Perplexing RCGF 26cc Issue

 Last year this engine started this weird 4-cycling behavior, worse at full throttle (WOT). Its not consistent. I can sometimes almost tune it out o the ground, but those same setting sputter terribly in flight. I even took the silencers off, no change at all, just louder.

Yesterday at the field this was just constant and not reassuring. I tried retuning it, and this was the best I got on the ground. In the air it worsened. I should have taken notes last year, when I took the engine apart looking for any issues. Not sure if I changed the spark plug but it would have been on the list. I haven't changed the ignition. It sounds to me like an air leak that leans out the fuel mixture as altitude increases, but then richening it should lessen the sputter; it doesn't. Any ideas are welcome. 

I have benched it and will be once again looking for issues, will change the ignition and the spark, see if another carb I have will fit. Something happened to this once perfectly running engine, I have no idea what.

July 1, 2021

May 27, 2020

April 5, 2020

Took the silencers off. No performance improvement, just much louder. 

These do bring the noise down.

Back on the bench... will drop the engine and try again.

Hangar 9 Pulse XT60 and its RCGF 26cc Flight Ready

 After yesterday's debacle, I moved forward with getting the rest of my fleet flight ready, today starting with the Pulse XT60.

Took her off the wall and out to the work table. Decided not to lug the wings out just yet. Spent an hour running her and tweaking the needles. She started right up and ran pretty well, but I felt she was running rich still. 

 After repairing the stripped aileron connector, I attached the wing and ran the engine to see if the ailerons wanted to play the fool and jitter, but nope, all is well. Has only been a problem on the Stik and the Stick.

I'm pretty happy with her and look to take her out tomorrow, weather permitting.  I will do a few cosmetic fixes before then.

This is right after starting her having had her on her back repairing the lead. She had to cough up some air first. As I wound the needles to full closed to reset them I stopped counting after about 4 turns... I set them at 2 and 2, finding that's the min to start and run up, probably ended up closer to 2-1/2 for the high, but closer to 3-4 for the low to get a smooth run up. It still stutters a bit with crash to WOT, but its quick and consistent. Last year she ran smoothly on the ground, but 4 cycled in the air at WOT. Will see.

Next up, one of the 30xx's and the helis. I am still putting off fixing the Waco, and maidening the 3rd Spitty.

Well that's just disappointing.

 So...

Lets start with "I had to reset the crash clock today".

I maddened the Ultra Stick today, and the maiden went really well. I had to put in a lot of up elevator, indicating that her CG was supposed to be a lot more aft than advertised. She ran fine once she was warmed up, in the air smooth throttle responses, great power and wonderful speed, decent vertical. I kept her up tossing her around a bit for a nice 10 min flight, landed, and on roll out she hit a bump and tipped forward stopping the engine. No harm.

All systems go!

Setting up.

After the maiden landing.

I took a break, shaking thumbs calmed down, breathing evenly again. I was really impressed, she was exactly what I expected and hoped for! I took the 1lb of lead out, increased the expos to 40%, added the down elevator to the flaps, needed 10 and 15% down for approach and landing flaps, fueled her up and took off again! Trimmed her out, and again really was having a blast. About 10 min into the flight I was flying from north to south. I had been flying high to test transitions between dual rates on the ailerons and elevator. Having the elevator go to 100% was way more than she needed, so intended to drop that down to about 75. I slowed, flicked the elevator to high rates, the right wing dropped, and then kept going. She stalled at about 40 feet AGL, spun clockwise twice and thumbed nose first into the ground. Somehow I stalled her...

Split into 4 pieces, landing gear, shattered fuse, and the wing in two. Not salvageable.

Some planes last for years, some for one to two flights... I am so disappointed. Not just the cost of the model, but the hours spent building her, the joy I was finding in her flight handling. Just so disappointed. I will get another, but not for a few months of grieving. So very disappointed. In a few days I will inspect and salvage parts, put the engine on the test stand and make sure she runs. Then I will put them all away until I feel like loving again.

Ultra Stick 10cc Flight Ready and Aileron Fixed!

 The other day I dusted off the EVO 10cc Ultra Stick and fixed a few gripes.  Today I finished and she is flight ready.

Last year the Ugly Stick died a fantastic death when the un-commanded aileron flutter caught up with me a year ago last June. I put the same electronics into the Ultra Stick, and the flutter was still there. So I exchanged the servos in the ailerons, and put a capacitor on the receiver to clean up and stabilize the power (see that last link). Today I finally put the wing back on and in the process of tuning the engine, noted the flutter is gone. G-O-N-E, gone.

Finally, a nice idle that is a little unstable, but not quitting, 

very nice high end RPM output, and no aileron flutter!

I love this plane. I hope her performance doesn't disappoint.

Evolution 10cc. Not a big fan of the carb.

Weighs in at 9-1/2 lbs, consistent with the weight last fall. She is "designed" for 7 lbs, I wonder if that's her electric weight? Her dry CG is spot on.

But it took a pound of lead (473gms) as one momma block under that white piece of foam, up against the forward bulkhead. It took almost as much if I used smaller weights packed in more forward, around the fuel tank. Opted to just keep the honker in place.

Tomorrow, weather permitting, we fly!

Fixing Gripes: 10cc Ultra Stick

Today I dusted off the Evolution 10cc equipped Ultra Stick, which has yet to be maidened, and set her up for flight.

The electronics looked good. When I checked the bind and the throttle, rudder and elevator, the latter wasn't moving, and I smelled the invisible magic smoke. Further examination revealed that the elevator connection at the control arm was kinda frozen, stiff. I loosened it up, lubricated it. 

I removed the elevator servo, and it was hot and unresponsive. I replaced it with a generic Tianjin RC MG996 high torque metal gear digital standard servo, and all tested good.

Took her out to the backyard and she started right up, ran fine, still spewing oil. I let it run for a bit, ran the range of the throttle. She runs up fine, but still tends to delay on pulling back to idle then slowly come down. This is a sign the high needle is actually too lean. I didn't spend time on it today.

I decided that I wanted to just go ahead and replace the aileron servos as well, using the same MG996 servos.

Tomorrow I will attach the wing and run her up to see if I get the aileron flutter on the left.  Between the capicitor and the new servos I hope not. Then the next step is to see if I really need the 1kg of lead to make CG. Traditionally this is done dry,  but the fuel tank is far forward and adds a lot of weight forward of the CG. I think I will cheat that and try to keep her light.

First Flight of the Season

 

It feels like I got off to a late start this year... 

I usually fly almost all year around, but work this past year took so much of my time that I left most of my hobbies behind. Now that I am "on sabbatical"  between gigs, I have some time.

I updated the iX12, expecting that to derive any number of nightmares, but it actually went pretty flawlessly. I think. It may have this new trick where it needs to have the battery unplugged and plugged back in to turn on, but we'll see. I charged it up completely having let the batter die over the winter. Update done. Cleaned out the planes I killed last fall, no need to be reminded every time I scroll looking for today's aircraft.

I took the Eflite Alpha Sport 450 out, as the first plane I fly every season. It was my first real plane, the one I learned to fly some 11-12 years ago, and I know it so well that it's comforting to renew my thumbs every season, and settle the "new field jitters" when I fly somewhere I haven't before. I thought I had taken a photo at the field, but alas... I did take a pic of the Cubbie. I flew several packs on the Alpha, and then just one on the Cubbie. It was a bit gusty, so the Cubbie took a beating, but landed fine. The grass at Wason Pond, in Chester, NH, where I went today instead of hauling all the way out to Hudson, was long and clumpy, so I took off from the dirt on the baseball diamond. 8 packs in all, about 40 min of flight. The first flight I overcontrolled a little, but by the end I was hand launching with no issues. It really felt good. A dad with some kids had just finished flying a Blue Angels F-18 Kite, enjoyed the show and I invited them over for some show-and-tell!  They loved it, and it was good to see them so happy. The dad has found a new hobby!

Tomorrow I think it's time to get the 10cc Ultra Stick flight ready, see if I can solve the "flickering left aileron" problem. Then the 26cc Hanger 9 Pulse XT going. Think the two 30cc's will follow. I am scared of maidening the 10cc Spitfire... past being prologue, but that too will come. 

And not let us forget the babies, my helis!!!!

Time to get up, clean up and tune up!

Ah, the smell of flying season, mmm... kinda musty.

Its time to start making things happen for the 2021 flying season. Renewed my AMA a couple months ago, but for no real reason didn't renew my club membership until today.  Been thinking about getting around to it for a couple of weeks as the weather warmed and the winds settled down. Getting my club application in today, made me a little itchy to shake off the COVID and winter blues, get downstairs and instead of just walking by, start cleaning and organizing the workshop, see what batteries I killed leaving them charged, and which engines are going to give me crap, see if I can get over being annoyed at how little it took to put serious hurt on the Waco I still haven't gotten around to wanting to fix.

At the top of the stairs to the basement. If I am running engines out back through the basement bulkhead I cat free the basement and then make sure no one listens to them crying to be let in.

Ah, the doorway to heaven. Or hell. Depends on my mood and how many parts my returning aircraft come down in. Painted the pole as people kept running into it.

I didn't even bother to put anything away last fall.... its a mess.

Here is my conundrum to start the season. My beloved UNFLOWN Hangar 9 Ultrastick 10cc that I have waited years to get and fly, is two pounds over her designed dry flying weight.  I put the servos for the rudder and elevator aft as the equipment bay, as you can see here, is packed. This puts a bit of weigh aft out on a long lever. I had to put that 1 lb (500gm) lead weight there to get her on CG. Literal dead weight. Between that and the oversized receiver/ignition pack, she comes in at 9 lbs dry, her design weight is 7 lbs. I could save maybe a quarter pound (250gm) or so if I changed to a smaller LiPO. I am not sure it would save even that much, forget how much it weighs. Half that 5200 mAh is more than adequate, and I could always go with to swappable smaller LiPOs. I am pretty sure I am going to do that. 5200 mAh is far more than a days flying would need. I could move the aft servos to the bay and remove the lead, but thats going to take a lot more work than it might be worth. I am going to add a capacitor, which I am not optimistic will solve the weird left aileron twitch. (These are the same servos but not in the same place, and I think a different receiver, so no idea why the same servo twitches. I also have a Tech Aero IBEC that may help. More on this problem here.  I have changed the servos before, and I have replacement ones on hand. I think I will step through it. Capacitor, IBEC, servos).

The tail servos aft.

I could squeeze those aft servos here, but still aft of CG, albeit not so far out on the lever.

I really don't want to go there... That block and spar support the satellite receiver.

The Waco spent all winter sitting there after I hurt her. I just don't want to find out what its going to take to fix her, but I do love this plane, so it won't be long.

And then there is the Spitfire and my long history with them... she has yet to be maidened and won't be until I get some fresh hours under my thumbs.

I am off tomorrow afternoon.  

I am feeling the call.

It is time.