Bad pinion rocks Frankenheli

I have replaced the tail shaft in Franky and took her to the garage for a test hover. The shaft was bent in a couple of places, along the mid shaft and near the tip. Weird.

What is curious to me is that I never had a severe vibration before. I re-checked, everything is balanced. The vibration is diminished but not entirely absent when blades off, and only happens at a certain RPM range, not above or below. I was turning the main gear by hand when I noticed an excessive amount of backlash, such that the main gear teeth nearly came of the pinion. Or should I say, its the other way around. Turns out the pinion is drilled off center... Curious I never noticed it before... neither the vibration nor the mis-drilled pinion. I suspect this is the cause of the vibration.

Off center drilled...

I also am becoming skeptical of these $10 HK mini-MEMS gyros. This one doesn't seem to hold the head. now; it did seem to before when I first fired up Franky. Maybe its the excess vibration from the bad pinion that sets it off a bit. I will start with a new pinion (damned if the one I have is barely too small for the motor shaft). If the gyro doesn't hold, I will likely try a Spartan Quark on her, but I don't feel like buying one just yet.

So, still no flyable helis.

All shiny again!

Dropped by HobbyTown USA while I was over in Mobile this morning and picked up some white Econo-cote and a new sealing iron sock. Now this, this is what a LHS should look like... In the same space as my LHS has, these guys had planes, helis, and parts, parts, parts! Now, they too only sold Eflite a/c, no Trex that I saw, but wow, I have no doubt that if I needed it they would have it (Arnie, they have that Carbon Z Yak -54 you want!). More than that, their customer service was outstanding. I walked about listening in, and their advice was knowledgeable and sound, given in a friendly way. All in all, very nice experience, and any time I am over in Mobile, I will be stopping by!

And with that white Econo-cote, and some red Ultra-cote I had on hand (I do like applying the Ultracote better, but once applied they seem the same), I completed the repairs on my Alpha Sport 450 I had started yesterday after I dropped her on her head during a botched landing.

This is what she looked like after the crash. The firewall was stove in (all 4 sides were pushed into the fuse), the side wall was cracked and internal supports fractured. While involved this was a rather simple repair once I planned it out. I replaced the supports with wood from Greg's crash, epoxied them and the firewall sandwich repair Greg advised, rebuilt the fuse behind the wheel mount with more wood from Greg's crash, and all that was left was to let everything cure and cote it today. I also re-coted the cote that stripped off behind the main gear when I repaired the mount a couple of days ago, so now her cote is all fixed.

While it looks a little orangey, it is the same red. I coted across the top between the firewall and the window. You can see one of the plywood sandwich pieces on the right behind the engine. 

You can see a hint of the extra wood that makes up the bottom of the fuse just behind the front gear, but the cote work looks great.

Here is the sidewall that cracked nearly off. You can see a small indentation, but other than that the repair came out quite clean.

Very excited to fly her tomorrow! Will be taking the Cubby and the (gulp) Stearman out to play too! Hope things go well! I soooo miss the Cornell, she was such an awesome flyer. I bought her a new tail wheel, a bit bigger than the one she had, so when she comes back from Greg's Magic Repair Shop, I will have a little gift for her!

They were dropping like flies...

Beautiful weather today out at BMF, but a tough one on our spirits. We had an incredible day, though there be piratey gusts coming from the NE today. Our winds usually come out of the south, but today we had shifting variable winds out of the NE and east causing us to use a right hand pattern and a lot of cross wind landings. Which explains in part why airplanes were dropping like flies...

Today's flight program!

I flew the Alpha first today, not wanting to fuss with the Cubby to start my day. It was so much fun! I love flying the Alpha and will always bring her to the field, I think. Perfect trainer! I flew her for several packs, recharged them and flew for several more. The winds were picking up as the afternoon progressed, and I was practicing crosswind landings. I was trying to bring my approach angle down, as I tend to start high above the forest at the south end because the trees scare me to death. Today's northerly winds required a runway 36 approach right over those damn trees. I had worked my way down, nearly hovering about 4 feet above the ground after aborting two landings, and the wind shifted. I should have applied power, but I thought I could set her down. Her nose dived and she landed right on it punching the motor through the firewall. No other damage! Using wood donated by Greg's dead plane (more on that below) I epoxied the firewall back in place and shored up the supports. A little red Ultracote and she'll be as good as new!

Cracked the side wall, stove in the firewall, no other damage.

My Cubby flew oddly, as is her habit, wanting to dive with the slightest provocation, and it took a lot of up elevator to get her to takeoff or to rise. I managed to bring her back both first flights, but it was a lot of work. This non-deadly experience finally illuminated what the problem has been, and I wonder if it is what was wrong with Phoenixcubby.

The angle of incidence along the main wing chord (blue line) should parallel that of the elevator assembly (the red line). You can see here that the current angles will cause the plane to want to dive and will require, yup, lots of up elevator to fly trimmed. To address this I worked the canopy and the tail to adjust these angles. Which worked fantastically! But on coming in for landing (there's always a "but" with Cubby) I flared and the entire empennage (the tail feathers, elevator and rudder) came right off the airplane! I guess I weakened them working the angles. No other damage and the tail was intact, just no longer attached. I gathered the parts, glued her together with a couple more toothpick spars in a couple of minutes, and put her in the trunk to dry. Just checked her out at home, added a screw to the elevator control horn, taped the tail a bit, and she's flight ready!

The Cornell flew wonderfully this morning! I completely figured out how to land her and did cycles over and over again! Flew several packs and enjoyed every minute of it. Then coming out of a loop a little too close to the ground to start with, I decided to open the loop up and before I realized my mistake she was heading into the ground with a slight roll. I lost orientation as I realized what was happening and she smacked the ground nose first. She is badly damaged...

The right wing is broken clean in half, held together by the cote, the firewall and engine mount is completely shattered, and there is a stress fracture of several ribs of the fuselage under the body just behind the wing on the right. I am so bummed, but Greg, our Master Builder, is confident he can have her flight ready in a few weeks! I hope so, I miss her already. Silly novice mistake... I had no business doing acrobatics that close to the ground. All the more reason to bring the Stearman out on Friday!

The Cornell crash also taco'd a 3S 3000 mAh Blue Lipo... 

I accidentally left it on the fence, boys. I'll get it Friday!

As part of our airplane death cycle, Greg's Edge 540 lost an aileron linkage. It was painful to watch. The plane suddenly fluttered like crazy, then stabilized. He knew it needed to land not knowing what was wrong at first, and turned to bring her in when all hell broke loose and she rolled continuously into the ground.

She is a total loss. The forward fuse was completely destroyed, his motor shaft is bent tanking the motor, and the fuse was fractured and crushed aft of the cockpit. The more he looked at it the more broken parts he found. He donated wood to repair my Alpha Sport, so a part of her will always be around, but it was heartbreaking for all of us. Greg took it well, but it really upset him. Its bad enough when we lose a plane, but an equipment failure as a cause is just horrible.

The misery ended with our good friend Ron's misfortune. On the maiden flight of his brand new, coveted Seagull Aircraft Harrier 3D the motor quit just after climbing out, forcing a quick, tail wind landing. The plane would not bleed off speed, and ended up without enough runway, nesting with the Ents at the south end. We all just stood there in silence as the whole episode unfolded. Excellent pilotage to recover and bring her in, but physics is God, and in the end won out, much to our, and Ron's, chagrin. Ron was so upset, and as I fished it out of the woods, he lamented it was destroyed. But really, the leading edge of the wings was all that was damaged from tree strikes. But as you can see in this stock photo, the leading edge of this plane is a deliicate lattice work. I didn't get a pic of his plane, I was just too upset to remember, but you can see from this stock photo that the leading edge is a thing of beauty. Ron swore he was done with Nitro after this, but 30% flows in his veins...

Others had a fabulous day! For instance, here's something you won't see very often. Paul with an electric foamie, a P-47 Thunderbolt he won at an Irvington Fly-in! Its a beautiful plane. He flies it with the grace and precision of his competition pattern heritage. We all just stand there and shake our heads as he executes a perfect 4-point roll time and again. He flew it the way a warbird deserves to be flown! He also took up one of his Extras, and made us again shake our heads in unworthiness.  He is our God.

Paul and Arnie tuned up the flight controls on one of Arnies new Yaks. One of the privileges of being in a club like ours is having people like Arnie and Paul work out the kinks on a new plane, giving the pilot a whole new flight experience!

Paul and Arnie

Jerry and Joe buddied a good series of flights. Joe did a great job managing the odd winds and the trainer landed gear side down every time. All in all, despite our losses, it was a really wonderful day at the field, and I can't wait for Friday, and if Ron's heartbreak heals, baked chicken for lunch! I have the Cubby and Alpha back in flight status, and I hope to have Jerry maiden my PT-17 Stearman, then take her up  myself, especially now that I killed the Cornell. Though, if I crash the Stearman, I will breakdown and cry like a 9 yo little girl...

By the way, resist the urge to run across the runway without your shoes on, or your wife will spend an hour digging the hundred little thorns out of you very sore feet... I'm just saying...

ERazor Excorcism Begins

I started the process of excorcising whatever demons possessed the ERazor 450 by stripping out the servos, removing the tail boom support struts, replacing the horizontal fin and the vertical fin, restabilizing the tail boom, and taking apart the rotor head and removing the broken main shaft halves. I found one set of one of the main blade grip bearings to be damaged, and replaced those. I am replacing the stock swash servos (which seem to be a variant of the Tower Pro SG90). I will also be taking the Hitec HSG 5084MG tail servo off the CopterX 250 and using it instead of the stock tail servo, which I suspect is the same as the stock swash servos. I have a replacement rotor head block coming since I think the washout guide pins are bent and may have contributed to the last crash. Some of the ball links are a bit stiff, and I will be addressing that as well. The swash assembly doesn't move as smooth as it should. I am confident they will move smoothly after this work is completed.

I am pretty sure that she is going to come out of this refit a very fine 450!

Pretty is for girls...

You gotta love EPO foamies. After a little foamie repair magic she's back! Yesterday Cubby 2 was in 5 large foam pieces after her suicide attempt. Today, after some epoxy on the plastic canopy, Beacon 3-in-1 Craft Glue, some toothpick spars along the major breaks, some packing tape and strategically placed Econo-cote, she is flight ready! I decided that I won't cote the whole fuse, but will just put a patch over the fractures as they are repaired. I will keep the wing coted however. I also threw another washer under the lower motor mounts to raise the thrust vector of the motor a little more. Now there are 3 nylon washersunder both lower attachements.

So far the lines remain clean. I did place a large piece of structural styrofoam in the electronics compartment to act as a fore-aft spar to help straighten out the sagging flex the fuse was developing from the serial repairs. This lined up the empennage better. I also epoxied a Velcro strap in the battery compartment. Between the Dual Lock Velcro and latch, if the battery escapes that and the addition of the Velcro strap, then it was meant to be.

The molded plastic cylinder heads were broken off. I decided not to try to epoxy them back in place on the right side.  This replacement Alpha 370 motor is remarkably durable! Since installing it I have had a number of crashes, each of which would have resulted in replacing a taco'd stock motor. Clean the dirt out of the spinner and this one is ready to go!

Pretty is for girls...

The selection of Cubbies in the less than 1.5 m wingspan range is limited for the ply/balsa-cote versions. I have decided I will eventually get the Eflite J3 Cub from Horizon Hobby, but want to wait before I undertake another big purchase and build.

Tomorrow I'll take Cubby out to BMF, bring her back in 5 pieces, and start all over again... it's what we do, my Cubby and I.

Memorial Day at BMF

It was a small crowd at BMF today that found calm to gentle winds with unpredictable very brisk gusts to add some excitement!

It was a beautiful clear day, quiet and just a great day of flying. It was calm one minute, blustery the next. As usual the winds were from the south, right down the runway. The challenge was the wind's unpredictability, blasting along at about 15 mph one minute so that the Alpha 450 was harriering in on low power on landing, fighting to make way, then suddenly be gone so she was dropping with no airspeed. I learned to make the approach with power, but I could maintain nothing that looked like a regular glide path. Sometimes she'd hit a wind shear and rise or fall suddenly straight up or down, often both, 1-2 feet vertically! That was especially cool to see when I had her humming along in cruise about 50 feet up over the runway and she would  bob and weave while I did nothing on the controls. It was a great day of flying, learning how to handle winds! I did put her down hard once after some of that harriering and I snapped off the landing gear. Some epoxy and an hour later she was back in the air doing the bobbing and weaving! I also solo'd the Cornell. With Arnie's help we tuned up the rates and expo and I practiced flying and landing her in the winds. I still need to work around the fact that her nose drops with pulling back power, so I need to come in with power on a clean glide path, or use a steeper approach and flare late. Otherwise she would land nice but immediately tip forward on touchdown. Landing without style or grace...

Cubby flew magically! I had a little problem with the split elevator not operating together like it is suppose to (the side with the control horn would move, but if there was any resistance the other side would not move out of the airstream as the connector rod between them was slipping). I tried CA, to no avail, but fixed the problem when I epoxied it. I accidentally broke the spring control horn for the tail wheel that linked the rudder to the tail wheel, so had to remove both springs. Turned out she ground handled 100% better without it, just castering about! I also learned I needed to apply power slow on takeoff, and as the tail came up, blast the throttle and she would takeoff nicely but with a very short rollout. Otherwise trying to roll it out scale like she would tip over her nose. I had her cruising, flying sweet, though she was a manageable challenge to handle in the wind. There something awesome about watching a Cubby go by just above eye level. I enjoyed flying her for several packs though it was a lot of work. It was going so well that she committed suicide. Coming out of a shallow dive her nose did not come up and she slammed into the ground, even though she had more than enough room to come out. I thought it was the elevator issue again... but the battery was no where to be found at the crash site. She had thrown her battery coming out of that dive! So, she cracked her wing, broke her fuse in the usual two places (fore and aft of the cockpit), cracked the canopy wide open, and I am down a battery I could not find. I already have the repairs underway, but I am beginning to think I don't want to buy anymore parts... I need a Cubby, always will have one, but maybe the time has come to upgrade to a ply/balsa cote one?

Frankenheli had issues... Never came out of spin up. She wanted to rotate hard right. I noticed later the tail rotor shaft is bent, but I don't think that was the issue. Is it the mini-MEMS gyro? I don't think so. She just didn't seem right and is grounded until I fix that tail rotor shaft and can sort it out. So, no flyable heli's. I am thinking of putting the new spare 450 pro head I bought on the EXI and returning her to flight status as a 2 blade fly barred heli. I haven't started the repairs on the ERazor either. I decided I am not going to let my helis become a time sink... I watch my fellow HeliFreaks spend so much time working out the kinks and not flying (though Cool Hand CJ seems to never have to repair anything and flies his 450 all the time), and as I blogged yesterday, I lost a whole day of flying because of that time pit. I will fly, fix easy things, and if I can't fly a heli due to major work, I will gladly put her back in the car and enjoy my planks!

Here are some pics from today at BMF!

Jim and his Trex 450. Can you see the heli right in front of him?

The front of Jim, smiling like a kid!

The boys in the pit. Look at that flag go!

Dick playing with a 450.

Arnie flying his rather agile "Cow". Our clubhouse in the background.

I'm taking a day off from flying tomorrow. Winds are supposed to remain brisk and blustery. Wed and later in the week things are supposed to become summery: Africa hot, dry and breezeless...

Now I need to fly the Stearman! I also want to fly the MX2 myself once Jerry thinks I am ready. Great flying day! Missed seeing the guys who weren't there today... hopefully later this week.

Blah-dee-dah kinda day...

Today was a flying bust, and a heli nightmare, but getting to see CJ and David Latil's family at least made it a good day at the field. Too windy for the Alpha and the Cornell.

The ERazor, which flew so well a couple of days ago, was simply possessed by demons. From shearing off her top Jesus bolt on first flight, to being weirdly responsive to controls, to spinning herself up on the bench (transmitter on, throttle hold on, transmitter on the table getting ready to test fly her, chatting with Jim (Devin's Grandfather) when she went unglued like the reciever released but kept running. I picked up the TX and it was on, throttle hold still on. She kept going until Jim reached under and unplugged her while I moved the other helis. Usually when the receiver releases like that the heli will shut down after a moment...), to getting a mind of her own flying off so that CJ finally had to give her a smackdown. She had demons. We finally crashed her to save her from going off the res. Sheared her solid mainshaft clean in half! She is getting a strip down, different servos, having her ESC reprogrammed, and getting a bath in Holy water before fly her again. Just plain wacky... That ate up a couple of hours.

Started tuning up the HDX500, learning she has some issues that ate up time and more time. Solving one problem lead to the discovery of anther, until we got to a point I just need to buy some parts and replace a servo. That ate up another couple of hours...

Tried Frankenheli only to discover her tail boom rotated  under flight pressure (darn thing is sliding depsite being very tight), and her ESC lost the throttle limits, so we benched her for the day without her skids leaving the ground. Jim noticed that the tail rotor had also come loose on its spindle which was making the tail bind, and not giving full tail rotor power.

So, after about 6 hours of standing over a bench and not flying anything, I was getting kinda cranky and decided to go home and squish the Lukey (world's best hugger!).

I decided to finish the refab work on the Cubby, so she is now ready to fly. She looks pretty good. I worked on Franky and she is flight ready. Tomorrow I plan on bringing the Alpha, the Cornell, Cubby and Franky to BMF and spend time flying. I only hope the wind allows.