using ethanol blended gas in California for the last 5 years or more and there hasn't been an issue with my engines that normal annual maintenance has not taken care of. So once a year at most buy a $10.00 rebuild kit and replace the diaphragm. You should be doing that with any gas engine if you want to maintain the best peformance.

Boosted:

Your c/g will effect the coupling, along with the amount of rudder deflection. I did not EVER need max rudder deflection for high alpha knife edge. I dialed mine back to about 40 degrees simply because more was not needed. Yes, there was more coupling when higher deflections were used but that's typical with any plane. Just as right to left K/E typivcally requires less coupling than left to right K/E.

Fro a hammerhead there are few, if any, planes that don't also exibit some pitch and/or roll coupling at the top of the turn. Most IMAC and precision flyers take a lot of time and "trimming" flights learning what will be required to mix out various things. They recognize that C/G, engine angles, aircraft weight, adverse yaw from ailerons, and other factors will need to be understood and compensated for in the trimming process.

If you are using the maximum amount of rudder travel that the Sukhoi has available you are inducing a fair portion of the coupling problem through excess. Neither version of the Sukhoi, be it the 35" or the 29%, requires more than 40 degrees of rudder to do anything and everything. With max deflection you are only throwing an aerodynamic brake out into the wind. Try flying it using a little less of everything and see what happens.

bari1

I too use nothing but gasahol. only one season so far, but with several gallons run thru my TOC, no problems at all.

Obee

Thank you gentlemen,

Betulio

greetings tom,
using sh bunny prop 22x8 with the canister and hop up kit, it gets 6700 rpms and it will hover but does not have enough power to climb out of it. with the stock muffler i get 7050 rpms and better performance. Why is that?

rctom

Because the stock muffler is designed to work with the engine and because it has less back pressure would be my guess.

TF

Tired Old Man

My Feedback: (1)

As with a tuned pipe, the best cannister performance will come with a pipe length specific to the engine size and port timing. Stock length headers do not put you there. Cannisters were never designed to increase performance, only decrease noise.