After having her tail gear roughed up and torn partly off on the crappy clumpy grass, I ordered a replacement carbon fiber laminate one from HK (couldn't find it elsewhere). It arrived yesterday, trimmed it and installed it this evening
Snow and winter weather have arrived, so flying is curtrailed for the near future.
I finished up the repairs on the 10cc and she's as good as new with her main gear back in place. I put a 13x8 prop on, instead of the 14x8. I wonder if it will improve her vertical climb if she gets more RPMs. I doubt it, but until I can get a 14x6 its what I have.
I also took apart the carb on the 30cc. I found that the metering valve gasket, the one with the metal wheel hanging in the middle, was upside down and the metal wheel was on the air side, not the needle side where it pushes the needle valve. It was upside down but worked for months. Huh. Not sure it was the problem because it was working, but I flipped it and cleaned the carb. I didn't find anything stuck, but she started right up when I put her back together, so I fixed something. I ran her to dry tank so she can stay unclogged.
I noticed that the tail wheel on the 30cc has taken a beating with the crappy clumpy grass, and was getting loose in its bracket. The bracket is carbon fiber and its delaminated at the hole where the wheel strut comes through. I just ordered a replacement from Hobby King.
I don't expect to be able to fly for the rest of the week, so, Happy Holidays!
When installing a gyro, always, always, always, walk through each programming step like it matters, or you will blow past NORMAL-REVERSE, and on starting your spin up will instantly experience the 960 degree Spin of Death (less if you have good reflexes and nail the Hold). And if you are testing on knobby asphalt this happens as an extra prize.
It was a weird wind day. It wasn't at all what the weather forecasters thought it would be, other than clear. It was a beautiful cold day, and the winds would be dead for the most part, but then a gust would slam in at 20 mph. They were mostly coming from one direction, but then started shifting. I would take off in one condition, and fly through several others, then land in another. It was mostly calm, so it was a tease.
I haven't flown the 30cc in a couple of months, so it really was no surprise I couldn't get her started. I even tried the electric starter. I have no doubt the carb is clogged... Yay... another project. She would have handled the winds fine.
So, I decided to fly and took my 10cc Sukhoi up! It was fun, a few pucker moments, and in the end I made a mistake and ended up tearing the landing gear off. All of them. Meh, easy repair, and a chance to fix a few things.
Tossed her around a lot despite the winds, which were fast aloft. A couple of times it was all she could do to make any ground speed.
The smaller tail wheel got yanked off. I built up the attachment point, used a bigger wheel, and bigger screws with some epoxy on the base of the mount.
All done up.
As designed the landing gear hard point pulled out. I reinstalled it. The cote in front was torn and a bit worn by gas, so I removed it, gas proofed (using epoxy diluted with alcohol) the wood, and in a few days will recote it, install the landing gear, and get her airborne again!
In a ridiculous move, the FAA today produced a ruling requiring the registration of all remotely piloted aircraft 0.55 lbs to 55 lbs starting on December 21, 2015.
Today was a dreary cold, albeit ill-temperate December day in New Hampshire. Cloudy skies, winds ~0-6 mph with steady gusts to 10 mph consistently and predictably from the north. The field runs north to south, so this worked nicely. 50 degrees (norm is in the 30's with snow by now) but after a while your hands get frosty. Its mostly tall clumpy grass torn up by the kids who play soccer and lacrosse on it (its laid out I think as 4 fields side by side), with parts at the north launch end more mud and less grass, so I launch there. A good day to maiden. I was quite anxious to do and not do this maiden. I spent a lot of time on her.
This was a longer ARF build than most. I worked for over a month and a half just to get the RCGF 10cc engine running, only to find out a quick manual choke of the carb was all she wanted to get started. Now she starts and runs like a champ. I learned a lot about this engine in that process, and learned a lot about how good the service was from RCGF-USA. Today we would see how the engine flies.
This Skyline Sukhoi SU-26 70 from General Hobby came in heavy for the airframe. Its an electric/glow 70 sized that I built with a 10cc gas engine on a 14x8 prop. Its technically a bit more engine for this plane. Performance wise, despite coming in at around 9-10 lbs dry (I need to re-weigh her, but that's what she weighed this morning), she flies fine and fast. The only thing I lose is unlimited vertical: she will climb but loses her grip and can't sustain unlimited vertical. I had been using a 13x8 in setup. I think I would lose thrust if I went back to the 13x7 because the max RPM didn't change much. Maybe I should track down the recommended 14x7? What do you think? With the 14x8 I get an idle around 2000-2300 rpm, and max around 7200 rpm. In flight she behaved a lot like she did on the ground tests. She idles nicely, no 4-cycling. She goes from Idle to Max throttle clean, comes back quick from 7200 to 3500 rpm, then slowly to 2300 rpm with visits to 1900-2000 rpm. On quick increase from idle to 50%, which comes out around 6300 rpm, pretty close to max, she will jump but then slowly increase rpm. This did not affect my sport flying today (I don't 3D...). I am considering a throttle curve with 50% around 4000 rpm, but this won't change her max performance of course. The right side of the fuse got a lot less oil, but the landing strut was still coated. Minor annoyance.
Here's the vid from today's flight. I had to clip the phone camera to my jacket, so what you get is what I got. I do run on a bit with the filming, but I love the clean sound this engine makes. The first part is the maiden. I had run her for a few minutes to warm her up, topped off the fuel, and restarted. As you know I had starting issues, but now she starts right away.
This plane flies sweet, as did her sister before her whom I flew as an electric. That was the red Honda one. On higher rates she is wicked responsive and quick. I had to dial down the low DR on the elevator to 25% and increase the expo to 45% on all the rates. Now I have found her sweet spot and she is a pleasure to fly. I need more landings to get her feel, and after this flight I put bigger wheels on her to see if I can keep the prop spinning on rollouts.
The difference from 2.5" to 3" may not look like much, but it usually makes a big difference in the tall grass, and lifts the prop nicely out of the cabbage. I had thought about going with the larger wheel when I first installed them, but was too lazy to remove them from the large axles they were stuck on. Today I unstuck those bigger wheels (subtitled: Vice Grip Always Wins).
Wanted to keep flying, but I was starting to get cold. Looking forward to my next flights!
I CG'd the Sukhoi today. It took a couple of oz in the tail, and I left her a shade nose heavy. I took an unweighed chunk of epoxied lead and set her in the tail. Surprised me that it was exactly the amount I needed. I epoxied it in and then created a couple of bridging spars to make sure it stays put.
I put the cowl on today having changed the prop to a 14x8 (Joe Nelson of RCGF-USA recommended a 14x 6 or 7, but when I stopped by RC Buyer's Warehouse in nearby Nashua, NH, they were NIS, so I went with the in stock 14x8 Xoar. I didn't think to pick up a bigger spinner while I was there, and ended up ordering one from them, a 3", and got it a day and a half later, today!
Listen to this engine purr... with the cowl on she is almost quiet! She does spit oil with the 30:1 mix, just a bit of oil clean up on the left underside wing and landing gear. I really didn't need to change the needle valve settings going from the 13x8 to the 14er.
I show her running my three standard run-ups. Running time at 50% on the Spektrum gimble, where she ran in the 6000's rpm, after about 20 minutes on a 240cc tank she slowed to a stop. I like to fly for 10 min, so this is a nice bingo. With the bigger prop she idled around 2300 rpm, any lower and she would quit. She produces very little if any thrust at this rpm. At full she gets up to 7100-7200 rpm and produces a very, very nice thrust. The second test is Idle to Full throttle. She comes up nicely to full and drops back to idle smoothly, taking a few seconds to drop the last few hundred rpms. The last test is Idle to 50%. She responds from idle to 4000's but then slowly climbs up to the 6000's. This lag isn't seen in going from Idle to full throttle, which is more important to me.
I am excited to be putting the RCGF 10cc engine in the Spitfire build this winter!
It took an absurd amount of work to get the cowl on. I had fitted it to get the length for the engine weeks ago, but once I had everything under the cowl the fitting work began. I had to flip the ignition upside down so it hangs partly down into the fuse, then I had to Dremel down openings to get the spark plug and muffler to clear. In the end the holes are a little bigger than planned. But judge for yourself, she looks sweet! I think she needs a black prop though!
I have been sharing the troubles I have had getting this simple RCGF 10cc engine to work. It got to a point that everything had been checked, checked three more times, rebuilt, and yet no one could figure this out. My latest failure was a downer, as there was nothing left to do.
I never lost hope because of the personal attention and guidance I got from Joe Nelson of RCGF-USA by phone and email. This not starting made no sense. He reviewed the Electric and Fuel video and he could find nothing wrong. He responded to my last email never giving up, and we went back to what we knew: too much or no fuel? I knew it wasn't flooding. This was an obvious question given starting the engine with an electric starter, and several times I had checked the spark plug and it was dry. This left not getting fuel.
Again, no sense. I could see fuel getting to the carb. Joe wondered if it wasn't actually getting in, and suggested I try choking the engine. This one doesn't come with a choke, generally is small enough it doesn't need one. So he suggested putting my finger over the air inlet and choke starting it. As soon as I read the email I was out in the garage, my finger over the inlet, and putting the starter to the spinner...
Now that its running, I ran it, stopped it, started it, over and over and she just get working like there had never been anything wrong! I think its time to put the cowl on!
I have two of these engines. As you may recall, Joe sent me a brand new engine and told me to keep the first one as he had discharged it as non-functional. I plan on putting that engine in the Spitfire I will be building this winter. If she runs, I will pay him for this one too, discharged or not!
If things continue to go this well, and I can get my engines from Joe, RCGF is now my engine maker.
As I work on trying to get the newer RCGF 10cc engine running, I am sharing my setup for comments and ideas on what might be going wrong with it, why I can't get either engine to run.
Please watch it, and comment! The first half is electrical, middle shows proof of spark, then fuel system, and the last part is all the stills you need to see the engine and setup.
