HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 29, 2012, 10:17 AM
Registered User
Sunny Sarfend on Sea. UK
Joined Jan 2008
63 Posts
Help!
Vic Smeed Coquette

I am currently building a Coquette from the plan off the Outerzone site & am having trouble with the dihedral angle, on the plan it's noted as "Dihedral = 4deg". I'm used to this being referred to as "Dihedral at tip/here = Xin or Xcm"

Having completely forgotten any geometry I may at one time have known from school (!) I've lain a protractor over the plan at the dihedral break on front spar, marked 4deg & drawn a line. Measuring the distance between the tip & this line gives 1.1/4" for the top 30" wing & 7/8" for the bottom 24" wing each side. Does this seem right? Most of the pictures I've seen on the web seem to indicate a much greater dihedral.

Has anyone got an original plan they could look at, I can't believe Vic didn't originally use the "Xin at tip/here" rather than degrees, or if you've built one what are your measurements?

Should add I'm building this for electric RET.

Thanks.
RSTMG is offline Find More Posts by RSTMG
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 29, 2012, 10:53 AM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
France, Centre, Amboise
Joined Nov 2011
1,682 Posts
The original plan clearly shows the dihedral as 3" on the top wing and 2.4" on the lower wing.
Why do people who redraw do this kind of thing? It hasn't even been "re-engineered" (joke) for electric. The rest of the plan is more or less as per the original...
brokenenglish is offline Find More Posts by brokenenglish
RCG Plus Member
Last edited by brokenenglish; Sep 29, 2012 at 10:59 AM.
Reply With Quote
Old Sep 29, 2012, 10:55 AM
Registered User
Ajax, Ontario, Canada
Joined Oct 2004
2,601 Posts
3.0" and 2.4" respectively
Applehoney is offline Find More Posts by Applehoney
Reply With Quote
Old Sep 29, 2012, 12:10 PM
Registered User
Sunny Sarfend on Sea. UK
Joined Jan 2008
63 Posts
Thank you both very much, thought it didn't look right. And yes, why do some feel the need to "meddle"!

Can now crack on.
RSTMG is offline Find More Posts by RSTMG
Reply With Quote
Old Sep 29, 2012, 12:27 PM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
Joined Sep 2007
4,884 Posts
Depends whether you want to remain totally authentic and use the free-flight dihedral or produce a model which handles maybe a bit better as a radio model - i.e. doesn't suffer from dutch rolling with rudder inputs, something the original never had to contend with. The figures which 4 degrees produce are not enough; however, although Jim and Brian will jump up and down on me for saying this, it would handle better as a radio model IMO with somewhat less than the original figures and I would personally use my general rule of "1 inch per foot of semi-span plus one inch under each tip". This would give 2.1/4 inches under each tip for the top wing and 2 inches for the bottom. Don't get me wrong it WILL fly OK with the original F/F figures, but lots of personal experience with (now) almost a dozen free-flight designs converted to RET electric radio and using dihedral derived as above makes me SURE it would handle better as a radio model with the figures I suggest - it depends which is more important to you, authenticity or flying performance.
Sundancer is offline Find More Posts by Sundancer
RCG Plus Member
Old Sep 29, 2012, 12:50 PM
Since 1952
Harry D's Avatar
Canada, AB, Edmonton
Joined Oct 2004
1,321 Posts
The original dihedral (if that's what the model in the picture has) does look a bit ridiculous!

Or maybe it's just an illusion caused by the camera angle.
Harry D is offline Find More Posts by Harry D
Reply With Quote
Old Sep 29, 2012, 02:11 PM
Registered User
Ajax, Ontario, Canada
Joined Oct 2004
2,601 Posts
I feel that if a plan is redrawn it should show the 'proper' dimensions and angles together with a note of suggested amendments for (whisper it softly .... :-) ) R/C.

A person attracted to a Coquette's looks (isn't that a coquettes purpose?) by the Outerzone plan mentioned and builds it in good faith for F/F is going to be sorely unhappy when it spirals into the hard stuff at first attempt
Applehoney is offline Find More Posts by Applehoney
Reply With Quote
Old Sep 29, 2012, 03:39 PM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
France, Centre, Amboise
Joined Nov 2011
1,682 Posts
George, Here we go again!
It isn't "performance" that's the issue, it's the way you want the plane to fly. Your RC flying isn't "better performance", it's just "different".
Also, respectfully, you missed an essential point. I was surprised by this topic, so I studied the Outerzone plan against my original. The Outerzone plan retains the pure FF mode. There's no mention of control surfaces, RC or anything other than FF.
Not only that but no-one appears to have noticed that, while the dihedral dimension is the only significant change to the plan (expressed as a useless 4 - probably RC theory, instead of a usable building dimension), the dihedral braces shown appear to still be those of the original plan!
I've been meaning to raise this problem for some time with Steve (Outerzone). There are number of historical old planes for which don't have an original plan, only a version that's been excessively modified by some of the redesigning and re-engineering "aces". Compare the "Vintage1" CAD Southerner with Bill Dean's superb drawing, and you'll see what I mean. George Reich's "Albatross" is another... Does anyone want a version that's been "re-engineered" by some CAD ace last week?! We should be keeping the original plans, which any builder can then modify as he sees fit. At present, in a few cases, we're losing the originals.
Obviously, all my rambling doesn't concern Hogal's superb work, 'cos he doesn't modify the design, he just provides an excellent alternative working drawing.
Sorry for "going on a bit"!
brokenenglish is offline Find More Posts by brokenenglish
RCG Plus Member
Old Sep 29, 2012, 03:54 PM
Registered User
Ajax, Ontario, Canada
Joined Oct 2004
2,601 Posts
> we're losing the originals.

Very true. There are a growing number of redrawn plans now offered, many with short kits, on which the original structure has been amended according to the draughtsmans whims and such are accepted in good faith by builders as being authentic, Not just in N.America .. there's a prominent vendor of plans in the UK whose redraws are suspect in some instances. Not least a Wakefield for which I submitted the designers beautifully drawn original, from which the version finally offered differed - particularly with propellor details. At least I'm happy to have a copy of the 'real' one.
Applehoney is offline Find More Posts by Applehoney
Reply With Quote
Old Sep 29, 2012, 04:02 PM
pd1
Registered User
United States, MA, Haverhill
Joined Jun 2006
2,157 Posts
I too looked at the two versions of the Coquette plan.
The second plan at outerzone is a copy of the first with the "grey" background remove to make the plan easier to read and print.
Sometimes while removing the background, the person cleaning a plan is left with a problem, some type can be unreadable. I've run into this a number of times myself.
Sometimes an educated guess will get the missing type, sometimes it won't.

I sometimes add missing wing halves and fuselage sections so it is easier for me to build the model. I thought sharing these plans would be a nice gesture.

The plans I have been posting have needed to be redrawn, if I have offended any one for taking the liberty of redrawing the plan I apologize.

If the tattered original plan scans mean that much, e mail me and I'll be happy to send the original un reworked scans to you.
pd1 is offline Find More Posts by pd1
Reply With Quote
Old Sep 29, 2012, 04:50 PM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
France, Centre, Amboise
Joined Nov 2011
1,682 Posts
Quote:
Originally Posted by pd1 View Post
The plans I have been posting have needed to be redrawn, if I have offended any one for taking the liberty of redrawing the plan I apologize.
No need for apologies!!!
It depends on what you mean by "needed to be redrawn"... Many old timer plans are less than perfect... but that's no problem!
What really annoys me (I'm ever so sensitive...) is that superb classic designs, with beautifully drafted plans by historically great designers, are ruined through needless modification by some guy with a few computer skills, all of which is passed off as "re-engineering" or "updating". This nonsense mustn't replace the originals, that's all.
brokenenglish is offline Find More Posts by brokenenglish
RCG Plus Member
Old Sep 29, 2012, 05:11 PM
Since 1952
Harry D's Avatar
Canada, AB, Edmonton
Joined Oct 2004
1,321 Posts
I'm not taking any sides here but in fairness to the person who went to the trouble of cleaning up this particular plan and posting it for the benefit of anyone who wants to use it, just take a look at what he had to work with.

Obviously, the 4 thing was an honest but (with the information we now have available) mistaken identification of the right side of the very blurry reproduction of 2.4".

Should he have just erased the blurry text, instead of giving his best guess as to what it might be? Maybe.

Can he be accused of deliberately changing things according to his personal whims, "RC theory", a desire to "improve" the plan, "re-engineering", or some other such thing? Certainly not!

Unwanted changes and modifications do happen (too often, unfortunately) and caution is obviously needed in using any reproduction of old plans or other documents. It would be nice if the person making any changes would provide some indication to that effect, but that doesn't always happen.

But let's not be too critical of those who have made an honest effort to help their fellow modelers. Particularly in cases such as this.
Harry D is offline Find More Posts by Harry D
Reply With Quote
Old Sep 29, 2012, 07:05 PM
Registered User
Warren B's Avatar
Mt Evelyn, Melbourne, OZ
Joined Dec 2008
650 Posts
My 10% larger Coquette flies really well as 3ch RC with a Schlosser 1.0.
It uses the original dihedral angles and wing incidence.

Rolls well on rudder if I feel like it and no dutch roll on this one.
Warren B is online now Find More Posts by Warren B
Reply With Quote
Old Sep 29, 2012, 08:33 PM
Registered User
RyanNX211's Avatar
Upper Arlington, Ohio
Joined Dec 2007
1,516 Posts
Quote:
Originally Posted by brokenenglish View Post
I've been meaning to raise this problem for some time with Steve (Outerzone). There are number of historical old planes for which don't have an original plan, only a version that's been excessively modified by some of the redesigning and re-engineering "aces". Compare the "Vintage1" CAD Southerner with Bill Dean's superb drawing, and you'll see what I mean. George Reich's "Albatross" is another... Does anyone want a version that's been "re-engineered" by some CAD ace last week?! We should be keeping the original plans, which any builder can then modify as he sees fit. At present, in a few cases, we're losing the originals.
Obviously, all my rambling doesn't concern Hogal's superb work, 'cos he doesn't modify the design, he just provides an excellent alternative working drawing.
Sorry for "going on a bit"!
Accurate Albatross plans are available. Unfortunately, I couldn't talk him into drawing up the prototype
RyanNX211 is offline Find More Posts by RyanNX211
Reply With Quote
Old Sep 30, 2012, 12:17 AM
Reduce the drama...
rick.benjamin's Avatar
USA, OR, Damascus
Joined Apr 2004
4,044 Posts
RSTMG started this post asking for clairfication regarding dihedral angle.
He shared which plan and where he downloaded it. Thank you.

I imported what I have of Smeed's Coquette into TurboCad but could not read the fuzzy plan to discover the answer to dihedral.

Thanks to Applehoney and brokenenglish for providing an answer.
I wish that whomever has a clear plan would reproduce it for the rest of us.

I find that all the Coquette plans I've downloaded are fuzzed and twisted.
If Vic Smeed intended this, well and good.
Perhaps the reason Coquette glides in a right hand circle.

For instance,
Decalage is +5.4 degrees, not +4.
Horizontal Stabilizer decalage is -1.54 degrees
Lower wing decalage +1 degree
Dihedral angle: Lower wing brace left side is 12.65 degrees, right side is 12.76
Dihedral angle: Upper wing brace left side is 12.43 degrees, right side is 11.98
Dihedral lower wing left =2.6937 inches, right=2.7168 inches
Dihedral upper wing left=3.3074 inches, right=3.1841 inches

If you wish 3.0 and 2.4 inches for Coquette, the dihedral angle is 11.31 degrees.
rick.benjamin is offline Find More Posts by rick.benjamin
Last edited by rick.benjamin; Sep 30, 2012 at 12:53 AM. Reason: add pdf
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Electra Vic Smeed tooheavy Vintage & Old-Timer Designs 14 Mar 17, 2012 05:19 PM
Popsy by Vic Smeed olmod Vintage & Old-Timer Designs 241 Mar 26, 2011 02:23 PM
Video Vic Smeeds Coquette Biplanes maiden SafeLandings Fuel Plane Talk 2 Jun 14, 2010 08:05 AM
Vic Smeed 'chatterbox' plan on UK ebay. vintage1 Vintage & Old-Timer Designs 5 May 15, 2004 01:55 PM