Continuing flights & videos of the Shoestring

I'll take the tach with me and the camera can catch lap times too. I'm itching to go again. I was fed up, but that never lasts long. I hope to get out tomorrow. Looks like 10mph or less winds, about as good as it gets. I was rolling through weeds that day it chased me. I think that's what caused that malfunction. I wish I had that on camera. I would have waved at it as it went over my head.

Mark Boesen wrote:fyi, here's about where i set up the tanks on my Foxes, about right where the first continuous cooling fin is.

Okydoky. I'll be able to try different positions and see if i can get a full flight out of this ornery beast.

Mark Boesen wrote:fyi, here's about where i set up the tanks on my Foxes, about right where the first continuous cooling fin is.

Thanks Mark,

I'll move it up a tad. I made the holes in the mounting tabs oblong as you suggested so I can adjust it.

Ron

...not saying its right or wrong, just what worked for me. I do think tank height is more critical for the 2-4-2 run of a fox compared to the r/c type engine that should run a steady rich 2 cycle.

Stay tuned for today's movie and accompanying flight report.
It's about 15 minutes long so it'll take a while to upload to the Tube.


I'm currently writing my report in a post that will appear below.

RknRusty wrote:Stay tuned for today's movie and accompanying flight report.
It's about 15 minutes long so it'll take a while to upload to the Tube.

15 minutes eh? Me thinks the flight report will be favorable.

standing by!

Ron

Full screen is best.



Last night and this morning I finished remaking the tank mount again. It's adjustable now. I made a pair of inch wide rubber band hooks from 1/16" aluminum ans wrapped them in rubber electrical tape, the gummy cohesive kind. The fuel might eat it, but it's fine until I can get some tool dip. The rubber bands aren't as cool as my strap, but then cool don't necessarily fly.

So I figured I'd never get it to needle right with the bubbles and that has nothing to do with the tank position, so I opted for normally vented. Especially after realizing Ron's Fox runs fine that way. At Mark's behest I made a point of setting it soaking rich and taching it before each launch. This was not possible with the uniflow plumbing because it would cut off or lean out before I could pick up the lines and the needle setting seemed sensless.

Anyway, first flight. I started rich at 11,000 RPMs and it didn't unload at all. I thought I was stuck with a long flat run until I tried some climbs and dives and it was 2-stroking in the climbs. So I did a few loops and such and ran it dry and landed.

Second flight, the needle was confusing again. It cranked at the same position as the first flight but sounded lean, so I opened it some more. It still flew leaner but ran fine. If you wonder why my loops and wingovers all start at different points, it's because the wind direction was changing. I can see the outboard wheel behind the inboard wheel, so I suppose it's yawing out some. I can also see the top of the inboard wing(or bottom if I'm inverted), so I need to address that. I tried an overhead 8, but botched it with no scare. But the one scare I did get was when I tried an outside loop from normal flight and it came in on me and went completely slack. I forgot the timestamp, but I'll find and post it later. By some miracle she came back to me with a bodacious yank and I saved it a few feet off the ground. Later I think I was trying a real figure 8(not a lazy 8 ) and it cut off at the top and landed on its nose. No damage, didn't even get dirty. Looking at the video, I was doing it backwards anyway. I've never done one before. I checked the tank and drew only a tiny bit of fuel out. I also tried an overhead 8, but got confused and just did a loop way up there... or something... I think.

Third flight. I was cautious again and just did some loops and wingovers, but landed dry. If I see and recall any other points of interest, I'll post them. My video commentary speaks of the pre-launch tach and needle settings.

So, what do y'all think about that?

I like these videos and admire your tenacity and calmness while you are "tuning" this model and set up.

ian1954 wrote:I like these videos and admire your tenacity and calmness while you are "tuning" this model and set up.

Thanks, Ian. I have my rough moments, but they pass. I presume you saw me cuss out loud at the end of Tuesday's video.

Very nice.

I hope I can apply some of this to my Fox stunt 35, which is about 2 run from broke in and ready for the plane. The plane however, is not painted yet.

Phil

I need to figure this out:
Look at 6:39. I tried to do a simple outside loop from upright. I do it all the time with my other planes, but when it was coming back up, instead of continuing the loop, it went slack and took off straight and inverted. I barely saved it and it yanked hard when it finally caught. I managed not to wreck it, but what could have caused that? I noticed that it's flying with the inboard tip down, could that be the reason? It turns outside loops from inverted flight just fine.

After you watch the plane go awry, take another look at the quick dance I had to do. Complete surprise. A lot of luck on that one. Almost a busted plane.

RknRusty wrote:

ian1954 wrote:I like these videos and admire your tenacity and calmness while you are "tuning" this model and set up.

Thanks, Ian. I have my rough moments, but they pass. I presume you saw me cuss out loud at the end of Tuesday's video.

Heck, I heard you cuss today when it cut out and nosed in!

Great news!!!!!!!!!!! I am so happy for you Rusty, I am also glad you didn't give it up and worked through the issue. Seems like some minor trimming is all that is left for a perfect flight. How did you like the 4-2? I find it gives me time to think between stunts.

This video was a perfect end to a great day. I was promoted this morning and now this!!! I couldn't be happier for you. 3/4 oz is all you should need for tip weight. Moving the leadouts is a bit trickier.

Ron

RknRusty wrote:I need to figure this out:
Look at 6:39. I tried to do a simple outside loop from upright. I do it all the time with my other planes, but when it was coming back up, instead of continuing the loop, it went slack and took off straight and inverted. I barely saved it and it yanked hard when it finally caught. I managed not to wreck it, but what could have caused that? I noticed that it's flying with the inboard tip down, could that be the reason? It turns outside loops from inverted flight just fine.

After you watch the plane go awry, take another look at the quick dance I had to do. Complete surprise. A lot of luck on that one. Almost a busted plane.

My guess is the lack of tension just allowed the plane to fly as it pleased. Tip down could have easily caused the lack tension while inverted.

Edit: watching more closely this time it looks like the wing drops and does a knife edge until it catches. May have been a combination of wind and tip low.

Hey, congratulations on your promotion!

The 4-2... I still need to warm up to that. I kind of like fast. But I think I'm moving too slow in the 4 stroke. I'm counting 5 second laps. I think most pilots do about 4 seconds, right? My 4 is more like a sputter than the clean 4 that the Fox does. I probably need to experiment with props now. Mark thinks I'll like the 10x4. I'm flying a 9x5 now. The bigger prop might let me run a little faster without having the runaway lean condition that kept shutting me down in the past. That idea comes from Ken and Mark.

I'll add some more tip weight until all I see is the wingtip. I don't think the yaw is that bad. I think it saved my ass from busting the plane today. Is it okay for it to be yawed out enough so that the outboard wheel appears to be trailing, but touching the inboard wheel. Or should I be looking for zero yaw? I have 2 degrees of engine offset and whatever the plans say for the rudder, maybe 3/8" offset.

Also, I'm sticking to the normally vented tank for now unless urged to keep trying to get the uniflow to work. What's the difference anyway? I like a lap of warning before it sucks air.

Is it tip low or tip high? If tip high add weight, tip low remove. It looked level in the video. Best way to tell is to take someone who knows what's going on and fly it straight out and level from you both upright and inverted. It's hard to see in flight from the pilots angle.

I wouldn't worry about the yaw at the moment. It's flying Ok and if it were me I'd fix the tip weight if needed and recheck. That way you are not doing too many changes at once.

Before you remove or add tip weight what length of line are you using? Should be 58' or so. I was flying with 62' lines and I had to add tip weight as I was tip high. I have gone down to the recommended 58' and have yet to see if that helps my tension issues.

I don't know what my lap times are I just know what feels fast or slow for me. Try a 9.5x6 it works good for the Fox, not sure about the TT.

Someone needs to fire up the Ken Cook Spotlight.

Ron

Outboard tip is high. In level flight I can see the top of the inboard wing. Same inverted I can see the upper side of the inboard wing.

RknRusty wrote:Outboard tip is high. In level flight I can see the top of the inboard wing. Same inverted I can see the upper side of the inboard wing.

Ok, guess just add a 1/4oz and see.

YEAH!!!
Now go join AMA and PAMPA and go find a contest!

I like the third flight needle setting, what RPM did you set it at? That's why it's important to use a tach so you can needle engine the same every flight. I think lap times on 60' line should be about 4.8-5.0 sec. flying 6' off ground.

I think you're ok with current prop the rpm is good and lap times are about right. The reason i was leaning toward an 10x4 was the fact that the 'modern' two cycle engine will often 'run away' on a rich needle setting and it needs to be setup to basically fly in a 'controlled' run away mode using the prop diameter to control RPM and pitch for lap times (hmm, wasn't this just discussed somewhere) about all engines will run a 2-4-2 or at least a rich 2/lean 2! You can also control the 'runaway' by adding a head gasket or two...but thats another thread!

I still think at some point you might look at muffler pressure, but its starting to get not broke, so no need to fix it.

Welcome to the world of ukie stunt discipline: trim, trim, trim, practice, practice, trim, practice, etc. where the goal is not just to do cool aerobatic maneuvers, but to try to do them perfect!

I'd get a notepad to keep tabs of what your doing. Also a stopwatch to time your level laps and keep track of flight time.

You might have a slight warp in wing, set it on table level and look at it, you might add a tab on aileron.

Mark Boesen wrote:YEAH!!!
Now go join AMA and PAMPA and go find a contest!

I like the third flight needle setting, what RPM did you set it at? That's why it's important to use a tach so you can needle engine the same every flight....

Now I don't remember. It was slightly richer than the second flight, so just under 12K I think. The first flight was too rich at 11.1k, the second was a tad too lean at 12k, because it hiccuped in the middle of one loop and cut off prematurely in another loop causing that unsightly landing. So, with the 9x5 prop we know where to run it. I'm going to have to do as you and Ken suggested and write all this down. I want to find a prop that moves it faster in the flats and still 2 strokes and accelerates in the climbs.

On another note, I'm trying to decide if my near catastrophe at 6:40, when I lost the tension during that outside loop, was only because I bled off too much speed climbing to my starting altitude. Or, is it more likely the result of the inboard tip flying low? Seems to me like inboard-tip-low would affect insiders more than outsiders, bringing it into the circle. But all of my insiders stay tight.

What are you running for lap times at level flight, actual? What length of lines?

if lap times are too fast you might need to add a head gasket to keep it from 'running away' or lower pitch prop.

If it really is to slow, maybe try a 10"x5" and cut it down 1" that would leave you with something like a 9x5.5-5.25?

How much weight do you have in the wing tip? And you're sure there no slight warp?

I don't know if this is the case, but sometimes you can fly thru your wake and the plane will do some pretty weird stuff, almost like somebody pushed it!

Mark Boesen wrote:What are you running for lap times at level flight, actual? What length of lines?

if lap times are too fast you might need to add a head gasket to keep it from 'running away' or lower pitch prop.

If it really is to slow, maybe try a 10"x5" and cut it down 1" that would leave you with something like a 9x5.5-5.25?

How much weight do you have in the wing tip? And you're sure there no slight warp?

I don't know if this is the case, but sometimes you can fly thru your wake and the plane will do some pretty weird stuff, almost like somebody pushed it!

On the last flight I flew 5 fairly flat low laps from 12:38 to 13:03. That's 25 seconds, so 5 second laps. I'm on 60', .015" lines. I would like to be a little faster, maybe 4 to 4.5 seconds. I have some APC 9x6 props, and I'll see what else I have. You sent me a few with the engine. I think the 9x5 is one I picked up at the HS. I have a wooden 9x6, I wonder how that would do. The next trip will be all about props and experiments.

I don't know how much weight is in it. I left the existing slug in place when I rebuilt the plane, and it was the inboard wing I re made. I have taken a straightedge and calipers, along with eyeballs, cannot detect the slightest warp.

The wind was changing directions, as is evident by my wandering choices of stunt locations, so maybe I just caught some bad air. Notice the clouds, you can tell it was turbulent. I suppose I need to add some weight to the wingtip. And next time out I'll try another outsider from normal flight, but start the climb earlier. They are just fine when started from inverted. The insides are all tight too.

I sure am glad to have it running better. Thanks for all the help.
Rusty

if you want to fly faster laps you probably need to go to muffler pressure and a 9x6 (might be a bit much) or a 10x5 cut down to 9" might net you a 5.25-5.5" pitch(?)

4 second laps, at level flight on 60' lines is pretty fast! I know you'd have great line tension, but your maneuvers will definitely be hurried. I would recommended you stay at 4.8-5.0 and focus on trim to improve line tension.

at 5 sec. laps how loose is the handle?

Watching the videos brought back memories, not straight away but I have remembered something that could merit some comment.

Most of my control line was diesel engined and I used to take the engines straight off the bench and plonk them in the aeroplane. I found out that the bench settings weren't optimal for the engine when it was in the air and a slight reduction in compression (diesel) and an even slighter richer needle made a noticable difference.

However, I had real problems with an Enya 15 glo engine. Its behaviour in the air was atrocious - it spluttered, hunted and, even when it sounded OK, would suddenly cut out. The aeroplane had previously been PAW 15 powered - I first thought it was the tank as I hadn't flushed it out properly but on the ground the engine ran fine and I could hold it in any direction with no problems with the engine not missing a beat.

The consensus of opinion in the club was the glo plug. This was swapped several times with no noticable difference. It was then suggested the the needle valve had a blockage and this was checked and nothing found. Then, one of the chaps looked down the venturi and could see the hole that the fuel dribbles through.

He took out a little spanner and adjusted it so that the hole was no longer visible and pointed towards the crankshaft and that made all the difference. The engine performance became rock solid in the air.