Pica Duellist 2/40 build
 

I'm building what I guess is the original kit and thanks to some threads on this forum I'm going to make these alterations; lengthen the fuse nose 3/4" for longer landing gear, double the first bulkhead and reinforce the mounting to the fuse, lengthen the main gear 3/4", install throttle servos in the nacelles and aileron servos in each wing half, add shear webs between the spars and just plank from the leading edge to the spars and an inch or so at the trailing edge leaving the wing open outward past the last rib supporting the landing gear (typical construction of most of the planes I've built), hollow all balsa blocks and cut way back on the size of the solid balsa wing tips. I'm hoping to get close to a final weight of 7lbs with OS 32SXs for power.

I've got the fuse built from the crutch up and started on the wing because I haven't reached a decision on how to build all the incidences in the plans that call for 2 deg positive on the wing and hor. stab and 8 deg down thrust on the engines. I know that some people have built the plane with 0 deg on everything and some have built it to the plans so I'm hoping some previous builders (or anyone else) will notice this thread and relate any experiences they had. I'm contemplating the 0 deg approach and wondering whether to lower the leading edge or raise the trailing edge or a combination of both.

RE: Pica Duellist 2/40 build
 

Keep all the incidence and engine thrust angles as per plan. The plane flies great with this setup.

I made similar mods to the wing of my Duellist, but planked the complete wing. It does not add that much weight. Takeoff weight is around 11lbs, and the plane handles it well. OS 50SX with tuned pipe pull the plane vertical if you let her go...

I increased the wing span by almost 3" per wing half, of couse installed shear webs to the mains spars and increased fin and rudder area maybe 50%. Elevator servo is in the back of the fuselage with direct linked pushrod, this helps to balance the plane and reduces elevator slack.

Last considerable modification to the wing was installation of split flaps, for little steeper approach angle - our field is not too long and there are trees in the approach area.

No real mods done to the fuselage, nose gear is a rail mounted Robart, the rails add enough strength to the tiny bulkhead.

RE: Pica Duellist 2/40 build
 

Beautiful plane speed-panzer. It's nice to know that the plane flies well with the planned incidences, that would make the build that much easier.

What size fuel tanks did you use and how long is the flight time?

RE: Pica Duellist 2/40 build
 

300cc (approx. 10fl.oz.) is the max. you can squeeze into the nacelles. I was afraid that the space for foam padding around the tanks would not be enough to prevent fuel from foaming, but it works ok.

Attached photo shows fuel tank, custom made inline header, and space for throttle servo aft of second nacelle bulkhead.
By the way, I did same as you plan to do and placed the main landing gear mechanism about 3/4" further out, to accommodate little longer legs. This required to shorten the nacelle underside balsa block, but I think it looks ok. Surprisingly, I did not need to lengthen the nose gear strut, as I expected. In fact, it was needed to do a "S" shape bend to the nose leg after it was installed to reduce too much "nose up" for the plane sitting on its landing gear.

RE: Pica Duellist 2/40 build
 

Photos from last weekend, my brother did some nice snapshots!

RE: Pica Duellist 2/40 build
 

As I look back on the planning I did for the gear length, I didn't consider the wing incidence to the ground. With that 2 deg positive wing incidence the leading edge is 3/4" higher than the trailing edge, so the nose gear may not need any added length to keep the wing level to the ground which is how I usually set up my trike gear planes. I'm glad you mentioned what you found.

I'm reconsidering the choice of the 32s and may use two OS 46s, with a 10 oz tank I should have the 10 to 12 minute run times I like to have. Then I can end my obsession with keeping it light enough to get good performance.

Your plane looks pretty good in flight too.

RE: Pica Duellist 2/40 build
 

I recall that this issue of nose gear strut length may have to do also with my choice of rail mounted system.

10-12 minutes are safe flying time, I would say. The alarm clock at my transmitter is set to 7:30 to have some reserve.

RE: Pica Duellist 2/40 build
 

I too have an in the box Duellist 2/40 and would love any build updates you can share, thanks!

RE: Pica Duellist 2/40 build
 

Unfortunately, right after I bought a new battery for my camera the camera died on me so no new pictures. Get a power plane, its been one of the most useful tools I had to build this plane (lots of blocks to cut to shape).

I doubled the fuse bulkhead for the landing gear and reinforced it with triangle stock (it's been reported to have been torn out by a couple of people). Don't believe the 6-8lb flying weight on the box. It looks like mine will be around 9lb. That convinced me that the 46s are going to be used. I decided to side mount the engines to get the carbs in line with the fuel tanks. The bad thing about that is the exhaust is going to get on the aileron servos and into the retracts. Thinking about how to seal them the best I can. The stock aileron setup is quite sloppy and heavy and I hated the way that the horn on the torque rods was to be made (I could imagine the clevis being cut in two before very long) so I opted for separate servos mounted in the wing. I installed another rib from the spars to the trailing edge and put some servo mounting blocks in between them. I also went with two servos for the engine throttles, with the engines side mounted they are going to wind up in the bottom of the wing behind the spars.

The instruction manual sucks. Read it over and look at the plans a few times before you do any gluing or cutting. The rear of the fuse under the stab is especially confusing, take care to get that figured out before you cut or glue anything.

Good luck with your build.

RE: Pica Duellist 2/40 build
 

I see another couple of threads on the Duellist. I wish I had seen them earlier, I might have wanted to consider a couple of mods to the nacelle location and landing gear length.
I got the wing basically built, with a few complications along the way. I figured on lengthening the gear by 3/4" but when I made the cutouts in the wing I discovered the servo lead routing tube interfering with the wheel wells. Cut the wheel size down a 1/4" and redid the cutout, I'm down to 1/2" more length now. Wish I had shot for an inch now. I changed my mind about the side mounted engines but only after cutting servo holes in the bottom of the wing. The bottom wing skin is taking on a rather Frankenstein look now. I also decided to finish the wing skins out to the end of the wing. The only advantage I have in doing it now is that the middle of the wing is built with one piece of wood across the joining ribs.
With the engines upright and still concerned about the fuel tank height I raised the tank 1/2" and built up the top of the nacelles and hollowed out the top nacelle block.
Not that many more pieces of wood left in the box so I'm making some progress.
http://i17.photobucket.com/albums/b7...c/IMG_0134.jpg

RE: Pica Duellist 2/40 build
 

[link=http://www.rcuniverse.com/forum/fb.asp?m=8269555]Plan Comparison[/link]

You might be too far into it by now. The post above compares the Pica kit with the Platt plans and the length of the retracts. I modified my Pica kit with the plan version for the mains. If you are flying off a grass runway you will appreciate the gear length.

RE: Pica Duellist 2/40 build
 

It's never too late. I measured the Pica plans and saw that I still didn't have enough length, so for the third time I cut out the wheel wells and extended the mains another inch. They pretty much match the length in the Platt plans now and since I already lengthened the nose an inch I should be alright. I fly off a paved runway but my landings still leave much to be desired so I do need the extra length. I see a couple of Duellists with three bladed props, I know why now.

RE: Pica Duellist 2/40 build
 

fly:

Looking forward to watching the build!

Attached pictures of the Duellist I built 17 years ago (boy, that makes me feel old!)

Back then, it seemed like a REALLY fast lander. After a few years of flying P-38's, it doesn't seem that fast at all.

Note the counter-rotating props: an old O.S. 46R I don't think they make anymore.

I built the incidences to specs and it does seem to climb a little as the throttle is increased, which might argue for a nacelle incidence closer to zero. Being too lazy to make that kind of mods on an old plane, I have just mixed in a little down elevator on my throttle.

Not your first twin, is it? It was mine and scared the daylights outta me!

I think the kit says it weighs @8 lbs. When mine came out @11 and flew like a barn swallow, I thought I'd ruint it with wing loading. Turns out just about everybody's weighs 11ish lbs.

You'll like it. Very exciting plane to fly. Make sure the retracts and their attachments are strong.

Mine requires a little weight in the tail: probably an effect of long nacelles.


mt

RE: Pica Duellist 2/40 build
 

Wow, I wish I had a plane 17 years old, I do have a wing that's that old. LOL What kind of P-38s did you have? I really want to have one. I'm investigating a scratch built one now.

It is my first twin, looking forward to flying this one.

I'm going to balance it before covering and I'm thinking of mounting the battery somewhere back in the fuse.

RE: Pica Duellist 2/40 build
 

Hi flythesky,

Just saw this thread of yours (been a while since i've logged onto rcu) and was wondering how your 2/40's coming along. I buil the same kit about 15-20 years ago. The plane is hanging in the garage at my folk's place. Haven't found time to fly it in the last 10 years... Awsome plane - hope to get back to it someday. Show us some pics if you have any!

RE: Pica Duellist 2/40 build
 

Made a little more progress since my last post but then Itook a break. Hope to get back to it soon, with pictures.

RE: Pica Duellist 2/40 build
 

Since you've already cut the wheel wells, might be too late for this suggestion: I built mine as a tail dragger which solved the prop clearance problem and reduced the overall weight a little by getting rid of the nose wheel/strut/retract and adding a much lighter non-retractable tail wheel unit. I moved the main gear out into the nacelles to retract rearwards. 4 oz "header" tanks in the nacelles and a single 12 oz tank in the fuselage. Downside is taildraggers can be more of a handfull on takeoff.

RE: Pica Duellist 2/40 build
 

That is exactly what I want to do with mine... make it a tail dragger! What retracts did you use (if you have the retract number?) also, do you have any pictures you can share? thanks!
Calvin

RE: Pica Duellist 2/40 build
 

I used Hobbico .60 size mechanicals with Robart Robo Struts.

There are pictures of it buried somewhere on rcu from an older post.

RE: Pica Duellist 2/40 build
 

Finally got back to it. main structure complete. Now for the next hundred things to do.

http://imageshack.us/photo/my-images/705/img0239ln.jpg/

RE: Pica Duellist 2/40 build
 

i know a lot of people will scoff at this suggestion. but why not use LA 46 or GP 42 engines. same if not a tad more pwer than the 32's and the same weight. swing a bigger prop.

RE: Pica Duellist 2/40 build
 

Biggest reason is that I already have the 46FXs.