Bidule 111

[JimD]

TopModel (France), under the banner of their ECOTOP brand, now offers the 3.0M Bidule 111 which is about the same size plane as the much beloved 3.2M Pilatus Porter. The Bidule 111 is designed around the DLE 111 twin cylinder gas engine. The DA-100 and DA-120 engines share the exact same size mounting bolt pattern and similar size and weight to the DLE 111.

Our dilemma...we have both a DA-100 and a DA-120 looking for a home...which engine should we chose?

Compared to the Porter, the Bidule 111 (being a non-scale airplane) has a smaller fuselage and less overall mass. Consequently, its AUW will be about 8-10 lbs. less than the Porter. Our Porter is the 3.37M span version so the 3.0M Bidule 111 has about 14-1/2" less span. Also, the included 1500cc (50 oz) fuel tank is a tight fit, so there will not be a 100 oz tank option here...that means the Bidule will be carrying 50 oz. less fuel and less weight in fuel.

So, the Bidule 111 is smaller and lighter weight than the Porter...seems like the DA-100 should be plenty of power for the size and weight of the plane. Then there is the muffler issue. Do we use stock mufflers and save the cost and weight of canisters or tuned pipes? Our reason for this plane is to have a backup tow plane that is less costly than either the Porter or Decathlon, and one that we would not be as reluctant to fly on less than ideal days. So, cost is a factor, and therefore here are our choices:

Bidule 111 Accessories:

Engine: DA-100

Spinner: 4" Dave Brown Vortech Aluminum Spinner

Prop: Xoar 26x12 Wood

Servos: Hitec HS-5645MG for Ailerons, Elevators, Flaps, Tow Release, Choke, and Throttle. (9 total). Hitec HS-5245MG for rudders (2 total). Hitec HS-7954SH for nose wheel sterring (one total).

Batteries: NoBS Batteries 2-cell 6.6v A123 LiFe 2,500ma packs, 2 for radio gear and 1 for ignition ( three total)

Wheels: DuBro 5" Treaded Lightweight Wheel for nose gear and a pair of DuBro 6" Treaded Lightweight Wheels for the main gear.

[JimD]

Thanks to Scot for picking up my large Bidule 111 box from ICare in Canada and delivering it to the New England Aero Tow Event last week! The next issue was how to fit it into my truck along with the Porter and Decathlon for the ride home...not to worry, it fit!

...and I need a trailer why????



Had to break out the parts and look at them as soon as I got home.



Making sure our servo choices would work was the next item on the build agenda. A pair of HS-5645MG's will fit into the aft fuselage openings without hitting each other.



Using the digital version of the HS-225MG, the HS-5245MG, we checked the thickness against the stab thickness. TopModel's suggested servo was larger and thicker so we like these better.One of the HS-5245MG servos will be fit into each side of the stab to operate the rudder on the twin fins.

[JimD]

The nose gear is massive, so we will be using a massively powerful servo to operate it, the HS-7954SH with steel gears!

The wheels will be the DuBro Treaded Lightweight Wheels which had a 3/16" (5mm) axle hole. The main gear axles and the axle bolt in the nose gear are all 5mm, so these will be perfect.





The spinner ring in the cowling is right on 4" in diameter.

[Asher Carmichael]

So, the Bidule 111 is smaller and lighter weight than the Porter...seems like the DA-100 should be plenty of power for the size and weight of the plane. Then there is the muffler issue. Do we use stock mufflers and save the cost and weight of canisters or tuned pipes? Our reason for this plane is to have a backup tow plane that is less costly than either the Porter or Decathlon, and one that we would not be as reluctant to fly on less than ideal days. So, cost is a factor, and therefore here are our choices:
.

Jim,
I think you're spot on. I have been wrestling with the choice of engines and was considering a DA 120 or a DLE 120 but your analysis has redirected me to consider my old basic DA 100 I have sitting in a box.

As you mentioned, the Bidule is smaller and lighter -and a little cleaner- than the Porter so parasitic drag may be less which also favors the 100 size engine choice. It's no problem to move to the 120 if necessary

My rationale for a less expensive tug follows yours, as well as the opportunity to try a trike gear, so I think saving some dollars on servos fits within the plan. You've obviously had good success with the 5645s. Likewise, I'll be using the HiTec 5645s as well on all surfaces and the 7955 for the nose wheel and release.

While there is a definite cost increase I will be adding MTW cannisters in lieu of the stock mufflers. Noise is becoming an ever present issue as evidenced by the recent decision to police noise limits at Triple Tree Aerodrome and other major flying sites.

I'm looking forward to following your build and getting started on my own in the near future.

[JimD]

Asher,

I used HS-645MG servos all around on Porter #1 with no issues. Porter #2 was built with HS-5645MG on all surfaces again with no problems. Both of those planes had DA-85 engines. Porter #3 has HS-5645MG servos on all controls except for the flaps which have HS-7954HS servos.

The Decathlon has MUCH larger control surfaces, so we used HS-7955TG servos on all of the controls and HS-5645MG on throttle, choke, and release.

I agree about the noise, so I will likely use canisters...have been considering the options...longer, shorter, front dump or rear outlet, etc. We could also use RE2 pipes for a power boost too.

[Josh Teague]

You have my attention Jim. Following with great interest . I think the idea of this towplane is spot on . Tricycle gear,twin tail, light weight. I can't wait to see how it fares in the real world .

[lenb]

Hey Jim,

I like the color. I have not even had the chance to open the Bidule 170 box yet. I'm thinking about mounting the ZDZ 180 on it with canisters ( since I have a ZDZ available.)

I agree the 100 may be fine, but what a beast with a 120 on the front. As I hear you say, bigger is better.
Is there a big increase in fuel consumption with the 120 vs 100?
Do you have room for another tank inside the fuse ? Maybe a 20 oz or so?

Looking forward to seeing more about the plane as it unfolds.
Thanks for posting.

len

[JimD]

There are a number of places where the covering needs to be opened for wing bolts, canopy bolts, anti rotation pins, and servo wires. We like to use an old soldering iron to melt the covering out of these holes and simultaneously seal down the edges of the covering around the opening.



Next, the two elevator servo openings were cut and the covering ironed back.A MonoKote trim iron makes the job easy.

[JimD]

From our experience with other models, we added hardwood triangle pieces along the back corners of the firewall and landing gear block. Balsa sticks were used as wedges to hold these pieces in place while the slow set epoxy cures.





Additional pieces will be added once these are secured in place.

[JimD]

Just got off the phone with Desert Aircraft and a pair of MTW-75H canisters, exhaust flanges w/ stubs, and 25mm pipe pieces are on the way...let's keep it quiet for those tender sailplane pilot ears! Going with a Mejzlik 26x12 2-blade carbon prop and a 4" TruTurn spinner. Good stuff all around!

[JimD]

The hinge points in the rudders and elevator seemed a little small to us, so we changed them out for Robart hinges that are a bit bigger.



To make the hinges fit nicely, we used the Dremel with a tapered bit to countersink each of the holes.





Always a thrill to get that first look at a new plane fully assembled (or close to it).

[JimD]

More triangle...we cut balsa triangle stock to add along the upper inside edge of the fuselage. When picking the model up with the canopy frame off, you tend to cup your fingers under this edge. When doing this, the plywood tends to want to bend and stress the joint with the sides. The overlap of these pieces isn't very much, so therefore the glue joint is minimal. By adding the triangle, this joint is nicely strengthened.

We cut the pieces of triangle and made doubles once the measurements were established.



First side pieces glued in place and pieces for second side ready to be glued.



Then we noticed that the same was true with the cross members, so we added triangle to both sides on all four of these cross members.



Much better! The instruction manual mentions that the strength of the glue joints is up to the builder to judge. It implies that there is just enough glue to assemble the model, but maybe not enough to really hold it together under heavy use. They pretty much say straight out that the builder should, at minimum, apply a bead of glue along even visible joint.

[Asher Carmichael]

Jim, any progress? I hope to start mine next week.

[JimD]

Asher,

We got a number of little things done, like plumbing the fuel tank. The included 1500cc (50oz) tank is designed to fit perfectly. After pushing the brass tubes through the rubber plug, we soldered on DuBro fuel barbs, pushed the pick up line fuel tubing on, and used a zip tie the secure it.

The landing gear was attached to the fuselage and the axles were added to the main gear.

The engine mount requires standoffis to get the correct spacing. We plan to use hard maple blocks for part of this and aluminum spacers for the remainder. These were ordered along with the other items needed to complete the plane.

The DuBro wheels arrived along with the Mejzilk prop, TruTurn spinner, standoffis, and servos, so we now have everything to complete the project. Our trip to the Muncy Flyer's Sky High Aerotow event has temporarily interrupted progress.

[Asher Carmichael]

Jim, I hope you don't mind me piggy-backing on this thread with my build experiences.
Like Jim and bob, I'm reinforcing the fuse with tri stock and additional bracing for the landing gear block. I used 1/4" aircraft ply to make another doubler to cover where the LG block ties into fuse longeron and sides. You'll also notice I filled in the opening in the fuse side with balsa so I can mount a multiplex 6 pin receptacle in that space.