Starting New Project RCM Cessna T-50
 

Hey Gang

About ten years ago I ordered the RCM Cessna T-50 plans. Finally I have decided to dust them off and fire up my Cad to draw the parts. About 30 years of drawing structural, mechanical and electrical things for a living Now I am drawing something I want to draw. One thing I don't understand about these plans. in some areas they specify for a part to be made of soft wood and I don't know what wood they are talking about because in other areas they specify balsa.

If it looks structural it might mean Basswood!

old, how about a little tutorial of how you are proceeding to convert the plans into cad. What cad are you using? How are you scanning the plans into the cad? Dan.

AutoCAD will allow you to insert Images and PDFs which you can scale up to the scale of the model you wish to design. Then it is a matter of tracing. The down sides are the most images not sharp enough after scaling up so some times you trace it at a convenient size and then scale it. The other BIG problem is the most of the images and other documents are not 1:1; vertical and horizontal, so you have to rubber sheet it by making a block out of it and the insert it with the vertical and horizontal scaling number you need to make the span and fuselage lenth correct! I use Bob's Documents and the Smithsonian for sources of better documents!

Dan, I am not going to scan them in. The problem with the plans is they aren't accurate as far as the shapes and sizes the years of them setting copies of the lines are distorted and warped to a small degree.. . I will redraw the entire short kit. there's enough info on the plans to get it right. I will test fit all parts on CAD before I have them cut. I do plan to "update" this model for flaps and retracts. I have also found several areas that without risking structural integrity I can lighten it up (Old plans).I am using AutoCAD 2014

Loud thanks, but I have looked at these plans carefully and they aren't accurate, and I agree with what you had to say.

Even the best of the line drawings you can find take days to justify the sections to the plan and profile. The I go to "airliners.net for as many photos that will help me see the true shape. The stuff I got for the Beechcraft 350i King Air I am finishing up had sections that were very round. But found some fore and aft end view that showed the sides bottom and top were not so round the had almost the same radii on the corners front to back!

Are you into solid modeling the models? Love to learn how that is done might speed things up and make stations that are more compatible one to the other. Sometimes I do not see the problem till I start making the cut side stringers.

Loud you are a big help to me, Thanks. I also have access to Cadworx which will let me actually draw the parts and test fit them. It does make the project a little reliable I guess but I have been doing autocad so long, I don't see any problems. I see what you meant about the drawings not being "true" . I am seeing that on this Cessna vertical stabilizer also and haven.t checked the horizontal or elevator yet..

I started drawing with angles , 'T' square and pencils of different hardness! Then a Amiga 200 and a then very good CAD program. Then to AutoCAD in '94'. been in it ever sense! All my designs are done 2D. I have used SolidWorks 2016 3D at work, but on simple shape and nothing like a fuselage or wing. I am hoping to get into AutoCAD 3D, I have ACAD 2014.

load, thank you for the information. Which Windows are you using AutoCAD 2014 in? Dan.

Add ~ w10 pro [who is load]

load is Loud with a typo.

ME AND MY BIG MOUTH, Cessna T-50
 

What I am using at the time is AC 10 light

Don't know that one???

Cessna T-50 Progress
 

I have spent the last few days studying the original plans from RCMS Cessna T-50. Thanks to Loud design and some of you others here, I decided to pretty much completely redesign this thing. I have been gathering information and also bought a plastic kit that I have been checking with calipers and mics and a scale converter for accuracy so I can take pictures of the vertical stabilizer, rudder and various other parts to import them into my cad for shape.. Someone suggested I scale the model, this is my first foray into drawing a plane. After checking at how exacting these newer plastic model kits are, I thought it a good idea to check one out for accuracy to use for outlines.

I take my hat off to the original drafter who drew this RCM model because the technology from 1964 and today is so different. I know what he did to draw this thing, but so far I have found so much out of scale, I have decided to redesign the model completely. I will still be able to use his plans to assemble and ideas for design. I just hope when I am finished it will fly a little better than a city bus.

old, is that the original AutoCAD 14 you are talking about? Dan.

One thing I do that you might try, is if you are a Excel user make a spread sheet with sections for the various parts; wings, fuselage[station/formers] and the trail components. take all your measurements and record them, then start drawing!! You can set up the scale formula so that you enter the raw measurement and Excel with fill in the scale-up measurement in the next column!

Loud, good idea

Dan, Yes. It's called CAD light because it's their mot simple version. You can do about anything with 2D you can do with 3D except make a model, it just takes a little more work and thinking.

Oldbassard, since all three threads are about the same project I've merged them into one thread.

It's a better way to do this since it makes it easier to find it later and follow the progress instead of starting a new thread about the same project every other day. So please keep all your T50 project posts to this one thread.

The Bobcat is one of my own favorites too. I'll be watching this with keen interest.

Have you seen the Paul Matt drawings of the T-50? Might those be a better place to start.

BM, I understand that, by all means

I have been having a better look at the design on this plane, Loud Design was right when he suggested using 3d. But that's about a 60 mile round trip for me to my sons office and I'd be in the way. I will tough it out with 2D and have already started. Later I will post some picts of my methods using 2D if anyone is interested