Gremlins

Today was gremlin day.
 
The winds at BMF where too high, so I pretty much was the only one with a bird in the air. They ran to 6 mph at first, but quickly bumped to 10-15 mph with variability, but pretty much from the east.
 
Started out the day with the Thunder Tiger eHawk. It remains a POS. She has such inadequate tail repsonse to elevator and rudder as to be virtually uncontrollable. Shot straight up though she is set up a scosh nose heavy. It was all I could do to get her back on the ground. I started thinking about all the things I might do to extend the length of the short servo arms on the already max travel and d/r servos... then I gave the damn thing to George Vilchez and his son Antonio. Let them sort it out. I had decided it wasn't making the trip to Dayton, so I had no problem giving it to them. They love the challenge and will undoubtedly get her flying just fine! You can see her sulking in the car aft her embarassing behavior today, in the above pic...
 
Flew the PulseXT 25e, practicing crosswind landings. The winds were due east, so landings from either end of our 36-18 runway provided a nice experience. She was buffeted and carrried in some gusts, rolls were done with caution, but it was fun to finally get somehing up in the air and get my thumbs back.
 

Set up to fly the Sbach and in preflight found her rudder servo was stripped. To be honest I didn't check it before I left the house so it could have taken a hit in the same incident that tore the tail gear off. When I got home I fortunately had the gear that stripped on the JR MN48, always that damn middle one, and replaced it. Reinstalled the servo, reset it and she's as good as new. (See my earlier post on changing servo gears. Waaaayyy cheaper than buyting a new servo, and so very easy to do)!
 
Took the EXI 450 Beast X out. Noticed a programming error and reversed the offending servo. Things looked good, took her back out and she did a major spin out breaking her tail boom and stripping the pitch servo. I hadn't put any inputs in. When I got home and changed out the tail boom, replaced the pitch servo and rechecked the programming I found a couple of things I should have changed in the rest of the programming after changing that pitch servo direction! The ever important reason detre gimbal response was all backwards, and the tail servo, for some reason, was set to sense in the wrong direction. Really? I'm not usually this careless... My inexperience with programming the BeastX, which itself is easy, caught up with me, and my inexperience flying it let me miss the mistakes I made. Now I have a FBL preflight routine... The spin out and twist was like a snap roll on the ground. The BeastX saw a wind gust on the rotor as a push to one side, and thinking it was correcting it pushed it over to that side, and thinking it needed more tipped it more. Meanwhile torque effect started a yaw and the mis-sensing tail gyro commanded a correction, but in the wrong direction. So, Dick Clark, what we saw, and why the boom snapped at the frame, was a violent and self progressing snap roll! The blades and that stalwart Tarot head survived, but I did replace the tail blades just because they were worn from tip strike. This time I went through the entire programming step by step, which took only a couple of minutes, made the correct settings, and took her outside. She flew just fine over my driveway in a still very brisk wind, and was perfectly controllable. Lesson I should have learned when I did the same thing with the Tarot yesterday: when you change one thing, especially a major thing such as a servo reversal, check the entire 3G programming.
 
Took my Frankenheli Tarot ZYX up and she hovered fine, and that vibration I noticed yesterday at certain frequencies showed up again. This time Dick Clark took a look and found the main shaft head bearing had some play small but quite noticeable. I changed out the entire head bearing platform from one I scavenged from another 450, and now she is tight. It makes a lot of difference. Tomorrow I will test fly her in the driveway. Like yesterday, in the brief hover before the vibration tried to shake her apart, she was nice and stable, suggesting the Tarot ZYX is a good stable inexpensive 3G system. I was quite impressed that the severe vibration did not affect they gyro at all, she held her head and her pitch/roll just fine. Impressive.
 
The HDX 500 flew fine, but I noticed a worsening abiity to hold her head, and finally had to set her down. On re-examining her I realized there was no rudder at all... the Align DS520 tail servo, probably 5-7 years old, had finally died. I ordered a replacement Himax ES9257 Futaba clone, same one I will be putting on the HK 500cmt. Half the price and people really like it. For my emerging sport flying its just fine.
 
So beating back the gremlins. Fixed everything except the tail servo on the HDX, but the issue identified. I am looking forward to building the HK 500cmt belt driven heli as its parts arrive this week. I am determind to push my heli skills forward hard these next few months. I haven't been able to fly the sim since the kids took over all the HDMI spots on the media room TV, but will be taking it downstairs to my bedroom TV and get some more time on it. Need work on orientation.
 
On a side note, I have been working on flying most of my helis at 100% rates with about 40% expo. My 500's are easily flown this way. I find I sometimes have to dial the rates down for the 450s significantly, to at least 75% to keep it from over reacting. Some people are very against dialing down the rates, but I really don't understand that. I can see for 3D, but I am no where near doing that... I think I will keep my rates wherever I am most comfortable withthe, and dial them up as I get better.
 
 
Thanks to Ray for the chili dogs!
 

Oh... so that's how I killed it...

Its amazing when one does what one is supposed to do, what one learns from that. Its also amazing how frequently we don't quite do what we ought and get away with it...
 
But, I haven't been getting away with it lately. I have been burning out motors on my Eflite Stearman, which calls for a 15 sized motor. I have found that to be an adequate motor, flying 3S, but just adequate. I have learned that my particular Stearman doesn't like flying 3S as it flies sluggishly and stalls easily. So I have been flying the motor, a HURC 3542-10 with 4S, and over time the system fails. I know the motor is rated for the 4S voltage, but was pretty sure I was exceeding 40amps and 550 watts, just not by how much. I wasn't sure if it was watts or amps or both that was frying everything, or if the motor failed or if it was the ESC, because after the ensuing crash the everything works fine.
 

Everyone tells me I need a watt meter, and I know I need a watt meter, so I finally bought me a watt meter. On eBay I bought a Watts Up Meter from All-Battery and threw on the EC5 connectors (it does not come with connectors. You solder them on, load end with battery leads, source end with ESC leads). I plan to stick this puppy on every plane I have! I do hope it doesn't lead to having to replace all my motors... or accepting less performance from my aircraft. I wonder how I can put it on my helis? I like this meter, simple, straight forward.
 

Today I put it on the Stearman. The HURC 3542-10 is spinning a 12x6 APC eprop. It does that easily. The motor is rated for 550W at 38 amps for no more than 60 sec. Fired her up with the wattmeter in line, pushed the throttle to the firewall. 48 Amps and 640 watts. Well, yes. Its over amped and over powered, so that's why the systems are frying. I replaced the 40 amp ESC with the Turnigy Turst 70A last week. I just ordered a PowerUp 25 Speed motor from HURC today, rated at 50 Amps and 740 watts for 60 sec. The motor is bigger, but I am pretty sure I can get it to fit in the cowl.
 
Well, this brick is likely to fly much better with the 25 sized motor. When I build the stock one I have NIB, I wonder if I should power it with a 15 sized motor and just fly it 3S? I don't look forward to returning to her high stall speed and mushy performance with limited vertical... If this arrangement works out I will likely build the new one, when the time comes, with a 25 sized motor and 4S.
 

Tarot ZYX 3 Axis Stabilization System: And Update

A while back I bought the Tarot ZYX Stabilization System and a FBL (flybarless) two blade head for my Frankenheli 450, as a less expensive alternative to the BeastX, which I have installed on my EXI 450. I bought a cheap aluminum head instead of the quality Tarot head, which I may get if I keep this system. I installed it today. Couldn't get it apart... I will likely replace it soon.
 
The BeastX is a magnificent system and is my stablization system of choice. It is well designed, easily programmed and works. The computer link is weak however, and allows updating of software on the device and limited parameter programming, but not programming of the device. This is fine as the button/sticks programming system, much like using an Align Gyro programming, is very easy to do.
 
The Tarot is a mixed bag... My first one failed outright, the set button caved in; sent it back and got a replacement. I decided to get the USB cable with the replacement gyro sent to me by the vendor, but I had no idea how it worked. The USB device is a simple cable with a dongle, but no software, no manual. The manual doesn't even mention the dongle, let alone how to use it. There is no software made by Tarot that I can tell. I installed the first software I found, which had a driver exe file I used, but uninstalled it when I found a better one, below. This first one here has the driver. I ended up using the one that seemed to show up in all the vids, and that looked like it had access to all the programming functions. I used this one. I didn't have instructions on it (they are available on his site) but it was pretty striaghtforward.

 
I connected the USB dongle to my notebook, and the ZYX gyro. Powered up the heli and set the rudder stick over as the gyro initialized, putting it into setup mode as described in the manual. The assigned COM slot showed up on the software and I clicked Connect. I selected F3C, and then clicked Setup. I walked through each tab one by one. It covers all of the programming steps on concsecutive tabs. I had problems getting the device and servos to respond to the inputs on the notebook consistently. I couldn't center the servos on the trim page, and it took a couple of tries to get the pitch, elevator and aileron ranges set. All the other tabs worked fine, but if servos had to move it wasn't consistent. I found if I reset the connections (started over) and went directly to the desired tab it increased the likelihood of response, but I never got the subtrim to work All in all it beat the hell out of following flashes and moving the transmitter sticks. In the process I failed to set the "gimbal" gyro settings on the next to last tab... When I tilted the heli the swash didn't move at all... I wasn't sure about that. I took the heli out and spun her up. I lifted off and BAM! I saw what happens when the gimbal setting is backward. The heli tiled left and when the gyro saw that it rolled hard left, instead of right to compensate. That's how I realised I failed to complete that setup tab...
 
Went back and set up the gimbal, and it compensates perfectly. It was set up backwards. I had to balance a new set of tail blades, and tomorrow I will have to change out the main shaft (slightly bent, sets up a vibration I can get rid of). I have a feeling its going to work out just fine. Tomorrow I will let you know!
 
UPDATE (6/21/12): This morning I changed out the shaft, though it wasn't bent much at all. I set her up with new blades, and took her out to the driveway. This time she lifted off and yawed left, but was otherwise stable. She did this depsite my compensating, a slow spin. I checked her out and while she has right rudder, the tail blades don't move all the way over, which I knew. I made sure the gyro was compensating in the right direction (pinch test). This tail ROM issues was one of those programming steps I could not get to reliably respond to programming inputs. I took her back to the lab and thought I would try the manual transmitter programming. I startd the process and held the stick over to enter the programming mode. Now before I misunderstood the instructions about the light sequence to know she entered programming mode. This time I held the stick over for a lot longer, then saw the cascade of the three lights that indicated she was in programming mode. I tried getting to the section of programming where I set up her tail range of motion and it worked one way, but stopped half way over to the other... So I abandoned the programming mode and decided to try going to that tab using the USB link. I thought that since I had not waited for the cascade of lights indicating programming mode before, maybe if I did the servos would respond. Well, here's where I learned that if you go into programming mode with the USB, the USB will not connect to the gyro. Okay... so I restarted and didn't hold anything over, and she connected. I went to the tail and set both ranges to max, as when moving it the tail didn't respond so I had no way of knowing wht to set (the servo not responding to programming thingy). I exited and now have full range of motion in the tail. This time she had a vibration at certain RPMs which I think I have calmed down a bit, but the yaw issue was gone, no idea what or why. I found I had to stabilize the CF tail pushrod as it vibrated and bent like a guitar string, using some supports I had in stock. The tail just didn't have enough ROM, problem solved. I kinda got the impression she didn't have much headspeed, and did I notice a two step approach to high RPMs? Problem for another day, though I reprogrammed the ESC.
 
So, I know she hovers, will let you know how she flies when I can get her to the field. I and rather optimistic!

 

 

I guess I could have squared the swash for the pic...

 

 

So you want to fly helis?

Kenny Chandler asked me to pen some advice for his brother who wants to get started in heli. Here's a slightly updated version of what I sent.
 
START HERE! Finless Bob's Tech Forum on Helifreak.com
Read, read, read these posts, watch the videos, before you do or buy anything, in particular ones involving setup. Don't be intimidated, it looks hard but isn't! join the Helifreak forum community: best thing I ever did learning to fly helis!
 
SECONDLY, find someone who lives very nearby who is good with helis and doesnt need to contorl everything your do... You can do this yourself though!
 
THIRDLY, SIM! Phoenix is best for helis.
 
FOURTH, let go of the fear of crashing. You will. And you will spend more hours repairing than flying. But it gets better. I'm still trying to figure this all out.
 
FIFTH: Stick with Align compatible clones. Part are everywhere and are cheap. Think about what happens if that maker stops making that heli and parts become scarce...
 
I would recommend starting with a 500 size electric heli. No plastic head or tail parts, all metal. Get a clone or a used Align. No less than a 450 size, which are cheaper to buy and repair, but a little harder to learn on. No fixed pitch or 250 sized heli's! When buying parts, generics are fine in most cases, just match the stock specs until you learn what you like.
 
Clones: EXI, Tarot are good. No matter what anyone tells you, yes Align is the best, but most people start with and most people fly Align clones.
 
ESCs: Hobbyking, Hobbywing, Gens Ace. HeadsUpRC also makes good products. Get a prgramming card... the Hobbywing one can be used on most ESCs. Cards make it sooooo easy compared to programming an ESC with a transmitter.
 
Batteries: Hobby King Turnigy, Hobbypartz, go least expensive and you will be fine, no less than 25C. Change all the connectors to EC5, and get the right connectors for the right end (ie battery is male plastic connector-female pins, ESC is female plastic connector-male pins).
 
Motors: Any of the Hobbypartz.com heli motors that match the specs for your heli are pretty good.
 
Gyros: Don't cheat here... Align GP780 are excellent and can be had on eBay for less than $100. They are a bit sensitive and can create a tail wag unless everything is vibration free. People swear by Quarks, but they don't come cheap, around $150. That said, they are simple, and work very well. Stay away from piezo gyros, you'll just end up replacing them. For FBL I like the BeastX, easy to program and it friggin' works. I am testing the Tarot generic one, which is supposed to be good, but I don't know yet.
 
Blades: generic, fiberglass or carbon fiber. Plastic can be good but are unreliable. I never have flown wood, but some people love them. ALWAYS balance your blades.
 
Servos: EXI from Hobbypartz, Hitec, Futaba, JR. I prefer cheaper metal gear except for my higher end helis, where I use all Hitec. Stay cheap at first because you will strip a few. The higher end ones you can replace gears on, so its not so painful. Solar 9g metal gear from Hobbypartz look like relabled EXI D213f. (Not sure I like them. I was replacing the EXI servos on my BeastX EXI 450 with Solars. Two are fine but the pitch channel servo freaked out on two consecutive servos during set up and fried them dead. I replaced that one servo with a used EXI and it works fine...).
 
Radios: I would likely go Futaba... I fly Spektrum, and like them, but Futaba seems more reliable. JR is the same as Spektrum, really, since they are the same company, just differnt tech. Any of their radios and receivers are compatible. Once you buy a radio transmitter, you will have to buy the same brand recievers, so a locked in. Choose wisely, ask around. DO NOT BUY CHEAP BRANDNAME RECIEVERS that are likely fakes, usually Spektrum. If its cheap its almost certainly a fake. Orange receivers from Hobbyking are not fakes and are surprisingly good inexpensive ones compatible with Spektrum DSM2. You don't need full range recievers for helis, park fliers or microlites will do as they never go that far away (if they do, not to worry, it won't be coming back... you'll loose orientationnand kill it).
 
Sources:
 
www.hobbyking.com - Their clones are good. Also, tons of part. Try to stick to the US warehouse (look for the little US flag next to items. Their 500 clone is a good one.
 
www.helidirect.com - HONEST, good tech support, not cheap
 
www.Hobbypartz.com - if they have it in stock, its usually a good value. Kinda slow to ship. Customer support on rcdiscuss.com. This is where I get most of my replacement parts
 
www.xheli.com - good clones. The EXI clones are very good and are Align compatible. Stay away from The Erazor, nice heli but you can only use their parts, and if they ever stop making that heli, you won't be getting any parts. Also, they are always out of stock of stuff, almost as much as they are in stock.
 
www.readyheli.com - like Helidirect
 
Get blades, only fiberglass or CF, online at eBay. Shop around. You will go through a lot of them, and they are best priced on eBay buying larger lots, like 3-6pairs. 500 sized blades can be tougher to find... most of the Chinese vendors are actually very good, just gonna take anywhere from 2-6 weeks to get to you. Always use Paypal.
 
Check out Radds School of Rotary Flight for a good primer on getting off the ground with the least trouble and crashes. http://www.dream-models.com/eco/flying-index.html
 
Take a look at my blog from the very beginning and follow a typical journey. I highly recommend learning to fly fixed wing first, but some people can skip that step. I wasn't one of them... You will learn fundamentals of control in a stable flight environment, and have quick success to build on. Heli's are very, very challenging.
 
Learn to fly flybar helis. They are classic, and easy. Flybarless is the future, but there will always be flybarred helis, and I like learning the basics from flybarred helis.
 
Enjoy!
 

Stearman Mock Motor Repaired

I mentioned last week I stalled the Stearman and chipped her teeth, damaging the bottom two cylinders on the mock motor. I had just placed the cowl the day before... the old one was in the trash, so I pulled it and removed a couple cylinders and grafted it onto the "new" cowl with some Gorilla urethane glue. Came out pretty nice!

 
Looks very good! I removed the cowl and reoriented the motor on the firewall so it is just a bit right vectored.

Goldwing Sbach 342 1500mm

My next plane! Click on images for a link to the item. I have set this up for high power performance, and will fly it with two 3S 3300mAh batteries in series (6S 6600mAh), and start with a 15x8 or 14x7 prop.
 

Goldwing Sbach 342 1500mm from General Hobby.

Turnigy L5055B-600kv 1500w motor from Hobby King.

Hobbywing Platinum 80A ESC (Opto) from Hobbypartz/Nitroplanes.

ExceedRC UBEC (6V 5A) from Hobbypartz/Nitroplanes.

Hitec HS-225 MG servos from Horizon Hobby.

Spektrum AR600x DSMX receiver from Horizon Hobby.

Very exciting stuff!

Crash-A-Day Program

It feels like that...
 
Took the PulseXT, Sbach, and Stearman out to BMF today. Perfect flying conditions. Kenny brought out his Stick, always fun to watch him whip that thing like a 3D machine (man can that boy fly...). Add that he's just plain good company.
 
The Hobby King Sbach 342 1000mm v2 flew wonderfully after her recent repairs. Had to shorten the canopy to get it to sit right; the firewall is pushed back about 2mm after that crash... hmmm. The cowl looks good too. I will need to get around to some cosmetic fuse work, but overall she looks good and flies sweet. She is a 3S machine. She flew well as a 4S, but heavy, slagging through turns, landing hard, and she tried to burn out her motor, curious since its rated for 4S. With a 3S 2200 - 2650 mAh she flies sweet. 3300 mAh bogs her down weight wise just a bit, but noticeably. With the 3S 2650 mAh she isn't super zippy but gets around well and has very good vertical. She snaps clean, accelerates well, and lands easily (though even with flaps she will stall a wing if one lands too slow). I did lose the tail wheel... tore right off in the hard scrabble grass. Fortunately had one I kept from the first Sbach. So, Power 15, 12x6 prop, 40A ESC, and 3S 2200 - 2650 mAh for a good 6 minutes of flight with 1.5 min bingo fuel. Rates are 30/30, 50/30 and 100/50. Flaps 20 and 40, though I may back the full flaps to 35 as she doesn't stall a wing at 35. I flew about a dozen packs with flawless performance, and I am starting to get used to her. Really love this plane and am already looking to get a 1500mm (55") version!
 
The Pulse, of course, flew flawlessly... practiced approaches and landings, long and short, with and without spoilers. Always predictable, stable and fun!
 

Then, there's the intrepid Eflite Stearman, pictured here just before she crashed. Last time I flew her I burned out the motor... or the ESC, not sure because they both work, but the motor fails at full throttle. Its also rated 4S, so I don't think its the motor, but that I am over peaking the amps on the ESC with the 12x6. I tried flying it 3S 3300 mAh today as its was designed for (so many repairs, I think its too heavy now, as evidenced by...) and she flew okay, a bit sluggish compared to 4S, working hard through loops and vertical. It was a fresh battery, 3 minutes into 8 planned climbing out of a low fly by the motor slowed then stopped and she dropped like a stone... managed to get the nose up at impact. Snapped a wing connection tab on the lower left wing, easily repaired. Snapped the landing gear clean off and chiseled off the bottom 2 cylinders of the mock motor, and broke the prop. No other damage. Spent the evening repairing the tab, building the landing gear block and recoting it, and cut two cylinders off an old Stearman cowl (I had just replaced this cowl the day before!) and grafted them onto the "new" cowl, with a near perfect repair. Needed to place a cowl tab, too. I also replaced the Hobby Wing 40A ESC with the Turnigy Trust 70A I had laying around. I haven't been using this ESC since programming it is a nightmare: the tones don't match the manual and the programming card is NIS at Hobby King. I mucked through the programming, and the only thing I need to test is the low voltage cut off... rather important, but otherwise the brake is now off and she runs sweet (In a curious set of design issues, Trust is the only Turnigy ESC I can't program with a Hobby Wing card, and the usual throttle range setting maneuver actually sets the brake as the throttle range is auto-detected). I believe I have auto-Lipo detect, brake off, auto timing and I have no idea what voltage cut off is... I ran the motor briefly at full throttle without load and it ran fine. I will power test it with a 12x6 prop and check the low voltage cut off. Need that damn programming card...
 
I was pretty pissed, mostly because this crash-a-day BS is annoying, and I am tired of repairing my planes... At least it wasn't the Sbach!