Hi Chip,
When designing aircraft, what CAD programs have you used? Which do you like best and why? What other resources(books, buddies, religious chants) do you use? Thanks for your help, Bryce.

I am an aerospace engineer and I use CAD daily. I use a program called Pro/E (http://www.ptc.com). This is $30,000.00 software/license. But, you can get student versions for $20.00 and they have all the functionality. I think they are limited in that you can not output certain types of files like iges, dxf, step, neutral etc. You can print drawings/plans. It has a fairly steep learning curve as well... not anything difficult, but there is so much functionality! It is regarded by many as being superior to Catia. There are some lower dollar CAD packages like solid edge, solid works, and Cadkey. For typical model plane type projects, they would be OK. I am building the plane in the attached photo... It is a 72" YAK 55. I am going to have the fuselage master CNC cut. So in this instance I am leveraging the ability of Pro/E to directly import the part file into PTC's CNC software with no "Translation" into a different file type. I have seen several AutoCad lite advertised, but I can not comment on these.

YOu will never believe me but I Microsoft paint is something I can draw anything with ease. For the original DV I drew it airfoils and all in paint, and then had the Japanese just blow it up however many thousand percent to get to 2 meter with fuse length. I the only thing that we altered from that hwas to move the stab up a half inch. From there it is
transferedinto Master CaD by the Japanese. I have always just been able to look at a plane and and tell the charecteristics instantly for some reason but never had any formal education about aerodynamics. I also really believe in the if it looks right it probably is and vice versa.

Chip

If you do not have the same "feeling" as Chip Hyde, you should then consider using some good 3D programs out there. I am familiar with Solid Edge and can say it is capable sofware. We use it for drawing a 4 seater homebuilt plane. Every part is made with rivet holes already pre-punched and everything lines-up really good.

We sure would not have been able to draw this plane on paint...

See it on www.dreamaircraft.com

I love it when people design by the seat of their pants. I develop regional malls and so few architects know how to draw with their hands. They all need ACAD or 3d Studio.

This is another program I know people use to design RC http://www.delcam.com/powershape/powershape.htm

Here is another screen capture example of the YAK I am werkin'......

very cool!

Very cool Yak. I have been using Solid Edge (at work) for years and consequently designed a pattern plane:

www.goecities.com/markhunt_2000/INSIGHT

Your Yak is inspiring me to start on an Extra330s. I know it's already been overdone but I think with a little tweaking it could be made into a fine widebody 2M pattern/scale/IMAC plane.

I spent most of my childhood drawing pattern planes...(dad flew pattern....pheonix, tiger tails, etc.)...I never did outgrow it....

Great forum....

It really doesn't matter what program you use, the flight charecteristics are always going to be determined by the "feeling" in the designers head. As for assembly ease I completely agree the more able and user friendly your program is, the better off you are. As for your 4 seat homebuilt project I think youd be surprised what can be done on paint as far as the drawing is concerned

I am already surprised it is possible to draw good airfoils with paint.

No offense here but paint comes FREE with windows and I am not sure it could draw a wing skin with all the rivet holes pre-punched so that when the wing is assembled, you already have the 3 degrees washout built in the wing. No jigs, no stress to the wing, it is built with the washout. The wing has 13 DIFFERENT wing ribs with 12 DIFFERENT nose ribs and every hole lines-up the first time we try it.

I am not saying that it could make me a better designer as I do not "see" how an airplane will fly before actually flying it so I may have to guess much more to get things right.

CAD is just a tool to document what is in the mind of the Engineer/Designer... Treasure in, Treasure out....... or.........Garbage in, Garbage out....

Somewhere I downloaded a free demo program called Design Foil.
After choosing a profile and windtunnel testing it in the program I then pulled a menu down to "export to Solidworks"
Solidworks opens and the profile is sketched....a simple extrude command and I had a 3D rendered wing. I think it took longer to open the programs then to actually create a valid wing.
I can't imagine what could be possible by someone whom actually knows what they are doing, unlike me!

Technology....it's awesome!

_Matt

"Hold my plane while I fly this beer...burp"

SOLIDWORKS 2004!!!!
I am using it as we speak. There is NOTHING I can't do with it. In mid design I can change materials of any and all parts to change my CG's and analyze material forces and stress points. I can modify anything as I go and look at the affect of different airfoils. Iv'e used it in hydrodynamic and aerodynamic design. I even double check the design of my ARF's to see where I can make improvements.

I USE SOLIDWORKS!
With Solidworks I can profile a wing root, a wing tip, the amount of ribs, program the material to be used, it's wieght and cg, the washout, the sweep......And when I'm done I "loft" the whole thing with a keystroke and I have an airfoil that I know will fly. I now have surface area, incidence, ...And in one click I can change it all.

Pro/Engineer... I can do all that geometry stuff... then go directly into Finite Element Analysis, (Pro/Mechanica) and then directly into getting tool paths.. for like maybe a cnc laser cutter, or a 3,4 or 5 axis mill to cut a master for a fuselage or wing....

http://www.rcuniverse.com/forum/upfi...27/Nl30475.jpg

or

http://www.rcuniverse.com/forum/upfi...27/Jf11452.jpg

regards

Yeah, Pro-E works great if you have 30 large to spend on it!!

LOL... I don't have the 30K!!!... I am going thru a divorce!!! SHE DOES!!!! RRRRR BEEYAUTCH!!!

But... I do work for a company (I am the R&D Engineering manager) that has 100 seats of Pro/E... and seeing as it is one of my primary work tools... well... you get the picture LOL...

100 SEATS OF PRO-E???!!! Where do ya' work??!! Must be gov't funded.

http://www.uav.com

and we are watching!!! LOL

Wow, 100 Pro-e seats.

I use solid edge. No great lofting capabilities, but I usually find a way to work around that. Working on a new 2M for this winter's building season...

Killer dude,.. keep us posted on the progress!!! Send me a DXF or an IGES or a STEP file!! LOL

good luck