Wellington build and re-build

[Dave Parry]

Thanks for that Dave.
The journal featured a build thread for the same SLEC Wellington fairly recently done by Phil Robertshaw.

Hi Steve, everyone builds different and you can never have enough build articles for those of us who are not that good or confident to tackle something like this without help, no matter how many have been built. It doesn't have to be the full build just some of your techniques on how you tackled certain issues etc.. even down to painting, I don't think I have ever had an article on painting a model.

Anyway its a great build and please don't feel under any pressure to submit anything.

[Steve Vodrey]

Thanks gents.
To answer the question on gear first I have a ten channel Futaba but am using 6 and 7 channel receivers.
Futaba users will already know that to get the full 10 channels needs a 14 channel receiver. The second receiver then needs to be at least an 8 to get both to work together.
I am happy with a 6 and 7 with a servo on every output. Power is fed into both receivers in two places as a safety measure. Separate switch and battery on each receiver of course. Model will be under 20Kg but I like the two receivers system.

[Steve Vodrey]

With all those servos I like to use locking multi connectors.
Four servos in a wing are connected with one action.
First I make the loom with the various lengths needed.

Loom.jpg (35.3 KiB) Viewed 18600 times

The multi connectors can be bought made up but are at set lengths and expensive. Making them up having to crimp each pin individually takes some time but makes for a tidy job.

4 way connector.jpg (43.71 KiB) Viewed 18600 times

Servos wired up means I can get on with the push rods. Not the best scale detail I appreciate but practical and accessible. Simple enough with 3mm threaded bar covered with carbon fibre tube.

Pushrods.jpg (39.08 KiB) Viewed 18600 times

[David Brown]

I have used them for years Steve, as you say they make for one simple connection without mixing up plugs. We have all done that . Ashlock used to sell them but I get them from Phil at Fighter aces now. They are available off the web but you have to buy large quantities I find. The Welli is looking great, looking forward to seeing it fly.

[John Greenfield]

Steve
Those servo wires really should be twisted, not flat. I know 2.4 is much less susceptible to "pickup" than 35meg but twisting the wires will provide better screening to both the receivers and servos.

John

[Steve Vodrey]

Thanks gents. Making progress slowly to get it airbourne. Presently running the second Zenoah around in a DR1. Don't know why I'm bothering really as its run great from new. Haven't had to touch it at all. After a good thrashing at East Kirkby it can come out and get fitted in the Welli.

[Brian Bellamy]

U.K. Jet shop in York also stocks ashlock connectors, you can buy just what you need, and very quick delivery.

[Steve Vodrey]

The welli is now like a painted ARTF and coming together quickly as I fit all the gear into it.
Hopefully this model will last some time (famous last words) so it's always necessary to have access to everything to change batteries and get to pneumatics etc.
The below shows how I get around the problem. The tray slides in the front into softwood rails. Switches will be fitted into the angle at the front as will the schrader valve. Access is by removing the front gunner turret which I still need to make.

Tray done.jpg (48.21 KiB) Viewed 18450 times

[Steve Vodrey]

Side and down thrust is checked now that the engines are installed. My trusty square lengths of wood get used again.

trusty square propellers.jpg (31.68 KiB) Viewed 18319 times

Side thrust just on the starboard engine. There are lots of opinions on this one....

thrust set up.jpg (44.79 KiB) Viewed 18319 times

With the wings together on the work table now is a good time to set up all the movement for the flaps and ailerons. I decided to split the flaps into two pairs one receiver for inners the other for outers. I used two operating channels so there is only one servo on each output.
Ailerons are on the same channel. I still get differential by offsetting the arm on the servos like we did before transmitter programming took over...

Aileron and flap set up.jpg (44.79 KiB) Viewed 18319 times

[Steve Vodrey]

Time to balance the Welli and see how much church lead is needed in the front. As it happens the C of G on this model is on the front wing tube so its easy to suspend from the garage ceiling.
I need a full kilo in the front to get it to balance wheels up. Incidentally this was the first chance I got to test the retracts. Made by unitracts they work perfectly.
Now is also a good time to check the all up dry weight. Mine will be coming out at 19Kg so keep the weight down if you're doing one unless you first register it under the exemption scheme which is probably a good idea from the outset.

Balancing and dry weight.jpg (40.77 KiB) Viewed 18284 times

[Steve Vodrey]

Looks like I have to build the front turret and chin if only to accommodate the nose weight.
Soon done. With all that wood I will start with a couple of pounds of lead in the front. Plenty of room for more if needed. It's quite satisfying bashing a piece of lead into shape. It's about as far forward as I can manage.

Chin piece.jpg (54.08 KiB) Viewed 18227 times

This will be sufficient for the test flights.

front turret.jpg (36.18 KiB) Viewed 18226 times

This morning I tried out different props on a Zenoah 26. Looks like a Graupner 16/10 three blade is the ticket. Getting about 7,000 revs static so not overloaded at all.
Not much left to do now before I have to bite the bullet and take it to the skies...

[Andy ward]

Looking Great Steve

[David Brown]

Will she be ready for the week end Steve,

[Steve Vodrey]

Thanks gents.
Welli will be ready for test flights later this month. Building delayed slightly owing to the better flying weather.

Steve

[chris-berry]

Looking very nice Steve!

A couple of Saito R33s would do the business!!

[Steve Vodrey]

Hello Chris.
Good suggestion. Just looked up the Saito R33 engine. They do look the business and would no doubt fit in the cowl and sound great too. At £799 each though I will give it a miss. I'm a bit of a Zenoah nut and besides they are fitted and running now. No batteries required either.
Now ready for test flights.

Steve

[Steve Perry]

The multi connectors shown are as per this data sheet https://cdn-shop.adafruit.com/datasheets/JSTSM.pdf

Pins Male SYM-001T-P0.6

Pins Female SHF-001T-0.8BS

Housing for pins SMR-12V-B, black or SMR-12V-N, white

Housing for sockets SMP-12V-BC, black or SMP-12V-NC, white

RS stock the SMR-12V-B http://uk.rs-online.com/web/p/pcb-pin-socket-strips/3922357/
and the SMP-12V-BC http://uk.rs-online.com/web/p/pcb-pin-socket-strips/3922509/
Female pins http://uk.rs-online.com/web/p/pcb-connector-contacts/6881303/

[chris-berry]

Hello Chris.
Good suggestion. Just looked up the Saito R33 engine. They do look the business and would no doubt fit in the cowl and sound great too. At £799 each though I will give it a miss. I'm a bit of a Zenoah nut and besides they are fitted and running now.No batteries required either.
Now ready for test flights.

Steve

Hi Steve, I like the Zenoah engines and you're right about all the other gubbins needed. You never know, its a future option. Good build thread...another one on my wish list!

What was the all up weight in the end?

Chris

[Steve Vodrey]

Hi Chris.
Those Saito engines would be perfect. The icing on the cake for sound and scale effect.
Regarding all up weight, this will be included in my journal article but it was more than I expected.
My mod to include flaps no doubt put the weight up slightly. I was aiming for 18Kg but ended up with 19Kg dry weight. That is all fine and legal but I would recommend anyone taking on this model to register it into the scheme to start with. Had mine been covered in heavier covering and more paint it could well have gone over. The scheme is free to LMA members and not a difficult process to go through as I had to do it with my B25.
Best to go through the scheme from the beginning of the build rather than retrospectively as the examiner quite rightly might need to see under the covering/sheeting meaning your prize toy going under the knife before you can do any test flights.

Steve

[chris-berry]

Thanks for the info Steve. I know they are generally on the limit for 20kg. As you say, it's worth registering early doors.

I'll read the article with interest!