da Rock

Good deal.....

So have you weighed it?

CRAZYRYAN

My Feedback: (1)

well then do it yourself!! I just flew mine today after one year ago when i crashed it against the fence for stupid pilot error reversing the aielerons damn me!! but it flies just nicely as it did before and its extremely sensitive but ill have to tone it down i have the dual rates for a less sensitive control so i can land it safely did a dead stick landing good thing it was close to field was able to roll it back towards me on deadstick! im going to recover it sometime soon im trying to figure out what color trim i should go with maybe just what it came with

epoxy123

I went with a 4 stroke set up and used 8/32 wardware to install the engine mount. Had to use a smaller fuel tank (10oz) since the locknuts on the inside of the firewall prevented the supplied tank to fit properly.

alfredbmor

I took my Sukhoi to the field last weekend I tested the 15 x 8 master aiscrew prop, Used Omega 15% added two oz Castor Oil to the brand new Fuel Gallon, Used an OS F type glow plug and had a nice response from my Magnum 1.2 four stroke engine 8,600 rpm ready to fly, I experimented two very pleasant flights, then at the second landing I lost the main landing gear for the second time in my planes life, It was a hard landing because I came to slow then it just stop flying and I have to handle the consecuences, but for sure the plane responded the way I was looking for a long time.

epoxy123

Did you balance as per the manual?
The gear area is the weak point on this plane...I tried glassing so I'll see how it goes.

Whistling Death

Hey Crazyryan here is a link for hundreds of [link=http://www.airliners.net/search/photo.search?aircraft_genericsearch=Sukhoi%20Su-31&distinct_entry=true]Sukhoi SU-31[/link]
color schemes.

CRAZYRYAN

My Feedback: (1)

thanks very much for the link

alfredbmor

Yes I balanced by the book, just needed to ad 1oz at the tail section because the magnum 1.2 is too heavy.
Now I found the fun with this plane, needed to experiment to find out, took me a while but now I have a very nice plane to fly, I am currently building a Carl Goldberg Ultimate Kit and I was planning to use my magnum in it, but now I do not know what to do since I do not want to leave my sukhoi with out this engine.

sherman89

The landing gear box is not the easiest place to get in to to reinforce that area, a suggestion is to first put tape over the blind nuts so you don't fill them up with epoxy. The stock gear will not take any abusive landings at all.

Whistling Death

What kind of gear do you recommend to replace the stock gear with?

sherman89

The stock gear is fine, just remember to loctite the gear screws in, if not they will vibrate out.

sherman89

Sorry BBowen, I messed up, it's the box area that the gear is mounted to that is the weak spot, in stock trim it is the box mount area that will not take an abuse.

Whistling Death

You are right, I separated the bottom piece of ply wood , that the landing gear is mounted to, on a hard landing after a dead stick.

alfredbmor

What I will do now that those partes are already separated, is to cut 4 hard wood blocks, attach to the box on the front corners and at the middle of the box, just where the landing gear begins, epoxi them to the box, epoxi the landing gear doubler and ply and finally attach four screws right on the hard wood blocks, probably this setup will mantain my landing gear on place for some more time than my older setup.

epoxy123

Replacing the gear metal screws for nylon bolts might help. They will shear off hopefully before the fuse gives in.

sherman89

Tried the plastic scews, the bottom still comes out. Triagle stock works good.

fxrider

Well guys I'm still flying my su 31 (too many flights to remember) since 6-30 with the same equipment and settings as my last post. The OS Fx 61 still flys it fine but I do have an ST 90 that has been sitting around forever. Sherman89 got my curiosity up and Im ready to give it a try.

As far as the plane, the covering sucks but for the price it's hard to complain and as I said in an earlier post, the landing gear is weak and must be beefed up. Other than that it is an easy plane to fly and land. I still get compliments on it's appearance and IMO one of the best rc aircraft I have ever owned.

I'll let you know the results of the engine swap.

sherman89

Fxrider, how did the 90 work for you, I'm still ripping up the sky with mine, took a hiatus to helis for 2 months but I'm back now to stay.

sdossett

Hi all.
Just starting a Hobbico SU-31 with Saito 91. My first 4 cycle and first acro/scale plane (been flying Hobbistar 60 with verve). Any thoughts on the Saito mounting? Best method to bolster the landing gear? Anyway..please keep typing, I have leaarned a lot from this forum already..so Thanks again.

sherman89

The landing gear box is difficult to get into in order to strengthen, make sure you cover the blind nuts before you start expoxying things, that way you can get the geAR RETAINING BOLTS BACK IN. aLSO MAKE SURE YOU BLUE LOCTITE THE BOLTS AS THEY WILL BACK OUT ON YOU. I am flying mine with a OS90 2-s. It's a blast.

rstearman

My Feedback: (185)

I have a Hobbico Sukhio, and it's been a great flier. Reinforcing the firewall is a must if your plan on over powering it. I went with a YS 91 with a hyde mount, dual low profile elevator servos under the tail, and pull pull on the rudder. It flies very simular to my late Byron Sukhio but cost 3x less.

sherman89

I am running an OS90 2-s after many gallons of fuel through an OS61, I have had no problems with the fire wall stock, I mean coming straight down rolling wide open, then full pull on the bottom and straight back into a full bore vertical snap, that is with every thing in high rates and wide open. This plane takes a beating, the guys at the field can't believe the torture I put it through. This my forth one, all due to pilot error ( running out of altitude and experience at the same time). I would never beat my 33% extra the way I beat the Sukhoi. It would come apart in the sky!!!!!

epoxy123

How in your opinion does the the SU-31 handle on landing?
What technique do you think works the best with this particular model? Nose down to the threshold then pitch to bleed airspeed or pitch for speed then power for altitude? I heard keeping slow on approach may invite a tip stall.

rstearman

My Feedback: (185)

It might depend on how you have the plane set-up. Mine is heavy, with the YS 91 up front and the dual elevator servos on the tail. It lands a little fast, similar to my h9 p51, but it is actually easier because it doesn’t float as much. I keep the air speed up (normal fly attitude) on final approach and cut the throttle just before touch-down. The Sukhio is a short coupled plane that can easily get away from you if your not careful, but being short coupled also makes it a great aerobatic plane, and a blast to fly.

sherman89

My Sukhoi is slightly tail heavy to get the good snap, and tumbles, so it has to have a couple of clicks of throttle off idle to land 2 pt, I have the servos in the center of the fuse to keep the weight at a minimum.I idle back for the approach, then on short final I add a click or two of throttle to check the altitude drop, then patiently wait for the ground. The trick is be patient, plan the approach, do not rush it to the ground, I carry a little more speed than I would like, but that is what the airplane wants in order to 2 pt. I do not stall it to the ground in a 3 pt. Remember, this plane is intentionaly tail heavy so a little more speed is required, maybe 5mph more.