Strega ARF Overview ViDEO)))))

[Gerald Arana]

Shug,

It was mentioned to use "milled" fiber to glue the wing/pan on. This is what I did with mine. Worked "schweet!" But he didn't tell you how to do it so here's how I did it: Mix the epoxy (both parts) with the milled fiber to a consistency of Vaseline and stick/spread it where you want it. Saves having to carve/match balsa and is hundreds of times stronger (than needed as mentioned in the other post). You can mush it around to any shape you want.

One caution: put tape next to the joint so you don't wipe epoxy onto the monocoat. Its a bitch to remove. (yes, I know; denatured alcohol works. Use sparingly)

I used an Enya 7033 and it had plenty of power but watch on hot days. Why? Because mine started without a battery hooked up while priming it. Good news is I didn't have my finger in the prop. It just scared the 'L out of me! Remember that when you are priming yours this summer.

Good luck and keep those great video's coming! Jerry

[John Christensen]

Shug

I have some milled fiberglass if you need some.

[Chris McMillin]

  The ARF isn't much like Kent's model, particularly in the details. The LE radius, for example, on Kent's model, cannot be replicated with the ARF, or if you tried to, you would end up sanding all the way through the LE wood on the ARF. I made a point to check that shortly after the ARF-Off, at the Team Trials, where Kent flew it. I would guess the LE radius on Kent's airplane is something like 1/2" or more and the "departure angle" where it transitions from the radius to the rest of the airfoil is much steeper.

  The ARF isn't all that close to the original Patternmaster, either, at least not the faithful reproductions like Mike Roger's silver and black one, which was clearly at the head of the class of the ST60 models that I saw. And his was *in proper trim* which put it way ahead of most of them at the time. It's much closer to the Cardinal series that made significant deviations from the original.

    That doesn't really matter too much, the ARF can be made to fly about as well as any of the attempted Patternmaster clones. The original was designed to take advantage of, and minimize the shortcomings of, the ST60, so it really needs that kind of power. It's never going to be an Impact, but it predated the Impact by at least 10 years. And time marches on.

   The deviations on the ARF are exactly what you would need to do to make it manufacturable. There aren't a bunch of people with sanding blocks and templates spending an hour or two per wing getting it exactly the right shape and symmetrical. That alone might double the cost and manufacturing time. But it's a simple matter to glue some sheets to a square hardwood strip. A few hours spent at the user end trying to fix a few less-than-ideal features can be weighed against the fact that you *didn't spend 6 months building the parts in the first place*. It's kind of miraculous that you can buy it, retail, for the price they ask, just think of how long it takes and multiply that by the minimum wage.


    Brett

Brett,
It's makes one wonder why they don't manufacture the wing with a wraparound sheeting technique, that way the wing leading edge would be as rounded as beneficial and there would be no carving.
Shug,
The ARF in your pictures look pretty good, decent enough to glue together properly and have a decent ship. If that bellcrank and leadout system came stock that's a huge improvement.
I changed from a "Windy" handle to a hard point "Ted" handle on my last big pipe ship and it made a big difference in the corner ease. If that model comes with big tall horns great, if not you might want to search some out. That helps a lot with the control loads Brett was talkin' about.
Chris...

[Brett Buck]

It's makes one wonder why they don't manufacture the wing with a wraparound sheeting technique, that way the wing leading edge would be as rounded as beneficial and there would be no carving.

  Two possible reasons -
It doesn't show that on the plans. I haven't ever seen the LJ plans, or the Strega plans, but at least the set of Patternmaster plans I saw shows it constructed exactly as they do it.  Of course if you build it yourself, you *know* to round it off and it takes about 15 minutes in a 6-month process. In the case of the ARF, it might still take 15 minutes, but on a 30-minute assembly schedule, and it takes some training. To produce the entire model to sell at a retail price of $159, or $189 or whatever it is, I would guess you have to get the labor cost into the $25 range or less -  to make *all* the parts.

They wouldn't want to change it anyway.  Those  involved consider the design to be some sort of sacred holy magical creation, so any change, no matter how slight, might make the magic escape. You can read above, I still think that people are irritated that anybody is changing anything, since it was right to begin with.

too time-consuming - have to glue several sheets together, edge to edge, trim to shape, then mold them around a form, probably wet, it to go around without splitting, then put the rest of the wing in a new jig, glue around all the ribs, then apply the molded part. With flat sheets, you can leave it in the jig, glue the sheet to the LE wood, easy to line up on the sharp edge run some glue around each rib, hold it down until it dries/cures/cools off, then flip the entire thing over in the jig and repeat.

  I think not rounding it off is a very reasonable production decision. You are already getting an entire airplane with 90% of the construction done for around $150-200 or something, doing a 8-10 hours of work to get the last 10% doesn't seem too onerous. I'm not going to build anyone 90% of an airplane for that kind of money!

   Brett

[Randy Cuberly]

Jst a mention here.
The Pattern Master Plans I have show a triple cored Foam wing.  This is the LJ Pattern Master not the Strega.  I suspect that Windy changed things around a bit by the time He arrived at the Strega.

Given the proper production tooling I would think that a balsa sheeted foam wing could be very cost effective as opposed to a built up structure.  It would of course be dependent on the volume of production to support the tooling costs.

Modern foam cutters can cut a wing like that in a matter of minutes!

Randy Cuberly

[Brett Buck]

Modern foam cutters can cut a wing like that in a matter of minutes!

  How long does it take to edge-glue balsa sheets, spread the glue, jig it up, hollow it out, etc?  You might be right but I would be surprised.

    Brett

[proparc]

  How long does it take to edge-glue balsa sheets, spread the glue, jig it up, hollow it out, etc?  You might be right but I would be surprised.

    Brett

As someone that does both built up structures and cutting my own foam wings, in terms of time, it is a wash. The both take quite a bit of time to get done right. People forget that you have to make the templates for the foam wing cutter and that takes a lot of traditional skill to get right.
The great thing about a well done foam wing is that, once you build it, it stays true until you crash it,(then it is not true anymore!!)

[Randy Cuberly]

As someone that does both built up structures and cutting my own foam wings, in terms of time, it is a wash. The both take quite a bit of time to get done right. People forget that you have to make the templates for the foam wing cutter and that takes a lot of traditional skill to get right.
The great thing about a well done foam wing is that, once you build it, it stays true until you crash it,(then it is not true anymore!!)

My comments were aimed at a situation where production tooling is available to greatly lessen the time required for each of those steps.  Individual templates do not have to be made for each wing cut they exist and a re simply used.

Production foam cutters are computer driven and do not depend on templates.

I also have built many wings both ways and agree that it's a wash as far as the labor is concerned.  There is an increased time factor involved in a sheeted foam wing for the sheeting adhesive to cure under pressure, but that is not paid labor time.

The tooling required would be the biggest detriment to an automated process and would require a larger outlay of cash than CL Stunt wings would probably support.  If R/C wings were made by the same process then the cost per item of the tooling would decrease tremendously.  Unfortunately the R/C guys are not as weight consious as we are and don't care if thier wings are not very light.

Brett,

As for edge glueing sheets, it really doesn't take all that long.  A Mama San could probably do a panel in 4 to 5 minutes and automation could greatly reduce that.

Please don't get the idea that I believe this is a practical suggestion.  As I said the quantity simply isn't there by a factor most likely in tens...or even hundreds to make it a practical process.

Even given much greater quantities the cost of an ARF would likely double, but the quality would also increase tremendously, and it would likely be worth the extra outlay.

Randy Cuberly

[Shug Emery]

You got very good advices above and I hope I will add a few more that will help you built an even better Strega that will fly slower and smoother

You did the right thing buying the Enya 61CX! Is that the Rear or Side Exhaust?   I have quite a bit experience using this engine and I believe I can give you some good advice about it. I have used the Enya 61CX S Pro Side exhaust with muffler to power my Strega that I used during the 2010 season here in Brazil. The combo flew very competitively and it help me to advance against my competitors.

Mine is a side exhaust...just got it yesterday. It will go on for sure.

If you run the engine like I did it will develop tremendous amount of Torque to pull your Strega like it is made out of feathers!

First let me tell you about 2 new tricks that are very very important. The Strega airfoil ain't the best so you need to do 3 things to help the wing do its job:

The 1st one you have already done, rounding the L.E. as much as possible.

The 2nd most important thing is to change the flaps. The flaps that comes with the kit are too thin and weak, twists very easily and that is bad.  So If you want the Strega to fly well, discard these flaps and make new ones in the same size, but make them strong using the thickest sheet of balsa that will fit with the wing. Do not taper the flap and also do not round the T.E. Very very important not to round the Trailing edge, leave it square! The square T.E. has proven to me to work much better, if you want to know why and the Theory behind this I will be glad to explain it to you. Most of the Top Flyers in the World use square T.E. for good reasons.  When I built my Strega I did these things plus I reinforce the flap with fiber glass and epoxy. This is the easiest way to make a strong flap, but not the best. There are better ways to make flaps, like using a torque tube of aluminum or a specialized carbon fiber tube with the fibers rolled at 45o. The important thing is making the flaps very strong so they will not twist easily.
Great suggestion. When you say taper...do you mean make the flap the same span all the way in length. The ones that come with it are thinner at wingtip, wider toward fuse.

The 3rd thing is to use VGs (Vortex Generators) or a zig zag tape like Igor Burger uses on his wings.
I need to read up on these more. This may be something for later. I am not that advanced.

If you do all these things your Strega will be much easier to fly. You will be able to fly slower and still be able to make beautiful corners.
A beautiful corner...sounds poetic. And not easy!

The Strega is huge and heavy but you got the right engine for it! The Super Ultra Mega Power Mighty Enya 61CX 
Whooooo Buddy))))))
The Enya 61CX comes stock with a small venturi, so you may need to open it up a bit  to develop all the power it can. It will depend on the climate where you fly, the fuel, the prop and the run style you prefer, I mean 2-2-2, 4-2-4 or 4-4-4.
I'll keep an eye and ear out for that.

The Enya 61CX is a different beast from all other engines and I have seen people complaining about the engine performance because they did not run as it was design for.  The Enya 61CX with or without pipe will run very strong if you use low pitch prop and launch above 10000 rpms. If you try to use a high pitch prop like a 13x5 or 6 it will work but it will not run as strong and speed control will not be as good.
I have many props to try from 12s to 13s at 4 to 5 pitch.

I will be glad to work with you in detail so you have a plane that will fly slow, with superb speed control and mighty in strong winds.
We get some good wind and I kinda like flying in it.....either fly in it or go home. Thankee for your help on this. I appreciate all the intel.

Here is my Strega ARC with the Enya 61CX S Pro with muffler and Bolly 13x4.5 3 Blade prop. This was early 2010 and did not have that many flights with it yet.  I started to fly the full pattern in 2008  and this was the year I left the bottom of the list and move to higher then the middle of the pack. I loved when it was very windy,  clearly I had the power advantage against the others.
That was fun to watch...and listen to the video. Like your flying site.


Also check your horns for strength.  I broke one easily like it was a toothpick! Also check the Pushrod endings, if they bend easy DO NOT USE THEM! I crashed my Strega one year later because the pushrod ending failed.  Get Titanium ones from Tom Morris
It had no horns with the kit but I have some large ones and plan to double them up as a many fliers in our club do.


Martin

[Shug Emery]

The Enya 61CX runs very smooth so I removed all the plywood from the nose. That is only needed for engines like the ST 60 that shakes a lot.

Martin

These are helpful to see. Especially the flap thickness.

[Shug Emery]

Shug,

It was mentioned to use "milled" fiber to glue the wing/pan on. This is what I did with mine. Worked "schweet!" But he didn't tell you how to do it so here's how I did it: Mix the epoxy (both parts) with the milled fiber to a consistency of Vaseline and stick/spread it where you want it. Saves having to carve/match balsa and is hundreds of times stronger (than needed as mentioned in the other post). You can mush it around to any shape you want.

One caution: put tape next to the joint so you don't wipe epoxy onto the monocoat. Its a bitch to remove. (yes, I know; denatured alcohol works. Use sparingly)

I used an Enya 7033 and it had plenty of power but watch on hot days. Why? Because mine started without a battery hooked up while priming it. Good news is I didn't have my finger in the prop. It just scared the 'L out of me! Remember that when you are priming yours this summer.

Good luck and keep those great video's coming! Jerry

I am going to look into this option too. They should be called ARFs+MODs 

Wow...engine started with no battery.....thrilling, daunting and dangerous)))))
Thanks for your suggestions.

Shug

I have some milled fiberglass if you need some.

Thanks a ton John. I'll take you up on that. Can you bring it to the next meeting?

[Shug Emery]

Brett,
It's makes one wonder why they don't manufacture the wing with a wraparound sheeting technique, that way the wing leading edge would be as rounded as beneficial and there would be no carving.
Shug,
The ARF in your pictures look pretty good, decent enough to glue together properly and have a decent ship. If that bellcrank and leadout system came stock that's a huge improvement.
I changed from a "Windy" handle to a hard point "Ted" handle on my last big pipe ship and it made a big difference in the corner ease. If that model comes with big tall horns great, if not you might want to search some out. That helps a lot with the control loads Brett was talkin' about.
Chris...

I am getting big horns. The kit did not have any horns with it. Thankee.

[Brett Buck]

The Enya 61CX runs very smooth so I removed all the plywood from the nose. That is only needed for engines like the ST 60 that shakes a lot.

   I think that this is a BIG mistake. I know it is debated endlessly, but I think it makes a difference even on smooth engines like the 40VF. What happens is it will generally work fine, but still have some session-to-session variation that can never be entirely removed.

   It may well be overdone on the Strega and similar to handle the ST60 or even worse, super-shakers like the Saito 72 and 82, but I wouldn't throw the baby entirely out with the bathwater. "Not coming apart" and "engine seem to run OK" is a far cry from "ideal".

  There's also a legitimate debate over whether the heavy plywood thicknesses are the best way to go about it, compared to other solutions, like larger areas of 1/64 ply, balsa/carbon sandwiches, etc. I do know that "1/8"/3mm light ply is very much weaker and less stiff than an equivalent mass of hard ply, even if it is much thinner.  You should have seen the stock Skyray 35 wing after the first minor crash, being both heavy, and weak, it just disintegrated, and every piece in it was broken.

    In this case, it comes the way it comes, and unless you are planning on building a new fuselage, not much you can do about it.

     Brett

[Chris McMillin]

You're giving out a lot of good, solid information here and there, Brett. I wonder how many really heed it, and know how "real" it is?
Chris...

[Jared Hays]

ST 60's shake...all 7 of ours seem as smooth as a babies bottom.

[Randy Cuberly]

ST 60's shake...all 7 of ours seem as smooth as a babies bottom.

Really?  I guess all the rest of us that have used a lot of them are just imagining all the vibtation!

You've got to be kidding...I'd hate to see the baby you're referring to!   

Randy Cuberly

[Martin Quartim]

Hi Shug,

Side exhaust engine got it! Does your engine has a red label marked 61CXR on the side? If it does it is a Ring one, if not its an ABN one, so we know exactly what we are dealing with.

I watched your video , you are sooo funny   ,  and I could see the flap and elevator horns are there, they worked fine for me. Also I saw the same pushrod threded endings that failed in mine. So I strongly suggest you not to use these endings, get Titanium ones from Tom Morris.

Sorry If I write to much  , but I just want to cover some things in detail to prevent you from crashing. These are critical things you should be careful:
 
1- The pushrod endings are glue into the carbon fiber tube and if not done properly they will fail.  So this is what I suggest you to do: sand just a bit the insides of the carbon fiber tube and clean thoroughly with alcohol, then scratch the pushrod ending and clean thoroughly with alcohol. Wait it dry and glue it with JB Weld, do not use epoxy for this job. Then wrap over the carbon fiber tube with dental floss and finish with CA to prevent the fibers to delaminate at the tip.

2- Replace the lead out lines and make safe ones with wrapped copper wire. I have seen a few failing after 1, 2....4 years of use.

Make the new flaps the same size and shape, just thicker and without sanding to tapper it front to back.

The APC 13x4 works good with this Engine/Model, but it did windup in windy conditions more then I like, especially when I set the engine in 4-2-4. Wood props hardly have their nominal pitch true, specially Zinger ones. As far as wood props the best I have tried so far are from JXF/Xoar. When I tried the 3 Blade C.F 13x4.5 and re-pitched the tip with less pitch it worked so much better.

Do not waste your time trying 12" props, stick with 13" ones. I suggest these props, APC 13x4,  Xoar 13x4 and 13x4~4.5 3B Carbon Fiber Props.  Use  .018 x 69'  lines or whatever is the AMA legal  maximum line length. We want this Strega going fast as a buttered rat when wacked hard but with long lines so for you it will be in slow motion and to reduce the line pull ... Whooooo Buddy))))))

The Enya 61CX in the beginning will not run that strong,  be patient,  it will improve and get stronger and stronger as you use it. Check the muffler, if it has a baffle in the middle remove it.

Once you start flying you can make a video and I will be glad to see how you are doing and we can work together to make little changes to fine tune the engine and improve the performance. There are several things we can change to make it better. I helped a friend far away like this and we had fun working together. It is very rewarding to me to help some one and see he getting better and better results.

I have flown quite a few models, but the Strega with these modifications was the easiest model to make corners, you will see what I mean when you fly it.

Well this is it for now, there is a few more tricks and details but will do them when the time is right.  ahhhh just remembered  I also suggest making the rudder 1.25"  taller and 1.25" wider or thereabouts!

Cheers!

Martin

[Martin Quartim]

These are helpful to see. Especially the flap thickness.

Just to make sure, I said I removed "all" the plywood from the nose, but not the side doubler plywood.

Martin

[Brett Buck]

1- The pushrod endings are glue into the carbon fiber tube and if not done properly they will fail.  So this is what I suggest you to do: sand just a bit the insides of the carbon fiber tube and clean thoroughly with alcohol, then scratch the pushrod ending and clean thoroughly with alcohol. Wait it dry and glue it with JB Weld, do not use epoxy for this job. Then wrap over the carbon fiber tube with dental floss and finish with CA to prevent the fibers to delaminate at the tip.

    That's a good point. The stock controls are actually pretty good by ARF standards, but gluing the wire into the pushrod is a potential pitfall. The problem is as you say, the shiny inside surface of the tube. Even on regular airplanes, I roll up a bit of 120 grit sandpaper and rough up the inside of the tube by rolling it around. You need to rotate the paper so it cuts through the surface epoxy and cuts the fibers.  I forget what was in the Strega kit, but make sure you cut some grooves in the wire part , too, with a Dremel cut-off wheel. Not deep and only towards the free end.

   Measure the depth you need, and mark it, or wrap masking tape around the wire, so you get the right length when you assemble it.

    Make a little tight-fitting balsa plug for the inside of the tube, poke a tiny hole in it with a pin and stick down inside far enough that it will let the wire go in far enough. Then glue it in place with a drop of Cya. Make sure the hole is still clear by poking music wire through it.

   Then clean everything with anhydrous IPA *and* acetone on a clean paper towel. After cleaning, don't touch it. Then mix up JB weld, poke as much as possible down into the tube, coat the wire, and then shove it together. You might have to use a lot of force, but you are making sure you completely fill the space with glue. A little will squeeze through the plug, but most of it will erupt out the end of the tube, so just clean it up as it gets pushed out. I use the excess glue to wrap the end with bare copper wire.

    A few air bubbles won't be fatal but you might need to wrap the wire with tape, and then tape lengthwise to keep the trapped air from pushing the wire out before it sets.

     Brett

[Shug Emery]

Hi Shug,

Side exhaust engine got it! Does your engine has a red label marked 61CXR on the side? If it does it is a Ring one, if not its an ABN one, so we know exactly what we are dealing with.
Mine has the Red label...is that the better of the two choices?


I watched your video , you are sooo funny   ,  and I could see the flap and elevator horns are there, they worked fine for me. Also I saw the same pushrod threded endings that failed in mine. So I strongly suggest you not to use these endings, get Titanium ones from Tom Morris.
I have reached out to Tom and see if I can procure some. Thanks for the idea.

Sorry If I write to much  , but I just want to cover some things in detail to prevent you from crashing. These are critical things you should be careful:
I really do appreciate you typing the time to share all the information
 
1- The pushrod endings are glue into the carbon fiber tube and if not done properly they will fail.  So this is what I suggest you to do: sand just a bit the insides of the carbon fiber tube and clean thoroughly with alcohol, then scratch the pushrod ending and clean thoroughly with alcohol. Wait it dry and glue it with JB Weld, do not use epoxy for this job. Then wrap over the carbon fiber tube with dental floss and finish with CA to prevent the fibers to delaminate at the tip.
So I shall for sure...

2- Replace the lead out lines and make safe ones with wrapped copper wire. I have seen a few failing after 1, 2....4 years of use.
I think I am just going to stay with the original lead outs rto see how and if they ever break. Just don't want to tear into it. Did replace the leadouts on my Nobler and it was a pain. Being that it is an ARF...I don't the urge.


Make the new flaps the same size and shape, just thicker and without sanding to tapper it front to back.
Ahhh...got it. Got the balsa stock already so this will happen....

The APC 13x4 works good with this Engine/Model, but it did windup in windy conditions more then I like, especially when I set the engine in 4-2-4. Wood props hardly have their nominal pitch true, specially Zinger ones. As far as wood props the best I have tried so far are from JXF/Xoar. When I tried the 3 Blade C.F 13x4.5 and re-pitched the tip with less pitch it worked so much better.

Do not waste your time trying 12" props, stick with 13" ones. I suggest these props, APC 13x4,  Xoar 13x4 and 13x4~4.5 3B Carbon Fiber Props.  Use  .018 x 69'  lines or whatever is the AMA legal  maximum line length. We want this Strega going fast as a buttered rat when wacked hard but with long lines so for you it will be in slow motion and to reduce the line pull ... Whooooo Buddy))))))
I just got an assortment of Zinger and APC 13x4 and 13x5 to start with. Love those Zoars. Have some for other planes. Expensive but beautiful.

The Enya 61CX in the beginning will not run that strong,  be patient,  it will improve and get stronger and stronger as you use it. Check the muffler, if it has a baffle in the middle remove it.
OK...I'll check for that baffle. Removing improves power?

Once you start flying you can make a video and I will be glad to see how you are doing and we can work together to make little changes to fine tune the engine and improve the performance. There are several things we can change to make it better. I helped a friend far away like this and we had fun working together. It is very rewarding to me to help some one and see he getting better and better results.
I will shoot a video for sure as I am a ham! Thank you for being willing to help.

I have flown quite a few models, but the Strega with these modifications was the easiest model to make corners, you will see what I mean when you fly it.
That is wonderful to hear. Working on better corners and legs in squares are goals of mine for this flying season.

Well this is it for now, there is a few more tricks and details but will do them when the time is right.  ahhhh just remembered  I also suggest making the rudder 1.25"  taller and 1.25" wider or thereabouts!
OK....I'll take a look at the rudder. Did you cut a new one or just add wood?
Mucho obligato.
I'd love to come and fly in Brazil sometime and shhot some video and fly. Seems control line active down there.
Shug

Cheers!

Martin

[Shug Emery]

Just to make sure, I said I removed "all" the plywood from the nose, but not the side doubler plywood.

Martin

Did you take it off and replace it?

[Shug Emery]

   That's a good point. The stock controls are actually pretty good by ARF standards, but gluing the wire into the pushrod is a potential pitfall. The problem is as you say, the shiny inside surface of the tube. Even on regular airplanes, I roll up a bit of 120 grit sandpaper and rough up the inside of the tube by rolling it around. You need to rotate the paper so it cuts through the surface epoxy and cuts the fibers.  I forget what was in the Strega kit, but make sure you cut some grooves in the wire part , too, with a Dremel cut-off wheel. Not deep and only towards the free end.

   Measure the depth you need, and mark it, or wrap masking tape around the wire, so you get the right length when you assemble it.

    Make a little tight-fitting balsa plug for the inside of the tube, poke a tiny hole in it with a pin and stick down inside far enough that it will let the wire go in far enough. Then glue it in place with a drop of Cya. Make sure the hole is still clear by poking music wire through it.

   Then clean everything with anhydrous IPA *and* acetone on a clean paper towel. After cleaning, don't touch it. Then mix up JB weld, poke as much as possible down into the tube, coat the wire, and then shove it together. You might have to use a lot of force, but you are making sure you completely fill the space with glue. A little will squeeze through the plug, but most of it will erupt out the end of the tube, so just clean it up as it gets pushed out. I use the excess glue to wrap the end with bare copper wire.

    A few air bubbles won't be fatal but you might need to wrap the wire with tape, and then tape lengthwise to keep the trapped air from pushing the wire out before it sets.

     Brett

Another good tutorial. There is so much more to all this control line control system than a feller would think. Again I will take heed. Thanks, it is appreciated Brett.
Shug

[Brett Buck]

Another good tutorial. There is so much more to all this control line control system than a feller would think. Again I will take heed. Thanks, it is appreciated Brett.
Shug

  It took longer to write than it takes to do it!  This all may seem to be overkill, but very hard-won experience with control system failures in airplanes of this general size and power suggests that you don't want to leave any chance of failure. Control systems in general take a massive beating in stunt, far more than even the biggest and fastest RC airplanes, and are one of the weak points. We are always trying to beef them up.

  ARF control systems are even more of a weak point. The Strega is about as good as it gets in terms of ARFs, probably because Windy/Zambelli/Brodak know how much load they take in this type airplane. It's one of the few I have seen that I would use mostly as it comes, and I think the leadouts are probably OK as delivered.  The ARF Nobler, on the other hand, is the worst, and I have seen them with the bellcrank worn to the point of failure in only a few flights, and there are endless examples of leadout failures or jams - it's a complete non-starter. The few compromises in the Strega are, again, reasonable production changes, and safe enough if you are careful.

    Brett

[Martin Quartim]

Hi Shug,
Your engine has Piston with Ring, and it will work better with fuel with more synthetic oil then castor oil.  I recommend using a fuel with 10%~20% nitro and with 20~23% Oil, of which 80% is synthetic oil and 20% castor.  I have been using this engine but the one with rear exhaust and with a tune pipe. I have been using  Byron Traditional 10/20 and it has been working pretty well for me.  Avoid fuels with too much castor oil.
It is hard to say which engine is better, all sport and competition heli engines are ring ones, but here most like ABC ones.  I canīt really say which is better.  I have used both and to me they work the same except the ring one seems to run a bit hotter, could be because i used more oil and more castor oil with the ABN one.  The ring one seems a bit more choosy about fuel, it did not like to much castor oil.
Yes removing the baffle will make a huge difference in power, installing a exhaust deflector also robs power. But sometimes we need to use them to control the power.
It was easy for me to make it bigger rudder, my Strega was ARC,  so I just add wood to it.
Come down to Brazil fly with us and have fun.  I am fortunate to have a circle 7 min from home plus  6 circles in different cities  within 1:30h drive.

Martin

[Shug Emery]

  It took longer to write than it takes to do it!  This all may seem to be overkill, but very hard-won experience with control system failures in airplanes of this general size and power suggests that you don't want to leave any chance of failure. Control systems in general take a massive beating in stunt, far more than even the biggest and fastest RC airplanes, and are one of the weak points. We are always trying to beef them up.

  ARF control systems are even more of a weak point. The Strega is about as good as it gets in terms of ARFs, probably because Windy/Zambelli/Brodak know how much load they take in this type airplane. It's one of the few I have seen that I would use mostly as it comes, and I think the leadouts are probably OK as delivered.  The ARF Nobler, on the other hand, is the worst, and I have seen them with the bellcrank worn to the point of failure in only a few flights, and there are endless examples of leadout failures or jams - it's a complete non-starter. The few compromises in the Strega are, again, reasonable production changes, and safe enough if you are careful.

    Brett

Got the Tom Morris threaded rods coming and will pay attention to all control hook-up. Engine received. Gonna trust the bellcrank and lead outs. They look good to me. Little beefing up here and there and work the belly pan wing joint. Again I thank you for your input on this.

Hi Shug,
Your engine has Piston with Ring, and it will work better with fuel with more synthetic oil then castor oil.  I recommend using a fuel with 10%~20% nitro and with 20~23% Oil, of which 80% is synthetic oil and 20% castor.  I have been using this engine but the one with rear exhaust and with a tune pipe. I have been using  Byron Traditional 10/20 and it has been working pretty well for me.  Avoid fuels with too much castor oil.
It is hard to say which engine is better, all sport and competition heli engines are ring ones, but here most like ABC ones.  I canīt really say which is better.  I have used both and to me they work the same except the ring one seems to run a bit hotter, could be because i used more oil and more castor oil with the ABN one.  The ring one seems a bit more choosy about fuel, it did not like to much castor oil.
Yes removing the baffle will make a huge difference in power, installing a exhaust deflector also robs power. But sometimes we need to use them to control the power.
It was easy for me to make it bigger rudder, my Strega was ARC,  so I just add wood to it.
Come down to Brazil fly with us and have fun.  I am fortunate to have a circle 7 min from home plus  6 circles in different cities  within 1:30h drive.

Martin

Reading up on the engine instructions and will start bench running it for break in...get it ready. Seems to dure pull your Strega around very well.
I checked the muffler and it had no baffle. will try the tongue muffler too that came with it.
The circles you fly in look great. We must fing a new field and I envy your sites. Never take them for granted)))))
Thank you.
Shug

[Bill Little]

Hi Shug,

I am building the ARC.  You have received a ton of real good information here!  Martin showed you his model in flight and Brett, a NATS Champion, has given you a lot of good info, along with the others.  The great thing in this day and time is that we can get info from the best in the hobby/sport!  I cannot add anything other than do it right and have fun with the "monster'! (can't wait to hear your comments on flying it! You will love it!)

BIG Bear
RNMM/AMM

[Shug Emery]

Hi Shug,

I am building the ARC.  You have received a ton of real good information here!  Martin showed you his model in flight and Brett, a NATS Champion, has given you a lot of good info, along with the others.  The great thing in this day and time is that we can get info from the best in the hobby/sport!  I cannot add anything other than do it right and have fun with the "monster'! (can't wait to hear your comments on flying it! You will love it!)

BIG Bear
RNMM/AMM

All that plus some help from club members too. Will start breaking in the engine and assembling and modding next week.
I just know that I am gonna enjoy flying this Strega. Hope it ups my game. Or better yet, that I am up to it's game.
Shug

[Martin Quartim]

Hi Shug,

I just removed the plywood pieces that you do not see in the picture of the nose of my Strega. The plywood on the sides was not touched. Saved a lot of unnecessary weight and made my life simpler dealing with the fuel tank. I Also I lighten up all the wing ribs to save weight. My Strega end up with 77oz. It had take apart wings though and it was covered with Ultrakote.

I recommend you use a piece of foam  1/4" thick to shim the tank, this will be pretty close to the ideal tank height for the Enya 61CX, that is, if you use a standard 1" high uniflow tank.

For the APC 13x4 a  6.0Oz tank will be good, but if you plan to use a bigger prop, like a 13x4 3 Blade C.F you will need a bigger tank. I place peaces of foam so the fuel tank is never touching the airframe directly, this is to avoid fuel foaming due to vibration.

I have seen a few ARFs crashing or worst, flying alone! All failures I have seen the wire did not break, but ran through the termination at the bell crank end. When one wire goes out all the tension goes to the other one and there is a high probability of double failure. That happen to my Pathfinder ARF after 3 years of flying. After it took off, when it was 3' high, the up wire ran through at the bell crank end, it did not break, the plane (which is a a tricycle)  hit the pavement hard and bounce back in the air, when it was about 5' high the other wire gave the same way and there went my Pathfinder flying without a pilot in command! It flew level until hitting the fence. I was lucky to have just a prop broken that day.

Since this incident I have been urging people to replace the LO wire of all ARFs and making reliable wire termination.

Martin

[Shug Emery]

Hi Shug,

I just removed the plywood pieces that you do not see in the picture of the nose of my Strega. The plywood on the sides was not touched. Saved a lot of unnecessary weight and made my life simpler dealing with the fuel tank. I Also I lighten up all the wing ribs to save weight. My Strega end up with 77oz. It had take apart wings though and it was covered with Ultrakote.

I recommend you use a piece of foam  1/4" thick to shim the tank, this will be pretty close to the ideal tank height for the Enya 61CX, that is, if you use a standard 1" high uniflow tank.
Good idea and I have the foam to do it.

For the APC 13x4 a  6.0Oz tank will be good, but if you plan to use a bigger prop, like a 13x4 3 Blade C.F you will need a bigger tank. I place peaces of foam so the fuel tank is never touching the airframe directly, this is to avoid fuel foaming due to vibration.
Got my 13x4 and 13x5 props. May run the engine today...but it is snowing.

I have seen a few ARFs crashing or worst, flying alone! All failures I have seen the wire did not break, but ran through the termination at the bell crank end. When one wire goes out all the tension goes to the other one and there is a high probability of double failure. That happen to my Pathfinder ARF after 3 years of flying. After it took off, when it was 3' high, the up wire ran through at the bell crank end, it did not break, the plane (which is a a tricycle)  hit the pavement hard and bounce back in the air, when it was about 5' high the other wire gave the same way and there went my Pathfinder flying without a pilot in command! It flew level until hitting the fence. I was lucky to have just a prop broken that day.

Since this incident I have been urging people to replace the LO wire of all ARFs and making reliable wire termination.
The wire seems to have the copper tube going through the bellcrank holes for the leadouts so I am going to hope for the best. Crazy accident.
I love your enthusiasm and your very kind to share all this info. Maybe I will call this plane El-Martino))))))
Gracias.
Shug





Martin

[Martin Quartim]

heheheheh   I will be honored!

C/L is full of tricks and I learned most of them reading the posts and exchanging emails with the flyers from this Forum.

Now it is my turn to give back and share what I know.

If you would built the Strega ARF without these modification it would be a bad flyer for sure. Now you will have a model that will fly very well.

I just remember another thing you may consider doing....hehehe here I go again..... The Strega has full span flaps and most likely you will need to twist the flaps to level the wings. The problem is that the flap horn wire is very very hard to twist and you will not be able to twist it without breaking the flaps. I made my flaps removable and sure enough I needed to remove the flaps to be able to twist the horn using good pliers. Some people fix this problem adding a deflector on the wing, or stick a bent piece of plastic on T.E of the flap, I sure do not like these solutions one pushes the air stream away from the flaps and the other change the the area of the flap, these methods are easy to do, but can cause the plane to want to roll when the flap works.

Martin

[Shug Emery]

Started breaking in the Enya .61 today. And an Aviastar .46 that is new. Also running an OS .40FP that was in a crash this past season.
Fun.....
Shug

[Shug Emery]

heheheheh   I will be honored!

C/L is full of tricks and I learned most of them reading the posts and exchanging emails with the flyers from this Forum.

Now it is my turn to give back and share what I know.

If you would built the Strega ARF without these modification it would be a bad flyer for sure. Now you will have a model that will fly very well.

I just remember another thing you may consider doing....hehehe here I go again..... The Strega has full span flaps and most likely you will need to twist the flaps to level the wings. The problem is that the flap horn wire is very very hard to twist and you will not be able to twist it without breaking the flaps. I made my flaps removable and sure enough I needed to remove the flaps to be able to twist the horn using good pliers. Some people fix this problem adding a deflector on the wing, or stick a bent piece of plastic on T.E of the flap, I sure do not like these solutions one pushes the air stream away from the flaps and the other change the the area of the flap, these methods are easy to do, but can cause the plane to want to roll when the flap works.

Martin

That removable flap technique is very slick. Looks easy too.
Thanks for the idea.
Shug