Wiiinnnnddddyyyy.....

Drove all the way out to Bob Miller Field hoping the winds would stay calm, but...

Here's hoping the winds die down... I really want to crash something...

Scare me...

A few years ago we were having dinner at one of those Hibachi places were the pseudo-Japanese cook (in this case he was really Japanese) tosses his knives around entertaining you with faux-danger. Except this guy's knife went flying, but he caught it, and demurely stated, "Scare me..."

I had been setting up Frankenheli's gyro when it became evident that the receiver was browning out and the servos were going nuts as a result*. I pulled the receiver from the CopterX 250 and bound her to Franky to see if that was the problem, and its not (I suspect the new ESC; of course I have no idea where I bought it from...). Anywho, I had to rebind the 250, and since I wasn't going to get to garage hover Franky, I thought I would tune up the 250 and give her a shot, now that I am using dual rates and understand expo better. (The last time I flew her did not go so well...). I also had put one of those Hobby King/Assan mini-MEMS 250 gyros on her and wanted to set that up and flight test her. So I rebound her, and set up her CCPM. I took her out to the garage, where I had to have the door closed due to the high winds outside. This gives me the heebie-jeebies 'cause there is no where to run if things get jiggy. I let her spin up on the ground, checked her tracking (sweetly tight) and then brought her up to a hover. She is a 250, which for heli people means she is exaggeratedly agile and quick in response to control inputs, whether the pilot is or not, and I am not, so that added to the tension. I had her in the center of the garage  in a low hover when I heard a loud POP! and immediately hit Throttle Hold as I saw the blades bouncing off the walls and heli going straight down (suggesting they went at the exact same time). These were brand new never flown fiberglass blades! SCARE ME!

She is undamaged. You can see the blades only damage came from striking the walls and stuff in the garage, and that the roots are cleanly snapped off. The fly-bar is slightly bent as the heli tipped a little when it hit the ground with the rotor momentum still spinning the rotor head.

A close up of the blade roots. I wonder what made them fail the same way at the same time... I was only hovering a little skittishly, though it did required a lot of positive pitch to do so.

Well, after I changed my shorts, I put new CF blades on her and reset up the CCPM, then took her back to the garage for an uneventful though brief proof-of-flight-ready hover. The battery was pretty wiped and I had no charged ones, so I called it a day for the 250. I am glad that once again the mini-MEMS seemed quite stable in controlling the tail (amazing how things work out after I read the manual). 

Man, that truly wigged me out, and my heart is still racing...

* UPDATE (5/3/11, 1545 CST): Turns out it was the tail servo. I bought a knock-off one, a DYS S9065 (a clone of the Futaba S9065). This was the first time it has had power, and I think it was shorted. It got hot and smelled, and responded to inputs variably. When I took it out of the circuit the ESC, receiver and servos work fine. When I put only it in the receiver, everything gets wacky. Bought it on eBay, so its a loss. Ordered a Hitec HSG-5084MG, my favorite tail servo, from Helidirect.

Phoenixcubby Day #3

The resurrection of Phoenixcubby continued today. I need to wait for the canopy before I can do anything else.  When I took the tape off of the wing yesterday, there was still a little dihedral, but this morning the wing was back to its original negative dihedral. I have re-taped it so maybe it will set in permanently this time.

The wing strut attachment point's got pulled in the crash. I have been missing one of the outer attachments since the Tree Incident, and in this crash lost one of the inner attachments.

I cut a piece of plastic from the old wing strut, embedded it in the wing and glued it in place. It will serve as a top to which I can glue the aft wing strut.

Nothing is ever easy... the motor mount did not match exactly, but was pretty close. I used nylon 6-32 3/8" screws I bought this morning at Home Depot. The brass nuts would not fit on the top (the yellow plastic firewall got in the way). I was able to attach the nuts on the bottom of the mount.

A posterior view. All of the screws screwed in nicely so they are not coming loose even without the nuts. I did use a little Locktite, though I don't know how that will work with the nylon...

Phoenixcubby! When the canopy comes I can put the wing on and then complete the landing gear's aft attachment (pics will come when I do. I came up with a fairly ingenious way to dynamically stabilize the aft attachment using a part of the old wing spar). Frankenheli in the background. Put her mini-MEMS gyro on and will be setting that up later this afternoon. May even finally spin her up!

Phoenixcubby Day #2

Today I stopped by my LHS (Orange Grove Hobby Shop) and picked up a roll of Top Flite Econo-cote in Cubby Yellow, and a motor mount to continue my work on resurrecting the Cubby (Click here for Day #1). I decided I didn't want to make the Cubby half red, half yellow... I have not done such an extensive cote job, so it was interesting work. I wasted a lot of the cote when I screwed up the mirror image for the other side of the fuse, but figured it out in the end. The surfaces are pretty irregular, and my lack of skill made for an adequate but not great job. (You can click the pics to see a larger version).

Not a bad job, actually. You can't see the seams and the fit and finish are pretty tight now that I look at it. The color matches the original Cubby paint pretty well. I decided to cover the entire fuselage to provide structural strength, as Greg suggested when I busted her up. You can see the crack seams as I didn't work them out much. Not pictured, I also put some yellow over the middle of the wing where I had put red Ultracote when I originally repaired her after the tree debacle. Wanted more yellow, less red. When I took the tape off that was pulling the wing into a dihedral, it actually had a nice soft dihedral remaining. When I put the stays back on I hope it doesn't pull the wing back down...

The new Exceed Alpha motor doesn't fit the original stock Cubby engine mount. It was a motor-ring-in-a-firewall-ring device. The new motor came with the silver mounting bracket, but it extends beyond the plastic firewall, so it wasn't going to work by itself. I bought another motor mount, the black one, epoxied it into place and set it with screws. That puppy ain't ever coming loose... The motor will be mounted to the silver bracket, and after I find some short counter-sink screws and nuts I can mount the motor mounts together and find out if the cowl will fit over it all. 

Kinda stuck now waiting for the canopy to come from Nitroplanes, notoriously slow shipping. Once that is in, I can finsh the plane. I am working out a plan to stregthen the wheel flange attachement... more on that later.

EXI 450 with Hobby King/Assan mini-MEMS 250 gyro

I rebuilt my EXI 450 after my gyro misadventure... And this time I set it up properly (helps to RTFM, read the frickin' manual...)! Here she awaits her test flight.

I test hovered her in the garage, wanting to keep the flight short because I just spent so much time putting her back together. Rebuilt the tail boom and tail rotor assembly, rebuilt the main rotor head assembly, replaced and re-setup the stripped servo's, reprogrammed the Dx6i, and setup the CCPM. Then I spent a half hour setting up and rechecking the  Hobby King mini-MEMS gyro. Then, it was out to the garage!  Short video clip shot by my 12 yo Luke from a distance with zoom, so apologies for the shakiness of the video.  I totally own the shaky piloting...

Phoenixcubby Reincarnation Day#1

My Cubby #1 is now Phoenixcubby, as it has died many times, and yet once again is coming back! Yesterday I stalled her fuse into three pieces... Today I debrided all the dead stuff, pulled the electronics, and started gluing her back to life. I used thick toothpicks cut in half as structural spars at the three major "joints" and 3-in-1 glue. I also cut out the back upper cabin "posts" where the plastic canopy wedges into the fuselage forming the aft attachment for the wing. You can see the white styrofoam I shaped, sparred and glued to fit (triangle shaped).

The fuselage taped to hold the glued joints together while they set. The white styrofoam can be seen on the top back of the cabin. I plan to cover the forward part of the fuse with Ultracote (red, as that is what I have) to pull it all together snugly. The little square in the front of the cabin is where the front seat went, but I lost that.

Since I have to wait for a new canopy before I can rejoin the wing, I decided to put it under tension to reverse the negative dihedral it has developed. I would settle for a flat wing, but would like to see a little dihedral.

Letting the glue set overnight. Will look to apply the Ultracote to the fuse tomorrow. I will take some tape to the paint and un-paint the sections getting the Ultracote to get better adhesion. I am thinking of painting the interior of the cabin flat black. When the canopy gets here hopefully near the end of this next week, I can put the whole thing back together and fly her again! The motor was toast, but I have an Exceed Alpha motor I had bought a while back for the Cubby that will fit nicely with a new motor mount.

The next question is when do I fly the other brand new Exceed Cubby I got when Phoenix ended up in the tree?

ERazor Feathering Bearing Bad Karma

Got the replacement bearings for the main roto feathering shaft on the ERazor today. I found that, as I suspected, the smaller inner bearing that had shattered left the outer ring firmly stuck to the blade grip. I had to spend some 20 minutes really working it out. In this pic you can see the extracted ring next to the replacement bearing. The larger inner bearing was also bad and I ended up replacing both of them. Put the blades back on, tuned the CCPM and took the ERazor out to the garage for a test run.

Hovered great for about 4 minutes with no tracking deviation, but then one of the main blades, reused from the first crash, cracked away at the grip and I had to hit throttle hold and drop her from about a foot as she became uncontrollable. Fortunately only the blade that cracked was broken but I changed out both of them since there were some signs of damage on the other blade as well (bent the flybar back into position). This blade failed down, not up, as the upper layers of laminate came apart (I bent it down a bit more to show the crack) so I am sure it did not break in the ground strike (the heli came to rest on her skids). New blades, reset everything, and hovered her again without any issues, clean tracking. ERazor is go!

Now if I could just hover at the field...