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Author Topic: Help with scale flying at the Nats  (Read 2943 times)

Offline Hemi Steve

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Help with scale flying at the Nats
« on: September 30, 2019, 07:41:52 PM »
All
Let me introduce myself.  I'm Steve and I live about 30 miles north of Detroit.  I started flying control line in the mid 50's and had a great time.  In 1959 I moved over to r/c and was i and out of the hobby as family and business needs varied.  I tended to prefer scale though I flew a lot of sport and a few pattern planes along the way. 90% of my models have been from kits, plans or original designs.  I've assembled a few arf's but get waaaay more enjoyment out of building.  over the past 5 years the LHS has sponsored a build competition whuch I have won every year...not braging but just saying I'm a good builder.  3 years ago I took up the handle again and am having as much or more fun as when I was a kid.  I'm a board member of the local r/c club and have found a bunch of old ukie flyers in the club.  I convinced the board to invest in a control line circle (grass).  With a bunch of volunteers we created a decent field from a plowed farm field. It's large enough to fly 70 ft lines.  Another board member and I have recruited some r/c fliers and are teaching them to fly control line (they have discovered it isn't as easy as it looks).

Anyway, I am on a mission to fly in the 2020 control line scale Nats.  I have a plane that I intend to use.  I have read and re-read the rules and am developing a list of questions for the experts here.  I don't want to get to Muncie only to find that my fronescon  doesn't comply with a rule. 

My plane is a 1/4 scale Brown B2 "Miss Los Angeles" golden age race plane. It's electric and weighs 10.5 lb ready to fly. She flies with an AXI 4130-16 motor on a 6s 5000mAh battery. All of the outlines, areas, rib spacing etc are correct The wing airfoil is not.  I have no data on what the original airfoil was.  Anyway, it flies beautifully (really pulls hard at the handle!!).  I've done the 5g pull test on everything which was kind of scary. It has flaps, rudder and throttle controlled by an r/c radio (all of my control line planes have an r/c throttle).

Here's a couple of pictures of her along with one of the full scale plane.

I plan to do an individual thread on each question.  I have learned on other forums that if you ask more than 1 question in a thread it doesn't work well.

More later

Steve


Offline Trostle

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Re: Help with scale flying at the Nats
« Reply #1 on: September 30, 2019, 08:39:52 PM »
So, what is your question?  You have a model that is a scaled down version of a full scale airplane.  That is certainly in compliance with the rules. You are well within the weight limits for the event.  Unless you are entering in Team Scale, you must be the builder of the model.  You did not mention which event you intended to enter - Sport Scale, Fun Scale, or Authentic Scale.  The different events have different documentation requirements.  The rules explain what documentation you need.  Whether it is important or not about the "non-scale" airfoil you mentioned depends on the event you enter.  Even then, how far the model's airfoil deviates from scale may or may not be important as the judges will have to detect whatever inaccuracy that may represent and judge accordingly.  The non-scale airfoil is definitely NOT a reason to not enter.  Look at the AMA scale rules if you have not already done so.  Then, if you still have questions, there are people here that will give good advice.

Keith

Offline Chris McMillin

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Re: Help with scale flying at the Nats
« Reply #2 on: October 05, 2019, 12:12:16 PM »
Good looking model.
Chris...

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #3 on: October 05, 2019, 06:11:48 PM »
Thanks Chris I'm glad you like it.  My Miss LA has an interesting history and it's amazing that she's still with us.


On Saturday August 1st 2015 after having won a local build competition I was preparing Miss Los Angeles and my 80 inch WWII Blohm and Voss BV-141 for my r/c clubs Scale and Warbirds event the next day when I had a LiPo fire in my garage. A 6s 5000 mah battery went off and burned through the charging table and ignited my racing slicks that were stored below the table. In the ensuing fire the wings for Miss Los Angeles were destroyed and the fuselage had serious heat and smoke damage. The BV-141 and several other planes were totally consumed.  It took until Thanksgiving of 2016 (16 months) before we could move back into our house.  During the Winter and Spring of 2017 I cleaned and restored the fuselage and built a new set of wings.  I flew her a number of times in the spring and Summer of 2017 in preparation for my clubs 2017 Scale and Warbirds meet.  In late July I had a really hard landing with her and broke the nose and missed the Scale and Warbirds event again.  I repaired the nose in the Fall of 2017 and did not fly her after that.  Fast forward to August 2019 and my decision to fly in the 2020 control line scale Nats.  Miss Los Angeles was a pretty nice flying r/c model and is quite good from a scale standpoint.  She's now converted from r/c to control line and I'm flying her to prepare us for the Nats. It's a really nice flying model.

Steve

Offline Chris McMillin

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Re: Help with scale flying at the Nats
« Reply #4 on: October 07, 2019, 09:55:09 PM »
Cool. Have you flown it control line yet?
Chris...

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #5 on: October 08, 2019, 09:45:45 AM »
Chris
Yes, I've flown it as control line.  It really flies nice.  I had previously done the calculations on what the centripetal force would be on a  70ft circle and the scale 230 mph.  it calculates out to a 34lb pull at the handle!  On the maiden flight I kept the speed down to a scale 200 mph cruise speed (50 mph on the model) so the pull was only 26 lb...still need a really strong grip on the handle.  I've flown about 10 laps at the higher speed to see what that was like.  It takes some getting used to for sure.  There is a picture of her in flight at the top of this thread.  I've got 3 flights on it and found that it pulls hard to the left on the take off roll due to the propeller "P" factor.  I have r/c control of the rudder and found it takes a lot of rudder to keep it out on the lines until the tail comes up.  I think I'm going to have a flying spinner cut for a clockwise rotation 16X8 prop.  I'll have the scale 20" prop and spinner on her for the static judging.  The weather is looking good for tomorrow so I'm going to try the flaps.  When I flew it r/c I didn't use the flaps so I don't know what she will do.  I'm starting with 10 degrees and a 2.5 sec deployment rate for the first experiment.  I expect it to be ok.

Steve

Steve

Offline Paul Smith

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Re: Help with scale flying at the Nats
« Reply #6 on: October 08, 2019, 10:40:24 AM »
Forget the scale speed.  What's the real airspeed?  On 70-foot lines that would be the time for six laps divided into 1800.

Also, in CL, line length measured from the grip of the handle to the thrust centerline of the model.
At a recent Scale Nats, any RC'er used lines that were 70' eye-to-eye and he was illegal on the long side.

So if the time is 24 seconds (4 seconds per lap) you are going 75 MPH true airspeed. 

While a 10-pound model is well within legal limits, it will pull really hard.  My advice is to throttle back most of the time and only use full throttle for takeoff and high flight.

You will have your best chance of winning a prize in Authentic or Team Scale. 
Paul Smith

Offline Paul Smith

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Re: Help with scale flying at the Nats
« Reply #7 on: October 08, 2019, 10:43:38 AM »
You mentioned it torquing-in on takeoff.  The answer is TIP WEIGHT.  Tip weight never sleeps. 
Move the battery to the outboard wing and don't bother with the left-handed rotation.
Paul Smith

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #8 on: October 08, 2019, 12:08:13 PM »
Paul, Thanks for the reply.

Tip weight counteracts moments about the thrust line (X-axis) from motor torque, flying wire weight, etc. while the propeller "P" factor produces a moment about the aircraft vertical  "Z" axis.  That "P" factor moment is produced by the greater propeller thrust on the right half of the propeller disk while the aircraft thrust line is angled up before the tail comes up during the initial takeoff roll.  It is the classic tail drager problem that full scale and model pilots need to deal with.  The"P" factor issue is made worse on Miss LA due to her very nose high attitude while the tail wheel is still on the ground. Clockwise propeller rotation causes the "P" factor moment to be to the right which is a favorable direction for Miss LA.

Also, the battery is a 6s-5000mAh pack that weighs 23 oz and measures about 6" x 2" x 2" It needs to be in the fuselage all the way forward to get my proper cg.  Of course I have installed tip weight to deal with the line weight and Miss LA flies wings level in horizontal flight.

Steve


Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #9 on: October 08, 2019, 01:03:56 PM »
Paul
Regarding speed and line length.

The model is flying on a 70 ft circle...the line length from the handle center to the longitudinal centerline of the model is 68 ft.  The actual flight path radius is about 2 ft longer than that due to the length of my arm.  My lap times are averaging 5.9 sec at what I am calling "scale" cruise speed.  Using your formula, her actual airspeed is 50.8 mph.  Miss LA is 1/4 scale so the  scaled up speed is 203 mph.  There is a lot of argument on the proper scale speed evaluation of models...that's the way I look at it. 

At the lap time of 5.9 sec, the throttle stick is a bit past half way on the transmitter.  The motor power  vs throttle stick position is very non linear so I don't know what the real power is.  I could put a telemetry module in to monitor the power but the truth is that as long as I have enough it doesn't really matter what it is.  At that 5.9 sec / lap power setting Miss LA flies comfortably at the high flight attitude.  The takeoff roll, lift off and climb is very realistic (in my opinion) at much less than full throttle.  It may be that I should reduce the pitch a bit but right now I'm ok with the prop I'm flying.  There is no advantage for me to reduce the cell count since I need that big battery for cg reasons.

I'm planning to enter her in Sport Scale in part because there are a few non scale details that are less obvious from 15 ft.  also, the cockpit is "semi-scale"  with a scale-ish instrument panel and only a pilot bust.  I'm preparing a 70" P-39Q with a proper full cockpit, retracts, detailed landing gear and wheel wells, rivet detail and realistic weathering that I plan to enter in authentic scale.

Steve

Online chuck snyder

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Re: Help with scale flying at the Nats
« Reply #10 on: October 08, 2019, 02:42:41 PM »
My Typhoon (15#) and OS 1.20 four stroke, 16" prop, will yaw into the circle when the tail comes up on the takeoff. Both main wheels still on the ground. Probably due to gyroscopic precession with some help from P-factor. Can't imagine that tip weight would help. Only takes a few feet to get back out on the lines.

Offline Chris McMillin

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Re: Help with scale flying at the Nats
« Reply #11 on: October 08, 2019, 03:59:37 PM »
I see where the lines are in that photo now. Nice.
Yes, I can see the destabilizing yaw set-up at low speed. Very authentic, I used to watch Bill Turner fly his replica. Slow application of power manages the P factor of the descending blade and allowing the airspeed to build before raising the tail which GP causes a left yaw too will help. Experience will show how well it can be handled. The prop rotation might be a key handling aid, worth a try. Launching down wind is also a problem with these forces, the left cross wind makes them yaw left too! But launching into the wind makes them lose line tension just when they are wanting to yaw left so the aid of the right cross wind is questionable! Probably starting out leaning towards it arm extended and then taking a step back pulling arm in would take up the line tension.

Love the Airacobra, my favorite. Wanting to build a Cobra II electric from a Red Box Top Flite kit basis. I have a lot of components.

Chris...

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #12 on: October 08, 2019, 05:27:57 PM »
Chuck
Precession is another factor for sure.  I have no interest in doing the calculation to see which effect dominates.  On first take off attempt on maiden flight I was really startled by the magnitude of the turn in.  On the 3rd attempt I figured out how much rudder it needed (a bunch)'  I did check the wheel tracking on a smooth surface.  She rolls straight.  As an r/c model I don't remember the left turn tendency being as pronounced.  I suspect that it's because I throttled up very fast and was tail up and off of the ground fast ( not very scale).  I want to keep things as simple as possible so if the clockwise prop deals with the problem, great.  I run clockwise props on all of my stunters and I like the way they seem to stay out on the lines on squares and overhead maneuvers.  Not a huge effect but for me I'll take anything that helps my flying

Chris
Mine started out as a Gold edition kit.  Did a lot of mods to go electric with retracts and flaps.  Motor cooling is a problem a as you might imagine with the very tight motor space.  I made a slotted spinner with scoops on the spinner backplate to help move air over the motor.  I also put a telemetry temperature sensor on the motor.  When the motor temperature gets too high my transmitter  commands the nose gear doors to open to improve the air flow. when the motor temp droppes the doors close  Works good..not very scale though.  For reference I'm using a Turnegy G-60 300kv running an 8s5000mAh battery and an APEe 16-10 prop.  She's warbird heavy at 12.75 lb.  I think this control line conversion will not require as much power in scale competition so the cooling issue should go away.  I'll know in the spring when I start flying it.  I'm going to run a bunch of simulations to see if I can optimize the motor, prop and battery for control line scale flying.  We'll see how that works out.

Steve


Offline Trostle

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Re: Help with scale flying at the Nats
« Reply #13 on: October 08, 2019, 07:49:18 PM »
Steve,

Two comments:

1.  "Scale Speed" is not a factor that is specifically judged in any of the CL Scale events.  However, the rules do stipulate various aspects of the model's flight.  Paragraph 9.2 stated that "... judging a scale model should be based on how well the model simulates the flight performance of the full-scale aircraft."  Paragraph 9.5 states that flight operations "will be judged and scored in relation to their scale-like flying ..."  Nowhere in these CL scale rules is the term "scale speed" mentioned.

2.  Gyroscopic precession manifests itself when there is a rotation around the lateral axis.  The faster the rotation, the greater effect of gyroscopic precession.  On a CL scale model, the only time that gyroscopic precession could be a problem is at take off if the tail is allowed to rise up to fast at the very beginning of the take off run (assuming a tail dragger).  With a clockwise turning prop (viewed from the cockpit and a tractor prop), the nose will have a tendency to turn left, (counter clockwise flying).  The adverse effects of gyroscopic precession can be alleviated by gradually applying power at the start of the take off roll which would generally be the preferred process for a realistic take off.  In other words, gyroscopic precession should not be a problem with your models unless you apply power too fast at the beginning of the take off.  Or, you could use "left handed" props with CCW engine/motor rotation.

Keith

Offline wwwarbird

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Re: Help with scale flying at the Nats
« Reply #14 on: October 08, 2019, 08:05:30 PM »

 GREAT looking models Steve, and welcome to the forum. Very refreshing to see another BUILDER out there! The weathering on the 'Cobra is very well done too. Good luck with your NATS mission, the competition is gonna have their hands full!  y1
Narrowly averting disaster since 1964! 

Wayne Willey
Albert Lea, MN U.S.A. IC C/L Aircraft Modeler, Ex AMA member

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #15 on: October 09, 2019, 07:05:41 AM »
Keith
You are correct about the gyroscopic precession. It can be a large or small effect depending on the angular velocity about the y or z axis.  there are other things that can also cause a turning moment.  The gyroscopic precession is more noticeable in PA flying especially in the "squares".

You are also correct that the rules are silent on the matter of "scale speed"  I have elected to fly at the scale speed for a couple of reasons.  First, it results in a manageable lap time and pull at the handle.  Second, I've watched many full scale aircraft flying at air shows where they are typically flying low and relatively close in.  In model airplane scale model flying it has been my observation that warbirds for example are flown too fast to look realistic.  I understand why and have been guilty of the practice.  So, since realism is very important in our competition I have asked my flying buddies if Miss LA looks right at my "scale" flight speed.  They think so. So that's where I am at the moment There has been much discussion in the r/c forums on this subject and I've not seen a consensus.

Wayne
I appreciate the complement on the weathering.  I have studied the subject and have found that most modelers tend to waaay over do the weathering of warbirds.  The degree of weathering depends on many factors including the specific airplane, the theater of operation, the season and weather we're doing a German or U.S. plane. For example, I did a Ju 87G Kanonenvogel.  I wanted to do a winter camouflage that is, in my opinion, very difficult to do properly.  Germany did not expect the war on the eastern front to last long.  When winter came the Luftwaffe standard camouflage didn't work on a snowy landscape.  Their remedy was to paint the topsides with whitewash which mas not intended to permanent.  As time wore on, the whitewash wore and washed away leaving a streaked and mottled dirty white with the underlying splinter camouflage showing through.  Here is my interpretation of Hans Rudel's Ju87G Kanonenvogel as it would have looked in the spring of 1944.

Steve

Offline wwwarbird

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Re: Help with scale flying at the Nats
« Reply #16 on: October 09, 2019, 09:08:19 PM »

Wayne
I appreciate the complement on the weathering.  I have studied the subject and have found that most modelers tend to waaay over do the weathering of warbirds.  The degree of weathering depends on many factors including the specific airplane, the theater of operation, the season and weather we're doing a German or U.S. plane. For example, I did a Ju 87G Kanonenvogel.  I wanted to do a winter camouflage that is, in my opinion, very difficult to do properly.  Germany did not expect the war on the eastern front to last long.  When winter came the Luftwaffe standard camouflage didn't work on a snowy landscape.  Their remedy was to paint the topsides with whitewash which mas not intended to permanent.  As time wore on, the whitewash wore and washed away leaving a streaked and mottled dirty white with the underlying splinter camouflage showing through.  Here is my interpretation of Hans Rudel's Ju87G Kanonenvogel as it would have looked in the spring of 1944.

Steve

 Wow, excellent job on the Stuka too, looks spot on. You're right on with the ideas and various (accurate) levels of weathering, I got real familiar with doing it back in my hardcore plastic modeling days. You're putting out some admirable work Hemi, we need more photos!  y1
Narrowly averting disaster since 1964! 

Wayne Willey
Albert Lea, MN U.S.A. IC C/L Aircraft Modeler, Ex AMA member

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #17 on: October 10, 2019, 05:31:58 AM »
One thing I've learned is that many plastic model builders go way way beyond control line or r/c modelers when it comes to detailing and weathering their models.  Making it even more amazing is the scale that they are working in.  I spend a lot of time reading their stuff on line to try to find techniques that can scale up to our flying models.

Having said that, Any time I start thinking I'm doing good on my models I watch this video       I know I'll never get to that level but it does inspire me to do better on whatever I'm working on.

Anyway, I'm glad you like the Stuka.

Steve

Offline wwwarbird

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Re: Help with scale flying at the Nats
« Reply #18 on: October 10, 2019, 08:28:55 PM »

Having said that, Any time I start thinking I'm doing good on my models I watch this video       I know I'll never get to that level but it does inspire me to do better on whatever I'm working on.


 I don't recall ever seeing a model that put a lump in my throat, that one did. OMG!!!  :o
Narrowly averting disaster since 1964! 

Wayne Willey
Albert Lea, MN U.S.A. IC C/L Aircraft Modeler, Ex AMA member

Offline katana

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Re: Help with scale flying at the Nats
« Reply #19 on: October 11, 2019, 02:49:54 AM »
I have to agree - that Russian models detail is waaaay beyond ridiculous - having the pilots stick movements coordinated with flight surfaces that you wouldn't appreciate in static or flight judging is outstanding, and why - because he can, I guess?

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #20 on: October 11, 2019, 06:24:58 AM »
I seem to recall reading that the cost to do that model was somewhere in the area of $250K.  As you study the details that number doesn't surprise me.  The thing that does surprise me is that the model was actually flown and further, it appears to fly nice. I can't imagine what the wing loading must be.

Steve

Offline Paul Smith

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Re: Help with scale flying at the Nats
« Reply #21 on: October 12, 2019, 07:48:07 AM »
The over-the-top professionalism of the Soviet F4B model dominated and KILLED the event.

It very quickly got to the point where they couldn't get four other nations to send teams to take their beating every two years.  Yes they were legal, but they still killed the event.

With the AMA system of 100 static points and 100 flying points the outcome of a contest is not so predetermined.
Generally, it doesn't take super-human effort to get close to 100 static points, so that level of detail doesn't score much.

The old AMA and final FAI rules didn't require much more than takeoff, ten laps, and landing.  So those lead sleds didn't need to fly very well.  Modern rules demand that models fly to win.
« Last Edit: October 25, 2019, 12:33:25 PM by Paul Smith »
Paul Smith

Offline Chris McMillin

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Re: Help with scale flying at the Nats
« Reply #22 on: October 20, 2019, 04:58:51 PM »
Bullshit.
The sanctioning bodies and their personel were responsible for the end of the control line Scale event.
Not people taking the time to build really fantastic Scale models.
Chris...

Online Will Hinton

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Re: Help with scale flying at the Nats
« Reply #23 on: October 25, 2019, 10:13:43 AM »
Bullshit.
The sanctioning bodies and their personel were responsible for the end of the control line Scale event.
Not people taking the time to build really fantastic Scale models.
Chris...
Very well said, Chris, very well said.
Thing is, we're seeing a nice resurgence now with some really nice models in each class.  I've judged the nats 6 out of the last 7 years and it has been a really great pleasure.  Haven't seen any models chase anyone away yet!
John 5:24   www.fcmodelers.com

Offline Paul Smith

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Re: Help with scale flying at the Nats
« Reply #24 on: October 25, 2019, 12:36:22 PM »
Bullshit.
The sanctioning bodies and their personel were responsible for the end of the control line Scale event.
Not people taking the time to build really fantastic Scale models.
Chris...

Sure, three men (and their shops) built three really great airplanes.  But when that was all the entries, there was no further need for the biannual award ceremony.
Paul Smith

Online Will Hinton

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Re: Help with scale flying at the Nats
« Reply #25 on: October 26, 2019, 06:49:48 PM »
I guess I'm missing something here.  Just WHEN was the c/l sclae event ruined and no longer exists?  What about the last several years of the nats, the several other scale events and the like?  I must have wasted my days at the nats looking at all those c/l scale airplanes that don't exist.  You know, the ones built in people's shops.  Hmmmmmm.. S?P
John 5:24   www.fcmodelers.com

Offline Chris McMillin

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Re: Help with scale flying at the Nats
« Reply #26 on: October 26, 2019, 10:40:51 PM »
Paul is trying to float his Soviet professionals ruined FAI CL Scale theory again.
Chris...

Offline Trostle

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Re: Help with scale flying at the Nats
« Reply #27 on: October 27, 2019, 01:55:27 AM »
I think one of the spikes in the coffin for the FAI CL scale program goes back around 1997 or 98 when the Scale World Championships (which up to that time included CL and RC) were held in Canada.  Only four countries signed up to send CL teams to that contest.  According to FAI rules, it takes 5 countries to sign up/attend to be classified as a World Championship competition, so the CL portion was canceled.  The RC event was held.  I do not know if the world championships ever had CL scale after that.  It was not long after that when the FAI Scale event vanished from the FAI rule book.

Yes, the Russians had some incredibly good airplanes at previous CL Scale World Championships, but I do no think that stopped other countries from participating.  It is just that not many countries wanted to send a CL team to Canada that year.

Keith

Online chuck snyder

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Re: Help with scale flying at the Nats
« Reply #28 on: October 27, 2019, 05:45:31 AM »
Keith,
C/L, F4B, was run at the world Championships through 2010. I suspect that the FAI rules still exist and are being used in Europe. But I don't have any reason to take the time to check that out.
Chuck

Offline Fred Cronenwett

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Re: Help with scale flying at the Nats
« Reply #29 on: November 27, 2019, 08:03:27 AM »
I saw that you had a Lipo fire. I always have the batteries in a case when they are not on the model being flown. I charge in a fire proof safe (locked shut) and store the batteries in a case that is latched. Some store batteries in a ammo can. I transport the batteries to the flying site in a small ammo can. Unless the batteries are being used always have them in a container that is latched shut.

Scale speed - don't try to match the scale speed the 5.9 sec lap is too fast, it won't look right for the realism during the flight. The true scale speed is an equation I would have to look up. You can calculate the scale HP and weight of the model. But if you did the math would tell you to be heavier that what will actually fly and the scale HP is not enough to fly the model. The only thing I scale is the dimensions and fly the model so that it looks right. My Piper cub will do a 12 sec lap and looks about right, they are slow. The B-29 does about 9 or 10 sec lap. The Spitfire can do a 7 sec lap. The CL stunt pilot might shoot for a 5.5 sec lap but in my book that is too fast for CL scale flying.

Also remember that line tension is affected Velocity squared. also put in an adjustable line guide, move it forward until you have enough line tension to fly but not so much as to be a problem.

I have a 14 lb B-29 bomber that has 34 lbs or more of line tension and fly on 65 foot lines at most. So I know what you mean by the large line tension.

Come on out to the Nats in 2020, it's a good time to be sure

Fred Cronenwett
AMA CLSCALE7 - CL Scale
Model Aviation CL Scale columnist

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #30 on: November 27, 2019, 12:05:57 PM »
Thanks for the reply Fred
I learned a very valuable lesson when I had the fire.  Since then I keep my batteries in a closed steel container.  I transport them in an ammo can with the lid seal removed and gypsum board separators and charge them in a steel container or outside away from anything that I care about.  When I had the fire the damage from the lipo fire itself would not have been too bad but the battery went off on a plastic table and burned through the top.  It ignited my racing tires under the table and the entire house from antic to basement was filled with very nasty tire smoke.  Making the problem worse was the fact that it took 20 minutes for the fire department to get here.  In the end the total damage was right at $500k.  99% was from the tire smoke.

Regarding the "scale speed" issue, I've read a lot of articles and there are a number of mathematical ways some guys use to determine the "right" scale speed.  None of the methods seem to work for all sizes and scale ratios.  I think it all comes down to the observers (judges) perspective and expectations about what looks right.  I have flown Miss LA in the 6.5 to 7 sec lap (70ft radius) time. Of course the slower speed reduces the pull at the handle which is nice.  I do have adjustable leadouts but I have not made a change there....thanks for the tip.  She flies a little tail low at that speed but I compensate with about a degree of flap and aileron droop to add a bit of negative pitching moment. 

So you like the look of the Spitfire at 7 sec laps?  What line length do you use and how big is the model?

Thanks

Steve

Offline Fred Cronenwett

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Re: Help with scale flying at the Nats
« Reply #31 on: November 27, 2019, 10:39:04 PM »
The spitfire is a hot rod with a .35 motor and a 38" span. I tend to fly at half power and rarely fly it that fast, mostly just cruise at the slow speeds (maybe 8 or 9 sec laps). I have big and small models the biggest being the B-29. scale speed is all about flying it to match the type of model It copied. I can fly the cub with a 13 sec lap but the spitfire would over run it mostly because I have a .35 in the nose. the lines are about 57 feet.

I don't have any models with 70 foot lines, I try to keep all lines for the larger models between 58 and 65 feet long

Where do you fly, if you are close to St Louis we are having a fun fly on June 27th, it would be good chance to test and tune before the Nats.
Fred Cronenwett
AMA CLSCALE7 - CL Scale
Model Aviation CL Scale columnist

Offline Hemi Steve

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Re: Help with scale flying at the Nats
« Reply #32 on: November 28, 2019, 06:41:10 AM »
Fred
I'm about 30 miles north of Detroit.  Not exactly a hotbed of control line scale flying. 

I'm hopeful that I will get some constructive feedback at the Nats so I can improve in each subsequent flight. 

How do you decide on line lengths for your different models?

Steve

Offline Fred Cronenwett

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Re: Help with scale flying at the Nats
« Reply #33 on: November 29, 2019, 08:22:09 PM »
For the line lengths mostly comes from experience and other models I have flown. but here are general rules that have worked for me based upon how much power the model has and the weight.

really small models that weigh less than 2 lbs (but not 1/2a) - 40-45 feet. These are so prone to get knocked around by the wind so I tend to avoid this size of model.

smaller 15 to .35 powered models (like the spitfire) - 55-60 feet. these are typically 2 to 3.5 lbs in weight

.46 powered models - I start at 60 feet (7 lbs)

the big models - .60 and larger, 10 or more lbs - 60-65 feet

Also here at Buder park we have a 75 foot radius paved circle so anything longer than 70 feet is risking running the wheels into the grass if I am not centered so I limit myself to 65 feet even for the largest models and just throttle back.

also you can adjust the line guide to increase or reduce the line tension.

I also have one handle / set of lines per model. I adjust the neutral elevator once and never have to touch it again unless I redo the leadouts or change something else in the control system. This means I have lots of lines, they are all labeled but I never have to adjust the neutral elevator at the flying site. this way I know how the model flies every time I take it out and don't have to make adjustments (I don't recommend doing this at a contest). On contest day the model works the way it did when you last flew it at home. I leave one connector on the airplane leadout and the other commector on the lines that way I don't install the lines backwards. I do check that up is up every time I fly.

Fred
Fred Cronenwett
AMA CLSCALE7 - CL Scale
Model Aviation CL Scale columnist


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