PART III- More 1/2A Test Flights- Report

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mark s
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Post by mark s »

Scott,

Great report!

Roid
ZenManiac
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Post by ZenManiac »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by sgilkey</i>
<br />i could have sworn i balanced that prop...guess that's why Kustom Kraftsmanship did a brisk business in aftermarket TD NVAs.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
<font size="2">Please entertain another newbie question: Do most of you guys balance your props? I can see how it may be more important with the 1/2A's running at 20K+, vs. limited B running at 14K, but with the smaller diameter, maybe it's not as important. On the other hand, the arrow fuse would be pretty flexible, so it may exagerate any imbalance.

Thanks in advance for your advice.

-= Dave</font id="size2">
Cajun
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Post by Cajun »

<font color="red"><b>"Overall at this point I consider the 6x2 to be a marginally inferior performer to the 5.7x3, though with certain key offsetting advantages.. Which might just make it the ideal spec prop for this class"</b></font id="red">.

Scott, I think you might be on to something here, although my thinking is based soley on your reports and not actually my test flying ,yet. This prop may take us away from the main problems with B and SSC. Slow down the strait line speeds reduces carnage and reduced turning ability reduces furballs which should reduce midairs, and the added thrust helps out weak launches.

If reality follows theory the 6x2 prop could make this class very interesting.

If our winds die down somewhat by the weekend we should be able to help out with some testing.
Thaman
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Post by Thaman »

with this class you put 6 or 7 planes in the air and there IS going to be a furball and a close one at that flying that close in and the turning ability of these planes there is going to be midairs from the furballs. that bring up what i like about this class is its lack of carnage. we have seen alot of midairs and they bounce off each other and the worst thing i have had break is a servo but now that i have gone to the 81mg's i dont think that will be a problem anymore
sgilkey
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Post by sgilkey »

I re-did the SUBJECTS of the three threads in this series so it might make more sense. I thought it would help to break it up but now I'm not so sure. PART I is the build phase. PART II is the first test flights phase without regard to rpm or weight restrictions, and testing of props. PART III is keeping the same prop but changing rpm and weight to test performance limits. Also testing of a Cox TD engine.

I'd be anxious to hear about testing with the 6x2, especially if folks get to try launcing in windy (especially downwind) conditions. Weather has turned foul again up here and I think I'm done with test flights for awhile. The other thing I like about the 6x2 is that it revs higher than the 5.7x3 which I think the Norvel will like, it seems happier at 20k or above. Don't know about the AP.

I would definitely suggest balancing the props. These things can really buzz and that can lead to fuel foaming. I also had problems with my Cox needle changing settings due to vibration. I HATE balancing props but i do it for all classes. if you run a bladder it's probably not important other than to be nicer to your radio gear.
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Post by Hat Trick »

Got a few test flight in yesterday and today. Temps around 40 degrees. Powermaster 15% castor synthetic blend. First generation Arrow at around 17 ounces with an AP engine. May not be to well broken in yet.

With the 5.7x3 I got 17,700 RPM. Plane flys well. Could cut it's own streamer. Verticle is around 75 to 100 feet. Launched easily. Will do decent sustained turns. Sa* * * *ay was dead calm and I launched it by just dropping it. No forward throw at all and it flew out straight and level with no problem. Today wind was blowing around 15 mph. I tried a straight down wind launch with a decent toss. It flew out but was hanging on the prop for a while until it got up a litle speed.

Tried a 6x2. Went up to 18,600 RPM. Launched and flew ok but vertilce was around 50 to 60 feet and it was a lot harder to keep up sustained turns although it would still turn just as tight for the first turn or two. Was ok but I liked the 5.7 x 3 a lot better.

Tried a MA 5x4. RPM was around 16,500. Launched ok into the wind but performance was worse than the 6x2. 40 to 50 feet verticle. Turned tight the first turn but would start to wallow after the first turn. Unacceptable in my opinion at the RPM I'm getting.

I'm not getting anywhere near the RPM Scott has posted. And nowhere near the proposed limit of 20,000. Am I just not getting these engines to run well or does the RPM limit need to be a lot lower?

I also got my 1/2 A starter that was on backorder and it does make strarting these little engines a whole lot simpler. I think the starter spins it almost as fast as the engine does!
Cajun
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Post by Cajun »

No flight reports yet due to wind. But I have test run the AP and Norvel Cl engines on test stand.

With the 5.7x3 prop and 20/20 Powermaster fuel they were both turning between 19K and 20K and still running cool. They are both as they came from the box. I haven't changed shims or anything and won't if they continue running this good.
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Post by ZenManiac »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hat Trick</i>
<br /> I'm not getting anywhere near the RPM Scott has posted. And nowhere near the proposed limit of 20,000. Am I just not getting these engines to run well or does the RPM limit need to be a lot lower? <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
<font size="2">Mike,

It looks like Scott was using 25% nitro in most of his tests. I just picked up some Hobbico 1/2A fuel (http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXEPD2). Says 25% nitro, but doesn't list the % oil. Can we assume that they know best? That was the only high nitro fuel that the local store had (that's $7/cup).

Thanks for the tip you mentioned to my brother Bryan about the starter. I picked up the only one at Greenfield Hobby in Milw on Thurs. WAAAYY more better...I actually got my AP started. I got four 5 min runs on the bench yesterday - then it decided to get stubborn and not start. Gave up for an hour, and it started. Even though the break-in in the manual suggests 10% nitro, I'm going to try the 25% to see if it helps with the starting issue.

This AP seems like a really messy engine. The muffler doesn't fit tight (just the wire clip over the exhaust port), and I've got black oily fuel all over the place. I think I see some fuel leacking out from the prop shaft, but it's hard to tell in the prop wash. My throttle servo is covered in oil. I used the fuel tubing over the needle valve trick, in case this was the source of some of the waste oil.

Thoughts on any of these issues? Or do these engines just need the proper alignment of the stars?

Call me spoiled by my 25FX.

Test Sa* * * *ay
Test Dip****
Test Sassy
Interesting censoring algorithm...
</font id="size2">
sgilkey
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Post by sgilkey »

Mike, when you hear a liiiittle bit more bark out the exhaust, the engine is running. the 1/2A starters turn a lot of rpm!

a 5x4MA is probably too much load, try a 5x3 Grish (if you can get one) or a 5x3 cox. My Norvel can turn the 5.5x4MA but it lugs it down a bit too much for best perf. another option would be to try cutting down a 6x3 MA to 5x3 just for testing, i would not see a SPEC class like this allowing prop mods. wish we could get the Grish props!

sounds like you did not like the 6x2 as much as the 5.7x3, which was my conclusion too, if all we're talking about is best performance. if we're talking about performance LIMITING, it may be another story. time and more testing will tell.

you're doing and posting more testing on the AP than others so it's too early to tell if your engines are dogs or if all APs are behind the norvels. anxious to see the posts of other AP users! If i can get 19k out of a Cox .051 it's surprising that an AP can't at least match that!

i used 25% nitro since I am flying in 30-40 degree weather and i figured the engines would run better with "hotter" fuel, plus 25% is what i use in them for u/c typically. but i did run 15% during my testing when i was needing to test reduced rpm, and even at 35 degree temps the 15% ran fine.
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boiler
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Post by boiler »

I finally got to the field to test my 1/2 A open with the 32 inch wing. It weighed in at 14 oz. Last night I dismantled the engine and soaked in 100% isopropyl alcohol. Scrubbed it today and then swabbed it with Castor before assembly. At the field I was going to use a cloths pin igniter but the battery was dead. Oh gee whiz this has a head modification that uses regular tower hobbies plugs. It had a bad fox plug in it so I changed the plug and put on my regular igniter. It popped! Turned it over to make sure it wasn't hydro-locked and then hit it with the electric starter. Took a minute to get it running probably because of the extra Castor in the engine. I used 15% Riches brew with 20% mixed oil. I added 2-3 ounces more Castor and used that for break in. Once started it ran pretty good but tacked about 15k. I put it up and it really flew nice. I had way too much airline control and dumb thumbed straight into the mud/frozen ground after only 2 minutes of flight. Everything was fine including the apc 5.7x3 prop Scott.[:)] It took a few minutes to clean it up and re-center the wing. I put more fuel in it and it started easily. I tacked it at about 15.5k now. Launched it and took it easy on the stick since I wasn't using a computer radio and didn't have dual rates. Boy does it roll. The turns were tighter than any plane I've flown before but it would only do one before starting to slow. After 2 turns the speed started to bleed rapidly. It would climb great for about 50 ft then it started to stall. In a loop it had no tendency to snap but after one it's speed started to bleed. The plane flew for about 20 minutes on two ounces of fuel and then I heard it starting to lean so I chopped the throttle to land. I forgot the carb won't close all the way without pulling back on the trim tab as well. When I took my eyes off the plane to grab the trim tab I spun the plane straight into the runway. Really easy to clean up this time and it had about 1/4 ounce of fuel left in the tank. I filled the tank again, started the engine much quicker this time and tacked it at 16k. I got a call on my cell phone so I just let the engine run. I had to leave the field to get some stuff for my wife. I think the plane as is performed as we expect a limited class to do. The speed was just a tad slower than ssc. When I get a 30% nitro with lower oil in the engine I expect I will get higher rpm. Only then will I know how the 32 inch wing will perform at the lighter weight. I have no armor in the wing so I need to build some of the small wings with armor and more weight to see how they do. I will also build some 40 inch with armor as well. It's supposed to thunderstorm tomorrow and then turn to snow. It felt good to get out there with just a sweatshirt and boots today.[8D]
Lee Liddle
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Post by Lee Liddle »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">It felt good to get out there with just a sweatshirt and boots today.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Boy, that`s not a pretty picture. Don`t stand too close to that prop Bob.[:0]

Glad the testing went well...good job.
drewjet
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Post by drewjet »

Oh, I can't get the vision out of my head now

Argggggg
Yawnego
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Post by Yawnego »

I guess Bob has put a new meaning to Chicken Stick now![^]
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boiler
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Post by boiler »

Lee you're one of the old geezer club now. You're supposed to forget about those things.[}:)] At least we can still TALK about them.[:D] Bill Geiple is a prime example.[:p]
sgilkey
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Post by sgilkey »

is this a flight test report or a scene from Brokeback Mountain?. geez, a sweatshirt and boots, nice outfit, cowboy!!!

The standard glow plug conversion heads usually really hurt performance. try the standard Norvel head, or the AP (the AP will swap but you have to swap the clamp and glow plug together- see my thread on heads. no pun intended to your sweatshirt and boots get-up. oops there's another pun, unintended).

the Revlite norvel is non-conductive on the cylinder, which complicates glow plug clipping. you need one that will clip to the head clamp. and don't clamp your head in the glow plug clip, Bob....

all right, all you guys are impressing me with your ability to land without breaking an APC prop. heck, bob even CRASHES and his prop survives better than mine. if you're implying i can't fly then i can live with that. at least i wear pants when i fly!
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