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Design It Yourself! - What you are designing around the Peter Miller series of articles


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Heres my project, its called a CEA/Jodel DR-1050 Ambassedeur
 

Heres the paper i used to draw the plane on
The Mag!
These are my reference Blue prints

My drawing station out in the conservatory
I have decided to incorporate speed brakes into it like the real thing, this is a little prototype of the mechanism I did

I decided upon a wingspan of 45" and a chord of 8" which gives an approximate wing area of 360 sq in. The wing will be made out of a centre section which is flat, no diherdral then there will be 18 degrees of dihedral under each wing tip
 
It is designed for a .20 to .30 two stroke
 
I haven't got any pictures of the actual plan, will take some tomorrow.

Edited By Peter Savage on 04/05/2009 01:17:25

Edited By Peter Savage on 04/05/2009 01:18:59

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Perhaps Peter you are being too specific. Plenty of peeps on here are designing and building without reference to the articles. I found them a good read and they certainly helped to get me kick-started with the idea of producing my own model but I have many ideas of my own and personally would design in a completely different way. Why not just make the thread your Jodel build (which I'm certainly interested in) and then see if some others are inspired to have a go also?
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Peter  Perhaps a series of tips on how to overcome design difficulties on unusual configurations might benefit a lot of us "oldies" who have passed the stage of basic design as you've oulined in your excellent article(s)
That is assuming of course that you have the experience -cough-cough !
 Grumpy Myron
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what would be good is maybe a follow on of explaining the things behind bi-planes wing area etc, i don't think i would design any bipes but i could see some people wanting to.
 
To anyone who likes the idea of my Jodel, i might be sending it off to RCM&E once it is finished so you might be ab le to have a go at building it. I am hoping to do a few small scale details on the prototype such as a landing light in the port wing and speed brakes under the wings, as per the full size.
 
I have found out the Plan Special Lysander i was going to build won't be released until autumn so i should be able to build this after the completion of my feugray.

Edited By Peter Savage on 11/05/2009 19:15:51

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  • 2 weeks later...
Peter , A nice little jodel flew in at my local air field at the weekend. the pilot was passing thru and stopped to refuel.We all stopped flying and cruised over to check it out . I remembered your plan and build thread and thought Id check up to see how your going with it.  Keep up the good work .your probably not getting the feed back you were after
 But keep with it and you will get noticed
Good work
Thanks Kiwi G...
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What kind of wash out do you think would be acceptable? i was thinking two bits of 1/16" under the tip rib and one bit of 1/16" under the next in rib.
 
Should be simple enough, i think i have got the right sized rudder now, it looks about right. Havent done much recently, been camping in tewkesbury for 4 days and i still have to go to college.
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The Jodel has sharply tapered tips. These could be prone to tip stalling, The actual Jodel as s lot of washout, not sure just how much.
 
I would say you want at least 2 degrees under the tip rib.
 
There is a simple way of measuring this. 1 degree over  a distance of 3 inches is 1/16" so, for example, 2 degrees over 6 inches would be  1/4" inch. 2 degrees over 9 inches would be 3/8" You can use these measurments to draw out a wedge shape.
 
JUst cut a suitable wedge from 1/4" balsa for the tip. A second wedge can be cut at half that size and fitted half way between the part of the wing flat on the board and the tip.
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Hi Peter
 
I've only just stumbled upon this thread, so sorry I didn't join in sooner.
 
I'm in the process of designing a Long EZ, using autoCAD and Profili Pro, though with the problems associated with canards I might put her on the back burner whilst I start with something a little more basic!
 
I'll try to get some sceen grabs on here when I get a few moments.
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batcho99.  The Jodel does have a nice simple box fuselage. IT just has a rounded turtle deck which is easy to do.
 
Don't ask me about canards. I don't know.
 
I do know that, having seen several bad accidents caused by propellers in unusual places I will never design a model where the prop is not in the normal place.
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i think the canopy will be a challenge, might be able to get n old bit of packaging, then pout it in the oven to turn it back into a flat sheet of thermoplastic, then i have made something along the lines of a vac former, a shoe box with a metal grate on the top which you attach to a vacuum.
 
Havent really had much time to progress on the jodel, i still go to college you see and my college year is coming to an end so i have to do all my assignments
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K&S have packets of suitbale plastic for moulding. Buy a packet of 0.030" plastic and drape mould the canopy.
 
First you need to make a strong pattern or plug the shape of the canopy. THis is the hard part. These days I use blocks of pine, sometimes glued to gether to make it big enough. I shape it with a power plane and Surform.
 
Attach strips of hard wood to the ends of a sheet of plastic and heat it over a heat source intil it gloes all floppy. THis takes exprience. Not hot enough and it won't mould but at least you can re heat and try again. Too hot and it bubbles and is scrap.
 
When hot drape the plastic down over the mould by holding the strips of wood. Use thick gloves. Pull down hard. It helps to heat the pattern in the oven so as not to cool the plastic too soon.
 
On second thoughts, until you are used to the idea buy two packets!
 
An alternative would be to make the canopy out of flat sheet. Not as accurate or pretty but few will really notice, only experts.
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Peter
A while back you asked rhetorically (think I've spelt it correctly )"what sort of things should I talk about? "
You just did it !  Brilliant I have tried making canopies  quite successfully out of booze bottles but I'll try your technique on all the "bubble pack "type rubbish I've collected over the years .Thinking about it they probably all need different temps to go floppy .
Another learning curve / challenge
Do you start off by heating the sheet in an oven? If so, What setting ?-Mine (er 'indoors's )is a fan job!
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The best plastic is acetate sheet.
 
No, you heat it over a ring. You have to be able to hold it and keep a close eye on how floppy it is. I use a gas ring but electric is probably better.
 
Many years ago a club member put a sheet of plastic about a  foot square in the oven without clamping it to a frame. His square foot of 0.030 plastic came out of the oven about 2 inches square and 3/16" thick! I don't think it was acetate sheet.
 
Fort more complex shapes I make a pattern and then cut out the shape inb plywood. You clamp the plastic to the plywood and heat it, then you push the pattern through the hole.
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