RE: The How To's of designing & scratch building planes.   
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
    Search This Thread  
 
Printable Version

All Forums >> RC Airplanes >> Scratch Building, Aircraft Design, 3D/CAD >> RE: The How To's of designing & scratch building planes.
Page: <<   < prev  1 [2] 3   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: The How To's of designing & scratch building planes. - 11/28/2003 10:47 PM   
Tamecat


 

Posts: 248
Joined: 8/29/2002
Last Login: 7/29/2008
From: Teaneck, NJ, USA
Status: offline 		How about a plane that has a 60 -72 inch wing span with a fuse lenght of 50 to 60 inches for starters. Do you want a high, mid, or low wing? Straight or swept wing? I suggest we use 40 to 60 sized engine. I believe we all have either of laying around somewhere. When I think about scratch building, wing span, fuse length and wing type are the first things I consider. Then the engine. Just my 2 cents guys. I think this plane should be a mid wing. Best of both worlds. The plane could be an advanced trainer type that borders on sport.

_____________________________

We aim to please, we sometimes miss!

Hide Signatures

(in reply to BMatthews)
       Post #: 26

RE: The How To's of designing & scratch building planes. - 11/29/2003 4:20 AM   
starcad



Posts: 233
Joined: 12/8/2001
Last Login: 5/30/2009
From: Tucson, AZ, USA
Status: offline 		OK Guys, I'll through in here. Is there an area I can upload a Basic Model Airplane Calculator that is in Visual Basic? That way we could all use the basic calculations. PS needs VB300 or VB400 to run.

Hide Signatures

(in reply to Dago Red)
       Post #: 27

RE: The How To's of designing & scratch building planes. - 11/29/2003 3:47 PM   
Eaglet50



Posts: 8
Joined: 10/28/2002
Last Login: 11/3/2007
From: Lexington Park, MD, USA
Status: offline
quote:

Actually I'm thinking that what we want is a table of proportions. Like the nose is X wing chords and the tail moment is N wing chords and the tail chord is 0.Twing chords and the tail area is 0.2453 the wing area. It would create a template of accpetable shaping that could then be sized to fit an individuals needs as to engine size and wing area preferences.


The book, Basics of R/C Model Aircraft Design, by Andy Lennon, has a chapter titled Basic Proportions of R/C Model Aircraft, that has exactly what you are talking about for several different types of models: the basic airplane (high wing cabin), flying boat, floats, glider, and aerobatic plane. These templates show the proportions for everything, including landing gear placement, dihedral, and control surface sizing. Each template (which is presented in 3-view format) also includes a table with engine displacements, wing areas, wing loadings, wheel sizes, and other. The chapter also describes how to lay-out airfoils from coordinates.

The book is actually a compilation of articles that Andy Lennon wrote for Model Airplane News back in the early-to-mid 1990s. The Basic Proportions chapter is a How-To in the November 1996 issue. Perhaps a good place to start would be to have someone scan these proportions, and then work through a design from there, because the proportions can still be an intimidating balance to some people.

I highly recommend the book, it has a wealth of knowledge inside that can be used at any level of experience. You could start with the basic proportions, then use the math in some of the earlier chapters to optimize things as you develop more experience and understanding. I think I learned more about practical applied aerodynamics from this book than all the courses and books I took in college!

< Message edited by Eaglet50 -- 11/29/2003 3:49:29 PM >

_____________________________

--Eaglet50

Hide Signatures

(in reply to BMatthews)
       Post #: 28

RE: The How To's of designing & scratch building planes. - 11/29/2003 5:10 PM   
EagleOne



Posts: 370
Joined: 5/18/2003
Last Login: 9/28/2006
From: Curitiba, PR, BRAZIL
Status: offline 		Oh yeah!!! This book has great information for designing airplanes.....If I won't be breaking any copyright law by scanning them and putting them here, I will do it ASAP.


_____________________________

"I didn't fail, I just found 10 000 ways that didn't work"


Hide Signatures

(in reply to Eaglet50)
       Post #: 29

RE: The How To's of designing & scratch building planes. - 11/29/2003 7:09 PM   
BMatthews



Posts: 9259
Joined: 10/4/2002
Last Login: 6/22/2009
From: Burnaby, BC, CANADA
Status: offline 		No scans please. You can quote basic equations and concepts since no one has a copyright on the basic knoledge but full page scans would be on the edge. We don't want to go there.

BUT it sure sounds like that info is just what we are trying to dupicate in a way. These average layouts will work but I was thinking that if we could develop some rules that could come together all in one place at one time then folks could design anything from the next Lazy Bee (short and fat) to a sailplane (long and lean) using the steps and be fairly certain it would fly. Doing that means having to enter and crunch a few numbers before hand. Unless, of course, you've studied hundreds of plans and can then use the TLAR method to come up with the design based on your studies.

Starcad, thanks for the offer of the file but I don't see any way to post it here. Did you get it from a site somewhere we could link to? Or is there anyone reading this that could host it for us on a page of their own? I'm a bit rusty on my Visual Basic but I think if you have the runtime module it'll run OK without having to have the whole package. The runtime modules are available for download at lots of places for free. If it does all we talked about above then it may be just what the doctor ordered.

_____________________________

Witty saying to be plagarized shortly.....

Hide Signatures

(in reply to EagleOne)
       Post #: 30

RE: The How To's of designing & scratch building planes. - 11/30/2003 12:22 AM   
starcad



Posts: 233
Joined: 12/8/2001
Last Login: 5/30/2009
From: Tucson, AZ, USA
Status: offline 		B,
Let me upload it to my ftp site and that way anyone that wants it can download it from there. I did this several years ago in VB. This is just the simple calculator that will give you the basics of a simple flyable design proportions. Not as in depth as Lee's calculator but it gets the job done. Note that this one has no error correction and trapping. The second version had error trapping and a lot more features however it was lost when my old HD crashed. I think I still have the notes I made and could get the airfoils part up and running again but that would take several days.

Give me a few hours tonight and I'll send up a link.

StarCad

Hide Signatures

(in reply to BMatthews)
       Post #: 31

RE: The How To's of designing & scratch building planes. - 11/30/2003 2:10 AM   
Eaglet50



Posts: 8
Joined: 10/28/2002
Last Login: 11/3/2007
From: Lexington Park, MD, USA
Status: offline
quote:

No scans please. You can quote basic equations and concepts since no one has a copyright on the basic knoledge but full page scans would be on the edge. We don't want to go there.

Yes, you are right. I wasn't thinking.

So, here are a few of the proportions that Andy Lennon gives for Basic Airplane, from his book, BASICS OF R/C MODEL AIRCRAFT DESIGN:

For Wings,
Aspect Ratio of 5-7
Semispan ailerons are 40% of the semi-span with 25% chord
Full-length Strip ailerons are 15% chord.

For Horizontal Tail,
Tail moment arm (from 1/4 MAC of wing to 1/4 MAC of tail) is 2.5 - 3 times the wing chord.
Horiz tail area is 18%-22% of wing area
Horiz tail aspect ratio is 3-5
Elevator area is 35% of tail area.

For Vertical Tail,
Vert tail area is 7% if ailerons available, 8% if it is a rudder only ship.
The rudder area is 35% of total Vert tail area (fuselage below fin counts in the Vert tail area computation)

Other proportions:
Nose moment arm (distance from 1/4 MAC of wing to engine backplate) is 1.5-2 times the wing chord.

MAC=mean aerodynamic chord. For a rectangular wing, this is just the chord of the wing.

Andy Lennon lists more items such as dihedral angle for high,mid, or low wings for both rudder-only and ailerons, landing gear placement for tricycle and tail dragger, and the table of engine displacements, weights, wing areas, etc. I will only post this much for now.

Again, I highly recommend the book for anyone who has an interest in aerodynamic design. The main problem that it might present to the novice is that since the book is a compilation of many individual articles, it doesn't necessarily present a focused process or method of putting all the information together into an aircraft design.

_____________________________

--Eaglet50

Hide Signatures

(in reply to BMatthews)
       Post #: 32

RE: The How To's of designing & scratch building planes. - 12/30/2003 9:48 PM   
starcad



Posts: 233
Joined: 12/8/2001
Last Login: 5/30/2009
From: Tucson, AZ, USA
Status: offline 		Sorry for not getting back to this subject for awhile. I've been busy doing some flying for what I hope will be a new job flying model airplanes!

Anyway, I finally figured out how to setup the download section of PostNuke and have uploaded Visual Model Designer. Please note that this is only a very basic VB program and there is NO error trapping. I should work if you have VB400 or greater on your computer, most newer machines and OS have this already installed. If not you will have to find the download site as I do not have it.

You can download at Arizona Modeler Magazine , following the download link in the main menu and then Software. It needs to be unzipped as it is a .rar or WinRAR file.

If anyone would like to collaborate on further developing the file please IM me for the VB source code.

Guy

Hide Signatures

(in reply to starcad)
       Post #: 33

RE: The How To's of designing & scratch building planes. - 1/4/2004 7:09 PM   
starcad



Posts: 233
Joined: 12/8/2001
Last Login: 5/30/2009
From: Tucson, AZ, USA
Status: offline 		Hi B,

You should be able to download it from this link by just clicking on the link.

Visual Basic Model Calulator

Hide Signatures

(in reply to BMatthews)
       Post #: 34

RE: The How To's of designing & scratch building planes. - 1/4/2004 7:10 PM   
starcad



Posts: 233
Joined: 12/8/2001
Last Login: 5/30/2009
From: Tucson, AZ, USA
Status: offline
quote:

ORIGINAL: starcad

Hi B,

You should be able to download it from this link by just clicking on the link.

Visual Basic Model Calulator


Yep! That works

Hide Signatures

(in reply to starcad)
       Post #: 35

MORE!!! - 2/3/2004 10:11 PM   
Dago Red



Posts: 2860
Joined: 8/14/2002
Last Login: 6/19/2009
From: Elmendorf, AK, USA
Status: offline 		Do we have any more Imputs by some of our design specialists? Lets see how much info we can get, pretty much making a thread that will help one out of any problem, or ask questions, hehehe.

Ive always wondered, people build their planes with certain angles , angle of attack, and so on. When i Built the MFD-1 , i didnt use any of that, i just cut pieces out and stuck them with glue. Was it pure luck it flew good, and flew good with the rudder ripped off? Do these angles need to be used?
Hum, maybe its true, I can fly anything, Thats what people have said.

Ok, heres a question im stuck on. I have a long ez, broken foam wing. I can fix it, but what is the best way to do it. Does any one have any helpful advise that I and or anyone else can use?

Hide Signatures

(in reply to starcad)
       Post #: 36

RE: RE: The How To's of designing & scratch building pl... - 2/3/2004 10:14 PM   
CafeenMan



Posts: 3915
Joined: 1/19/2003
Last Login: 6/20/2009
From: Spring Hill, FL, USA
Status: offline 		I just answered this question on a FAQ page on my site. Too much, but if you care about my opinion, it's here:

http://www.airfieldmodels.com/faq/miscellaneous.htm

_____________________________

Work is what I do for the love of it. A job is how I pay for it. :)
Please visit AirfieldModels.com

Hide Signatures

(in reply to Dago Red)
       Post #: 37

RE: The How To's of designing & scratch building planes. - 2/4/2004 11:49 PM   
Slacker



Posts: 231
Joined: 12/13/2003
Last Login: 1/15/2005
From: Cumming, GA, USA
Status: offline
quote:

ORIGINAL: Eaglet50

quote:

Actually I'm thinking that what we want is a table of proportions. Like the nose is X wing chords and the tail moment is N wing chords and the tail chord is 0.Twing chords and the tail area is 0.2453 the wing area. It would create a template of accpetable shaping that could then be sized to fit an individuals needs as to engine size and wing area preferences.


The book, Basics of R/C Model Aircraft Design, by Andy Lennon, has a chapter titled Basic Proportions of R/C Model Aircraft, that has exactly what you are talking about for several different types of models: the basic airplane (high wing cabin), flying boat, floats, glider, and aerobatic plane. These templates show the proportions for everything, including landing gear placement, dihedral, and control surface sizing. Each template (which is presented in 3-view format) also includes a table with engine displacements, wing areas, wing loadings, wheel sizes, and other. The chapter also describes how to lay-out airfoils from coordinates.

The book is actually a compilation of articles that Andy Lennon wrote for Model Airplane News back in the early-to-mid 1990s. The Basic Proportions chapter is a How-To in the November 1996 issue. Perhaps a good place to start would be to have someone scan these proportions, and then work through a design from there, because the proportions can still be an intimidating balance to some people.

I highly recommend the book, it has a wealth of knowledge inside that can be used at any level of experience. You could start with the basic proportions, then use the math in some of the earlier chapters to optimize things as you develop more experience and understanding. I think I learned more about practical applied aerodynamics from this book than all the courses and books I took in college!


I'm 16 and I want to be an aeronautical engineer, and I'm good at math and can understand a lot and if I can't figure out something, I can ask my dad who is an architect, so he's REALLY good at math. Where can I find this book? I'd really like to get it and get an early start on being an aeronautical engineer, and I would like to be able to DESIGN and build my own plane, then watch it fly. I'm currently building a P-51D Mustang out of plans from a 17 1/2" free flight plane that I've taken and multiplied all the demensions by 2, then I'm going to slim the wing a little, because the FF version is really thick. So, where can I get that book? Could you give a link to it, if possible?


_____________________________

Like one wise man once said,
"Mmm, doughnuts." -Homer Simpson

Hide Signatures

(in reply to Eaglet50)
       Post #: 38

RE: RE: The How To's of designing & scratch building pl... - 2/5/2004 12:19 AM   
Dago Red



Posts: 2860
Joined: 8/14/2002
Last Login: 6/19/2009
From: Elmendorf, AK, USA
Status: offline 		Well, check your local library. Mine has it. I took a look at the book, it was ok. I like to design and built, and pray it flies!!!!!!
There are a bounch of sites out there too to look at, like the ones in this thread.

Hide Signatures

(in reply to Slacker)
       Post #: 39

RE: RE: The How To's of designing & scratch building pl... - 2/5/2004 12:30 AM   
Slacker



Posts: 231
Joined: 12/13/2003
Last Login: 1/15/2005
From: Cumming, GA, USA
Status: offline 		I want a book that explains all the steps and calculations to designing an R/C plane. Does anyone know of any other books that you would suggest.

Hide Signatures

(in reply to Dago Red)
       Post #: 40

RE: The How To's of designing & scratch building planes. - 2/15/2004 4:32 PM   
dicknadine


 

Posts: 2144
Joined: 7/17/2003
Last Login: 6/24/2009
From: Greensburg, LA, USA
Status: offline 		why not pick a specific plane, military- sport- multi engine--etc. provide a small 3 vu, let all the guys produce their version. could be different size class's. all kinds of variations possible. dickl

Hide Signatures

(in reply to starcad)
       Post #: 41

RE: The How To's of designing & scratch building planes. - 3/5/2004 4:46 PM   
dicknadine


 

Posts: 2144
Joined: 7/17/2003
Last Login: 6/24/2009
From: Greensburg, LA, USA
Status: offline 		is this thread dead or what? no responses since last month!! maybe it was a bad idea to begin with. too many people want to open the box and fly!!! I am ready to start on the plane. lets have some imput!!!! have 10,000 3 views to donate. dick

Hide Signatures

(in reply to dicknadine)
       Post #: 42

RE: The How To's of designing & scratch building planes. - 3/5/2004 5:52 PM   
ramrod25


 

Posts: 60
Joined: 12/14/2002
Last Login: 1/13/2009
From: Fort Towson, OK, USA
Status: offline 		I've posted this before - but it may be helpful. I have found it very useful.
Regards
Ramrod25

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to dicknadine)
       Post #: 43

RE: RE: The How To's of designing & scratch building pl... - 3/6/2004 6:40 AM   
Dago Red



Posts: 2860
Joined: 8/14/2002
Last Login: 6/19/2009
From: Elmendorf, AK, USA
Status: offline 		Well, how about a quick review on fixing my Long EZ's foam wing.

I glued the wing back together, making sure it was straight. Then cut to slots the width of a dowl rod. I used Gorilla Glue gluing it toghether. I applied 2 rods on top and one on the bottom, seems to be very strong and sound. Well, find out after it takes to the air once more.

Hide Signatures

(in reply to ramrod25)
       Post #: 44

RE: RE: The How To's of designing & scratch building pl... - 3/6/2004 6:50 AM   
CafeenMan



Posts: 3915
Joined: 1/19/2003
Last Login: 6/20/2009
From: Spring Hill, FL, USA
Status: offline 		That seems strange to me. First, dowels are heavy - spruce would have been a better choice. Second, there is more load on the underside of the wing. I would think you'd want the two dowels on the bottom and one on the top. Sounds fine though.

Be sure to check the spanwise balance before flying it again.

_____________________________

Work is what I do for the love of it. A job is how I pay for it. :)
Please visit AirfieldModels.com

Hide Signatures

(in reply to Dago Red)
       Post #: 45

RE: RE: The How To's of designing & scratch building pl... - 3/12/2004 5:36 AM   
Dago Red



Posts: 2860
Joined: 8/14/2002
Last Login: 6/19/2009
From: Elmendorf, AK, USA
Status: offline 		sorry it took so long to answer. The reason for 2 on top and one on the bottom. The plane has 3 rods running through the wing. aileron,rudder, and the anntena tube, its a pusher, cant have it hanging out. I have to shave the bottom dowl anyways to make it fit over all the tubes.

Hide Signatures

(in reply to CafeenMan)
       Post #: 46

RE: RE: The How To's of designing & scratch building pl... - 3/13/2004 4:18 PM   
kevin pelletier



Posts: 130
Joined: 7/2/2003
Last Login: 6/21/2009
From: east hartford , CT, USA
Status: offline 		i want to desigh my first plane qeustion what is a tail moment arm?

Hide Signatures

(in reply to Dago Red)
       Post #: 47

RE: RE: The How To's of designing & scratch building pl... - 3/13/2004 6:36 PM   
F86_SABRE


 

Posts: 980
Joined: 2/4/2002
Last Login: 6/23/2009
From: Malta, MALTA
Status: offline 		Hi,

A question to the list. Is there anybody who can describe the best method of establishing fuselage lofting?

Thanks

Regards

Reuben

Hide Signatures

(in reply to kevin pelletier)
       Post #: 48

RE: RE: The How To's of designing & scratch building pl... - 3/13/2004 11:28 PM   
dicknadine


 

Posts: 2144
Joined: 7/17/2003
Last Login: 6/24/2009
From: Greensburg, LA, USA
Status: offline 		when you refer to lofting, are you talking about a full scale aircraft, automotive, boat, etc. it is a method of drawing lines, FULL SIZE, on metal plates painted white. which was photographed, then the full size parts were cut from it. it was the bible in automotive/ aircraft design before the advent of the computor. still have callouses on my elbow's and knees. dick

Hide Signatures

(in reply to F86_SABRE)
       Post #: 49

RE: RE: The How To's of designing & scratch building pl... - 3/14/2004 7:38 PM   
F86_SABRE


 

Posts: 980
Joined: 2/4/2002
Last Login: 6/23/2009
From: Malta, MALTA
Status: offline 		Hello Dick,

Thanks for your mail. I was refering to the lofting porcedure to be adopted when you have a drawing and there are few or no crossections of that plane. How can one extract an approximate additional crosssections from the given drawing? There are some people who use a cut up plastic model (1/72, 1/48 or 1/32 type) to solve this problem but as yet I have not tried it so I dont have much experience in this regard.
Thanks again.

Regards

Reuben

Hide Signatures

(in reply to dicknadine)
       Post #: 50

Page:   <<   < prev  1 [2] 3   next >   >>  
All Forums >> RC Airplanes >> Scratch Building, Aircraft Design, 3D/CAD >> RE: The How To's of designing & scratch building planes.
Page: <<   < prev  1 [2] 3   next >   >>  




Jump to:


 
Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America


1.781RCU1