Ian's Rocking Donkey

Nice!
So the engine cage mates to the front of the cowling correct? Will you be cowling the engine in as well?

Jim

Edit: I just saw how the case mounts to the firewall, very cool.

Dude! That donkey is Rockin'! Can't wait to see how it turns out. But, with all that dihedral, how are you going to launch it?

The Bad Pun Mark

Dihedral... Never seen it in CL. Not sure what it will do.   

I am not being negative mind you just genuinely curious. Looks good though Ian!

Dihedral offers some problems with the lines pulling the inboard wing and causing the model to roll inward. Otoh, a polyhedral like the Jim's Corsair eliminates the problem by having level outer wings to receive the leadouts in a straight line.

Cribbs74 wrote:Dihedral... Never seen it in CL. Not sure what it will do.   

I am not being negative mind you just genuinely curious.  Looks good though Ian!

Well, my guess is that it's going to need a fair bit of down trim and right offset.  Looking at the picture, I'm guessing about 15 degrees of dihedral?  Since the wings are airfoil shaped, therefore giving some amount of lift, the combined lift will be vertical from the fuselage centerline.  Since holes in the leadout guide appear relatively close to the wing's lower surface, approximately the same distance below the wing as the bellcrank, the inboard wing will be mostly horizontal.  That'll place the fuselage vertical centerline and the wing's lift vector around seven degrees inwards towards the pilot?  If it had been a flat sheet wing plane, the issue wouldn't be so bad in level flight, but it would still try to fly inside the circle when up elevator was applied.  

Just as an observation, and if it were me building the plane, I'd make leadout guides that hang lower.  I'd hold the fuselage level and measure from the wingtip down to a point that is horizontal with the center of the bellcrank.  Then I'd bend some wire with two loops that are even with the bellcrank.  Look on Outerzone for C/L plans of scale high wing planes to see how they do these wire leadout guides.  

But then, I could be totally out to lunch.

The Hanging Mark

Here's a crappy drawing, but it should explain what I'm talking about:


The Artiste Mark

The ever-popular SIG Deweybird has wing dihedral and leadouts which run parallel to the underside of the wing. (I know because I have a kit sitting in front of me). Instructions say the wing halves should be glued with a 3/4" block under one wing-tip. I'll let the mathematicians in the group figure out the angle. Obviously it works ok in this example. The design/kit has been around for a long time and all reports are that they fly pretty well. I'll get mine built one day! (One day!!)

Rod.

By the way, after all that speculation, the "Donkey" ain't no Spitfire by the look of things.

The dihedral is 14 degrees, Mark was close but no cigar.
 
There is scale, semi-scale and practical but similar. A scale Spitfire is a difficult model to fly and not for the faint hearted.
 
A lot of British modellers have learned this the hard way - the elliptical wing while beautiful and emminently practical for a WWII warbird has the ability to stall and take the plane into a flat spin. Not just a tip stall - the whole wing!
 
The real thing
 

After getting addicted to the "Windy" videos as promoted by Rusty - I decided to try som of Windy's techiniques for finishing a model. He makes it look easier than it is (well for me anyway!).
 
First of all, I manage to find the acrylic green putty that he uses. Marvellous stuff but his videos aren't "training" videos - so here are some of my mistakes.
 
1. The putty is marvellous but I put it on bare wood at first. Big mistake!!! It sets too quickly on bare balsa and then is difficult to sand without taking the surrounding balsa out. The dust also gets into the grain and won't come out easily.
 
2. A thin application (less than 1 mm) dries quickly - any thicker and the drying time incrases exponentially. !/16th inch wasn't dry overnight!
 
Applying it after sanding sealer (sanded of course!), indicated holes that you didn't know were there using a "wipe on, wipe off technique).
 

 
Then I tried the silver dope. Ken warned against this because it can affect the top colour but I am experimenting.
 
I had not mixed and sprayed for a while and my impatience got the better of me. I went too thick and too quickly between coats. A major sanding job ensued.
 
But as Windy pointed out - after sanding the siver dope - the shiny areas indicate low spots. (Also some dings I have made through careless handling.
 
Anyway - more filling, more sanding, more doping and a vicious circle until I get it right.
 

It's looking really good Ian! That Donkey IS rockin'!

Unfortunately, you have arrived at the step that seems to be the bane of my existence! The "fill, sand, repeat until you wish sandpaper had never been invented" stage of finishing. I am primarily a stunt guy, so this is one of the necessary stages in most of my projects (I currently have two stunters stalled at this point), but it doesn't mean I have to like it! Fortunately, all of the (tedious) work you put in will be rewarded in the end!

Any particular paint scheme are you thinking of using?

I like the cowling Ian. It hides the engine nicely.

The video was fantastic!

Good going Ian. I'm glad I introduced the Windy videos to the forums and you took an interest. Being a stunter that will never be seeking 20 appearance points at the Nats, I'll probably never take finishing this far but I really enjoy seeing it being done. Kind of like music, I can appreciate it while only dabbling in it myself. I'm looking forward to watching you slowly go mad looking for dings and scratches, and finally finishing the plane. I was working on the Skyray yesterday and talking(in my head) in Windy's voice.
Rusty

Also, I just re-read the first post and I shot Coffee out of my nose at Jim's quote about the Donkey. 

I have been sanding and filling, filling and sanding this evening - it is tedious! I am determined to try for a nice finish. I don't know how the super stunt chaps cope - this is taking hours for such small bits of wood.

I am planning on a WWII RAF colour scheme. Not too detailed - I won't be doing panels and rivets - definitely not got the patience for that!

Need more practise spraying.

I am doing a dope finish on mine Ian so I will be going down that road here soon. Keep at it I am sure it will turn out well!

Does anyone have any knowledge as to how one hand rubs a dope finish to a glossy shine?

Ron

Cribbs74 wrote:I am doing a dope finish on mine Ian so I will be going down that road here soon. Keep at it I am sure it will turn out well!

Does anyone have any knowledge as to how one hand rubs a dope finish to a glossy shine?

Ron

Very fine sandpaper first (UK - coarser than 1200 grit, regular paper change, use "Windex" to wipe off and or tack cloth).

Following by car paint cutting compound/polish. Here in UK, 3M Perfect It , available in different grades but quite expensive. £25 for a bottle. Keep wiping off Windex until shine remains.

Microfibre cloths and regular changes of cloth (can be washed) a must.

Now this is prone to disaster - I am heavy handed when sanding and if you chose the wrong grade of cutting compound ......................

It is also long and laborious but can produce an almost mirror like shine. Make sure the dope has had plenty of time to cure and only use this on a clear top coat over any colouring.

Only needs fuel proofing now and then it will be ready of engine and tank mounting followed by the rest of the stuff needed to help it fly in circles.
 

That really turned out well Ian, I was concerned at first, but it looks great now. Love the scheme.

Ron

Nice work Ian. Really sharp looking.

I definitely agree with Rusty. Very sharp looking!

KP

Very, very nice Ian. It really looks the part!

Not finished yet
 

Nice choice on the prop allows you to use no tip weight.
Torquing the right wing down helps keep the extra weight being added to the overall engine load-should be a peppy flyer on that 4.5 x 4.