Flyboy Dave

My Feedback: (21)

I have my eyeball in here as well....I have a 40 and the SD both collecting dust.

FBD.

softail99

My Feedback: (33)

Looking back at the measurements on my plans. The right wing is some 5/8" longer. I had ser num 52, I think that's right. I wonder if it got worse the higher the numbers. 1/8" wouldn't be enough to even worry about. I wonder just how much a wing could be off to make much difference. Bill, if you are looking for a 2/60 built, I might sell mine. Dunno but it wouldn't be a give away.

Has anyone tried the JR 9303 with the dual throttle mode yet? Just bought one and looking forward to setting that up. Wanna ck out what all the hub bub is about. If someone has feedback on that mode I would love to her it.

Rick

William Robison

My Feedback: (3)

Rick:

When I'm ready I'll just build mine.

But some pictures and "Pireps" on how it flies for you would be appreciated.

Twinman has made several posts about throttle mixing on the JR radios. You might do a search using "Throttle Twinman Mix." the Google search (at the bottom of the page here) works a lot better than the built-in RCU search engine.

Bill.

ehfleming

My Feedback: (5)

Hello Blade47,

I am happy but embarrassed that someone else has beaten me to building the plane, ...again. You are catching the inconsistencies of this kit. I will try to blame most of the "mistakes" on the original MAN plans, like the different length in the wing panels. There were some errors and omission that I tried to to correct before putting the kit in "production". Thanks to Bill, I think most of them were caught. I included the MAN reprint with some of my construction notes to myself. I hope they stayed with the kit.

There is one mistake that I have to fess up to. Be carefull when building the nacelles. The nacelle sides are not cut correctly, they were cut for a wing with a tapered LE. Of course, the SD has a STRAIGHT LE. The wing cut out for the inner nacelle side is cut about an 1/8" deeper than the outer side. Worse, if you align the firewall to the front edges of the nacelles, the firewalls (along with the entire nacelle) will have a negative incidence, pointing the engines towards the fuse. NOT a good thing. I would build the nacelles with the wing cut outs flush with the wing, but making sure the formers and firewalls have 0 degrees incidence relative to the fuse. I believe this will work with the least hassle. What you do with the slightly longer (or shorter) sides is your call, modify, cut or just leave them.

Also, I would recut the firewalls from aircraft ply, instead of using the supplied lite-ply.

I will be watching your build with much interest. If there is anything you think I might be able to help you with, just ask. If you reach points of extreme frustration[][&o][sm=confused.gif][sm=drowning.gif] during the build, feel free to vent. You can also PM me. There were some decisions I made reflected in the kit that are singularly my preference. For instance, the cut outs for the retracts were made with SpringAir 400 Series in mind. Although, I think about any should work.

Good Luck

Blade47

Thank you for the information there Mr. Fleming! I will re cut the firewalls along with F1 as i will be using a nose/firewall retract ( ROM ) and 85 deg mains.

I may call upon your support as I move along with the build.

PS: yes your added notes did come with the kit.

Cheers

Flyboy Dave

My Feedback: (21)

I don't suppose it would hurt to kick the firewall angles "out" a couple
degrees ? Wouldn't it make the SD more spin/crash resistant in the
case of an engine out, like the Twin star ?

FBD.

William Robison

My Feedback: (3)

All:

Ed Moorman has done several experiments with varying amounts of out thrust on the engines of twins. He has settled on seven degrees as ideal.

My Tiggerkitty has 1 1/2 degrees out on the right engine, the left is dead away. All my other locally built twins have no out thrust. ARFs are assembled with whatever the builder put in them.

So far I have not crashed any model twin for any reason. Full scale is another story.

Many full scale GA twins use out thrust, and at three degrees you'll never tell the difference in forward thrust. Seven degrees still has no visible effect on the plane's flight with both running, but to me it just looks awkward.

So it's your call. Seven degrees is a very good "Safety net," and it's a lot less expensive than a rudder gyro.

Bill.

PS: Good to hear from you, Ernest. I was going to call and let you know this thread was running. Hadn't gotten to it. wr.

timfarrar

Hey guys, I just purchased me a Pica Duellist from ebay, It should be hear in another week.
I'm going to keep an eye on this thread because Ive never built a twin before, But mine is the 240.
Did you say yours is a 260? I didn't know there was a 260.
Let me make sure I understand correctly, The right engine should be 7 deg. to the right and the left one straight ahead.
Are the same mistakes in the 240 kit as the 260?
I'm mostly concerned with the Nacelle's, I will have to really watch that because I'm sure the eng. pitch and the Nacelle's being straight make or break a twin.
Is there a need to increase the size of the rudder? or is size on planes OK?
I was thinking of two OS 48 4 cycles for mine, what do you think?

William Robison

My Feedback: (3)

timfarrar:

What you have, the Pica kit, is what we call the Duellist 2/40 Mk I version. On it the wing and horizontal stabilizer are mounted with two degrees positive incidence, the engines have five degrees down thrust. No side thrust on either engine.

The Duellist 2/40 Mk II version had a slightly larger wing, and both the wing and horizontal stab were mounted with zero incidence. The engines, in the Mk II version, had no down thrust. The vertical fin and rudder were modified to decrease the roll coupling in knife edged flight. The Mk II 2/40 was never kitted.

All the changes were made to have the plane Mk II perform better in aerobatics. The Mk I had different characteristics upright and inverted, but it was the better trainer version.

EHFleming, I, and some others got together a few years ago, we all wanted a larger Duellist. We designed and produced a "60" size version, at about 86" wing span. Ernest and I held the orders open for about a year, and sold a total of 50 Super Duellist 2/60 kits. These were done on a cost basis, sharing all the set-up expenses, and by buying all the materials in bulk orders we kept the cost as low as we could.

If you want the 2/60 version send a PM to Flyboy Dave, a buddy of his has one for sale. Probably $250-$275 plus shipping. And it's a large box

Engines. The 2/40 was originally designed to fly with 0.30 two stroke engines, but it was so disappointing that the minimum engine was raised to 0.40 two stroke. Your OS 48 four stroke engines are if anything marginally more powerful than a sport 30 two stroke, I'm afraid you will be unhappy if you use them.

Ideally the engines will weight around 12 ounces, the plane tends to be nose heavy anyway. If you insist on four stroke engines for the Duellist 2/40 your best choice is the Saito FA-82, and even they weight 16 ounces each. Best is a really light weight 0.60 two stroke.

Bill.

Flyboy Dave

My Feedback: (21)

I've only had two twins....but I would not even think about building a kit twin
without at least 5 degrees "out-thrust" on each engine. Up thrust, or down
thrust is meaningless when considering survivability with an engine out.

Consider this.... a Twin Star, with 7 degrees out-thrust on each engine (which
looks funny) can take off and land with only one engine running. This is abnormal
but highly desirable with a twin engine plane.

Out-thrust does look funny on the ground, but there is a "saying" about twin
engine aircraft...."when one engine quits, the other engine will lead you to the
crash site".

I have a Duelist 40, and a Super Duelist....both kits. Regardless of down thrust,
they will both have "out-thrust" on both engines.

FBD.

timfarrar

William & Dave:

I will respond to both of you a little, Thanks for helping me out here.
First I would like to get the 260 especially sense it has the two piece wing, but I need to start out little, and Ive already ordered this 240, ( I paid $172.50 including shipping ) Do yall think that was to much, If so maybe you shouldnt tell me. HA HA
Boy! Im sure disapointed to find out about the weight problem with the 4 strokes, I didnt even think about that, I was just thinking of those two 4 strokes sounding through the air.
Being as how Ive never had a twin before I need to listen to you.
Dave:
With 5 to 7 deg. right thrust in both engines, should we increase the size of the rudder, What do you think, I havnt seen the plans yet but in the pictures on the internet, The rudder looks awfully small for a twin.

THANKS AGAIN YOU GUYS, TIM

Flyboy Dave

My Feedback: (21)

Tim....Welcome to RCU....[sm=thumbup.gif]

Don't be afraid of the 4-strokes....go with the "coolness factor". The price you
paid was about right....don't worry about that either.

The only thing that will save a twin in an emergency is....a big rudder.

FBD.

timfarrar

Dave:

What size engines are you going to use on your 240 Duellist? and which one are you going to build first? the 240 or the Super Duellist?
Is the Super Duellist the 260 ?

SEEYA , TIM

Flyboy Dave

My Feedback: (21)

Yes, Tim....the SD is for 60, size engines, and really larger. I have a pair of
NIB OS 40FSR engines assigned to the regular Duelist.

I will build the 40 sized first. [sm=thumbup.gif]

William Robison

My Feedback: (3)

Tim:

The Duellist series aircraft fly fine with no out thrust on the engines, and still fly fine with either engine out. With no out thrust. The airplane was designed to be safe with an engine out.

Many scale twins are just about automatically dead when an engine is lost, the B-25 and P-38 models for example. Even these planes can be flown on a single engine if the speed is kept high, but out thrust makes them much easier to fly with one dead.

The Duellist planes do not need out thrust, they are capable of take off, flight, and landing on a single engine. However, out thrust wont hurt anything but your eyes.

Quote:

With 5 to 7 deg. right thrust in both engines...

Please note, Tim, that it is not RIGHT thrust on both engines. The engines, if not pointed straight ahead, should be angled away from the fuselage - right on the right engine, left on the left.

Summary? If you want out thrust on your Duellist you can do so, but it's not needed.

One of the few things I dislike about most twins is having both exhausts come out the same side, or both cylinders sticking out the same direction, I just find them to look nicer when they are symmetric. Chuck Auger, who was involved in the early design of the 2/60, built his 2/40 with rear exhaust piped engines. Pretty. See first picture. My "Pet" K&B 40 engines are easily reversed, note the mufflers in the second and third pictures.

Bill.

timfarrar

Wow, I'm really glad you let me know that about the thrust, As you seen, I was thinking both would have right thrust.
With the 2/40 being designed to handle eng. failure, (I'm wondering) Would you still need to use a little rudder and aileron to keep it straight in the air?
I'm sure the answer is yes, but thought Id see what you have to say anyway, You may have had it happen to you with your Duellist.
What do you think about the rudder, Is it big enough, It appears that you built yours according to the plans. Nice job by the way, The exhaust is a cool idea !
When turning those crank cases around, Did you need to leave the sleeve the same and just turn the crank case? ( wondering because I do have one K&B .61 )
I would really like to use those 4 strokes though, But I do understand what you were telling me.
Can you invert the engine's on a Duellist? I know on some kits you have to go with the plans so the tank level will be right. How is the Duellist ?
Both of those planes are cool, But I'm like you, I like a clear canopy.
I haven't made up my mind on my finish, I'm thinking maybe a military scheme, Kind of copy the P-38.
Do you have retracts? I got some spring air from a friend.
Is the Duellist just a model or is there a real one?
I really appreciate all the advice your giving and I know there was some effort in sending pictures, I hope you have a good day!
I'm fixing to go and start my cover job on my Bristol f2b, I want to be finished soon so when the Duellist gets here, Ill be ready, But you know how that goes, Something will slow me down.

SEEYA , TIM

William Robison

My Feedback: (3)

Tim:

Quote:

With the 2/40 being designed to handle eng. failure, (I'm wondering) Would you still need to use a little rudder and aileron to keep it straight in the air?

All twins except center line thrust planes like the Cessna 336/337 Skymaster, will need rudder correction for straight flight on a single engine. And the rudder as drawn is more than large enough for the Duellist.

Quote:

When turning those crank cases around, Did you need to leave the sleeve the same and just turn the crank case? ( wondering because I do have one K&B .61 )

To reverse the K&B 40 engines you just switch the front and back plates, the cylinder sleeve, piston, rod, and head are left in their original relationship. The K&B 61 engine can not be reversed.

Quote:

Can you invert the engine's on a Duellist? I know on some kits you have to go with the plans so the tank level will be right. How is the Duellist ?
Do you have retracts? I got some spring air from a friend.

You can invert the engines on a Duellist, but if you don’t want the cylinders sticking up it’s best to lay them on their sides. Fuel problems could well come with them inverted, without major rework there’s no way to lower the tanks.

Quote:

Is the Duellist just a model or is there a real one?

The Duelist is entirely the product of Dave Platt’s mind, even though it does bear a slight resemblance to the F7F Tigercat.

Bill.

timfarrar

Bill :

You must have been doing this stuff for ever, You really know what your talking about and it shows.
The problem with the tanks when engines are inverted is just what I thought, I haven't got mine yet to look at the plans but from all the pictures Ive seen, I thought it look like the tanks couldn't be lowered enough.

THANKS AGAIN , TIM

William Robison

My Feedback: (3)

Tim:

Here's a shot of a 2/40 Mk II near completion, and an early layout of the 2/60. With the 2/60 you might get away with the inverted engines, but you can easily see the 2/40 wouldbe a bear.

Bill.

>>EDIT to add PS: When you get yours you can compare the tail and see the most obvious difference between the Mk I and the Mk II. wr.

timfarrar

Ok ! Bill:

I look foward to getting mine and getting started.
You know I just thought of something, I bet you need to place your radio as far back as possible for this plane.
If so, I may try to scale out the cockpit a little, If not, Ill need that room for the radio.

SEEYA , TIM

Again, Im glad I came across you guys, Ive never had a twin and this is the one I wanted to start with.

Blade47

I will post more Pic's of the wing build this weekend .... one or two small mods to the wing.

timfarrar

Hey Bill !

I got my plane in today and I see now why the OS 48's probably wouldnt even get it off the ground.
I see the difference in the tail, The 2/60 has a sub-fin, I think I may do that to mine. Actually I may shape it like a P38 rudder. I dont know, Im going to finnish my Bristol f2b first and then give everything serious thought.

Oh! and I do have two Saito 65's but one isnt running good. Ill have to fix that for sure if I try those.
I also want to check out that F7F Tigercat, If I like it, I may copy its looks a little.

SEEYA , TIM

William Robison

My Feedback: (3)

Tim:

Ordinarily I wont discourage the use of any Saito engine, but in the case of the Duellist 2/40 I think the Saito FA-65 engines would by a bad choice.

As I've said the plane tends to build nose heavy, the four stroke engines have to be mounted forward aggravating the nose weight, and the FA-65n engines are the heaviest of the mid block Saitos, at 19 ounces each. 38 ounces engine weight.

The FA-56 engines would give you 31 ounces, at 15.5 ounces each, but you would possibly have too little power to be happy. If you went for the FA-82 your engine weight would be 32 ounces and plenty of power. But at a price, Horizon doesn't give them away.

No, the Duellist just seems most fit for two stroke engines. If you hollow all the blocks, don't use too much glue, and build the plane carefully a pair of K&B 4011 ringed 40 engines makes a very nice plane. And you can reverse the exhaust on one. As an alternate, the K&B Ringed 61, the 6550 engine, just a hair heavier than the 4011, is also a good choice. Can't reverse the exhaust though. Or for a real hot rod get a pair of the K&B "Twister" 61 engines, a pair is currently $200 from MECoA.

Bill.

Blade47

Every day a little more done...

Pic 1 Just shows that I built up around the retract housing to mate to the wing skin a little better.

Pic 2 Built up the wing block with 1/4" ply then balsa filler to the wing skin.

Pic 3 Cut the wing tube down A LOT save some weight and the tube does not support past W5.

Pic 4 Cut in the servo holes and ran string to the middle for later wire pull.

Pic 5 just a pic

now for the other wing

hattend

My Feedback: (20)

Speedy build there, Pete.

Looks really good. You're gonna let me fly it when I come down there, right?

Don