SE5 restoration

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[gilesfordcrush]

This is going to be a record of the restoration of a DB scale SE5 I bought about 18 months ago. It was fully functional with a Super Trigre 3000 and futaba radio gear. It was a little tatty and much of the structure was starting to show signs of age. I flew it many times though and it was a great model to fly, being quite big and heavy it handled wind well and looked just right in the sky.

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/image0009.jpg"/>

I decided to improve the model after a heavy landing cracked the fuselage near the bulkhead. I started to strip down the front of the model - and quickly ended up with a collection of fuel soaked balsa bits. My repairs to this area became an almost total fueslage rebuild.

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/SE5%20refs%20042.jpg"/>

You can see from the pics what bad condition the bulkhead area was in. I didn't have the plans for the model, but Eddie at DB scale was able to provide these, and I was able to visit the Balsa Cabin in Maldon, Essex as I don't live far from there, and started to rebuild it!

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/se5%20end%20of%20stripdown_%20054.jpg"/>

I have never built a model before, I've been flying for years and my building experience was limited to ARTF models. So I took my time when construction the fuselage. I added some extra bearers for strength in a could of places.

Presently (Nov'06) the main reconstruction of the fuselage is finished and I'm starting to fit radio gear before I do the final covering to make sure I can get everything fitted easily before it is covered up!

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/se5_fuselage%20001.jpg"/>

My plans for the model involve:

Covering using poly-c and linen, painted with WarbirdColors PC10.

I'm going to add diahedral to the wings as the original builder didn't seem to think this was needed!

I'm going to have loads of questions for all you experienced builders over the winter, so I hope these pics have given an idea of what I'm up to. I have some nice video of this model flying, perhaps I can upload this somehere if anyone is interested.

[gilesfordcrush]

my first question is concerning the throttle linkage. I have positioned a servo right behind the bulkhead and I intend to use a metal linkage with ball joints at each end to provide a very positive linkage with little freeplay. The previous linkage was to a servo much further away and along a wobbly route using plastic tube in plastic tube - most unsatisfactory.

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/se5_fuselage%20008.jpg"/>

Is this a good way of doing this? Is there any reason why I shouldn't do this - like vibration from the engine upsetting the servo?

Giles

[p51p47]

Looks fine to me..............I've mounted servos directly behind (& even on) bulkheads for years and never had an issue...........as long as your servo grommets are fresh, correctly fitted, and the prop is balanced, you should have no problems what so ever.............

Phil

[alan c]

fine for the thorttle, but dont have the servo that way for the control surfaces,   nice re-build by the way,  wonder just how many models get binned, instead of stripped, and re-built?  look forward to this one,   

[gilesfordcrush]

alan said: fine for the thorttle, but dont have the servo that way for the control surfaces

what way of servo mounting here is wrong for control surfaces? Or are you refering to the ball and socket linkage?

[alan c]

no,  rock the servo back and forth across its width, then try it front to back,  you will see what i mean,    its more rigid in a fore and aft mounting

[BrianB]

Hi Giles

Why will you be adding dihedral if, as you said earlier, it's such a nice model to fly in the state it was?

Sorry, but I had to ask!

[idigbo]

Hi Giles

Why will you be adding dihedral if, as you said earlier, it's such a nice model to fly in the state it was?

Sorry, but I had to ask!

Brian, presumably because it should have dihedral .

Se5a's had two settings for dihedral, the factory fresh angle, plus, in the field of action, a few pilots had their riggers reduce the dihedral, presumably to make the machine more unstable, ie more manouverable.

Watching with interest, Ian.

[BrianB]

Then perhaps this is a model of a "reduced" dihedral one Ian?? 

[idigbo]

Reduced would infer that it did actually still have some though

Looks like it was a nice model once upon a time.

Giles, have you picked your colour scheme yet?

[p51p47]

I'd imagine some dihedral would only improove matters on a model such as this ?

[Dragon Wings]

Giles,

My plans for the model involve:

Covering using poly-c and linen, painted with WarbirdColors PC10.

I could be wrong, but to the best of my knowledge (and limited experience) PolyC is not a 'shrinking' material like the old shrinking-dope. You would therefore have to tighten the linen covering by some other method.

But I could be wrong

Cheers,
Steve

[gilesfordcrush]

Hello chaps, thanks for all the replies so far.

I understand about the servos now! I'm glad there is not some terrible problem with the ball and socket method as I like the solidity of this method

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/temp%20003.jpg"/>

I want to add diahedral for two reasons - firstly, as pointed out, they did have some when built, and
secondly it will (in my opinion) look nicer with it. I've got a small movie clip of the SE5 landing
- it looks somewhat "plankish" with these two flat wings. If you look at pics of other SE5's with dia, it
alters the look of the aircraft wihout it.  If anyone wants this video I'll e-mail it to those who ask. 5Mb Quicktime MOV.

Yes, it flies fine as it is - but I do tend to stooge around the sky rather than try and evade Fokkers (!)
so some extra stability will be just fine, thankfully I don't require massive manoeverability!

As for paint scheme, green (not brown as it is now) but I've not got further than that! I'd like something
different with some historical significance. I have an RFC tunic button that I intend to fit in the model somewhere - kind of flying history!

Last night I removed the rudder and tail skid servo tray. This was behind the cockpit and I plan to relocate the servos much closer to the CoG. I plan to use long closed loops for this. You can see in the pic some closed loop system which I've not seen before - are these any good? I'll be doing much more convincing wiring too!

[img]http://www.rcmf.co.uk/gallery/albums/userpics/14651/temp%20007.jpg"/>

I'm hoping that by moving all this weight further forwards I'll help with the balance of the model. It did have quite a large ammount of lead at the front.

Re: Poly-C - I've covered using poly-c and tissue before. I like the fact it does not shrink - it still provides a tight covering. Hoping to do the tail plane with the linnen tomorrow.

Question - would a Futaba S148 be powerfull enough for my elevators - on a short metal link

I'm going to Duxford tomorrow - I think they have an SE5, looking forward to seeing the new airspace hanger.

Giles

[yzfmike]

Giles

The closed loop system you show is good. The idea is that you connect the wires to the pulleys, and adjust the pulleys them to tension the wires. The pulleys are rotated via the servo pushrod - this way the wire tension does not put radial loading on the servo output shaft.

I think, remembering your model, that 148s are not man enough. I'd consider something like Futaba 3010s with a 6v power source (5 cell NiMH).

Mike

[p51p47]

Have to agree about servos..................Futaba 3010, or something like the Hi-Tec HS 645 are good middle of the road, 5/6kg servos for large models................

If you plan on having the servos in the back end, with long extension leads, a 6v power supply will also be a good move. Make sure you run 'twisted' cable (I use Ashtek silicone coated wire), rather than the normal ribbon cable suppied by Futaba/JR etc....twisting the '+' and '-' around th signal gives a degree of interference rejection compared to a normal flat cable on long leads.

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Phil

[gilesfordcrush]

I'll get a Futaba 3010 for the elevator. This has made me think, the elevators on the original kit specify one servo for each side, in the lower wing, driving the upper elevator with a connecting rod. My model has a servo for each elevator, ie four servos. two in the lower wing and two in the upper wing. Perhaps if I had Futaba 3010 servos in the lower wing I could do away with the servos in the upper wing? This would reduce the wiring, and also reduce my rigging time!

These servos are 17 quid each!

Giles

[rvary]

Hi Giles

This is looking excellent. As you see, I've finally got access. By the way, please don't tell me that's your beautifully restored Capri that you're using as a building board.

I don't see any problem with having the throttle servo mounted as you have. Although one of the posts makes a good point about it rocking more than being mounted fore and aft: I hadn't thought of that.

Closed loop for the surfaces is the authentic way: I don't think that the SE used a pushrod for elevator. Looking at photos of the original, it seems to have a closed loop for the elevator, and the 7/8 scale SE5 at Popham certainly does. You'll need to mount the servos fairly far forward in that case, to get the correct angle on the elevator cables. As you say, it'll help with the CG as well. The surfaces will appear to have more play in them than a pushrod, but it doesn't seem to have been a problem on my Tiger Moth, or Matt K's enormous Pik 20.

There's a really nice paint scheme with a red nose: I don't know what the origin is, but it might be something to do with Albert Ball? (flew SE's on 56 sqn, and used a red nose as his symbol, according to Cecil Lewis's autobiog). I can't find a decent picture but here's a sketch: You are not allowed to view links.
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I'm sure someone else may know a lot more about this than I do.

Alternatively you could use the scheme form the classic Frank Wooton painting: see You are not allowed to view links.
Register or Login. Easier to paint!

I've not tried linen covering, but it should work with shrinking dope. I tried silk on a model once and it wasn't a great success: it didn't shrink much. Most of the homebuilders today are using polyester fabrics like ceconite (which heat-shrink), and adding UV protection with a polyurethane paint and/or non-shrinking dope. I guess it's like solartex for bigger planes. Come to think of it: what's wrong with Solartex? It's available in olive and antique linen colours...

Definitely need some dihedral: it's a characteristic of the original. Otherwise it'll look like a Fokker DVII head on

Good luck with it

Rik

[p51p47]

Giles.

I'd fit 2 'aileron' servos...............1 on each side in the lower wing. If you use a decent (as you have bought) servo with 5/6kg's torque, this is ample to drive the lower aileron, with the upper one connected to it with a pushrod.

I'd also look at fitting closed look controls to the elevator and rudder as Rik suggests. The look excellent, and are easy to fit, adjust and keep any unwanted slop out of the system. Just use the scale cable outlet points, and position your servos according.

Phil

[gilesfordcrush]

Hello Rik, Phil,

I need some good reference for where the rudder (and tail skid) closed loops come out of the fuselage. As for the elvevator - how would a closed loop system work? I believe that there was a small mechanism sticking up from the fixed, forward part of the tailplane infront of each elevator, and both above and below. So there must have been some complicated cable runs to pull the elevator about - I'll post a pic of my pushrod mechanism - it is nice and simple.

I could always run a dummy elevator closed loop system on the tailplane - wires running from one side to the other to simulate the correct linkage!

Rik - I was only using the Capri to put the fuselage on for taking that pic - I don't work on the car! Thanks for the links for colour schemes - I do like the all green, but I'd like to get some correct Squadron numbers etc.

Giles

[p51p47]

Guy.

The Se5a's tail skid was non steerable, so you only have the rudder cables to worry about.

As for the elevators.................to use closed loop, I'd split the 2 elevators into 2 separate surfaces, then using a horn on top, and one below, operate them off separate servos in exactly the same way as you'd do a closed lop rudder..................

I'm trying to dig out a decent 3-view line drawing showing the placement of the cables.

Phil

[selleri]

When linking to Airliners.net there is this neat little link near the top

[ Medium Large Fit Screen ]
URL (link) to this photo: You are not allowed to view links.
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So you would have these two little babies ones and not the 'orrible long one  ::cc
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[gilesfordcrush]

Guy? Giles!

I had a steerable tail skid before, and it really helped with ground handling, I'm planning on doing this again, with a closed loop seperate to the rudder. It might not be totally accurate, but it works very well.

I like this:

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If mine looks like that then I'll be pleased. I wonder if that is the one I saw at Popham with Rik?

Giles

[Pup Cam]

The original had a hinged, if not steerable tail skid.   There are some good photographs that will help you here:
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I hinged the rear section of the original one piece skid on my Flair SE5A with two mylar hinges fixed into a slot cut into the liteplay skid.   This was done in an  attempt to stop me wiping the thing off sideways.  Its been successful so far and the bonus is the ground handling is great.

With regard to the wings.  When you add the dihedral can I suggest you consider changing the way its rigged.  I would change from the "traditional" one piece top and bottom wings to the modern port half wings rigged as one unit, starboard half wings as a second unit and a fixed centre section in the style of the Flair Tiggie and Stearman (I think).    Much easy to rig/de-rig at the field.   When and/if my aging DB Pup gets restored I shall be doing this 'cos handling, transporting and rigging the one piece jobs is a real pain in the ....  Looks great in the air though!

Alan B

[rvary]

Hi Giles

Yes, that's one of the ones that visits Popham (there are three). They have a website: You are not allowed to view links.
Register or Login. Obviously a couple of non-scale bits: the engine is a flat 4 so the prop line is too high. And a steerable tailwheel. One was for sale recently: I was very tempted, but then I remembered I had a mortgage. And a family. Never mind.

[Mike Deans]

Another site to browse with some good pictures , the video unfortunately does not seem to wamt to work these days ( unless it is just a temporary glitch ).


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Mike

[idigbo]

The real SE5a had a steerable skid, complete with another run of closed loop to steer it, so yours would be even more accurate done that way

Ian.

[gilesfordcrush]

Hello all,

Christmas got in the way of my SE5 rebuild - I'm back on the case now!

Alan B (PupCam) suggested that I should split the wings to help with rigging. I like this idea.

I see that DB scale are doing a "wing retaining system" that allows you to clip the wings into the fueslage (You are not allowed to view links.
Register or Login).  I'm thinking that when I cut the wings to introduce the diahedral I can fit this system and leave the centre section of each wing attatched to the fuselage and the wings on each side permanantley attatched to each other via the outer cabane strut, and they would fold together for storage. Or I could have the upper wing as a single wing, the two sides of the lower wing attatched to the upper wing with the cabane struts, and the lower wing centre section attatched to the fuselage permanentley. Either way, with the centre section of the lower wing permanentley attatched to the fuselage I can leave the undercarriage attatched also, and the wings would be fully rigged when stored, so my rigging time would be greatly reduced!

I'll post new pics in a day or so.

Giles

[Geoff_Sleath]

Somewhere you say you're going to repaint the model green rather than the original brown.  You also mention using PC10.  My Flair SE5a is painted with Spectrum PC10 and it's definitely more brown than green.  Perhaps you'd better check the shade.

Looks like it'll be a splendid job when it's finished.

Geoff

[Pup Cam]

.... I can fit this system and leave the centre section of each wing attached to the fuselage and the wings on each side permanently attached to each other via the outer cabane strut interplane struts and they would fold together for storage.

Or I could have the upper wing as a single wing, the two sides of the lower wing attached to the upper wing with the cabane struts, and the lower wing centre section attached to the fuselage permanently.

Hi Giles,

I would definitely go with the first suggestion.  That way you get two easy to handle lumps about 38" long.    Simply make a jury strut for each side from a piece of thin ply or something to hold the wing root ends in the position they would be when attached to the fus. This keeps the relative positions of the panels correct, avoids straining the interplane struts and fixings and keeps the rigging tidy. 

With the second suggestion you get one unmanageable lump, the top wing, made even more unmanageable by adding the the two lower panels which will then flop about getting damaged etc. 

Good luck and keep at it.

Alan B

[gilesfordcrush]

Alan et all,

Thanks for your thoughts thus far,

I like the idea of having a jig to keep the two wing halves in the correct poition relative to each other. If I remember correctly most of the rigging at the centre of the aircraft is attatched to the top of the cabanes above the fuselage, or at the wing root of the bottom wing, meaning that to take the wings off leaving two centre sections on the fuselage most of the rigging will need to be unclipped. One benefit of this is that the rigging will help keep the wing section on, but I'll be left with the two wing halves with rigging flapping about - but I could add a method of retaining the rigging in its position on the plywood jig as suggested.

By the way - cabanes are above a fuselage and interplane struts are out on the wings? Is this right?

Geoff asked about PC10 paint - I'm using the Warbirds PC10 - I trust it will be a correct colour. I have yet to decide a colour scheme other than it will be a traditional markings SE5, I'd like to do some more research on this.

My progress this week - finishing off small bits of fuselage construction - time consuming. Working out how my closed loop systems will work for the rudder and tail skid, I've made a new servo tray for the rudder and tail skid servos. I've also covered my rudder with the Poly-C and Nylon covering, it was wet when I finished last night, so I'll see how it is when I get home. Pics to follow chaps I promise!

Giles