Bates 1/5.5 Sea Fury Build

[Nick Somerville]

 

the extra layer of carbon cloth stiffened up the lay up nicely. Had a bit of a tense time cutting up the moulded forms following a good sanding with fine wet and dry, but went better than I thought. Trusty Hegner fretsaw for rough cutting to within a few mm and then sanding outside in the breeze with a mask. The forms conform closely to the wing skins with just a touch of directional change at the outer edges fore and aft. This was due to the way the battons I had fixed to the back of the mould had effected the shape. Fortunately the orbital sander had removed most of the offending discrepancies in the mould. Hopefully as I build up the internal detailing I can pull the edges in to perfectly match the wing profile.

[Nick Somerville]

 

wheel wells cut out around the covers and doors. Inside you can see the temporary infill rib profiles I had tacked in place to ensure the wing sheet didn’t take a flatter profile. It’s a big opening for the 5 1/4” wheels and when trial fitting the sheets I could tell they wanted to lie flat.

[Nick Somerville]

Wing tips ready to be added. 0.5 mm ply core. It’s good to have something to sand down to, but ensuring all is square becomes essential. Re the gear door mould, I do hope Dirk (‘The Moulding Magister’) wasn’t looking at my posts ?.
 

[Piers Acland]

Great work Nick.  Following with real interest.

[Nick Somerville]

Radiator and oil cooler intakes roughed in and fillets at the leading edge step blended. Might be worth putting the wing on one side now to make a start on the fuselage as at this stage, when nearing completion of the wing, there is a danger of rushing. I haven’t either made or purchased the gear door hinges so another reason to set it aside. It will be good to take a fresh look at the progress in a month or so as I am getting a tired if seeing the same bits on the bench.

 

 

 

[Nick Somerville]

So the wing has been set aside and a start made on the fuselage. First up a simple crutch for the upper body with the fin post built in as the last former. A simple diagonal temporarily holds it vertical. Next job sheeting and then the fin and rudder need to be constructed. The cockpit is cut out later.

 

 

 

[Nick Somerville]

A little more work done. Fuselage top now sheeted except for the area around the exhaust outlets and rudder completed. Next job is to revisit the tailplane and elevators for a final check/sand and then glass cloth them. I will get them up to the primed point prior to gluing in place. With the too part of the fuselage on the board it will make setting the +2 degree of incidence easier, though I cant help feeling the tailplane is going to get in the way whilst building the rest of the fuselage. Jerry’s notes on the plan suggest doing it this way so I am not going to digress. Also once the tailplane is secured the fin can be built up. 

 

 

[Nick Somerville]

One other update: the power plant has been purchased and should be on its way. I have  wanted a multi cylinder engine for as long as I can remember. It’s one if the reasons I chose to build this model as it is ideally suited for a British made Laser 360V Twin. 

[Nick Somerville]

First stint of glass clothing. 24grm / m2 lightweight using Easy Composites EL2 resin and AT30 slow cure hardener, that allows lots of time to work all the parts. I have 48grm cloth for the wings and fuselage as all the sheeting I have used is pretty light/soft.

 

[Nick Somerville]

With the glass clothing of the rudder, elevators, tailplane and ailerons complete its good to do a bit of detailing. The trim tabs (5 in all) have been cut into the structures which have a little 0.4mm ply internally to reinforce the otherwise weakened structure. The cuts go only so deep as to give the impression of being separated. The exit shrouds are formed from litho that has been heated and then pressed into a tapered grove in a hardwood block. The linkages are adapted cheap aluminium 2mm ball joint connectors. There are subtle differences between the rudder, aileron and elevator shrouds but the linkages should work fine for all. Rudder tab sorted 4 to go.

[Piers Acland]

Very nice Nick.  What is the shroud made from and how did you shape it?

 

Piers

[Piers Acland]

Scratch that.  I should have read the text more carefully!

[Nick Somerville]

 

Spent an enjoyable few hours at RNAS Yeovilton this morning taking up close photos of their Sea Fury exhibit. I already have a load of ‘Walkabout’ photos and a fine book on the Sea Fury, but nothing comes close to seeing your subject in the flesh. 
Removed upper half of fuselage from bench and have glued the tailplane in place after lots of measuring to set the 2.5 degree positive incidence from the datum line as per the plan. My benches are not so deep hence setting up on the floor, which I know is also very true/flat. Once set a couple of carbon cloth reinforcements were added from the inside to strengthen the contact area. Next task is to build up the fin. Still have my concerns that the rear flying surfaces are going to be a nuisance as I build the lower fuselage. Probably time to get the Robart model stand out again.

 

BTW for any Vaught Corsair enthusiasts the example at RNAS Yeovilton is quite something. I did take a few pictures but it was so atmospheric in its restored original state that I had to move away for fear of getting any ideas! 
 

[Timo Starkloff]

Thanks for the nice building log ?
It's already twelve years ago since my first and last visit to the Yeovilton museum when visiting a friend nearby. What a great collection!

 

Timo

[Nick Somerville]

 

Fin built up and faired in along with tailplane. Still need to cut out the balance tab aperture and add the tab to the rudder.
 

On the full size there is a distinct added formed fairing that should be possible to emulate using thin litho plate. I won’t be able to add this until the fin has been glassed though.

 

 

Here is my power plant. Laser 360v. It’s a lovely piece of engineering (Thanks Jon) but not nearly as  imposing as the Centaurus engine as seen on display alongside the Fury at RNAS Yeovilton.

 

 

 

 

[RottenRow]

Old Warden has a cutaway Centaurus, amazingly complex with all of the internal gearing for the sleeve valves. It’s worth a look if you are ever there.

Brian.

[Nick Somerville]

Been fiddling with the tail retract as sorting its installation needs doing before any further progress is made to the lower fuselage. For a large model it’s rather tight at the rear as you can see in the following photos. 
 

Here you can see the carbon cloth reinforcement for the tailplane and the carbon elevator pushrod with 3mm threaded rod passing through the mounting blocks for the upper retract pivot. By some good fortune the pivot point is in the ideal location and the pushrod moves freely.

 

This is the retract pivot bracket on the bench showing the small aperture for the pushrod.

 

and here with both elevator and retract pushrods positioned and the upper pivot pin in place. The other pivot point is below the servo. The servo is a Hitec mg 85 so plenty powerful enough for the tail steering and with a pair of springs to drive the steering horn it should be well protected from the inevitable jolts when taxiing. Hopefully I can simply drive it from the rudder channel using a y lead so mo additional receiver/transmitter channel required. I will paint it all a silver grey but in reality only the wheel and the lower brass parts will be visible.

[Jon H]

I dont wish to be gloomy, but although it looks awesome that tail wheel unit looks rather heavy. I know you say in the OP it works out to about 55g, but you then have a 22g servo and a wheel plus other sundry items so 100g all up? 

 

If so, that weight will need to multiply by least 6 as this will give a bit of an idea of how much lead you will need to balance it out given the moments. 600g of lead in the cowl just to balance the tail wheel, plug the weight of the wheel itself gives us 700g.  1.5lbs of the models expected 24lbs is accounted for by just the tailwheel. Its not ideal. 

 

If you are able to relocate the steering servo forward you can save .3lbs in ballast just by moving a tiny 22g servo. This is why WWII fighters often end up needing tons of lead. Noses are short (especially on radial engine fighters) and tails are long. 

 

My Sea Fury uses a really light plastic retract for the tail wheel and even with all the radio and batteries forward i still have 2lbs of lead in the cowling under the engine. My model is built about as light as it can be and its 23lbs. I wouldnt want it much heavier than that. I dont know how the weight of my glass fus compares to your built up version, but overall your build is much more detailed and much heavier. 

 

If you can, i would get it all together as best you can a c/g it now just to get an idea of the AUW and how much ballast will be required. If you are getting up over 25lbs already before finishing etc it might be 28 when its done and that is heading towards manhole cover territory. I would tend to set 25lbs as an absolute maximum and its easier to make modifications now than when its finished and on the scale. 

 

Im not trying to be critical, the quality of your work is fantastic, its just a note of caution as a flying brick is no fun at all. 

 

Edited July 13, 2021 by Jon - Laser Engines

[Nick Somerville]

Plenty of useful pointers there Jon

Thank you. Having now reweighed the whole unit with and without the servo I can see that by ditching the servo and taking an additional pair of closed loop wires from the steering horn springs directly to the rudder horn, I can make some good weight savings. Without the servo I can also cut back the back of the carriage so the auw of the unit will be about 70grms including the wheel and mounting parts. I can live with that as the tail end feathers are all lightly built as is the rear of the fuselage.

Going by my P47 build I am estimating that this model will be in the 20- 21lbs range. Lets see how it progresses but any followers feel free to make a stab at the final AUW and I will procure a suitable prize for the winner. Jon gets a manhole cover though if his 25-28lbs is correct ?.

[Martin McIntosh]

Should not have looked at this thread because it is one of my favourite aircraft and I am stuck for something to build next. However, having seen Jon fly his I doubt very much if I could emulate it. Maybe a smaller version, say Laser 180 powered at 1:5 scale or a bit less? Brilliant build so far and a credit to you.

[Piers Acland]

Great work Nick.  As you said earlier, it gets quite tight at the back end.  Have you checked that when the tail wheel is raised, it does not snag on the closed loop wires running from the rudder servo back to the rudder horns?  Just a thought.  

[Jon H]

If you can do it to 21lbs then i will tip my hat to you.  My YT job is a hefty hector and on a few occasions when folk have asked me how heavy i just tell them to pick it up. On more than one occasion (following expletives) the guys doing the lifting have checked to make sure i didnt nail it to the ground! 

 

Its as light as it was ever going to be. Forum posts on rcu suggest 26 is the normal weight for them so i think i did well at 23 (i think its 23, need to weigh it again). 

 

As for the manhole award, put me down for.... 24.8 ? 

[Martin McIntosh]

Started to watch this with interest since I have just received the Sarik plans and canopy for a 77" version, 25cc power they say. Cowl no longer available (250mm dia) so I shall mould my own. Hoping to keep the weight right down because I only intend to use a Laser 180 which powers an 18lb Spit very well. Unable to get an estimate of the AUW for mine but what does yours suggest?

It would seem to me that you have an awful lot of servos and other bits near the wing TE. Is that as per the plan? My plan shows servos quite rearward in the fus so because of the short nose and a much lighter motor I shall put them as far forward as possible. Any thoughts would be appreciated before I start to hack balsa.

My plan shows a folding wing with a 30" long birch ply main spar so that is out of the window to start with.

[Nick Somerville]

Martin, firstly the 6 servos for flaps and ailerons are all mini sized KST jobs so pretty light and not that far behind the c of g. The other servo for the pneumatic sequencer is also a mini sized one so I am not too worried. The plan showed standard sized servos on the c of g but with snakes running to all the surfaces, but I am just not a fan of snakes. The rudder, tail retract and elevator servos will be fairly heavy duty jobs set on rails well forward in the fuselage. 
The plan suggests petrol engines in the 45-65cc range and an auw of 19 - 24lbs. I think my Laser 360 will be a tad over what is needed and I am still hopeful of achieving 23lbs. 
Re the folding wings. The example I am building was originally built with fixed wings so thankfully I am keeping to scale by not adding the complexity, which in any case would likely be well beyond my abilities.

 

At 77” your Fury should be ideal for the 180 if the tail end is kept light.

[Jon H]

Folding wings sound cool but they also sound like they might shorten the life of the model. It isnt something i would be bothering with that is for sure.