New Badass!

Today I ordered my new replacement Eflite PulseXT 25e! I am excited to get her back, even if she is the third one... My love affair with this plane has not been cheap. Here's hoping she's my last one... I have been in a funk since I drilled the second one into the ground...

The Little Guys!

It has been a long time, too long, since I have flown my fixed wing heli's. The little one that started it all, my Syma S107, and the twins, the Walkera CB100's, troublesome, dainty things that they are. The Syma is a 3 channel, and the twins are 4 channel helis. The Syma has an internal battery, small, get about 4-5 minutes of flight then have to plug it in again. The CB100's use a 1S 650 mAh 20c battery, of which I can charge only two at a time over about 30 min. Fortunately I have a dozen. These little guys are so much fun! It is interesting as its been at least a year, and what I have learned since then has changed how I look at them. I understand a lot more about them. I want to fly the CB180 tomorrow if its flight ready!

Assan GA250 Test

In my last post I pointed out the wag my Align GP780 developed. Two of them, actually. Using the same heli, I installed a Assan A250 MEMS gyro, a $10 gyro from Hobby King. Yup, $10. I am not sure it is much better than a piezo... Here's a short vid of the test (I flew several). It works fine, no wag. This also illustrates that the tail system is otherwise intact.



UPDATE 2/29/12: The seller of the second gyro has kindly responded to my refund request. They are interested in helping me solve the gyro problem if they can before refunding, and offered up another 780, or the new 790. What I know of the 790 is that its a step back, a budget 780 using SMM instead of MEMS. This might be a good idea, they work fine, but are "softer" than MEMS. Along with a hinted at software update, maybe it will be less sensitive than the 780?

How not to make a canopy...

I blogged last week about losing the canopy of my Sbach 342 in flight. I also wrote about how I was not optimistic about getting a replacement from Hobby King (still waiting as I write this). So, I made one. Despite my having absolutely no idea, it came out alright, and more importantly, I learned a few things so version 2 will be even better!

I made a paper mock-up of the base.

Transferred it to file folder cardboard.

I then cut out a styrofoam copy, and sanded it to shape.

Took a little work getting the angle. I have better ideas but at the time, this was my crappy method.

And then I completely ruined it when I found out Bondo melts styrofoam... 

I peeled off the Bondo and tried to save it with Hobbico filler. Didn't work either.

So, I made a wood frame. Got the angle right this time.

Covered it with sheet balse, trimmed it and sanded it.

Used the filler to, well, fill the rough spots.

Sanded it smooth.

Sanded out some spots to lighten it.

Then primed it.

Painted it with black gloss lacquer, several coats.

Applied Monokote points in red and white. Bolted the canopy on, taken from salvage of the Eflite PulseXT. I had to work it on, and found that window glue, nor CA worked well, and made a mess as the canopy didn't fit perfectly. I used felt to line the edge of the canopy to help it fit. 

Its hard to tell, but one of my failures was getting the back of the new wood canopy to segue into the back of the fuse. There's a large gap and the canopy comes out high. But it works! 

I plan to build another one using the lessons I've learned, and I think it will be perfect!

By the way, I ordered a canopy for a 1250cm Sbach sight unseen from Nitroplanes hoping it would be a complete one like the original. Its not... its a ginormous piece of clear plastic. It covers the whole plane...

Align GP780 Tail Wag

My 4 month old GP780 on a seasoned 450 heli started to wag. I tried decreasing the gain, and it slowed the wag, but did not abolish it. Increasing the gain sped up the wag. I changed everything that might cause a vibration, no joy. I tried it on another heli, still wagged. That gyro just left for Align USA for eval. It will turn out to be fine. Some on Helifreak say its just too sensitive to vibrations and many have had to abandon it for this reason. Well, a new GP780 arrived today and guess what... same wag! I doubt these are bad gyros, just too sensitive which makes them unusable. I am trying to return it to the eBay seller for a refund so I can buy a Spartan Quark from Helidirect. I love Align, and am looking forward to building my Align 600e FBL heli soon, but maybe without Align parts as I had planned?

Here's vid of the wag, even though its strapped down tight!



UPDATE (2/25/12): See the Assan GA250 MEMS test.

HDX 500se Main Gear Grind

I have been shearing teeth off the main gear of the HDX 500se pretty much every day I fly her, without explanation, usually when bringing her up to speed while the rotor was already turning. I had read that the main gear one way bearing can get gummed up and lock once in a while causing teeth to grind off. When I replaced the main gear this time, I took the one way bearing out and soaked it in acetone, shaking it and the bearing. I was amazed how much crap came out as I cycled through the washes. Then I dried it, and soaked it in silicone lubricant, and reinstalled it. It actually turns much cleaner. Looking forward to seeing if it solves the problem!

Squirrel!

CAUTION: Ground is closer than it appears. When you are flying aerobatics and coming close to the ground, its a good idea to know just where the ground is...

Spin, reversed, ran out of airspace, parked it hard against the ground and the only giant concrete pipe segment in the area. My ADD kicked in and I lost track of where the ground was. This is my second Eflite Pulse XT, the first died an ignoble death due to a bad transmitter battery, doing pretty much the same thing.

Crap.

Busy doin' a whole lot of nothin'

Bad weather these past couple of days... Haven't tackled the issues that came up with the A-10 Warthog the other day. Everything worked but the motors didn't make a peep... something between the receiver and the ESCs most likely. Not likely to be the motors. Taking a look at those later.

I think one of the reasons I keep stripping gears on the HDX 500se is that on some hard landings the tail blade strike the ground. This can stall the main gear and that can account for the stripped teeth. I decided to put a wheel on it, but I may make it a skid. I used a piece of control rod, put a Z-bend in it and ran it through a hole at the bottom of the tail skid, the rod running up the tail skid and secured to it with a couple of  wide plastic wire ties. Not sure I am fond of the wheel.

I broke out the Frankenheli. I had it set up with a longer boom and 365mm blades, a stretch 450. I flew her several times, but I just could not get the blades to track. I even took the head apart and redid the feathering shaft, still could not no matter what I did. I decided to drop back to standard 325mm blades, and she tracks well. Not sure what was up with that.

The $10 Assan MEMS gyro I trialed is a piece of crap. I had to crank the gain up to 100% (real 100%), and now she has a quick tail wag. If I drop the gain down the wag period drops, but is wider. I even tried down to 15% where she wouldn't hold her head, and the wag persisted. I rechecked all the programming and its correct. I will likely put a good gyro on her and if I bend the outrage boom I'll make her a regular 450. I will be keeping the regular 450 blades on her. Grounded until I get a new gyro.

Still no news from Hobby King on a new canopy... I suspect they will just wait until I go away. I will probably have to buy a replacement plane for parts... crap. No more planes that don't have replacement parts available.

Will they, won't they?

HobbyKing customer service put to the test. I have purchased hundreds of dollars of aircraft and parts from them, will they show me any love? Hobbyists have long lamented HobbyKing's low priced equipment, versus their notoriously unreliable customer service. Here's a chance for HobbyKing to prove their mettle. I reported the loss in flight of the canopy from my HobbyKing Sbach 342 1000mm V2 aircraft, a model that shows that HobbyKing makes good quality products. While still at the fligtline I sent HobbyKing a request for help finding a replacement canopy. Overnight here's their response, from Ian, quick, to the point, utterly unhelpful, with my challenge for them to step up their game. Let's see what happens...

UPDATE 3/2/12: Well, they won't. And why I have to go to a forum to make a suggestion instead of them taking what I am sure is a very freq request for parts to a meeting themselves is beyond me...

Quote:

Your request (#185173) has been deemed resolved.

Andrea, Mar 02 15:44 (HKT):

Hi Ken , Thanks for contacting the HobbyKing Support Team Sorry for late reply. We are sorry we do not have requested part for sale at this moment. You may consider logging in our forum and making suggestion. Our marketing and management team review customers’suggestions online. Thanks for emailing support. If you have any other questions, please let me know. Regards. Andrea

Isn't that special...

It started as an early, cold, blustery and gloomy day at BMF today. 5-10 mph winds, steady and increasing to around 12 mph. They stayed pretty consistent, no big gusts, as the day went on, shifting from the east to southerly. The damp field dried up, and the rain stayed in the clouds. For a few moments we even had some fairly clear skies, things warmed up and the winds settled, but it was not to last, and within half an hour the cold gloominess returned, the winds picked up, and the conditions for flying weren't optimal. Which is to say we had a ball!

Kenny Chandler flew pretty much every second, switching from his Ugly Stick to his Edge. He was pulling some crazy stunts in the wind with his Stick, upside down Harriers, Hurricanes... crazy stuff, grinning like a teenager in a strip club the whole time!

I brought out my Eflite Stearman which can handle some winds, but conditions got worse and I only took her up for one uneventful flight.

I spent a lot of time flying the HDX 500se heli, as helis can do pretty well in higher winds, and had a blast. After about 6 flights I auto'd her down when Kenny was taking off. As he passed I spun her up again and heard that sound that a heli makes when main gear teeth are shearing off... crap. I still don't really understand why this happens. The blades were still spinning slowly, she was in normal mode which I switched to after landing, and I spun her up slowly... like I had done a dozen times before (I was practicing autorotations). When this happened we'd been flying for at least 6 hours, so no big deal, it was time to stop anyway.

In between heli flights I took the Thunder Tiger eHawk 1500 up for a spin! It was a bit breezy, so I never really got to trim her out. She flew marvelously for the most part, certainly the newly positioned aileron servos proved an excellent solution. I don't know if despite having a nose heavy CG she was still tail heavy, but her elevators with their limited movement proved inadequate for sound pitch control. Did the winds play a role? She didn't like to glide, odd for a glider, but responded well with power, suggesting the elevators need prop wash to cause any pitch changes. I may try flying her again, perhaps with some nose weight, before I decide to remove the servo tray and redesign it to allow the elevator servos to line up so I can put longer control arms on them for more throw. After landing her (I didn't keep her up long with these control issues), we were discussing options for the elevators when something happened mechanically that rendered the left elevator inop. Maybe a sign I need to do the redesign.

The pisser of the day wasn't a crash, but the loss of the canopy from my Sbach, just after I figured out her best configuration. Just plane blew off...Crap.

With everyone of the flights today, despite brisk winds, she always took off sweet! I have to use 30% rates and 30% expo on takeoff, and generally fly her at 50/30, with 100/30 for antics. I had originally set her up with a 10x7 and 3S, but was a bit disappointed in her performance last week. We discussed options and the consensus was I should prop down to a 9x6. I flew her with a 3S and the 9x6 prop, which was met with murky power responses and no vertical. Tried a 8x8 and stopped that idea in taxi when it was clear she was way under powered: the gerbil was screaming on the wheel, but even the pitch couldn't make up the difference in thrust. I changed her back to the original 10x7 and she definitely was finding her giddy-up, but she still seemed a touch underwhelming. Even on high rates her spins and rolls were anemic. Steve Burton had stopped by and watched some of this, and wondered out loud if a 4S would do the trick. I knew the ESC could handle the voltage, but wasn't sure how the motor would tolerate it. I figured if it melted I had a bigger motor I could switch to, and if it didn't, well there it was. So I decided after all these prop swaps to try a 4S with the 10x7 and WOW! Sweet Jesus, she rocked and she rolled! She hauled ass and spins and rolls were snappy! I was grinning from ear to ear as I ripped her around the skies, flipping her over her wing in every axis, trying to throw her cote with snap rolls, high speed verticals with twister rides on the way down!  This is what an Sbach is supposed to fly like! The timer beeped, I slowed her down, took the downwind, turned base and her canopy just jettisoned... Really? After all that and on a lazy base she loses her canopy? I still need to figure out her landing habits, but I turned final and landed her without incident. Kenny thought he had a bead on the canopy's landing spot, and we spent about 30 minutes challenging the snakes and junk in the trees around the landfill, to no avail. It was unlikely we would find it and we didn't... Just when I found her sweet spot.

Hopefully HobbyKing can part with a replacement, but I am not hopeful...

All in all, it was a pretty awesome day of windy flying!

Thunder Tiger eHawk 1500 Arises

And rather cheaply too, I might add. I described earlier how poorly her maiden went, that I had a pic post crash that I cannot find, that Thunder Tiger wanted a lot of money for a new fuse, that I redesigned the wings by throwing the aileron servos out there (work awesome now) and that she required a lot of work to rebuild. Here's the resurrection of the eHawk in pictures!

The entire nose was crushed and splintered, the motor mount/firewall disk shoved out of the opening, and there was nothing left to attach it to. I had idea how I was going to rebuild the firewall, hence I was also looking for a new fuse. CA'd things back into place and secured them with epoxy when I saw excess epoxy pooling in the nose. I realized I could mold a new firewall out of pure epoxy! So I taped her nose down on paper towel and poured epoxy in... You can see it pooling here.

Taped upright, left overnight to cure.

Some Bondo work to smooth things out.

You can see the paper towel pattern in the firewall. I drilled out the mounting holes using the old motor mount disk as a template. I had thought about drilling out a circle and using the remaining flange for the motor mount disk, but thought this better since the new wall was thick.

I ended up replacing the box hex screws with flat screws to gain more clearance with the new prop spinner. These screws worked fine with the spinner, but were a bit long and protruding into the motor itself when screwed in. They cleared the motor rotor, but I had another option and liked it better.

This is what the motor looked like mounted before that change.

The tail rod had snapped off where it connected to the fuse. I cleaned this up and gave it a clean flat surface. I also redid the back shelf of the wing mount which can be seen on the left.

The tail rod fit sweet into the end of the fuse. Originally they were joined with a smaller cone of fiberglass that came out from inside the back of the fuse and fit inside the tail rod. I epoxied this and the next morning was initially pleased with how sturdy it turned out. Looked clean! But a few flexes and it was loose again. More on this later, because at this point it was working fine, but with handling came loose.

Had to build a tray for the servos. I needed to get everything lined up perfectly. The double center wood had to be cut out as the servos fit snug next to each other so their control arms clear the fuse. I placed with CA and secured with epoxy.The purple line delineates where the servo horns will be.

Here you can see the servos abut against one another.  Underneath each abeam servo shelf is a 1 inch leg that gives each tray shelf 3 points of attachment. Barely room for the servo arms which run from the servo out towards the fuse.

During the above work the tail worked loose. I CA'd it in place properly aligned, but it had to be secured better. I thought of just using epoxy, but wasn't sure that would stand the flexing... so decided to use a 1 inch wide piece of fiberglass cloth to wrap around the joint. I used CA edges on the cloth to keep it from unraveling, which made it difficult to keep from unwinding from around the rod. Ended up using floss to wrap around the cloth to hold it in place while the epoxy ser. This was cosmetically unappealing, but certainly sturdy.

I sanded down the epoxy I used to soak the cloth once it dried and it was so uneven it looked horrible. I decided to Bondo the whole thing... can you see I have been making this entire process as I went along?

In the end I sanded down the Bondo and got a mostly smooth surface, but not good enough, so I covered it with black electrical tape and it looked great! I painted with gloss black lacquer the section of the tail rod CF that had sanding abrasions to clean it up. Sweet.

 Nice work, if I do say so myself. Hopefully soon we will see how off her CG is... and see if she will fly! All her surfaces work and she has some mighty ailerons now! Still not impressed with the throw of the tail surfaces, but the servo control arms are so short to clear the fuse there isn't much more I can do. I shortened the control surface horns, and maxed the travel on the servos. Best I can do.

Just take those pants off...

Funny, they work so well on my Eflite PulseXT and my Cosmic Wind, but, well, a picture is worth a thousand words...

Trim flight of the Sbach. It wasn't a hard landing, and the speed was not great. She touched down and peeled them right off...

I had maidened her a week ago, and she bent her motor box. Rebuilt her, with pretty darn low rates and higher expo. She still needs to be dialed down from 40% with 30 expo on aileron and elevator. So after trimming her out and tooling about a bit I brought her in, she touched down... it was a short roll out to say the least.

,

Placed the landing gear on the fuse for this shot. The cote just peeled right back. The landing gear block just popped out.

Closer view of the peeled fuse. You can see the hole in the wing.

The closer part is the wheel box. Its pretty frail.

Side view. The rectangle to the left is the landing gear box, where the gear plate is attached. I missed getting a pic of the repair... I used popsicle stick to run two frame pieces across the back of the gear box (right edge of the box, next to the red velcro). I ran three pieces of 4mm square stock along the right and left fuse after replacing the broken stringer at the top. I ran the stock along it, and did the same on the other side, and one down the middle. This supported the popsicle stick wall I built earlier. I then replaced the landing gear box with CA after some judicious trimming, and set it with Gorilla glue inside the box.

On their way past the plane, the wheel pant poked a hole in the sheet balsa, also quite thin. I pulled it back up and CA'd it, then applied a little hobby filler. Sanded it down, and recoted it. There was no other damage.

All done, underside.

Propped down from a 10x7 to a 9x6. On a subjective static test it felt like it had a lot more thrust. In the trim flight she again seemed a bit under powered, but the motor should provide more than enough. Looking forward to seeing what happens next.

Wearin' me down...

Last time I flew the Erazor she crashed when I tried to turn her and psyched myself into a spin. I rebuilt her, some surprisingly slight damage, and hovered her. She stripped her main gear. What? Stripped another one. Noticed the mesh between the pinion and the main gear was off, reset the main motor so they touched with a paper between. Stripped another gear... Decided to remove the cover and get to the pinion, and damn, whodda thunk?

The one on the right is worn completely out... I was surprised. It has been almost a year and a half, so it was about time. I need to pay more attention to this. The one on the left is a replacement. The original is a 11T, the new one is a 12T. The old one looked like the new one when I started! Set up the pinion and main gear, and ran her without blades to check the mesh, backlash and make sure it wasn't overheating. Worked awesome! Tomorrow I will fly!

Back to Basic 2 Blade FBL

I decided to set my EXI BeastX FBL system up as a 2 blade system rather than as the 4 blade system I had originally set up.  I didn't have much success flying her. There was some pitch instability that made her jump up and down violently. I don't know if it was a link that came loose or if it was the BeastX (which does all the CCPM mixing and pitch control beyond the pitch curves). I don't know if one of the blades went rogue (the swash stabilizer arm had bumped one of the swash control rod ball links off, thought I had addressed it, but maybe not?). I am learning a lot about this BeastX and look foward to mastering it before setting it up on my Trex 600e Pro FBL later this year.

Two Bladed EXI 450 BeastX FBL.

CopterX Swash, generic (Tarot, most likely) FBL Rotor Head. I took the feathering shaft out to inspect it and grease the bearings. Its a standard 450 feathering shaft. Not sure what else I expected, but I like that.

The kit included this silver aluminum piece. It had 3mm threaded holes on either end, and another in the base. I have no idea what its for...

Looking forward to seeing how this goes!