Thursday, February 21, 2019

Off to a slow start...

I started on the Spitfire, but wasn't very motivated to begin with. Curiously that was my mood when I started the first one three years ago.

I started on the left wing because it was on top in the box. First thing I noticed was that on that orignial build I had the servos for the left wing on the right wing and vice veraa. This put the control arm back on the wing instead of more centered, and I complained about short control arms not realizing until now what I had done!

I started off slow, not really into it, and took my time working through the usual build problems that occupy so much of our time and energy in a build, but that are the heart of why I enjoy builds: thinking problems through to a fairly good solution, making the least a messy effort as I can.


The box, with the decals on top createa a little excitment about finishing a beautiful model. Phoenix Models are always well boxed.



Like last time I used the CA hinges on the flap, and use Du-Bro small hinges on the aileron. What I noticed is how little support in the wing there is for the hinge.  Under the forward edge where the hinge slide in is about a 5mm wide bar, then the balsa skin. Most of the hinge is just hanging in the air inside there. I decided to epoxy the wing side to add support, and CA the flap side.



I felt last time that the control horns were a bit short, and found enough of these longer aluminum horns to use in all the wing servos. They are a bit bulky, but lite and sturdy. The Tactics us a Futaba spline and the horns are too. I think I had bought them for this purpose and forgotten about them.



Installed horn. This sucker is solid.



Used shrink to hold the internal plug of the aileron servo extension together.



The flap (left) and aileron (right) surfaces, servos and contol rods installed. I used the stock screws and back plate for the flap, instaled before I put the flap in, but on the aileron I started to, and really didn't want to deal with alignment of the screws and backplate, and then having to cut the really overly long screws. I always use CA to hold the control horn in place durimg installation, knowung its on the cote, and decided to use mid sized servo screws that don't come out the other side with CA. I am not sure I like this... there is a lot of load on the aileron horn. I may change to longer servo screws and see if they are long enough to backplate... we'll see. One problem I forsee is that the flaps and ailerons are goingnto be on a Y harness. This means I cannot sub trim them in the radio, and will need to made physical adjustments to get them equal in deflection. Small problem, but a problem nonetheless.

Slow start. But now I am super excited and can't wait to get back to work on it!

Tuesday, February 19, 2019

RC Aces Club, North Hampton, NH


Taking a look at a new flying club, RC Aces out of North Hampton, New Hampshire. The field looks great in photos, large, clean and well cared for, though membership is a bit steep in cost, it looks to be well worth it. While SNHRCC in Hudson is only 15 miles away, it take almost the same amount of time to get to each site. RC Aces is about 28 miles, both take 30-40 min drive time. I am impressed with the flat runways, wide field without obstruction, and relative lack of restrictions on flying times.

Gary Hoffman brought this to my attention as it is his new field, and it looks to be worth the trips. I will need to check it out as soon as the weather improves!

Well, it's about time.

October 15, 2017.  That's when I bought my second Phoenix Models Spitfire 0.46-0.55.

The first build (part 1part 2 , part 3, part 4, part 5, part 6), was simple, with some serious time however, spent on getting the retracts right. The end was simple too... crashed on her maiden when she hit a tree during an otherwise perfect flight. That maiden and crash was in July 2016, and I took it hard. It took over a year for me to get over it, but I pulled the trigger during a Towers Hobbies sale in October 2017 on this second purchase. This model is such a great flier, I couldn't resist.  I got the 7 servos 5 days later. And for the next 492 days it sat at the end of the shelves in my workshop.

Excited by my recent success at getting the RCGF 10cc engine on the Stik to work again, and having the pain of the maiden-crash wane enough to allow me to want to try again, I opened the box with the box in it, and then unboxed the manual to review. Tomorrow I will start the build, and when the funds are available purchase the rest of the parts, including a RCGF 10cc gas engine. I am planning on using a Tech-Aero Ultra BEC (a nice design, UBEC and remote ignition cut out), and use a single Pulse 2S 5000 mAh LiPO as a receiver and ignition pack. I will use a single receiver switch and fuel port situated internally, and a Spektrum AR8010T 8 channel receiver. I may add a Hobby King Orange 3 axis stabilization system. Time and again impressed by simple setup and operation, and excellent functionmof the excellently priced, quality systems. I thought about using the Spektrum AS3X, but having had issues with the ill fated Spektrum Alpha 6 Stabilization System I trialed., and seeing lukewarm reviews with similar stories, I am not interested in using the 7 Channel AS3X system. I will be using Tactic TSX 47 Digital servos I purchased, and I happen to have the original servoless electric retracts from the original Spitfire that work fine. The powerplant will be a RCGF USA 10cc gas engine.

So, time to review my old build posts, and start collecting the parts. I plan to take this build slow and spread out the costs over the build weeks to come. Exciting!

Monday, February 18, 2019

Eureka! Stik is up for flight!


Yes!!!!  Success! The clue was that the engine was flooding at idle, fuel just spraying from the muffler. I suspected the metering side of the carb, so today reviewed a Walbro Diaphragm Carb video and confirmed that on the metering side I have the gasket in the wrong order. The gasket goes against the carb and the metering diaphragm over that. On the pump side the diaphragm goes against the carb and the gasket over that. I fixed the metering side and reinstalled the engine. Started on the first try!   The meter side is the lower one in the diagram below, which is pretty much the carb for the RCGF 10 and 15 cc engines. 

It's very cold outside, but I spent a few minutes tuning the engine. I didn't spend too much time, just got a decent albeit fast idle, smooth transition to full power and a decent high RPM. I had also read that the carb is too big for the 10cc motor, and fast throttle changes can cause loss of vacuum. This was solved by slowing the servo speed, like on landing gear and flaps. For starters I slowed it to 0.2s, and may slow it more once I get it tuned. I am going to wait for warmer weather before tuning it further. Right now I am just thrilled to have it back, occasional four cycling to boot!  Can't wait to rest that "Days Since Our Last Crash" Clock!

Sunday, February 17, 2019

Stik still grounded. Flight Sim Updates

I have been leaving the RCGF 10cc engine on the Stik alone this winter, just not having the motivation with the cold, windy and snowy weather, to do anything about it.

I ruined it somehow...  It had been running fine, four cycling a lot despite good tuning and unable to extinguish it. I have since figured out that the RCGF ignition misses and that's why it was four cycling. I'll be replacing it, and am thinking about using an RCExcel ignition, or come other.

As described I took the engine apart to clean it and see if I could get it to run more cleanly. In the process I broke and then replaced the piston ring. I am confident the cylinder and spark are now fine. 

I also took apart and cleaned the carb. I flushed it, and it was pretty clean, the screen filter was clean. I changed all the gaskets. On the fuel diaphragm side I changed the metering diaphragm, and checked and cleaned the metering needle. I made sure that the metering lever was level with the top of the block. I put it all back together again. I am pretty sure I did this right, but this is one of the things I think is the major problem... the carb.

Today I rechecked the spark, and it's the same. I used a different Hall sensor, and it sparked the same, every few revs it misses, but it sparks.

I took it outside and tried starting it. I quickly noticed fuel spraying from the muffler. I drained the tank. I ran the starter and when it stopped spraying and then it coughed a couple of times! Clearly its super rich. Both needles are at 1-1/2 turns. This suggests something is wrong with the carb, likely the metering system.

I am going to give it one more shot, take apart and recheck the carb. If I can't get it running I am asking a gas skilled friend to take a look at it, and if he can't, then asking RCGF USA to fix it for a fee. I do plan to change the ignition, but I think something is wrong with the carb, and I should be able to fix rather than replace it.

 *****


Got some sim time in today. I learned that Phoenix Flight Sim ended with 5.5.1, and that the rumored Version 6 will not be coming out as the company has folded. This has been a great fight sim for me, and the free updates made it an incomparable bargain. 

Flying the sim made it clear that my skills have deteriorated over the winter of not flying. It didn't take long to get my fingers back, but I need to work the sim a lot more. I am flying off the Horizon Hobby Test Field. Flew planks and heli's today.

I am looking into getting the Horizon Hobby sponsored Real Flight simulator when I get some spending money. 

Flight sim time makes a difference!