I think I can

Another discussion on thrust and power kind of sparked my comments for the start of this thread. I often hear (or read) people saying that "this plane has plenty of power" with a certain engine/ prop combo. And sometimes people get the idea that "plenty of power" means simply that it had sufficient power to takeoff and, perhaps do a wingover or whatever other maneuvers they, themselves, were capable of doing. As long as it gets through the maneuver, it has "plenty of power."

But I like to watch the wingover, and that is where I get my first impression of how much "power" a plane really has under its present set up. (And I acknowledge that we should be using a different term, but this is what most people use. And we all know what I am talking about.) Matt has an expression of "I think I can." This is from the story of "The Little Engine that Could." (Certainly your mother read that story to you when you were little. Maybe you still read it on occasion when you go to bed.) The little engine in the story had to go up a hill. And it said "I think I can, I think I can" all the way until it made it. "I think I can," (but it wasn't sure until it reached the very top.)

Sometimes our airplanes react the same way when they start the wingover. They are saying "I think I can. I think I can." Watch some of the Beginner or Intermediate flyers some time at the next contest. Or just look at your own plane to see how close it comes to this description. If the plane slows down on the way up, if the lines begin to get a little slack, it is almost like it is saying "I think I can, I think I can."

There are some airplane/engine/prop conbos that just go up and over when they are pointed that way. And that is true whether we are talking about 2-stroke with mufflers, 2-stroke with pipes, or 4-cycle set ups. The planes that I am talking about don't pick up speed, although the engine may pick up a little, as it begins the climb, to compensate for the added "pull" of gravity that adds an extra three or four pounds to the drag of the plane. But the plane just goes up and over, almost as effortlessly as when it was flying straight and level. The only indication that the pilot has that anything is different, is, perhaps, the sound of the engine.

Some planes will just pick up and go over while the lines stay tight all the way. And others, well, they will be saying "I think I can, I think I can." Where does yours fit in the mix?

Just the start of another conversation. And, please, don't get off the subject. This is not intended to promote one set up over another.

Good topic - I've been practicing the pattern with my OS 46LA powered TEOSAWKI. This is my first stunt ship that I'm not worried the least little bit about it making the wing over. The lines stay tight the entire time through the pattern. It's amazing how much easier it is to fly the pattern with a solid perfoming ship with the right power.

My problem with my other planes is controlling the speed, (whipping) but still having the power to keep the lines tight. But the TEOSAWKI has given me the correct feel standard!

I used to suffer the "i think i can" syndrome quite a bit.
Experience has helped that go away, but every now and then, I miss the needle and it shows back up!
I think it is a matter of experience, but a CF prop which has lost it's pitch can REALLY give you fits.
Bill <><

I did a little experiment with my Stalker/Gladiator the find out where "I think I can" and I thought I could" diverge. I have a pretty comfortable range of needle settings before "I can't" occurs. Other areas where this syndrome shows up are in high winds, a model that does well with marginal power and light wind will fail miserably when the wind kicks up. I have a Veco Chief powered by a Veco .35 (TCC late model), it weights 39 oz. In 3-5 mph winds this model is a joy to fly, but above 5 mph it gets harder and at about 8 mph I put it away. I haven't tried it yet, but I think more power would really help. I have a GMA reworked Veco (on loan from Gary Tultz) that I'm going to try, maybe a .40 somewhere along the line too.

I have, as we all have, watched allot of flights and many with similar models but different power. I've come to the conclusion that there is no substitute for HP. That doesn't mean the whole unit is overpowered, but power in reserve, just because you have the HP to go 120 mph doesn't mean you have to, you can still go 50 mph, but it does mean you don't have to slow down going up steep hills.

Great topic, I'll watch this ine close.

I have a Sig Twister with a box stock Fox .35 and has a bit of this "I think I can" in the wing overs and some other moves, not bad, just a little noticeable. It's the take offs that are iffy! The plane weighs 36 oz. and I am using a 10/6 Top Flight wood (paddle style) prop. I put on a 10/7 and cured the take off problem but I have been told this is a no-no for the Fox, too much pitch.
I already have my neddle set at a wet 2 cycle and have no 4-2-4 so I can't really play much more with RPM's (can I?)
Any suggestions would be helpful... I put a 3/4" tripler on the nose for looks and vibration dampning so changing the engine is not my prefered route... But I might do that at some point. I do have an L&J that has not been run-in, but I don't feel that I am that good of a flier to put that nice of an engine on a plane yet...

Thank you!

Phil,

Just for grins, go up in diameter and down in pitch. I run a 10.5x5 prop on my Fox. It's an ABC, but generally it's just smoother. Take an 11x5 normal width prop and cut it down. Try 10% Nitro and at least 25% all castor for a stock Fox.

Mine powers a 40 oz Sig Mustang with all the Jim&Todd Lee mods. It's got a 50 inch built-up wing. With all the combinations I've tried the larger diameter prop works for me.

I think Marvin Denny (Bigiron on this board) has some of the absolute sweetest Fox 35 runs I've ever heard). I think he uses smaller props (9 to 10 inch dia) on his Fox powered Novi series. Perhaps he can suggest something as well.

Balance up a 11 x 5 Zinger wide and put it on that Fox 35. Works for me. Works even better if you rework the Zinger from a "prop kit" to a prop. First take off you do you'll find yourself flying 10 feet behind the airplane because of the much more rapid acceleration than you are used to.

Phil,
Could you elaborate on the takeoff problems? I am having a hard time visualizing what can go wrong there!

Phil,

The solution may be to put the Fox in a built-up job, and try something else on the profile. I have a box stock Fox 35 that spent its first 100 flights or so on an RSM P-40 profile at 34 ounces. This combination worked quite good, or so I thought, although I felt that power was adequate but not heroic and the plane was a bit of a handful on a breezy day. The same motor then got put in my 38 ounce Gieseke Nobler and wow!, it really rips now. With a 10x5 super M prop and 58' eyelet/eyelet lines, the plane is just awesome. Instead of a "I think I can" feel in climbs you get a "ho-hum, up/down who cares" sort of constant speed and line tension. This plane gives me the feeling that I could go up into a wingover and do little whifferdills directly over my head as long as I felt like doing them. Its also my best wind flyer. It feels like the horsepower doubled from the P-40 to the Nobler. In a decent light built up plane the Fox becomes a "can", not a "think I can" motor.

Changing the motor on the profile with the tripler may be a pain but not impossible, just use the alunminium pads lots of people posting on this board do, then you can make multiple switches and learn about several motors, not just the Fox its drilled for...

Thanks Guys... I am just getting into running Fox engines. The last three planes I have built all had OS MAX-S or FP 35's so I am getting used to Fox's and enjoying them.

I will try the 11/5 prop next. I have already been running 10/29 GMA Powermaster fuel.

Part of the problem could possibly be that my lines are more like 65'... On take off it's just kinda sluggish for the first 1/8 of the circle and the there is not much pull on the handle, almost like free flying, I still have control of the plane, but it has that certain "pucker factor" until the lines pull full tight.

I am also comparing the Twister to a Banshee. The Banshee is my first flapped plane and I learned quite alot from that plane (Yes, the hard way!) The Banshee has the MAX-S with a 10/6 and has no run issues (that my limited experience can tell)

I bet the 11/5 prop will do the trick...

Phil.... you might want to check wheel alignment. If the plane tends to turn in during take off this will cause low or no line tension and some "interesting moments". Don't ask how I know!

>I have a Sig Twister with a box stock Fox .35 and has a bit
>of this "I think I can" in the wing overs and some other
>moves, not bad, just a little noticeable. It's the take offs
>that are iffy! The plane weighs 36 oz. and I am using a
>10/6 Top Flight wood (paddle style) prop. I put on a 10/7
>and cured the take off problem but I have been told this is
>a no-no for the Fox, too much pitch.
> I already have my neddle set at a wet 2 cycle and have no
>4-2-4 so I can't really play much more with RPM's (can I?)
> Any suggestions would be helpful... I put a 3/4" tripler
>on the nose for looks and vibration dampning so changing the
>engine is not my prefered route... But I might do that at
>some point. I do have an L&J that has not been run-in, but I
>don't feel that I am that good of a flier to put that nice
>of an engine on a plane yet...
>
> Thank you!

Phil,

You might not be looking at all sides of your situation. What length lines are you flyin on..either eyelet to eyelet or center of airplane to the handle, be sure to let us know which? Also, how much does the airplane weigh?

By the way, are you flying off hard surface or grass? If grass, is it long and gnarly or a nice smooth surface.

Ted,

Work has kept me busy the last few days, I did not intend to ignore you (or anyone)...

I just measured my lines... 61' 5" and I believe that they are made from RSM .012 gauge strands. My Twister weighs in at 36 oz.
The nose on it is 6.5 inches from the L.E. to the end of the nose. The elevator is 13.5 inches from the center of hinge line of the flaps to the hinge line of the elevator.

I have not noticed any obvious tweaking of the landing gear. I have the thin Dave Brown 2" wheels (looks a little small for the plane)

I have flown the plane five times. Each time taking off from an asphalt play ground then stepping back after gaining control and flying entirely over grass.

My observation so far is that I probably have a touch too much wingtip weight (maybe?) The only mods I did are: I added wing tips much like a Banshee, instead of the blunt tips from the kit. I made the fuse to look a little more like a profile Smoothy from the canopy back, adding a balsa tripler(like a Smoothy) for vibration. I made the rudder to look kinda like a P-51 style. But I used only wood from the kit and tried to (in my own non-scientific way) maintain the same square inches as what is shown on the plans.

My cousin, Hawk Hawkins, gave me some L&J parts for the Fox and I I attemped to install them myself ... Larry now has the engine for inspection and re-assembly I should have it back sometime next week... I did no damage to the engine so Larry will put it back together for me no problem... Thank you Larry, I would have put that head on with a shim...Oops!

So there it is in a nut shell! I hope to fly it again next weekend...

Hey guys, a little update on the "I think I can" Twister...

I had the opportunity to get out to Whittier Narrows a couple weekends ago and had the pleasure of flying under the the watchful eyes of Warren Walker and a couple of other experienced flyers and heres what we discovered...

First, my lines are a little too long for a 36 oz Twister with a Fox .35. I did get the L&J from Larry Foster and followed the break in to the letter and the L&J, after five flights is just starting to sweeten up and run real smooth and consistent. No burps, no hesitations!

Second, I did not have good neutral between the flaps and elevator. I replaced the flap to elevator rod with a threaded clevis and solved that problem. It's OK for you "old timers" to laugh here! I know us "newbies" can be entertaining! Anyway, no more hunting.

Third, my line spacing at the handle was way too wide and I was massively over controlling. Took a Tom Morris handle and set my lines on the innermost holes and slowed things down (I had been using a EZ-Just) I really needed to add a couple more holes and move the lines even closer, I was still over controlling... Which brings me to this past weekend...

I still have a bit of a slow poke off the launch. I now believe that this could be avoided by turning the plane upwards and get the 2 cycle run just before launching. I will try that next. Once it is is the air it is fine.

The bad news is that with my controls so sensitive it is still a little squirly... To the point of being non-forgiving... Yea, you probably guessed it by now. She bit the ground pretty hard while inverted. Clipped the rudder just as I was trying to pull out of an outside loop, pancaked it down and busted the fuse and tail sections into 6 (Thats one more than five!!) pieces. But after being mad and not talking to myself for a couple days I took about 20 minutes and CYA'd it back together! A bit uglier than before but she still looks straight and true! My first concern was the L&J sittin' on the nose of this mess, but the Fox tucks away real nice on the Twister and it escaped without even a scratch. (I fly over grass, whew!)
I did the repairs on my Banshee this week too. I will be flying that until I get shorter lines... I am still determined to get into the contest mode this spring... I will be joining The Knights of the Round Circle this month... Yea, baby... It's all coming together, I love the smell of castor in the morning!

If this is a profile, you can add a shim (piece of plywood) under the flap horn and slow down the controls. This will slow down the flap, but will speed up the elevator unless you lower the elevator pushrod on the horn or lengthen the elevator horn. So, add a shim there, too, if needed. Just make sure you don't raise only the elevator horn and get more flap than elevator.

Now, get a fully adjustable handle. The Tom Morris handles are cheap (inexpensive) but for that kind of momey you do not get full adjustment capabilities. Buying a good handle or two is a good investment, and can not only make flying easier and more fun, but will sometimes even save an airplane.

I know "zachery vat you mean". To all you in Beginners or Intermediates, do as I say, don't do as I try to do. IF your plane will not do a wing over without real effort, STOP all maneuvers, fly it out (boring) land re-adjust the needle or prop or fuel. At least you can make a second or even your third attempt or take home the plane. It gets tiresome and embarassing picking up all those pieces for the trash can.

Len,

...and all the others here...

We have so much power available in the newer engines and setups that we may easily forget to "fly" the maneuvers. Most of the slowing on the RWO entry turn that I've seen in recent years has been from slamming the corner too hard.

It can be 'finessed' and still be tight. It takes quite a bit of flying to get the feel of it. Ted, on the old CS Modelnet threads, spoke often about preserving V. Without velocity, there's less pull, lift, and all of the other good things. Losing velocity by too sharp a control input will get the huff-n-puff staggering climb, exit, or shape.

I repeat, even with the strong engines available, a tad of finesse can keep an amazing amount of the speed of when approaching the turn, AND with a cleaner, quicker turn, it will also look better.

IMHO

Finesse? I'm a combat flyer. Hand me that .72.

Hi Len,
Interesting thread!! A good friend of mine was BRAVE enough to let me fly his new PAMPA piped plane. First time I ever flew a plane that got faster climbing up the wingover!!
My own experience is related to a Buccaneer 746P, beginning and winning with a ST46, changed to a TT Pro 46 (WOW), to a Magnum 53 (SUPER WOW).
Power DOES make a difference!! From having to "FLY THE PLANE" to "flying the pattern"!! Really feel most folks don't experiment with different prop combinations to utilize the full potential of their engine and plane.

For a quick/crude test, I have noticed that if the engine's static thrust is same/less than the weight, you got inadequate power. If the engine seems to produce more thrust than the model's weight, you should be a happy camper. This was noticed while holding the model vertical and setting the NV. The 47 oz Humongus/K&B .40 #4055 did not produce any more thrust than model weight, and was always trying to crash out of an OH8. The OS .46LA was like a transfusion, and would do OH8's until it ran out of gas. Once I did a T&G at the bottom of the 4th loop of the clover...in tall grass...and it popped back up out of the weeds and blasted straight over the top, nice and snug. Before anybody beats me to it, yep, the prop will make a difference with this test, flatter pitch getting the advantage, and of course a horizontal pull against a good pull scale would be much more accurate. But when you're out with a new airplane, it's not bad to do this quick test to see what you have to look forward to. Steve

I measure wingover time. Time UNDER 3s for large models close to full line length is OK. You will get good experience after few tests.

If you compare lap time and wingover time you also see what your engine does in figures.

>I measure wingover time. Time UNDER 3s for large models
>close to full line length is OK. You will get good
>experience after few tests.
>
>If you compare lap time and wingover time you also see what
>your engine does in figures.
>
>igor

This is a very good test, Igor. From the point where you start the wingover and then return to the starting point again it should be very close to your normal lap time. We need to allow for the fact that the plane is turning a corner and needs to accelerate back to speed--twice. The time should, thus, be slightly less then our normal lap time as a result (You mention 3 seconds for the tip over--half a lap).

Some set-ups can do this very quickly because the engine over accelerates in the climb. And some will dive from the top and not slow down. Both of these actions will tend to mess one up, so it sometimes becomes a delicate balance in fine tuning an engine to give us the proper characteristics we want. Adding or removing just a couple of thousandths in head shims is often all that is needed.

John D'Ottavia gained considerable fame (and fortune?) flying his notoriously heavy creations with Fox-35 power. Many have told me, including John himself, that he did 50' wingovers on 60' lines......indicating that he "knew he could". John's stuff flew even in the winds.

See Ya

Steve's test is interesting. I've done the same thing just fooling around with someone else's airplane whilst waiting for them to get the safety thong on. I flew many flights on a K&B 4011 with a 52 oz Humongous very solid everywhere. I have only observed the ABC K&B 40, but it is my impression that the dykes ring K&B 40's are more powerful engines. I am, as we speak,letting the dope dry on an airplane for a 4011. If you want to experience the 'I think I can', just overcompress your diesel a hair.

Hi Jim,
That K&B Dykes ring 40 was the power of choice for Dave Hemstrought, Stan Powell and Les McDonald for quite a while. They do have an OUTSTANDING run when set up properly. Different from the C/L ABC version that came out a few years ago.
Bill <><

Len, it look obvious that if a low quality power train slows down up and then accelerates down, you gets the same wingover time, but it is not exactly so. It is because if you once lose a time, then speeding up does not get it back. If you have to go 200m by speed 10m/s you need 20s. If you go first half by speed 9m/s and the second half by 11m/s, you need more than 20s. If you really want the same time, you must go second half 11.25m/s – means you must accelerate more than decelerate, and that is typically not happening – because of quadratic drag/speed dependency – it is easier to slow down than to accelerate.

I want to say that if you measure from 45 deg to 45 deg elevation what is very close to full half lap – or even better from begin of pitching to begin of pitching, when you suppress most accelerated segment at end of wingover (it speeds up really only on total end of wingover where the nose is pointed down), the wingover time really reflects slowing down and thus limits line tension overhead.

I personally fly slower lap times then my buddies here. I do typically 5.45, they do 5.3 – 5.2 and one prefers 5.0 but our wingovers are very similar 2.8-2.9. So I prefer to measure wingover time instead of lap time. And I ALWAYS found that reliable adjusted setups show little deceleration. So I tend to believe little instability is not bad. I remember that Brett wrote somewhere too much acceleration is not any good, I think that also dead constant speed (model to air) is also too much.

>Len, it look obvious that if a low quality power train slows
>down up and then accelerates down, you gets the same
>wingover time, but it is not exactly so. It is because if
>you once lose a time, then speeding up does not get it back.
>If you have to go 200m by speed 10m/s you need 20s. If you
>go first half by speed 9m/s and the second half by 11m/s,
>you need more than 20s. If you really want the same time,
>you must go second half 11.25m/s – means you must accelerate
>more than decelerate, and that is typically not happening –
>because of quadratic drag/speed dependency – it is easier to
>slow down than to accelerate.

I agree that you have to speed up considerably more to equal a slow down for the same distance. (A car driving 60 miles per hour takes an hour to drive 30 miles over and back. A car driving 30 miles per hour takes the same hour just to drive the first leg. It is a "little" hard to increase the speed in this instance to make the round trip in the same time as the first car.) I was just using this as a variable. But for our purposes (or yours) just timing the wingover will be fairly accurate.

>I want to say that if you measure from 45 deg to 45 deg
>elevation what is very close to full half lap – or even
>better from begin of pitching to begin of pitching, when you
>suppress most accelerated segment at end of wingover (it
>speeds up really only on total end of wingover where the
>nose is pointed down), the wingover time really reflects
>slowing down and thus limits line tension overhead.

One deviation from accuracy here. I realize that this is just a slip of your calcualator (or typing fingers), but half a lap would be from level to level in a wingover. Timing from 45 degrees would be a quarter lap. It would probably be more constant however (no loss of speed in the corners) but more difficult to judge the start and finish in order to time it accurately. Timing quarter laps is also difficult in level flight, even if just from timing errors from your thumb.
>
>I personally fly slower lap times then my buddies here. I do
>typically 5.45, they do 5.3 – 5.2 and one prefers 5.0 but
>our wingovers are very similar 2.8-2.9. So I prefer to
>measure wingover time instead of lap time. And I ALWAYS
>found that reliable adjusted setups show little
>deceleration. So I tend to believe little instability is not
>bad. I remember that Brett wrote somewhere too much
>acceleration is not any good, I think that also dead
>constant speed (model to air) is also too much.
>
>igor

Essentially you are timing maneuver speeds here, and that is where tension is at its most critical point. It is also what affects our own timing as we fly the pattern.

I noticed this in timing Paul with his 4-cycle set up. His lap speeds were noticeable faster (4.8-4.9 seconds) but his maneuver speeds were essentially similar to what Matt was flying with 5.3 second laps. You are going the other way in flying slower lap times but increasing speed in the maneuvers. You end up with the same consistency, however.

Another thing I like to do is time the square eight. This only works when you are timing someone who is relatively consistent in size and placement. Then a 12-13 second double square eight works out about right for us. Here the loss of speed in the corners and the acceleration back to speed both come into play.

I think from hearing both of them talk that Brett likes less acceleration out of the corners than Ted, for instance. This is always a matter of personal preference, but we like a little, but not too much. Too much is used in the sense of the plane speeding up in the maneuvers. (Here Matt uses the term "zippy".) Ideally, we would like the flying speed to remain the same, but with quick acceleration back to speed coming out of the corners. With Matt's pipe set up, that means a "burp" (increase) torwards the top of the loop and anything over 45 degrees, a "thud" (quick decrease) coming down, but, again, a quick "burp" (increase) at every corner of a square or triangle. But, as I have said, that is choice. Different flyers set up their planes in different ways.

>>> I realize that this is just a slip of your calcualator (or typing fingers), but half a lap would be from level to level in a wingover.<<<

No, I am just lazy to read carefully what I once wrote … I do not mean “elevation”, I mean “pitch”. Just if I see the model entered wingover and its nose already reached 1/8 of loop (45 deg). The same on end of wingover.

>>>I noticed this in timing Paul with his 4-cycle set up. His lap speeds were noticeable faster (4.8-4.9 seconds) but his maneuver speeds were essentially similar to what Matt was flying with 5.3 second laps.<<<

Yes, it is typical, also all 4C flyers here do it that way, they just enter figure with a speed, but 4C engine does not accelerate, so the result in figures is same speed.

>>>Another thing I like to do is time the square eight. This only works when you are timing someone who is relatively consistent in size and placement.<<<

I do not think it is very consistent. I think flyer learns reflexes to timing that the result is proper size, so if you change the speed to higher, the maneuver is slightly smaller. Well – typically if you take care you do it well, but wingover is wingover – you just MUST do it in proper dimensions.

>>>>I noticed this in timing Paul with his 4-cycle set up. His lap speeds were noticeable faster (4.8-4.9 seconds) but his maneuver speeds were essentially similar to what Matt was flying with 5.3 second laps.<<<
>
>Yes, it is typical, also all 4C flyers here do it that way,
>they just enter figure with a speed, but 4C engine does not
>accelerate, so the result in figures is same speed.

THANK YOU LEN AND IGOR!!!!

Somebody from Texas please read this statement.

Flying at about 5.1 is as slow as I like to go with my current setup (which is somewhat as you describe / ala PW). This type of run results in very slow maneuvers (I watched Doug fly my plane, so I am not arguing with him anymore--it is slow--get over it Moon Doggie)

4.8 or 4.9 much better in the wind. Keeping the speed up is very reassuring, and since the motor is set more on the back side, and with the higher RPM the speed is more constant and resists wind up. I really do not feel this is any different than a 2 stroke running in a flat 2 stroke (with a reasonably large prop). I think the OS VF setup was essentially the same TYPE of run, but the PW style smaller prop did not produce the same kind of vertical performance as say a Saito 72 with a 13" prop, so there was some slowing in the verticals (not bad, just different).

I like the timing of the flat speed faster pattern better. It is easier to get the "rhythm". Pattern flying is very much about getting the rhythm.

>
>>>>Another thing I like to do is time the square eight. This only works when you are timing someone who is relatively consistent in size and placement.<<<
>
>I do not think it is very consistent. I think flyer learns
>reflexes to timing that the result is proper size, so if you
>change the speed to higher, the maneuver is slightly
>smaller. Well – typically if you take care you do it well,
>but wingover is wingover – you just MUST do it in proper
>dimensions.

That was why I added the last statement. The person must be consistent in size and placement. If he is all over the place, makes 60 degree high sides, or goes to half a circle in width, his times are going to be different from someone who is placing his maneuvers relatively accurate. There can also be a difference in one who has shart corners and one who has rounded corners (less slow down). but I would expect yours to be relatively accurate and would be interested in timing you.

With Matt, he is reasonably consistent from flight to flight. And, if he starts to get too big (or tall) we adjust his pattern to get him back. Thus I can time the eights to see how his times are, too fast, too slow, to get an idea of how the maneuver speed is in comparison to the lap speeds he is running.

And it is all relative. As you say, if someone flies on timing only, then a faster run will result in larger patterns, not faster times. I do think most people adjust this, however, so the better flyers will still be quite consistent.