looking for software : CAD, aerodynamics, simulation

[Victor Duarte]

hi im looking for free airraft design software :

airfoil calculus and simulation
aerodynamics simulationmech parts analisis (finite elements)
dynamic systems simulation (mech assemblies)

there are some on the net but if someone really experimented them, wellcome

thanks to all for every usefull tip

victor

[Helidev II]

For CAD I would recomend Alibre. Im a subscribed user, and have found it to be a good program.
You can start with the basic package, and then upgrade with add on packages as you need them.
Some of them arent particularly useful for what your looking at, however others like ALGOR design check are quite useful. (I havent upgraded to it yet though).
Apparently you can run FLUENT on it, however I havent heard how it goes, and beleive a seat on FLUENT runs tens of thousands of dollars, but havent had a chance to price it yet.
Dont waste your time learning AutoCAD, its time consuming and of limited value. Alibre is very user friendly, youll be modeling in no time.
The other programs your looking for, if you find them could you let me know?

[Victor Duarte]

hi christian, i have a few CAD free softs but dont like them.
i m very used to 3ds max so i look for a similar way to design (4 wiews, NURBS modeller) ... i didnt knew alibre, gonna try it and its a french soft..cool..

if you want an ideal aircraft design soft check : http://www.hanleyinnovations.com/airfoils.html
a dream for us.. a nightmare for my wallet !!!!

for stress analysis i found http://www.lisa-fet.com/download.htm based on the finite elements method, but only limited to 1300 nodes, sufficient for simple parts but useless for complex/molded parts, like can be some... very slow to download (7 files, low server)

for airfoils i have aerofoil, could be pretty nice but its BUGgGY !!!!

friendly

victor

[donshoebridge]

Victor,

Looking at the requirements that you've set, I doubt you're going to find anything for free. You should be able to fine pieces in several different programs, but unless you are going to spend a serious amount of money, you will not find them altogether in a single package. Having an aircraft design split between many different software packages is going to be very labor intensive, time consuming, and the resulting data will not be very accurate.

You would be best off to use an all-inclusive package like SolidWorks. There are other packages that can be used, but whichever way you go, it's going to be expensive. Example: The base package of SolidWorks will cost $3,995USD. A step up from there would be SolidWorks Office for $4,995USD. The extra $1,000 gives you a photo realistic rendering package (PhotoWorks), a hardware package (which is useless for aircraft), a feature recognition package (FeatureWorks is for recreating feature details of imported 3D models), an animation package, and a handful of other stuff that rarely gets used.

The base version of SolidWorks has FEA (CosmosWorks Express), but it can only be used on individual parts, not assemblies. For an additional $4,000USD (?) you get the full FEA package (CosmosWorks) that will do assemblies, as well as optimize parts to eliminate weight by removing unneeded material.

To do flow analysis, you would need CosmosFlowWorks. CosmosFlowWorks is used specifically for computational fluid dynamics (CFD). I don't know how much it costs, but it's not cheap!

The base package of SolidWorks allows you to grab components in an assembly and move then to see how they would work and interact with other parts in an assembly, but it depends on how you put the model together. To do real motion simulation, you're going to need CosmosMotion, which is a package specifically written to do motion simulation and kinematics. Again, it's not cheap.

The bottom-line is that if you are wanting to do all of the things you stated above, you're not going to do it for free. There are plenty of 2D packages that can be downloaded for free, but from a functional and ease-of-use standpoint, they are several orders of magnitude below AutoCAD, which is orders of magnitude below SolidWorks.

[Victor Duarte]

Don, thanks for this accurate pro opinion, i really appreciate and must agree with you ...

partitionning work on several softs , i dont like it.. yes solidworks i would love it..
for rendering, no problem, i have 3ds max, i m skilled on it..

i just thought about autocad in order to keep a coherent software pool..
but indeed all persons talk about solidworks or CATIA ... both are expensive and must be considered in a R&D way..

i m not in R&D yet, just say i m surrounding all the needs..evaluations...good/wrong ways.. i just progress now by closing wrong doors, eliminate bad ways.. and confirm the ways i took are fiesable..

i like your opinion as i guess you have a strong experience in that.. if you think i must be "shaked", just do that, better stop now than lots of bucks later ;) (if something can stop a deep-inside-passion).

thanks don
best regards
victor

[donshoebridge]

Victor,

I use SolidWorks every day at work, and many times during the week at home. The licensing agreement for SolidWorks states that if I use SolidWorks at work, I can have a copy at home. Since I don't have $5,000 just laying around, I have to wait for my work computer to be upgraded before I can upgrade at home. In short, if you're an engineer, designer, or drafter, see if you can find a job with a company that uses SolidWorks, then you can have a copy for home.

There is also a students version and a cut-down version. I don't know what the functionality or cost of either is, but you can find out at www.soildworks.com.

If you have any other questions, feel free to ask.

[Victor Duarte]

thanks don !
i asked solidworks for a demo... i m not an engineer at all..alas... just someone with a good comprehension of techinal data.... and some good ideas i hope..

i would work for design but i cant find than kind of position here.. my job is teaching and using 3ds max for commercial, video games and all imagery ...

i m not affraid of solidworks .. just would ask : is it really THE sof for aero design? i know most mech part willnot be a problem, even dynamic sims .. but do you use if for airfoils/blades etc ? is the CFD really effective ? (i guess it is as its a product from DASSAULT , if they dont know aero.. well, no one else knows)

as you may have seen by there i m going for build a rotor... yes (i can hear you shout)

if i cant afford SW.. i ll ask a friend to "lend" it to me
(SW have a tolerant strategy for "students" , they know that if a person learns on SW..there are great chances that he will recommend to buy it... or buy it)

thanks for your recommandations, don....
victor
(and great job for hornet, it was in my short list for a quick build, before i knew this forum, bu the way, have you a dealer in EU ?)

[donshoebridge]

Victor,

I mentioned upgrades in an earlier post. Well, I've just now been upgraded to SW2004, and I must say - IT SUCKS!!! SW2005 has been out for a couple of months now and I have access to the disks at work, so I'm going to load 2005 to see if it's any better than 2004.

SW2004 introduced a materials database that is integrated with CosmosWorks, and to a lessor degree it's integrated with PhotoWorks. The material database also has surface textures that can be assigned based on the material type. The problem is that the surface texture does not integrate with Photoworks. So even if you specify a material and a surface texture in the SolidWorks area, you still have to specify a seperate material and surface texture using PhotoWorks. And worse yeat, you can't modify the standard materials that come with SolidWorks 2004. You must make a copy of the materials database, tell SolidWorks where it is, and then you can modify the copied database. But the biggest problem I see with SW2004 is that the surface data between the SolidWorks database and PhotoWorks don't talk to each other. Damn!

Another problem that I've seen with SW2004 is that it is REAL SLOW by comparison to SW2003. I don't know why either. I'll get SW2005 loaded and see if it's any better than SW2004. So if you have access to a copy of SolidWorks, DON'T LOAD 2004. It's a real pig!!!

[donshoebridge]

I forgot to reply to your question about using SolidWorks for airfoils and blades. Sure, why not?!?! I do. Here are some samples.

[Friendly]

Don, I played a little with a program called solid edge, Is this the same software. It was great but I did not have enough know how to do anything but the sample stuff.

[Victor Duarte]

hello don ..thanks for awaring me ! i was getting a copy of 2004, i saw 2205 beta, didnt try it, but im gonna reconsider that... i see you re a little angry about upgrades, i would also be considering what you say !! .. but in a way... photowork is fine for rendering but isnt the spine of SW .. yes that sucks if you have to re-tailor each material property twice.

i can see you "explore" some aircraft designs..interesting but at the lower left corner, is it a kind of "propulsion" ? :D :D, i m joking.. i saw a kind of turbochanger in your compound ... is it an indication you think around tip jets ?

my question was more about stress and flow analysis, could you test some features?
does SW have a composites design capability ?

maybe you should take a look at my webspace and browse some drawings (sorry i didnt put them on a page)
http://zeeoo.free.fr/helico/
http://zeeoo.free.fr/gyro/
http://zeeoo.free.fr/misc/

you will quickly see what i have to draw/test particularly the rotorhead (eigen, fatigue, sizing) and the blade ...

thanks for your opinion don

victor

[donshoebridge]

Don, I played a little with a program called solid edge, Is this the same software. It was great but I did not have enough know how to do anything but the sample stuff.

Mark,

This post is going to make me sound like I'm a SolidWorks employee, but I'm not, nor have I ever been, nor have I ever worked for any of their resellers. Please consider the following text an educated opinion, and not an attack on you. This post/reply is for all to digest.

Solid Edge is not SolidWorks. In fact, pardon my French, but Solid Edge is the biggest POS in the world!!! Solid Edge is more expensive than SolidWorks, and is about half as functional as SolidWorks. Not to mention that Solid Edge is really buggy.

I've worked for 2 different companies that have/had Solid Edge, and in both case the experience was the same - GARBAGE! I've had very heated arguments about the differences between Solid Edge and SolidWorks with many people, including my boss (Director of Engineering) and the Director of Software Development at Unigraphics (now EDS) about Solid Edge’s lack of functionality, piss-poor GUI design, and how buggy the package is. By comparison to SolidWorks, Solid Edge is slow to learn and has a choppy work flow to it, and core areas that get used to most haven’t changed one bit over the 4+ years that I’ve been exposed to it.

Some people might think that I have bad attitude toward Solid Edge because I learned SolidWorks first, when actually, I learned MatCAD first, then AutoCAD, then Solid Edge, and then SolidWorks. I became aware of Solid Edge and SolidWorks when I use to work for United Technologies. At the time, our department used AutoCAD exclusively for test equipment design. But because of pressure to get the job done faster, we had to find better tools. So we did a comparison test between SolidWorks, Solid Edge and MechanicalDesktop (or as I like to call it MechanicalDoorstop). SolidWorks won hands down.

Solid Edge is ok as an upgrade from 2D AutoCad, but for major engineering projects, I will never use it again. I would rather take a job at McDonalds than use Solid Edge again. Yes, it’s that bad by comparison.

[Victor Duarte]

i agree : workflow is the gain, just like in 3D films, if you need N softwares, you spend a lot of time/money in fitting them , learning them to match your needs, often it generates lot of problems..

looks to me SW is pretty efficient... i will tell when i will have learnt enough..

don, another evidence you said right : i tried LISA (finite elements stress) and could even import a DXF ... you must edit all the nodes in a text editor ! so... > to the dish.

SW seems to have a good modeler and the features of cosmosflow are desirable..

thanks for your opinion
victor

[donshoebridge]

hello don ..thanks for awaring me ! i was getting a copy of 2004, i saw 2205 beta, didnt try it, but im gonna reconsider that... i see you re a little angry about upgrades, i would also be considering what you say !! .. but in a way... photowork is fine for rendering but isnt the spine of SW .. yes that sucks if you have to re-tailor each material property twice.

i can see you "explore" some aircraft designs..interesting but at the lower left corner, is it a kind of "propulsion" ? :D :D, i m joking.. i saw a kind of turbochanger in your compound ... is it an indication you think around tip jets ?

my question was more about stress and flow analysis, could you test some features?
does SW have a composites design capability ?

maybe you should take a look at my webspace and browse some drawings (sorry i didnt put them on a page)
http://zeeoo.free.fr/helico/
http://zeeoo.free.fr/gyro/
http://zeeoo.free.fr/misc/

you will quickly see what i have to draw/test particularly the rotorhead (eigen, fatigue, sizing) and the blade ...

thanks for your opinion don

victor


Victor,

The core focus of SolidWorks is not fancy pictures, although it doesn't do a bad job at that. The core focus of SolidWorks is to design and engineer, which it does quite well. Yes, there are bugs, and rough areas of the program, but overall, it is the biggest bang for the buck. It'll do about 90% of the functions that the big packages will do, namely Unigraphics, Catia, Pro/Engineer, etc. But the difference between SolidWorks and those packages is that SolidWorks is more automated, easier to learn, and therefore, much easier to use. The downside is that you're not going to open a 5000 piece assembly in SolidWorks and have it be very functional, and the same can be said for Solid Edge, Inventor, Mechanical Desktop, Velum, TopSolid, or any of the other PC based MCAD packages. True high-end functionality and power does not come from a PC based system. It comes from Unix based systems such as Catia or Unigraphics. But times are changing and were now starting to see PC based high-end packages, but there is a penalty in the form of stability and a much greater need for higher processor speeds and greater amounts of RAM.

As far as composite design, I don't know of any package that will do what you're wanting. This is due to the fact that there are so many uncontrollable variables that must be taken into consideration such as humidity, temperature, the type of epoxy, if you are using carbon fiber or Kevlar or whatever, the number of layers, are the layers biased, thread counts, etc. It would be too big of a task for any package to tackle.

[Victor Duarte]

tkanks again don,

my GF is an architect, worked on Velum, on a high number of parts..
well i dont need 5000 parts assembly.

i have a soft for composites analysis (didnt installed it yet) i cant say anything .

to overcome composites problem in SW is there a way to define non-linear properties or non uniform materials ?

thanks
victor

[joeheli]

Nice desings. Are you plannig to makes does for real?

[Victor Duarte]

hi joe, i m not shure your e talking to me .... anyway
i d tell : if they work, if im shure of the reliability, if i can PAY them, i ll do them !
i tried to think the whole design accordingly with my "manufacturing" capabilities, only simple parts, simple shapes...

lets say, if i get my parts properly sized and drawn, i can make them before the end of the year.. someone working for a world famous pump manufacturer can tool them..
it s quite impossible.. i have not the knowledge of an engineer. thats why i need a helper like solidworks. but even with SW i dont plan to have them for christmas ;)

else .. i ll build a hornet or gyrobee, not in despite but because i will have experimented that aircraft design is not for me. ;)

thanks a lot for your opinion joe
victor

[joeheli]

Yes I was tacking to you zeeoo. Keep the good work, you really have the talent.
Good luck!

[Victor Duarte]

well.. sincerely THANKS for encouragements joe,
GOOD flights to you !!

[donshoebridge]

to overcome composites problem in SW is there a way to define non-linear properties or non uniform materials ?

I know there isn't anything in CosmosWorksExpress (single parts only). There may be that capibility in the full blown version of CosmosWorks, I don't know.

[Helidev II]

Don thats some nice modeling in solidworks.
While I agree that someting like solidworks or ProE would be ideal, the $5000 isnt practical for those who are trying to start their own design, unless someone wants to fund the software. :)
This is what I like about alibre. I have had AutoCAD Inventor, and 2000, ProDesktop, and now a licsenced version of Alibre. My cousin works for ACAD in Aus, and so I get a free copy every now and then, however I prefer to pay for alibre.
By comparison Alibre cost me $1500AUD, for the basic package. Now that V8 is out it has 3D scetching. Upgrade to the Pro version and you get photorender plus a couple other bits, go to Expert and you get Nastran, ALGOR, and one other I forget.
One of the nice things about alibre is that you can by the basic pakage, then upgrade as you need the extra bits.
Zeeoo, let me know if you decide to get alibre, we both get a bonus through their refer a friend program.

BTW, the cheapest CFD program I have found is $30,000.

[Helidev II]

Hey Don, you havent been hacking into my computer have you, that one place looks alot like my 2 place. :)

Did you model that pilot yourself. Ive been looking for a manakin to download, but havent had any luck yet. Where did you get it?

[Victor Duarte]

hi christian,
don really convinced me with SW, i download it actually, but i m also for evaluate Alibre, but didnt find a demo version ...
i ll look for BTW info, sounds good.... where did you get it?

if you need a manakin i can model one for you, i have a lot of 3DS max designs, just tell me the format you need (IGES, DXF, ASE) or other, i ll make it downloadable on my site. do you want it dummy-like or realistic, do you want it with segmented joints (neck, wrists, knees, spine etc) then you can rotate each part or a monobloc mesh (in sitting position) ?
friendly (to all)

victor

[Helidev II]

If you can make it with movable joints, elbows, shoulders, knees and hips would be great. Alibre uses STEP format, but IGES is OK too. It doesnt need to look pretty, just give some cale to the design with a pilot and passenger in the seat. Needs to be about 5'10" to 6'.
I agree that SW is a good program, I just think that Alibre, for 2/5 the cost has 95% of the functionality, plus its easier to use for those who dont use it every day.
In the 6 months Ive had Alibre I havent had to use the service center once. There hasnt been 1 service pack out to fix bugs.

[donshoebridge]

If you can make it with movable joints, elbows, shoulders, knees and hips would be great. Alibre uses STEP format, but IGES is OK too. It doesnt need to look pretty, just give some cale to the design with a pilot and passenger in the seat. Needs to be about 5'10" to 6'.
I agree that SW is a good program, I just think that Alibre, for 2/5 the cost has 95% of the functionality, plus its easier to use for those who dont use it every day.
In the 6 months Ive had Alibre I havent had to use the service center once. There hasnt been 1 service pack out to fix bugs.

I made my model. Ergoman (as I call him) stands 5'10" and weighs 225 pounds. All of his joinits do function. This is a major plus when a change is needed, like the height of the seat. When I make the change, the seat moves and all of Ergoman's limbs move acordingly - the feet stay on the peddles, the right hand stays on the joystick, etc. It really saves a bunch of time!

[Helidev II]

Thats exactly what I need, unfortunatley I have to ration my time, and the last time I made a man I lost him when I forgot to save him.
How far have you got with those designs you posted?

[donshoebridge]

The model in the first picture is what I called the AG-60 Threasher, because it looked like a shark or sorts. I started that design using SolidWorks 98 several years ago when I was the VP of PRA 63 in Michigan. I came to grips that it was WAY too much for a newbie to tackle. But it did have several items that, even today, would be considered inovative.

Here are some examples.

The engine that I was going to use was a 4.3L Chevy 90 degree V6. The turbo sharger unit that Victor noticed is for driving the pre-rotator. The Rotor head was to have at least 3-blades, but more than likely, would have had 4-blades. The pre-rotator was to be a concentricly mounted impulse turbine and driven by the air supplied from the turbo. The air would exhaust upward.

The cockpit was designed to have a seat with adjustable hight, and in-flight repositionable rudder peddals. Between these 2 items, I could have fit anyone from 5'0" to almost 7' tall (about 6'8" or so)!

The wings were intended to help unload the rotor systems for higher speed flight, and the constant air supply from the turbo would have kept the rotor blades spinning.

The second model/image is of a 4-cylinder, 2-stroke air-cooled ducted-fan/engine system for use on a scaled down A-10 Thunderbolt II. Engine power was calculated to be in the range of 250-300 HP per engine. The fan was to be directly driven with variable pitch.

The third image was something that I've just started playing with. I call it the Gemini. If/When finished, it will be a 2-place pusher gyro, with a twin boom tail arrangment. I have an idea for a new rotor head, but I'm not going to tell you what it is, or how it works. Sorry.

The forth image is of the tail feathers for my Hornet. I'm currently building all of the composites for my Hornet. The foam core for the vertical stab has been cut and shaped and is taped onto my Hornet right now. I trying to finish the seat assembly (which is also a custom composite design) so that I have something to sit in and make engine noises and fly in my hangar. :p

The M-16/AR-15 is one of my personal toys. The model was just an excersize.

The seat and man image is of an ejection seat design that I was playing with. I use to maintain ejection seats in the Air Force (F-16's). They are very interesting and require a very high degree of detailed thought.

[Vance]

Hi Don, I was wondering how Auto Cad compared to Solid Works. I have a little experience with Quick Cad by Autodesk so I thought it would be nice to get Autodesk's more advanced product. The president of my local EAA chapter can help me with Autocad, but not Solidworks. I am not an engineer but I enjoy making doodles on the computer and I think it would be fun to do three D. The drawings you have done are quite inspiring. Thank You, Vance

[donshoebridge]

AutoCAD is nowhere near the caliber of SolidWorks. You can do 3D in AutoCAD, I did it for years before I first learned about SolidWorks. But the way in which SolidWorks functions and handles 3D models is where all of the power is. Yes, you can do 3D in both, the specific methods and botton clicks will be vastly different, but the basics of 3D for both packages are the same.

Basically, all 3D parts are drawn by starting with a 2D profile, and then applying a 3D command to that profile. Example: a simple piece of square tube. You start by drawing a square, then you extrude that square to a specific length, which makes a square bar. Depending on which CAD package you are using, to make the bar hollow, you can do a few different things; 1) you can cut the center out by making a 2D profile on the end of the bar then extruding a cut through the bar, 2) before you extrude the first square into a bar, you can draw a second square inside of the first, and when you make your solid extrusion, it'll automatically core out the center to the second square shape, or 3) like in SoildWorks, with only one square drawn, when you make your first extrusion, there is an option to hollow out the bar right then. It's actually called a "Thin Feature" and when the extrusion is made, the 2D square becomes the geometry for a wall that can be of a specific thickness, and the thickness can be to the inside or outside, or both depending on what you want.

Basic 3D model making isn't all that tough. Once you learn how to make basic, individual parts on one system, it wont take to long to figure out how to make them in a new system

[Victor Duarte]

vance , if you consider CAD works, then solidworks, even autocad is ok..

for pure 3D , i recommend 3DS Max ( i teatch it so, if you need tips..) or even Maya or Lightwave... if i recommend 3dsmax thats because you will find the most important community of 3D artists on the web, then lots or ressources.

modeling for a film or videogames (my job) and for CAD is different , but you use quite the same techniques.

[Vance]

Thank You for your imput zeeoo, I am not an artist. In the past I have always built things that were in my head to see how they would look, feel and work. This has worked well and I have had some great adventures. My streamlined racing motorcycle had only 2.87 square feet of frontal area. First we cut out station lines from cardboard every seven and one half inches and built the frame and suspension inside. Then we built a transparent body so we could see where things would fit. I could not have done this on a computer with my level of skill and I don't like computers enough to want to spend the time to learn. I like to feel the metal as it comes closer to my fantasy and I like to put it in a friends hand so he can see what is in my mind. As I get older, lazy and have less tools and more infirmities, I make less things and more doodles because doodles are less work and require less space. I would like the doodles to be usefull as a bassis for forming the metal. It sounds like Don is saying that SolidWorks is the answer. Thank You, Vance

[Vance]

Hi Don, I keep reading your post to understand what level of SolidWorks I need. I am retired, so I will have to buy it and I would like to not make a mistake. I can probably figure it out from your post. I would appreciate any aditional imput you would care to share.

I have found QuickCad to be especialy usefull for weight and balance and where to put the rotor head and the weight limits and effects of various people locations. I have had to guess the weight of components that are not built yet and it seems to work well with metal. I get into trouble when I try to guess at things that are well outside of my experance like composits. It is easy to leave things out like hoses or fluids.

The other posibility would be to hire it done. I have found that getting the tool and learning to use it is much better from a life's path standpoint. I do hire an engineer from time to time and I don't do most of my machine work. Certain types of welding make me nervous as I only have one eye left. It is nice to interact with people, but so often the concept is held hostage by the working relationship.
Thank You very much for your help, Vance

[Victor Duarte]

well, vance you re right, theres nothing like feel and touch metal or other.. thats whit i wanna do my proper machine... and like a few here, if i finish it, i ll certainly do othe.
your work on a moto is very interesting .. thats right, at a time, you must take somem foam, wood etc and make a moke up;.lets say 3d art is a quick way for me to "sketch" and see some volumes.. is there place foor the engine etc, as you see i need now to get it into a professional CAD software, this becomes mechanical more that artistic, no problem i have a technical background .
i agree with don solidworks is a good solution, expensive if you consider to buy it, perhaps you can test it in a "beside" way before, thats what i m going to do...
christian (helidev) also talked about Alibre, its a good product for smaller needs, its cheaper, i wil also test that.
to read you, vance, i just wann take my saw, some pieces of alu and wood and...
but i need to have it all drawn before...
have you a pic of your work?
thanks
victor

[donshoebridge]

vance , if you consider CAD works, then solidworks, even autocad is ok..

for pure 3D , i recommend 3DS Max ( i teatch it so, if you need tips..) or even Maya or Lightwave... if i recommend 3dsmax thats because you will find the most important community of 3D artists on the web, then lots or ressources.

modeling for a film or videogames (my job) and for CAD is different , but you use quite the same techniques.


3D StudioMax!?!?!? If all he wants to do is make fancy animations, then I'd have to agree. But 3DS Max is not an engineering package.

[donshoebridge]

Hi Don, I keep reading your post to understand what level of SolidWorks I need. I am retired, so I will have to buy it and I would like to not make a mistake. I can probably figure it out from your post. I would appreciate any aditional imput you would care to share.

I have found QuickCad to be especialy usefull for weight and balance and where to put the rotor head and the weight limits and effects of various people locations. I have had to guess the weight of components that are not built yet and it seems to work well with metal. I get into trouble when I try to guess at things that are well outside of my experance like composits. It is easy to leave things out like hoses or fluids.

The other posibility would be to hire it done. I have found that getting the tool and learning to use it is much better from a life's path standpoint. I do hire an engineer from time to time and I don't do most of my machine work. Certain types of welding make me nervous as I only have one eye left. It is nice to interact with people, but so often the concept is held hostage by the working relationship.
Thank You very much for your help, Vance

Since even the base version of SolidWorks is not cheep, I don't like to tell anyone to go buy it. However, the basic package will do everything that you want to do and much more. Even 3D AutoCad will give you enough power to do gyro design. But the biggest problem is early in the design when everything is still very fluid. SolidWorks will allow you to make real fast changes and still maintain bolt hole patterns between parts. This is just a pipe dream for AutoCad.

[Victor Duarte]

3D StudioMax!?!?!? If all he wants to do is make fancy animations, then I'd have to agree. But 3DS Max is not an engineering package.

"vance , if you consider CAD works, then solidworks, even autocad is ok..
for pure 3D , i recommend 3DS Max ( i teatch it so, if you need tips..) or even Maya or Lightwave"
have i said 3dsmax is an eng package ? no don, i have 3ds, its about 5000$, if i started this thread thats because i need opinions on a professionnal CAD package in this kind of cost, thanks for giving me yours, be shure i pay them careful attention.
by the way you told about an A10 scaled airplane, i found this site : http://www.a10productions.com/

[Ken_Boling]

Hey Don, any chance of getting copies of your Solidworks files for your "Ergoman"? I have been planning on doing something similar to help in CG calculations on a design I am working on (tractor gyro). I too use Solidworks on a daily basis and find it to be an excellent design package.

[Vance]

Thank you Don, Both Machine shops I use and the foundry that I use have AutoCad and I was wondering if SolidWorks files can be read by AutoCad program? I'm not sure that I have gotton an unbiased answer from them. The tube bender and plastic molder that I use have both. The composit guy I use has neither. The aeronautical engineer I use has both and then some. Thank you again for the help, Vance

[donshoebridge]

Hey Don, any chance of getting copies of your Solidworks files for your "Ergoman"? I have been planning on doing something similar to help in CG calculations on a design I am working on (tractor gyro). I too use Solidworks on a daily basis and find it to be an excellent design package.

Let me find out how big the files are. If they're a reasonable size, I'll post them on my website for free download. I'll ket you know.

Don

[donshoebridge]

Thank you Don, Both Machine shops I use and the foundry that I use have AutoCad and I was wondering if SolidWorks files can be read by AutoCad program? I'm not sure that I have gotton an unbiased answer from them. The tube bender and plastic molder that I use have both. The composit guy I use has neither. The aeronautical engineer I use has both and then some. Thank you again for the help, Vance

AutoCAD doesn't play well with others as far as reading different formats. SolidWorks on the otherhand reads just about everything including; Pro/E, Unigraphics, Solid Edge, Mechanical Desktop, Inventor, Catia, DXF, DWG, Parasoild, IGES, STEP, VRML, ACIS, VDAFS, and Cad Key files.

[Vance]

Thank You Don, That is very helpful, Vance

[donshoebridge]

My 3D model of Ergoman has been uploaded to my website and is free for the taking. Everyone, feel free, including you Victor. :o

The file is 2.5meg in size. The assembly file will be looking for several "dead weight" files that I did not include. So when SolidWorks starts asking for them, just say no. Here's the link...

http://www.geocities.com/donshoebridge/solidworks/

[Victor Duarte]

thanks don, i ll get it when i get SW 2005 download complete

[Helidev II]

Don, I couldnt download it, said the site was unavailable?
I had the same problem when I tried to download the specs for the hornet yesterday, and had the same prob.
Do you have a download limit from your site?

[Helidev II]

Got the specs, still cant get ergoman :(
Must congradulate you on your site, and the specs for the hornet Don, top work.
Might have to get one of those while I play around with my design.

[donshoebridge]

Got the specs, still cant get ergoman :(
Must congradulate you on your site, and the specs for the hornet Don, top work.
Might have to get one of those while I play around with my design.

Sorry about the website problem. I'm going to be taking care of it very soon. I'm going to be pulling EVERYTHING off of Geocities. They have been screwing me over for the past few months now with the same error that you recieved.

I'm working on a new site where I can start selling some of the machined parts that are used on the Hornet. I'm also working with a couple of other people that have gyro type products, as well as a guy that is offering up his machining services. The new site is lacking content right now, but what there is looks really cool!

I have a Parasolid model that I can send you. You could still use Ergoman in this manner, but you wouldn't be able to change any of his features except for the material density. If not, then all I can say is keep trying. Sorry. :(

[Ken_Boling]

Thanks Don!...Ergoman opens and work great for me.

[Helidev II]

Ill just keep trying for now.
Strongly resiting the urge to ask for a price on the hornet, have to get helicopter CPL first :(

[Helidev II]

OK got the file, but its in SW format which inst compatable with Alibre :(
Any chance of saving it as an IGES or STEP (best) format?
Thanx Don.

[donshoebridge]

Iges and STEP formats are going to be HUGE! What else can you import? Parasolid? Acis?

[donshoebridge]

Here's a Parasolid file. Try this.

I tried and Iges and a STEP just now and the Iges was over 6meg, and the STEP was over 7meg. The limit for Geocities upload is 5meg.

[donshoebridge]

DAMN! The forum will not allow me to attach a 175k zip file! What gives? No matter. I'll post it on my site with the other one.

http://www.geocities.com/donshoebridge/solidworks/

[Victor Duarte]

hello
i got SW 2005 working on my machine few minutes ago
i m amazed, in just a few seconds i could design a simple drilled plate, extrude it,see a cross over etc,
really looks good, intuitive, with just the functions you need , just like a machine shop, i love it,
perhaps my mind will change as i discover some bugs or faults but it really appears to me it s a good software..indeed

don, a question please ... can i have a perpective view of the part instead of a tri metric one ? or is my FOV wrong ?

thanks!

[donshoebridge]

Victor,

SolidWorks typically does not show all of the icons/buttons when it's first loaded. If you right-click on one of the toolbars and select "Customize...", then click on the "Commands" tab in the dialog box. Then scroll to the bottom of the "Catagories" window and click on "Views". In the "Buttons" window, you will find a button for Perspective View. Just drag it to whatever menu you want to have it one, and in the location you want it in.

You can also turn on Perspective View by going to the "View" menu, and selecting "Display", where you find "Perspective".

The Perspective button is much easier to deal with, and after you've had a chance to poke around in SolidWorks, you'll be wondering where some of the other buttons are. You can place any number of buttons that you like from the right-click "Customze..." screen. I would also suggest that you turn on all of the tools bars that you think you might need, and then add the remainder of the buttons to each of them. Once you find the tools that you really need, and the ones you don't, you can clean up your tool bars by removing the buttons you don't want by going to the "Customize..." screen, then drag the button from the tool bar back to the screen.

[Victor Duarte]

thanks a lot don !
this way of working is perfectly right for me, i use to customize all my softwares.
like in most of "monster" sotware packages, i learnt to think "just ask yourself what you need to do, the software may have a function to do that".
about composites, i v seen theres a generic "fiberglass" material with some A to S variants, but the elasticity modulus is not entered :( ..
i m amazed this soft has a very good workflow, wizzards that are not gadgets.. and a VERY clever and efficient interface ... i m like a child with his new toy..
i guess next week i ll have my rotor in the box, then i ll try to perform some stress analysis and optimizations.

thanks for your help (i found pers view)

[Victor Duarte]

i v got to search for online standard components ressources...
by the way i have to turn my firewall off.. thas a problem

[donshoebridge]

TURN OFF THE PERFORMANCE E-MAIL OPTION!!! This might take care of that problem. It can be found by clicking Tools, Options..., System Options tab, General, and it should be about 2/3 the way down the list on the right.

[Victor Duarte]

thanks Don, it turned off.
the problem, on my opinion comes from the FlexLM licence manager server, SW tres to access it and my firewall doesnt allow , so , conflict. thanks anyway for the tip ;)

[donshoebridge]

Post some pictures when you get a chance so we all can see what you've been working on.

[Victor Duarte]

hello don and others, ok ,there are some screenshots of my advancement 3 days later.
these parts are only tests (i didnt post all the tries), not definitive.. just throwing the stepstones.. but SW 2005 really rocks !

[donshoebridge]

This looks like the beginings of a 3-bladed rotor head.

[Helidev II]

Whats that midle shot FEMA?

[Victor Duarte]

yes don it s right, a 3 bladed hingeless semi-rigid, more to come...
christian, i dont know what is FEMA, geographical software ? the middle shot is a 6061 plate used as flapping spring, the colors are stress analysis, useful to see where your part may be weak or where the deformations will be distributed ..

[donshoebridge]

I think he ment FEA. No matter.

One suggestion... Don't use a thin piece of 6061 as a flap spring because it'll fatigue and break. Use a slightly thinner piece of 4130. You should also be able to find spring tempered flat stock like a 1/2 to full hard 302 stainless steel.

[Victor Duarte]

right don, i plan to use a spring steel plate, i dont know the grades in english.. in fact there will be 2 plates and a rubber/elastomeric core between them, to prevent eigenmodes and allowing to drawn an air duct in it (you said tip jet ? why not, it works with or without tipjets, so i include it in my design)
i just did a try with 6061 because i v no such steel in he SW library.. anyway, it gives a good idea of where are the weak points.and helps to shape it,
i just analyzed an hollow extruded VR7 airfoil blade with correct CoG and CoT the time dramaticatically increases :( , i just regret Cosmoworks doesnt perform torsion tests..

[donshoebridge]

It'll do torsion, kinda. You have to lie to it. Put a moment arm on the piece and apply the force. That's how I do it.

Also, as for no suitable steel in SolidWorks, add your own. Go to www.matweb.com for all of the specific details about whatever material you want to use, including European materials and their US equivalents.

[Victor Duarte]

thanks don, good link.. yes i had the idea to add an arm, i tried it on a part and it deformed it as if it was.. jelly ... i ll try again
thanks for your help, once i ll have a good design, it may be suitable for others i hope..

[donshoebridge]

Actually, you need to add 2 arms. Then apply your forces to the arms in opposite direction. For instance; 1Kg up and 1Kg down at equal distances away (say 1 meter) from the intended axis of rotation. The result would be 2Kg/Meter of torque.

[Victor Duarte]

it works fine !

[donshoebridge]

There is one method that SolidWorks suggests using to apply forces directly to a part at a specific point. Create a projected "Split Line" then apply your force to that. In the attached image, you can see how you would do this. You would apply 2 forces - one to each of the Split surfaces in opposite directions. The only problem with this method is that you'll have to do a bit of hand calculating to determine the actual torque forces.

[Victor Duarte]

the blade, for those interested in that

the blade has a VR7 profile, thicken at the root, 10 degrees progressive twist
the stress test was made with 10 tons centrifugal force and 300 kg under the blade

thanks (thx don)

[Helidev II]

Looks nice victor.
Yes did mean FEA.
How many points can you do with standard SW, and which FEA program does it come with?
Alibre comes with a basic version of ALGOR, but I havent upgraded to try it yet.
I must say Victor, your progress is pushing me along much quicker than I was previously travelling.

[donshoebridge]

Christian,

Standard SolidWorks comes with CosmosWorks Express. It's an embeded, parts-only version of Cosmos. I don't know how many nodes there are, or if the count can be adjusted. Sorry.

[Victor Duarte]

hi christian and don, well, my previous job is 3d designer so, its easier for me to understand SW, i don start from scratch.
of what i know, SW as don said uses cosmoworks, there is no limitation in the number of nodes but you can adjust the "size" of the mesh used to calulate,so the accuracy
more to come
christian, let s keep running a friendly challenge, that makes us progress even faster ;)
don, thx for participating
cheers

[donshoebridge]

BTW, I've updated my website to show the progress of my Horent build. I've also posted a revised version of the Hornet Documentation, if anyones interested.

[Victor Duarte]

nice work don,
may i ask questions ? your work on the seat is interesting, dont you think there should be a metallic frame in the foam ? i mean to attach it to the frame.. and two lateral triangles to improve resistance.. just suggesting ... are you gonna use kevlar?

btw i thought in an easy way to rigidify this kind of foam : you just have to cut small grooves each inch on the lenght (1 miliimeter large x 1 centimeter deep) and fill them with epoxy, this way, they will rigidify the surface, thats what i call "honeycomb for the poor" and i plan to use it on the fuselage...

for my fuel tank : i plan to mold it this way : i ll get an inflatable cubic baloon (they exist in toys r us) then to cover it with roving and paint it with several layers of a latex mix , when its dry, i just deflate the balloon, this way i can build a crash proof tank, what do you think about that ?

thanks again

[donshoebridge]

In the first image, you'll notice the seat back which is sitting on the floor. The dark colored rectagular patches are 1/8" thick aluminum plate. They will attach to the diaganol braces. The seat spine (middle image) also has hard-points bonded in under the glass. But no matter. I'm going to change it (again). I'm sure I can simplify the design, and lighten the overall weight at the same time. The seat back can be bolted to the airframe as a seperate unit by removing the spine. To tie the engine mounts to the diaganols, just a short piece of 2x2 tube can be used. The seat bottom would become a seperate assembly and would be supported with aluminum angles between the keel tube and the underside of the seat. This format will make it MUCH easier to build, but also provide a means of customizing the seat height without too much difficulty.

So for those people that are following my progress... Yes, the documentation is going to change again. Sorry.

[Victor Duarte]

ahh don, you re not lucky , i m the only interested in your work ;)
well its better that you upgrade your docs as needed.
sorry i didnt see the alu parts on your seat, thought it was tape. that way it looks good, i m interested in how you make it "makeable" to other persons.
i tried a first assembly of the parts of my rotor, opinioins wellcome,
more to come

regards

[donshoebridge]

Victor,

I know it's been awhile since this thread was active, but how did your 3D, 3-bladed rotor head turn out?

[tyc]

... looking for free airraft design software :

airfoil calculus and simulation, aerodynamics simulation, mech parts analisis (finite elements)
dynamic systems simulation (mech assemblies)


If you want to learn aeronauticl design, there are no shortcuts.

Since you already know how to use a computer, odds are you know how to use a spreadsheet but as to the CAD software, you may wish to consider picking up an old copy of PRO DESIGN II or one of the updated versions. There should be plenty of these older and still very useful software copies around.

Why PRO DESIGN? For a young engineer or the backyard hobbiest, it is nothing short of excellent. It is a 2D CAD software and back in 88 when I was the lead speaker at the ASNE collequium as held in Philadelphia, most of those present were used to using those one hundred thousand dollar (government paid for) CAD systems and had a hard time believing then that there was a PC CAD system selling then for only $100 - one which would match anything their more expensive systems did. As I specialized in PVHO designs, the few drawings which were included in that offering raised eyebrows.

It doesn't take one very long to "pick up" and "run" with PRO CAD. It does not run on MAC or Linux machines, just MS but once you have the idea in your head, with PRO CAD (I believe they have another name for it now) you can essentially touch-type your ideas into 2D drawings, all of which can be printed out on just about any desktop printer or more professional ones with larger media if you like, all of which are also readily available, new or used.

Hope this helps.

tyc

[Resasi]

Don tried logging in to your site to update on your build but denied access???