Sopwith Camel by Mike Dowling - FINISHED - Model Airways - 1/16

[Mike Dowling]

Yet another question John ! Regarding splitting and re-joining the bottom wing - I don't find the instructions for this to be very good. I understand about blocking up both wing tips to the correct height and I assume the metal joining bits are the gutter shaped pieces with holes in them, one for each spar. However the instructions state that 'the spars should lie flat in the cast joints and the underside of the outermost ribs will be elevated'. How can the spars lie flat if there is an angle on the wings ?

 

Thanks also Ken for the diagrams, I can see that as long as symmetry is maintained it should be OK.

[jablackwell]

Hi Mike,

 

The instructions for this state:

"Create the lower wing dihedral by tapering

the bottom ends of the front and rear spars

so that when they are rejoined by parts

CAW38 and CAW39 they will lie flat within

the cast joints and the underside of the

outermost ribs(CAW06) will be elevated

25/32" above the work surface."

 

This means that you have to file or sand down the BOTTOM side of the lower wing's spar at the point where it attaches to the metal casting.  I used two small wood blocks, each 25/32" high, placed under the last wing rib to get the angle set correctly.  When I built the lower wing, my wing sides were not connected. The long wooden spar piece was left in two parts, with the center disconnected. That way, I did not have to saw them apart later. If you built this as one large wing, you will have to separate them into left and right wings using a knife or saw, being careful to cut precisely in the middle of the two spars. Images attached for you.

 

~john

 

 

 

 

[Mike Dowling]

Oh silly me !! Thank you John.

[Mike Dowling]

The wings are nearly finished now. I just have to be really brave and cut off the ailerons  (!!!) before hinging them, doing the dihedral for the lower wings (blocks drying) and putting on the aileron horns.

 

[Mike Dowling]

I was really brave and cut them off !! Not too bad actually with a razor saw. Sanded them down and then put them back together again !!! This time with hinges ! I have to say I nearly had a complete sense of humour failure doing those hinges - very tricky but they even go up and down. I'm impressed anyway !

 

I started the fuselage sides the other day but I have had to take them apart three times because of the stupid 'various scale' plans that I seem to have. Just when you get something spot on anther plan looks miles out ! Hey ho, we love modelling really. I have put in the corner pieces which get deadeyes and rigging attached later.

 

 

[jablackwell]

Mike,

Nice work on the wings and aileron hinges.  Recommendation: take some old sewing thread and tie the ailerons to the wing such that they are flat (in the same plane as the wing). This will protect them from damage, and will make running the control rigging a lot easier later on in the build.

 

Have fun with the fuselage!  ;-) 

 

Best,

~john

 

[Mike Dowling]

Good tip John, thanks for that. When you built your fuselage did you use the recommended jig ? It looks from your log a if you didn't.

[jablackwell]

2 hours ago, Mike Dowling said:

Good tip John, thanks for that. When you built your fuselage did you use the recommended jig ? It looks from your log a if you didn't.

Hi Mike,

 

No - I didn't use the jig, though I would recommend it. I used the plans and used the time-honored tradition of pinning down the wood to the plans. You absolutely need a completely flat board on which to build.  

 

~john

 

 

[Mike Dowling]

Hey John, a really tricky question for you ! Fuselage, horizontal formers, position 'D' on the plans. Should the bottom former attach to the bottom of the side uprights or should it attach on the pre-cut ply frame above the square cutout ? I know it is only 3/32 lower if that is the case but piece CAF13 the fairleads frame has to sit on top of it by the looks so the small height difference will be crucial .

[jablackwell]

5 minutes ago, Mike Dowling said:

Hey John, a really tricky question for you ! Fuselage, horizontal formers, position 'D' on the plans. Should the bottom former attach to the bottom of the side uprights or should it attach on the pre-cut ply frame above the square cutout ? I know it is only 3/32 lower if that is the case but piece CAF13 the fairleads frame has to sit on top of it by the looks so the small height difference will be crucial .

Hi Mike,

 

That horizontal former is glued to the pre-cut plywood frame.... just above the cutout (flush with the top of the cutout). That cutout is for the lower wing (metal brace for the main spar) to fit into. 

 

~john

[Mike Dowling]

Brilliant, thanks John - the diagrams are very confusing, one seems to show it above and one below so your help is much appreciated.

[Mike Dowling]

I really do find the instructions for this build confusing. The five plan sheets all vary slightly in their measurements so trying to get sizes right is a real challenge. Also I realised when I started that the 'supplies' to build the plane with are less than generous and in some cases simply not enough. I have had to add some spare wood from other builds in order to make up the shortfall.

 

Anyway, enough of my whingeing, the fuselage is done and next it is on the really fiddly bits !!

 

 

[popeye the sailor]

what you want to determine is the pitch of the prop......the twist.   the leading edge of the prop is thicker than the trailing edge......just like a wing.  as L.H. said the root of the prop is thicker that the tip.

[Mike Dowling]

Popeye, I have sort of given up on my prop for now after all I won't need it until the end. The one I ordered came today ! Teensy problem is that it is 17 inches long not 17cm !!

[cog]

Just scale it down At least you have a good example to work from ... can't you switch it against a smaller one ...

[Mike Dowling]

Carl, amazingly enough no one seems to make propellers that small in wood - only plastic and not many of those. I may try and scale it down though.

[cog]

I think you'll manage with the live example, and xken's tutorial. On the other hand it is odd a 17cm prop is unobtainable ... I'll have a look with the RC boys here in the Netherlands, maybe I can find you something

[Mike Dowling]

Carl, any luck with the prop ? I have been looking everywhere and can't find one.

 

John, if it's not too cheeky - how much of the pipe plumbing did you actually mange to do ?

 

[jablackwell]

13 minutes ago, Mike Dowling said:

Carl, any luck with the prop ? I have been looking everywhere and can't find one.

 

John, if it's not too cheeky - how much of the pipe plumbing did you actually mange to do ?

 

Hi Mike,

I did most of it. I skipped getting to the back of the instrument panel for all but the most visible piping (airspeed from the pitot tube is very visible, for example). The fuel lines are all visible, so important to get done. It is tedious. A pair of mini pliers and a lot of patience are needed.... but it is worth it.

 

~john

[cog]

Not yet, found a 10" which is still too large, did find a 6.5" but that one was plastic (yak) and a bit to modern for your airplane ... search continues

[jablackwell]

Mike, you can find some interesting results by searching google for "wooden model airplane prop".  Check these out for example:    https://www.hobbylinc.com/rc-airplane-wood-propellers  

 

~john

 

 

[Mike Dowling]

Thanks for that John. I have found several sites including the one I 'accidentally' ordered from but they are all far too big. I will keep hunting but I can see my pathetic attempt going on the front after all.

[Mike Dowling]

Update folks,

 

The cockpit is more or less finished. There is the surround to do (I think it's called combing) and a few more pipes which have to be done later. I had a huge fight with the machine guns which took me ages to fit but got there in the end. I hated the seat which came with the kit so have customised one which I think looks a lot better. Also added a firewall that wasn't included in the kit.

 

Next stage is to tie loads of turnbuckles onto the sides before doing the fuselage cross bracing.

 

 

 

 

[Mike Dowling]

John, with hindsight, would it have been easier to do all the tailplane rigging before adding the side braces ? I know the instructions don't say to do that but I wondered what you thought.

[jablackwell]

Mike,

The brace rigging for the empennage is distinct enough that there would be no advantage to adding its rigging earlier.  Now, maybe you mean control cabling? That might be easier to do prior to running the whole fuselage bracing wire set.... but either way, it was not too difficult to handle with a couple of tweezers. I found the rigging of the ailerons more tricky with the plane, nose down on a jig. In fact, I really didn't like that part of the build at all.... but I suppose there's nothing one can do about it. That's just the way the bird was built. 

~john

 

[Mike Dowling]

Thanks John, I did indeed mean the control cabling. I'm not sure about the jigs either. I didn't use the twirly one at all!

[Mike Dowling]

I forgot to take pictures underneath !!

 

 

[cog]

Mike,

Can you give me the measurements of the prop. The smallest ones I can find are 9" or 10" which is a wee bit to large to have it twirl around ... but I wouldn't mind giving it a try meself ... (a good excuse to do something else then twisting, folding, and glueing PE)

Love the look of your model ...

[Mike Dowling]

Carl, the propeller is 17cm long and 1cm thick in the centre. It is a peculiar shape which didn't help my efforts at all. I think if it was a normal shape I might have managed better.

Thanks for the comment anyway.

[cog]

I'll have a go at it, and shall let you know if I get as frustrated as you