New Projects - Page 10 - RC Groups
Thread Tools
Nov 02, 2017, 04:59 PM
Nose down, you're gonna stall
rowdyjoe's Avatar

Yak 130 90mm Refurbish


I picked up a good deal on an older version of the 90mm Freewing (i.e. Ready2Fly) Yak 130 and have begun the job of refurbishing it. It's not in bad condition but, it was missing parts that were easily replaced via Motion RC spare parts. It appears to have suffered a bad landing at some point in it's career and was put away with incomplete repairs. The front landing gear strut retaining pin was bent so, I un-bent it, both horizontal stabs were missing along with the right main gear and retract unit. Additionally, most of the gear doors were MIA. There are a couple of blemishes that need some TLC but, the needed parts are on order or on-hand and it's coming together quicker than I expected. However, with the holiday season fast approaching, it probably won't be ready to fly until early next year. It's a good winter project.
Sign up now
to remove ads between posts
Jan 03, 2018, 04:53 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
More on the Yak 130 ...
First flight was short and not so good. As it turned out, the "zero" position of the elevator was incorrect and the plane acted like it was severely tail heavy. The elevator control system is nothing like I've seen before. It is completely housed inside the aft section of the fuselage and controlled by two servos. It is supposed to be set to the correct position during assembly but, was not. After a near fatal crash on the first flight, I double checked the CG and determined the correct position via the "new version" of the instructions and asking questions on the extensive forum on RC Groups. 60 clicks of down sub-trim came very close to the correct "initial" position.

About 2 weeks later, after relatively minor repairs, flights 2 thru 5 were successful. Flight #2 was a bit shaky as I trimmed it out but, all worked out OK. Duration with a CNHL G+ 6s 5000mah 70c battery was about 2 min. The landing was a bit hot but, uneventful.

Flight #3 was a bit harrowing as the front nose wheel axle backed out and jammed the nose gear doors leaving the front wheel partially protruding. I landed on the mains and held the nose off as long as I could. When the nose dropped, the front gear doors departed but, were easily recovered. While attempting field repair, I found the errant nose wheel axle retaining clip on the bench (go figure ). Due to missing linkage for the small front gear doors, I flew the next flight without them.

Flight #4 was great. A little trim for roll and pitch and she was flying straight and true. I had read that this was an anemic flyer on 6s but, found that not to be true. The prototype of this plane is intended to be Russia's answer to the A10 so, it's not supersonic. They also have a trainer version. IMO ....flight is scale-like and solid and it handles very well at low speeds. Duration for this flight was about 2.5 min and the landing was easy. It will float forever if not slowed properly on final.

Flight #5 was the best. No issues and very solid. Duration was 3 min. 15 sec.. The battery was warm, as it was after all flights, cell voltage was 3.7 range on all cells and IR was 2 across all cells. The landing was a "grease job" in no-wind conditions.

I LIKE the way it flies and can hardly wait for decent weather to fly it again.
Mar 27, 2018, 09:11 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
I recently picked up a 2nd hand Sbach 50cc IMAC bird (89" WS). It is made by Goldwing and has a DLE 55 on the front, Airtronics digital metal gear servos (high torque), and a smoke system. I spent the last couple of days giving it a bath (removed lots of dust) and getting to know it inside and out. During the inspection process, I discovered a mud-daubers nest in the canopy hatch. It scared me half to death when a live one flew out as I lifted the hatch off. :
This plane had been hanging in a large metal garage/work shop for a few months (years?) but, other than dust, it looks good. I installed my receiver in it today and began checking control movement after installing good batteries. I found that all control surfaces needed mechanical trim changes but, they are all correct now.
I checked the CG markings on the wings and verified them with the manual I found on-line. I don't know how this old girl flew with the CG 1.5 inches too far forward. I doubt seriously that it flew aerobatics very well. I also found an old heavy duty battery mounted right up against the firewall. It wasn't attached to anything as it had no leads and it weighed about a pound. I assume it was there just for the weight. It's no wonder they needed so much nose weight with the CG mis-identified. Balancing the plane will be the last step before I fly it.
I also removed the fuel tank to make sure the tubing was flexible and the clunk was moving like it should and that it was free of junk. After reinstalling the fuel tank, I couldn't help myself. I put some gas in the tank, pumped the prop several times to get fuel to the carb and started flipping the prop. After about 5 flips with the choke on, it fired up and surprised me. It ran rough with the choke on but, it ran. I shut the engine down and turned the mechanical choke off, flipped the prop a couple of times and the engine blasted to life ....at full power. I almost had to change my shorts on that one. So, I shut it down again, reversed the throttle, and started her up. This time she needed idol and throttle curve adjustments which were easily done as I listened to the sweet sound of the engine running with pitts style muffler. I think this engine actually starts easier and idols a bit better than my other one. I haven't tried the smoke system yet but, all is hooked up and looks like it will work. It has the Sullivan Skywriter for a pump. I need to focus on getting the plane flying correctly before messing with smoke.
Once I get the CG worked out on this plane I think it will be a really good flyer. A few years ago I lost my favorite 50cc IMAC bird after both elevator servos burned out at the same time ( suspect it was caused by a failure in the Smart Fly). I don't have to describe the carnage from that. It was ugly. The Edge was from the same company (Goldwing) and flew really, really, well. It made me look like a much better pilot than I am and I'm hoping to get some of that back with this Sbach. We shall see.

Garry
Last edited by rowdyjoe; Mar 27, 2018 at 09:16 PM.
Mar 29, 2018, 07:32 AM
Registered User
Capt. Roll's Avatar
Awesome Garry! Sounds like you are on the right track to get the Sbach back in the air. Would continue to check every system on the plane, especially electrical to make sure there is no corrosion in the plugs and connectors.
Mar 29, 2018, 09:22 AM
Nose down, you're gonna stall
rowdyjoe's Avatar
Roger that. So far, all is looking good but, I'm still looking


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Carrotcake's NEW RC8T"e" project(s). New/Current owners Welcome-tips/info. carrotcake Electric Power Cars 423 Oct 20, 2014 09:54 PM
Discussion New scale boat project jimmy777 Scale Boats 7 Jan 28, 2013 03:37 PM
Discussion My Scale Project Overview Since 2009 catcat Scale Helicopters 4 Jan 17, 2013 12:15 AM
Discussion Im New, Asking some questions about my new project me madjoe 90 1/2A Planes 19 Jun 07, 2011 12:44 AM
Discussion New Project = new problems !! danny_boy Dock Talk 4 Oct 23, 2008 12:38 PM