Wellington build and re-build

[Robin Senn]

Hello Scott

Thank you very much for your advice regarding the flight behaviour of the Wellington. It is reassuring and highly appreciated to have some tips from an experienced Wellington Pilot in the light of the nearing maiden flight. If it is alright with you I have some ( or actually a bunch of them... ) addtional questions regarding the flight setup and the settings you found best for the plane.

Did you install flaps in your Wellington? If yes, how much throw did you give them and how much down trimm was required when employed?

From what I have found in the forums the CoG set at the main wing tube should be allright. Did you use that too?

You have mentioned sluggish roll response. Did you use the 20mm aileron throws suggested by Toni Nijhuis? In general where did you deviate from the given throw settings? And I am not sure what "opposing expo" could be?

When you say the rudder is "rubbish" I assume that there is not much response to the rudder inputs at the beginnig of the take off acceleration?

Sorry about all the questions, but having the opportunity to pick the brain from someone with first hand experience is highly appreciated.

And yes, I agree about the trasportation issues and a certain fagility of the design. While I have a Ford Transit for transportation, I see the potential for damaging something during loading/unlaoding or the transport itself. Building special "wing racks" for to fit the wings in the car is one of the remaining bigger tasks. Especially as the OS GF40s dont like it if they are not level during Storage and transport. They immediatly fill up with fuel and need some time to dry out afterwards.

Greetings Robin

[Timothy Huff]

If I recall correctly, there was a linkage between the flaps and elevator trim on the Wellington. This meant, iirc, that if the pilot retracted the flaps without first retrimming to neutral it tore the trim-box off the fuselage-wall - deeply unpopular with the ground crews as it happened with some frequency. I'm still casting through my books on the Wellington to find the specific text where the sense in, and reason for, this linkage of trim and flap position was made. I *think* it was nose-up trim as many Wellingtons tended to drop the nose in turns with the flaps deployed. (This is further complicated by the C of G being too far forward in the Merlin-engined Mk II, which uniquely had ballast weights in the tail).

As soon as I dig out the text I'll post it here. NB that merely because the full-size aircraft does have such a linkage, does not mean yours will necessarily need it, and it can of course be achieved simply on the Tx.

[Scott Edwards]

[quote=

Did you install flaps in your Wellington? If yes, how much throw did you give them and how much down trimm was required when employed?

From what I have found in the forums the CoG set at the main wing tube should be allright. Did you use that too?

You have mentioned sluggish roll response. Did you use the 20mm aileron throws suggested by Toni Nijhuis? In general where did you deviate from the given throw settings? And I am not sure what "opposing expo" could be?

When you say the rudder is "rubbish" I assume that there is not much response to the rudder inputs at the beginnig of the take off acceleration? [/quote]

Taking the above in turn:

No flaps on mine, and they're really not needed at all. Landings are smooth and slow, and it takes off without them just fine.

CG is on the main wing tube. I just used strong thin tope to hang it from the roof by the wing tube to balance. I needed about 900g of lead in the nose. This CG seems spot on, I haven't adjusted it at all.

I set my ailerons to 20mm (no differential) and it was very slow in the roll. I increased throw to 30mm but it was still very slow to start a roll, but then rolled too fast ! I settled on 20mm throw with some positive expo. Normal expo (negative on Futaba) makes the control surface 'softer' at the centre of the stick. Positive expo increases the throw around the center of the stick. It is perfectly flyable with 20mm throw and no expo, so this is just an adjustment for personal taste really.

I have 2 degrees of right thrust on the starboard engine, and 0 degrees on the port. There is still a very strong swing to the left on take off though. The rudder alone isn't strong enough to compensate for this, so a strong working tailwheel is essential. Ease the throttles up, and keep it straight with the tailwheel and let it accelerate smoothly. It takes off in a surprisingly short run. In the air I use rudder to try and balance the turns, but I don't think it has much effect.

My landing technique is to line it up from a long way out, and slowly drop the throttles, but never to zero or the model drops too quickly. Slow greaser landings are the aim which the model is more capable of then I am. I don't drop the throttles to idle until it's on the ground.

It really is a fabulous model. It has a wonderful slightly nose down sit in the air, and feels incredibly solid and stable. It's not aerobatic of course, but looks fabulous flown gently at a scale speed.

Short flypast video below !

https://youtu.be/xXp3zQwmFwg

[Robin Senn]

Hello together

@Timothy: Interesting tidbit about the Wellington. I can imagine that those linkages were rather despised with the maintenance crews. I can imagine with wartime trained green flight crews and the added stress of coming back from a bombing mission over occupied Europe that those linkages had to be exchanged quite often...

@Stuart:
Thank you very much for all that valuable information. It answers a lot of the questions that were open for me. And of course it creates one or two more...;-)

But now I can put the questions regarding the CoG and the aileron, elevator and rudder throws to rest. I will start there with the default settings given in the plan and develop from there.
Altough I will have to revisit the issue with the right thrust. I haven’t actually set any, as the plan didn’t define any. But that isn‘t really a big issue. Do you think it does actually help?
In regard to the flaps, I intend to fly the plane on smaller local airshows in the future, and as Switzerland is rather small, not all of the flying fields have room enough for your preferred landing technique. So sometimes shorter and steeper approaches are in order, so that is where I think that the flaps will come in handy.

Also having deployed flaps will allow me to keep the engines throttled up a bit more. While both engines have been run in quite well, having a bit of a higher idle gives me some additional peace of mind.

And yes, it is a fabulous model. Your model is really looking great in that short fly by video. Gets me motivated to have it up and running in early summer. And those Lasers are really sounding great. Nothing against those Zenoahs that most are using, but the that dinny two stroke sound just doesnt do the plane justice...

So thanks again for letting me pick your brain

Greetings

Robin

[Robin Senn]

Hello together

Progress on the Wellington has been a bit slow as I got sidetracked by another model project. I got the opportunity to buy an unflown ESM BF110 already fully equipped which kept me distracted for a while...

Anyway, after having shelved the 110 I returned to the Welli. THe plane has now received all of its camouflage and next will be the roundels and markings. After thatthe windows in the fuselage will be glassed and after that its final assembly and testing...and of course checking how much of lead it will require to get the CoG in the correct postion.

Greetings Robin

[Robin Senn]

Hello together

Finally the painting stage has come to a close. Had to assemble the Welli for a a motivation shot. While it is not the greatest paint job, I am satisfied with it. With the size of the model, the dings and scratches from handling and transport will start to accumulate in no time anyway...;-)

The plane has no historical original...the identification is purely my own invention with some artistic license. Also it has mixed up certain elements of a Mk.III and Mk.X mixed together. But it is looking definitely like a Wellington which is enough for me.

Now comes the time to put back all the hardware I have removed for painting and then we will look for good weather for the maiden somewhere in June.

Ij the background I have solved now also the topic of how to synchronize the motors without compromising their perfect carburator settings. I have now programmed a separate thottle curve for each motor, which allows me to synchronise them electronically before each flight. At least until both motors have reached their final state, at the moment they are not competely run in and I expect them to still change a bit over time.

But that will be the fun part of it....when the Welli is flying...;-)


Greetings Robin

[Scott Edwards]

That looks fantastic Robin !!! May I ask what paints and glow fuel proofer you have used please ?

I use car paint now (basecoat and 2K lacquer) but it's getting harder to get and expensive in the UK, so I'm always interested in alternative solutions.

I have found the model to be quite fragile, it's heavy but uses traditional building techniques, so there's often some minor repair work after each flying day. The wings in particular are very big, heavy and awkward. That's all part of the fun of large models though !

[Robin Senn]

Hello Scott

Thanks.

The camouflage paints are some specially mixed Acrylic paints filled into spray cans from a swiss supplier. A bit expensive to be honest, but woth the money. IFor fuel proofing I used 2K satin clear spray cans. The black is also 2K paint from rattle cans. Both the clear and the black are fuel proof. You mix them up just before spraying. Got both quite cheap from the local hardware store.

I also looked into car paints, but they did not have the colors required. Also I found in the past, that they need rather heavy coats.

And yes, the plane seems fragile I give you that. At the moment I am on a side project, constructing a storage trolley for the wings in order to be able to roll them out of the way when needed and to prevent "hangar rash". The wings with the landing gear and the engines installed are rather arward to maneuver with the weight concentrated on the lower end.
I am actually also a bit worried how the construction will hold up to the engine vibrations over time. But we will cross that brigde when we are there...;-)


GreetingsRobin

[Freddy Vandermeeren]

Hi Robin,
I like yr. Wimpy...Due to a lot of other projects, I'll start building mine starting next year x-mas. I already have yr. dream available....2x Saito fg33r...what a sound.
By the way, everybody seems to build the upper engine nacelles to short as on Tony's plan. Actually they extend, as below, right to the leading edge of the flaps. I've been to Brooklands last monday to document R for Robert to get the model right. Looking forward to hear more from this thread. Tks. guys for the valuable support. I'll use yr. experience in my build!

[Freddy Vandermeeren]

By the way....how did you guys solve the wing fastening to the fuselage...there are many ideas how to do this....but I might still learn from you!

[Scott Edwards]

By the way....how did you guys solve the wing fastening to the fuselage...there are many ideas how to do this....but I might still learn from you!

Like you I didn't like the Plans' wing retention method of just self tapping screws into the wing joiner. You might get away with that for a bit, but long term - nope.

Instead I used two plywood strips (6mm thick, 30mm wide and about 300mm long) that are glued through the fuselage so their ends protrude about 50mm outside the fuselage. These end tabs have a 6mm captive nut inside.

These fuselage tabs locate into slots in the wing root, and then 6mm plastic bolts go through the wing surface into the captive nuts.

I hope that makes sense ? There are a million ways of doing this, but I wanted something simple, secure and easy to get too. The retention bolts are visible but put I put them in from above for ease of access, it's a huge model to have to turn upside down !

[Robin Senn]

Hello together

Thank for piping in to the Wellington build thread. Things have gone rather slowly over the last few week due to some health issues getting into the way. ( I am due for a replacement hip joint coming next week...which will delay the maiden into early fall....bah.. ....)

Anyway, the plane is now ready except for weighing in the CG and an egine runup test without cowls. I also solved the storage and transport issues of this rather ungainly plane. That was a quite a bit of a project in itself and cost more time than anticipated.

If I would build the Wellington once again, I would definitely change the wing layout and partitioning. In a future build i would definitely make a Center Wing panel containing the LG and the Engine to be fixed to the fuselage with only the outer wings panels removable. That would make transport and assembly much less arkward although it wouldtake up more space in storage.
But anyway, that issue is now solved too.

@Freddy: THank s for your positive words. While I am rather happy with my OS engines, I feel a bit jealous about your Saitos. They are really great engines. We have several of them running in our club and with a ring muffler and a big enoug prop they soud like four stroke heaven...;-) And as an additional advantage you wont have to butcher the cowls like I did for my single cylinder engines...

And yes, I admittedly went with the plan when doing the (too short) engine nacelles. At that moment of time, i hadent done too much researh regarding the nacelle forms and assumed there would be a real life variant with similar layout. But I actually never found anything resembling Tonys interpretation. But alas, what is done is done and it still looks like a Wellington which is enough for me. I am pretty sure, that over here in continental Europe only a few very selected people will notice the fact of the short top nacelles...

@Scott: Actually I went with the wing fatening proposed by Tony. While it seems arkward at first, it isnt all that of an hassle as I will be assembling the plane on a pedestal, so access isnt to big an issue.
I have used this fastening technique before, without any problems arising. But maybe I just used to have thuings a bit more complicated...;_)


Best regards Robin

[Robin Senn]

Hello together

After a long hiatus from the Wellington i got back to it and put the last few hours into the build. Altough "hours" is a bit of an exaggeration as the only thigs left to do were checking the CoG and checking i the engines are running in synch. But it really seemed like a boat full when I have burnt out a bit on the build last fall.

Anyway, having gained back the motivation it took a week of counter checking everthing and setting up the CoG until the maiden flight. Unfortunately I had to pack a whopping 1.5kg of lead into the nose, bringing the Take of weight up to 21kg. But actually 21kg is still ok for this bird as it makes it less successible to the winds.

The engine synchronisation was also something that worried me last fall to quite some extent, but was in the end completely anticlimatic. The two OS 4 strokes were well run in and with some slight adjustment of the idle trim completely in synch.

Also the maiden flight was rather anticlimatic. As Stuart alredy mentioned in this thread the Wellington flies like a big trainer in the air.

Take off was a non issue as the plane took of after 10 Meters already with no swerving tendencies. The two OS GF40 are actually too much power, and most of the flight was done at 1/3-1/2 power.
But the sound is really great. I didnt use flaps when landing, as they were practically anchoring the plane in the air when deployed. I will have to reduce them quite a bit and add some down trim.
The landing you see in the video was a bit long, as I gave it to muich power to correct the slope. But the Welli rolled out into the filed with no damage to it.


All in all I am very happy how the plane flies as well as it looks and sounds in the air.

Now I just need to figure out the flaps setting and get somebody with a good video camera for the next flights...;-)

Greetings Robin

(Sorry for the bad quality of the videos...but I took what people sent me by Whatsapp....)


https://www.youtube.com/watch?v=PzBi8C4 ... bmd0b24%3D

https://www.youtube.com/watch?v=rv-9AVh ... bmd0b24%3D

https://www.youtube.com/watch?v=Q7dPePk ... bmd0b24%3D

[Scott Edwards]

Well done Robin ! All that work is worth it. I've got 21 flights on mine now, a bit of hangar and transport damage, but nothing has gone wrong and it's a super thing to fly.

[Robin Senn]

Hello Scott

Thank you for your kind words. And yes, going with the experience of the first flight, this plane will actually see more action than I anticipated. It is a joy to fly and has an awesome presence in the air.

At the moment I am doing maintenance and improving on some details on the model, as the first flight was a literal "shake down cruise"....;-) I lost 3 out of 8 of the cowl screws, also the cable tree in the fuselage and one of the ignition modules came lose. But all in all these are small things to do.
The big topic will be to find the ideal flap settings in order to better slow down the plane during the landing. I cant always rely on the field at the end of the runway to be free....;-)

Betst regards


Robin

[Robin Senn]

Hello together

Here a quick update to all the Wellington pilots. Yesterday I experienced my first single engine flight with the Wellington. While I always feared this situation as it being the worst case for the plane, the actual event wasnt all that terrifying or taxing.
It actually it took me a good 30 seconds until i realized that one of engines was out..I was rather high as I was still fiddling with the flaps setup, as I noticed something was off with the sound and the plane took more forward stick on the throttle to get up to speed again......until then I had already turned twice over the dead engine without an issue.....



Anyway, I called in an emergency landing and had to take another two turns over the dead engine to get to final as the wind direction didnt allow for another approach. I did the turns with about 75%power on the remaining engine and everything went well.
I arrived a bit fast at the runway and shut off the the remaining engine before settling in for a long but uneventful landing. Not damage done to the plane...only to my nerves.

But all in all the plane behaves pretty normal with one engine out, I noticed no tendency to veer off or other similar behaviour you would expect in such a situation. As long as there is enoug power to keep the speed up, the planes flies practically the same as with two engines.
Which allows me to bury one of my greatest worries when flying the Welli....so from now on I will be a bit more relaxed during the flights....

Did any of you have similar experiences with Engine outs?

Greetings Robin

(P.S: The reason for the engine out was fouled fuel line which I seem to have crinked during the last maintenance..)

[Scott Edwards]

That's fascinating to read ! Thank you for sharing. I too will now fly my Welly with a little less worries !

[Steve Vodrey]

Speaking of disasters my Wellington after a summer of engine problems bit the dust at a local field following loss of signal resulting in a vertical spiral descent. The damage was quite extensive.
Anyway after getting parts supplied by SLEC I set about starting the repairs this week.

[Steve Vodrey]

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[Steve Vodrey]

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After a couple of days its like something from the Natural History Museum

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