MX-Bach RCGF-USA 35cc Update

Pre-flight checks after changing the prop. Sweet engine. 

Gotta love RCGF-USA for excellent pricing, quality engines and great personal service!

This is a good video of her sound, power and nice transitions. There are 3 idles, Flight, Approach and Landing, to prevent stalling out at lowest idle. I do this on my engines that run for about 30-60 secs and may quit at low idle. This guarantees a safe flight idle, and an effective approach and landing idle. Each are heard distinctly here. I also have a 2 sec up throttle speed, and a 1 second back throttle speed, both give a smooth transition over the throttle range when sudden changes are made with no noticeable effect.

Time to fly!

4 Blade 500 Not So Much

Since I had to change the swash control arms, and the Align 4-Blade Head already had them, I decided to try that head again. I bought heavy duty 600 sized control arms and cut them to fit, and made some mods.

I raised the butt a bit.

And put 600 size tail blades to help with the extra torque. 

Not sure they are needed, but why not. With the 500 tail fin the longer blades were not getting a safe clearance. 

These are wide chord, and clearly MUCH bigger at 93mm than the 500 size, about 78mm.

I put a 600 size tail fin, stiffened with the original 500 tail fin, giving good clearance.

Well, it was always one thing or another, and the blade holders were a tad loose no matter what. It just really wasn't worth it, other than being cool; it doesn't add anything so was becoming a pain in the ass. I know I could make it work, I just kept thinking how much easier it is to just be a two blade. So I ordered a new set of swash control arms today, be here in about a week, put the Tarot 2 blade head back on, and made the tail 500 size again. Waiting for the swash arms, just don't want to take them from the 4-Blade head.

Painted the tail blades white, putting a red strip on them, will balance them and reinstall. Kinda glad to have a flying machine rather than a flying experiment.

Tower Hobbies Uproar V2

I am looking for a nice flier to replace the Ugly Stik 40 that I loved, but killed. I was looking at the more expensive Hangar 9 Ultra Stik, which is sweet, but expensive and a bit overpriced. Instead, I found this smaller plane, 1200mm (48") that can handle a 10cc engine lijte the Evolution 10cc which would be a little big for this plane, which is perfect. This is the Tower Hobbies Uproar V2, for $100, fits the bill perfectly. A fun simple aerobat, its a nice fit for the subjectively weaker Evolution 10cc. I would put bigger, stouter gear on the front and back, probably with the oversized big wheels from the Stik, and use standard sized servos. I would need to beef up the hardpoints, but she can take the weight. This would be a nice plane to thrash around and practice with.

This is a bit exciting!

(Hmmmm...  can't help but think I am settling and just need to wait and get the Ultra Stick.)

RCGF-USA 10cc at the shop...

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I pride myself on being able to work on pretty much every part of my aircraft, but no pride is lost sending the RCGF-USA 10cc to the shop where the company owner will personally take a look at it. I think this is only the second time in a decade I have had to send one in. It needs work I just don't have the tools to do. It needs a new cylinder head since the spark plug hole is stripped, which I can do and likely at least a front main bearing, which I could do, but I couldn't get the front base off to get to it. One of the things I love about these RCGF-USA engines is Joe Nelson's personal advice and care. I can call him, email him or send something in to him.

I am a bit worried he may tell me it just needs to be replaced, in which case I plan to put an RCGF-USA 15cc engine in, instead of the 10cc. I should know in a couple of weeks. Int the meantime, there the Spitty is, naked and cold... this one has at least 6 years on it, I think.

Spitfire Engine Blown Sparky, Kaput

I thought that I was nearing the end of the Spitfire #3 build, but during the engine run-ups the post-crash RCGF-USA 10cc I just didn't like the sound of the engine, and she didn't seem to get up to full RPM/power. I found the following thrust results, average of 3 measures of static thrust, the aircraft weighs 8 lbs dry. Using a Thrust to Weight ration of 0.7, the plane would fly fine with 5.6 lbs of thrust (I couldn't find any other estimate of Thrust to Weight for gas):

14x6x2: 5.4 lbs

13x6x2: 4.2 lbs

13x8x3: 4.4 lbs

She just doesn't sound right. I am not confident the bearings, especially the front one, are okay, and I think she should produce more RPM.

The spark plug stripped, I think it was coming free during these run ups, and afterwards it just came loose, and it wouldn't tighten. I will be sending this engine to Joe Nelson at RCGF-USA to take a look at and see if he can solve the problems he finds. I suspect she will need a new cylinder head and bearing(s), possibly a new spark plug. 

In the meantime I am considering taking the RCGF-USA 10cc from the Sukhoi and moving it to the Spitfire. That engine runs perfectly, is the same exact engine, and would be a simple exchange. When the repaired engine comes back I can put it in the Sukhoi. I am stalling on that because it runs and works perfect in the Sukhoi and I don't want yo screw around with that. Patience...

Spitfire #3 Essentially done!

Last night I essentially finished the third Spitfire. I installed the fuel system, engine, and the electronics, the wing is joined to the fuse and everything works!

Rather full upper equipment bay. Fuel tank forward, reciever on the starboard side, 2S 2300 mAh LiPO on the port with the mai  power switch on underside of  th throttle switch. Snug and cozy.

I really like the simple switch from Hobby King. Its electronic so will fail "on", and has a nifty multicolored battery charge detector. On line in, one out. I hadvto trim of the handy flanges. Great price even if shipping was steep, almost the same price as the part for the guy on the bicycle speed delivery.

Another view of the equipment bay, looking aft.

The cowl is done, the engine and muffler holes cut out and it has been fitted. Needs to have needle access drilled out still, but its done. Leaving it off for the first engine start to make sure there are no issues. That's really all that is left, first fuel, first start and run up!I do need to find some letters for the side, didn't like the ones ai got for being too narrow (ordered them online, didn't get a good look). I'll put my initials on either side of the fuselage rondels.

Dry weight is just shy of 8 lbs (~ 3.6 kg).

Spitty Update: Wing joined, Tail feathers done

Tail feathers done. Completed the horizontal stabilizer and the rudder, connected their control assemblies.

I completed the wing Y harnesses and joined the wings. I decided as before that its just easier with all the wiring.

Tail feathers and wing joinery setting and drying.

Elevator and rudder servos and their connecting rods.

Red fuel vent. I decided this time to put it aft of the wing. There isn't really a good place anywhere forward.

I also plumbed the fuel tank, clunk and vent. I am thinking about how to get the 3-way in place without crimping it with a tight turn while keeping the line to the carb short. 

Next I will set up the engine, then the electronics.