The flying monkeys got me...

Helis and fixed wing

AMA 957918
IRCHA 4345
AMA Intro Pilot Instructor

Wednesday, November 25, 2015

Twinstar maiden goes perfectly!


The 4S, I learned, is a little tall for the hatch, so a piece of Velcro as tape holds it on. As an experienced builder ya think I would have test fit the battery before I left the shop...


Early afternoon, cold breeze from the south, sun
low on winter horizon standing unfetteringly bright just a few degrees above the southwest tree line.

The fall grass is thick and clumpy, but there are parts where its almost mud. I carry the Twinstar over to one of these barrens and face her south, down field. Check control surfaces, check flaps, check full power run up. Look, listen, feel. First flight. Be a good girl.

It's time. Full throttle, and she fights her way down the runway, such as it is, and as she clears the grasping grass and gains speed, the powerful torque of twin props rolls her to starboard. I easily correct and take her into a right climbing turn to clear the western tree line, avoiding the sun line. She gains altitude too easily. Nose down trim, a bit of left aileron trim, a tweak here and there, and in a few passes she is trimmed out despite a choppy wind aloft.

The power setup is spot on. The 4S nestled in nicely and she is balanced now. She won't go vertical, but she is aerobatic. In fact, my low aileron settings are too high for even high settings, and I had the low rate tuned to about 35%!

I try to slow her for a landing approach, a long one, but even with 50% flaps she is fast on the final. I need the higher aileron throws at approach speeds with the flaperons down. She descends nicely, predictably, but fast. Several landings and approaches, its just the way she is. And she puts her nose down when those back wheels touch the thick cabbage, and she buries her nose wheel and abruptly stops, stuck where she came to rest. It's a walk in taxi almost everytime.

A couple of times I manage to find a muddier less grassy spot and she rolls out. But her props are green with grass she had cut and thrown into her wings, and the green slaughter coats her props, belly and nacelles.

I fly two or three packs, at 10 min a piece I have already forgotten. She was quite an easy flier.

I had brought the 30cc gasser, but even after this fine flight set, I really am not in the mood, so we pack up and head home.

Flying is better with friends, but no one is home, so I fly alone, and thus my stay is brief.

It was a great maiden, good design, good build, good engineering.


Nose wheel is bent back by the grass.

Preflighting the Twinstar

Preflight testing of the Twinstar this morning, planning on a maiden today after some Honey-do's.
She has Sky Power 40A ESCs. The 480 Plus motors are rated for max 450 watts, but they caution running more than 400 watts sustained. I am running a switching voltage regulator instead of the BECs.

Ran the motors using the 3S 2200 mAh. I got about 7 min, 350 peak watts, around 35 peak amps. On the 4S 3300 mAh it peaks at over 700 watts, 37 amps! On time testing I got 15 min with some cells dipping to 3.4 V.

I need that flight time, so I set up a throttle curve and at a top curve endpoint of 50% produced around 430 watts, around 27 amps. At 50% of that throttle curve it produced around 230 watts and 12 amps, and gave me that 15 min runtime. The 3S 2650 mAh gave me about 10 solid min before.

So I plan to fly her 4S 3300 mAh set at 10 min with 5 min bingo, using a throttle curve to bring the power down so I don't blow the motors. I can fly the 3S 2650 mAh if necessary but would need to remember to remove the throttle curve. Not likely to do that.
More on the maiden later today!

Tuesday, November 24, 2015

Great Planes Twinstar EP Ready to Maiden!

Well, that's embarrassing... So I am watching the cat play with a white piece of plastic down in my shop... Wait a minute. Let me see that. Sonofabitch. It's the plastic Nose Gear bracket thingy. (Apologies to Great Planes...).

So I installed the nose gear and the nose cone, on the Twinstar EP, put a fresh 3S 2200 mAh battery in, checked CG (fine), and ran the motors at 50%.  Got almost 7 min, but it took them down to 3.5V. I need to see how it does with a 2650 mAh, or I will need to get the recommended 3800 mAh.



Trimmed that...



 






Bench test. Power to spare.  50% Throttle, 3S 2200 mAh, got close to 7 min but went down to 3.5V/cell.




I find their lack of faith... disturbing.





But for a nose block, the Twinstar is done.

The motor mount arrived from HeadsUpRC today, allowing me to complete the install of the port side motor and nacelle. All that is missing now, on The Plane of Missing Parts, is the nose wheel block, coming from Great Planes/Tower Hobbies. Once that is in, she will be complete within a few minutes, ready to CG and maiden.

After installing the port motor I ran them on a 3S briefly. Plenty of voltage/power. I wiIl need to see how much time I get on fresh 2200mAh. I am looking for 7-10 min of sport flying. I believe she is rated for a 5000 mAh or something ginormous. I already have a lot of connectors and adapters in there adding weight, but could easily change the EC3 one I have to EC5 and series in a pair of 2650 mAhs.



Saturday, November 21, 2015

Thursday, November 19, 2015

The Plane of Missing Parts

Does twice make a trend?

As my Great Planes Twinstar project has unwound I found I was missing a motor mount, now graciously on its way from HeadsUp RC, and today I found that the Nose Wheel Block, the white nylon part that secures the nose gear to the airframe, is also missing. I keep all the bags and boxes, checked, not there. I went through the trash, not there. I crawled around on my knees and belly looking on the floor and under the work benches, not there. I called Great Planes/Tower Hobbies and a replacement is on its way.

UPDATE:  They never sent me the part, which is okay because I found the missing one. Cat stole it. No, seriously.



Between these minor annoyances and the problems I had with the RCGF 10cc engine, I wonder if I need to tune my RC mojo.

I finished the wings, but for the left motor for want of the mount.





And installed the rudder/steering servo, and the elevator servo.



And finally the tail.




I am stopping here for today. Next time installing the control rods for the empennage and steering, the latter once the nose wheel block arrives. Looks like another week before she will be flight ready.

In the meantime I await the RCGF 10cc.

Tuesday, November 17, 2015

Eflite Stearman Maiden

Beautiful day, virtually windless. Perfect time to take the Eflite Stearman up for her maiden flight. The takeoff and first flight was hairy. Despite being on CG she flew a tad tail heavy, her DR and Expo were off (too low), and it took some sick skills to get her back down.

Over a couple of flights I found her happy place, she rolls like a pig, buy otherwise handles predictably. I enjoyed the flights and flew three long 3S 2650 mAh packs.






Saturday, November 14, 2015

RCGF 10cc Update: Try, try again.

UPDATE: Its running fine!  Read the UPDATE.

At my last posting on the RCGF 10cc engine with an update, I was having the ups and downs of our hobby, trying to get a new engine to run. If it wasn't for the exceptional one-on-one service from Joe Nelson at RCFG-USA, I would have abandoned this long ago. After this, Joe and I are going to be drinking buddies! I haven't had such personal attention from a dealer, someone who is more disappointed about this than I am.

So... this morning I ran out to RC Buyers Warehouse in Nashua (if they don't have it, you don't need it), and picked up a Hanger 9 Power Pro HD Starter. I McGyvered an EC5 connection to the alligators on the starter and ran it off a pair of 3S 2650 mAh Lipos in series (~24V).  I used this to try to start the RCGF 10cc (more on that in a moment). I didn't mean to run it in series,but I fogot I didn't have a parallel cable and used the series thinking it was a parallel cable...  Since it worked well, I decided to unsolder the gators and installed an EC5. This evening I made up a series connector and tested it at ~12V 5300 mAh. Runs fine.







Now about the engine. I used the starter this morning, and I could not get the engine to start. I ran some experiments that showed that the vacuum was sufficient to feed the pump and fuel was coming out of it just fine. It was filling the pump outlet line to the carb; fuel was getting to the carb. Was wasn't it starting? Check spark, all fine. I decided to remove the engine and check the carb. I tried blowing in the inlet with the throttle open, and I couldn't. Don't know if I should be able to with the needle valve not being metered. I took it apart and removed the needle valve, used Gumout to clean it. With the needle valve removed I could blow through it fine. I put it all together and tried running it again, still no joy.

Joe Nelson (RCGF-USA) and I chatted and he got some calls with issues like mine, and spoke to some skilled pilots, and he realized that those of us having problems weren't using starters. As we thought, hand starting didn't develop enough vacuum. With the starter it clearly moved the fuel. The other guy who used a starter once he was told to had his start the first time, his problem solved. I have no doubt I needed the starter, but is there something wrong with this motor? Why? Joe got it running before he sent it back.  I am out of ideas.

Well Joe has a new engine coming to me with a return label for this one. He's going to see if he can get it running. I've uninstalled the engine and ignition, cleaned it and packed it to return, waiting for the new one.

I hope there isn't something wrong with me and my setup. We'll know if I can't get this one running.

I am optimistic the engine will be fine. I am not optimistic that I can get it running...


Sullivan Skylite 4" From Hobbylinc

I needed to go to a 4" tire on the 30cc MXS-R to keep the prop from touching on roll-out, mostly a problem on landing in the thick grass at Joppa Hill. As she slowed she has a tendency to ass-over-teakettle if she doesn't finish the roll-out in the thinner cabbage. I boosted the gear off the fuse with some spacers, but she still needs a little more.

I picked up a pair of Sullivan Skylite 4" wheels with aluminum hub from Hobbylinc.com.  I unboxed the shipping container and noted the package of one wheel was opened, but didn't care until I realized on opening the closed one that the opened one was missing the screws that secure the hub. I was annoyed, but after rummaging through my stock I found 6 bolts and nylon lock-nuts that would work. Its always something.  They look great!



The one that was opened was opened along the top only, this is after I removed the plastic.




Thursday, November 12, 2015

Great Planes Twinstar EP



I love a twin. If it had stayed in production, I really was looking forward to picking up the Eflite Twin Otter was my dream aircraft, but they discontinued it before I could get one (they were quite expensive).  I was very excited when Great Planes announced it was coming out with the Twinstar EP.

Given my doldrums with the RCGF 10cc engine, I made myself happier by pulling the trigger on the Twinstar, from Tower Hobbies for $139 delivered. I first went through my stock: I have nearly everything I need. I have a HURC Power Up 480, close to the Rimfire 30-35-1250, so I only had to buy one more. I have a HURC 40A ESC, but decided to buy two new Sky Power 40A ESC, and another Power Up 480 Plus motor to pair up with the one I have. I have 4 Hitec HS-82MG micro servos, NIB, perfect.  I also have a Spektrum AR600X receiver, and a couple of 3 blade Dynam 8x6 props (or I could use a couple of the Master Airscrew 3 blade 7x4 props, but I really don't like the short chords on Master Airscrew props). I decided to use a voltage regulator rather than the Linear BECs that come on the ESCs, not being a fan of them. The only thing left is to see if I can use the 4S 3300 mAh batteries I already have, or if I need to buy the 3S 3800 mAh batteries they recommend. All of my 3S are 2200 mAh and 2650 mAh. I will pick up a couple of APC 8x8 props since they are recommended. I'll have to wattmeter and time the different props when I am all set up.

I am pretty excited!


RCGF 10cc Disappointing... Hope fades


UPDATE: Its running fine!  Read the UPDATE.

Well, the experiment using an RCGF 10cc engine has ended, and its a fail*... Many others have had a lot of luck with this engine, but its been a bust since I got it. I am so disappointed, I really like the look of this motor, and the service RCGF-USA has offered. There is still hope, but its fading.

*UPDATE (11/13/15): The engine may be giving me grief, but the service from Joe Nelson at RCGF-USA is exceptional! I woke up this morning thinking that the only thing I haven't done is bypassed the pump using a simple siphon feed. In my conversation with him he test runs them on a bench tht uses a gravity feed without the pump. It ran. this fits with my work identifying the pump as the likely culprit. He's looking at my pump pics too, but in the meantime he's sending me a new pump. I will test the motor without the pump and I wholly expect it will run. I will replace the pump when it gets here. He's made it clear if I want at anytime to send it back he will replace it with a new one.  We can't expect perfect parts, but with perfect customer service anything is possible!

I opted for it as it has a ringed cylinder, it uses the 30:1 mix, and has a standard muffler. It was priced similar to the Evolution10cc, which prefers 40:1, has a glow type muffler, and has a non-ringed cylinder that requires a tender break in period. The RCGF was just easier.









I got it about a month ago to go in my Sukhoi SU-26. I couldn't get it to start... I went through everything I could think of. I finally pulled the spark plug to check spark and the plug came out with its threads and wouldn't go back in (but it did spark). RCGF-USA took it back (I think it cost me $20 to send it by ground).  They had it a week, I wrote and found out that despite my email exchange, they had no idea why it was there and were waiting to hear form someone (hello, name and address on the box). Joe at RCGF-USA changed the cylinder head, got it running, and sent it back. I got it today, totally psyched to have it running. Installed, and... nada. Once again went through everything and just couldn't get it started. I isolated all the systems, electrical and fuel, and the only thing I found was a dry fuel pump. I put some fuel directly in the carb through the wide open throttle, and it turned over for a couple of seconds but there was no fuel to keep it running.  That was the only time that worked. I took apart the pump and it was bone dry. The Quickfire is wet, there is fuel to the pump, and I primed the line from the pump to the engine. I took apart the pump, and I tried changing the metal plate and the butterfly valve gasket order to see if it was put together wrong, and that didn't work. I put it back the way it was when I opened it. I couldn't find an exploded drawing of it to see the right arrangement, but the outer gaskets are clearly against the outer plates, so there really is not much variation left. It 's got a metal plate the Walboro's don't have with the butterfly gasket on one side, and gaskets sandwiching that between the outer plates that hold the metering line and the fuel in and out lines.



RCGF 10cc Fuel Pump Disassembled.

Then reassembled:









I have a couple of emails and a call message in at RCGF-USA. If they can't help me get this running and soon, I will need to return it. I don't see a point to trying an exchange for a different one, I mean this is a simple engine, and it ran when they had it, so what's left?

I really had hope to maiden her this weekend.

Wednesday, November 11, 2015

Returning faulty HK 3-axis DSMX Reciever



I decided, once I realized this cost me $25, I need to return it to HK for an exchange. Recall that I planned on using this on the Eflite Stearman but when I plugged it in it didn't light up and then shorted out. Got the RMA today and will mail it out to the return site in NY tomorrow.

Stay tuned.

UPDATE: HK quickly replaced it, no problem. Haven't installed this one in anything yet.

Thursday, November 5, 2015

C-47 Skytrain Redux

She is a curious flier, one moment docile and balanced, the next cartwheeling across the grass on takeoff. A few months ago she tore off an engine and smashed up her fuse a bit. I fixed it and used wood filler to gap the gouges. I left her in the wall for a few months.

Today I sanded down the filer, pulled off some of the stickers and used up the last of the of the olive drab paint for the topside. Tomorrow I'll finish the bottom with gray, and complete the stickers. Then, another try at flying without drama!