# 3D CAD and Model Engineering



## vascon2196 (Jan 19, 2013)

Howdy folks...just wondering...

For those of you who have used 3D CAD (like SolidWorks) for your model engine builds...what has been your overal experience? Is 3D CAD a must-have when designing and building a new engine? Was it hard to learn?

For those of you who still use 2D CAD...what would convince you to transition into 3D CAD?

I just recently wrote an article featured in Digital Machinist magazine regarding 3D CAD and model engine building...wanted to hear what you guys had to say about the topic.

Just curious...

Thanks!


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## robcas631 (Jan 19, 2013)

I learned Acad 12 for win. Back at that time it wasn't that hard to learn! Right now I am looking to obtain a student version of acad for win 7. Can't find it yet!


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## aonemarine (Jan 19, 2013)

Funny you should ask,  Im sitting here modeling an engine in Alibre right now.  Is 3D cad necessary??  Well a 100 years ago they did with out it.  For me its a time saver. I can build and visualize what im doing much better than just on paper. I have really enjoyed cad modeling and feel that I can avoid costly mistakes by doing so. Anyone that wants to design and build thier own design should consider having a cad program.


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## Brian Rupnow (Jan 19, 2013)

Vascon---I use Solidworks for my business designing machinery and automation. There is a steep learning curve. Is it absolutely necessary?---Not at all. I have been designing machinery (including engines) for 47 years. The first 32 on a drafting board, the next 3 in Autocad, and the last 10 or12 in 3D Solidworks. Would I go back to the board or 2D?---Not on your life!!!


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## robcas631 (Jan 19, 2013)

Is thre a student version Acad software?


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## kf2qd (Jan 19, 2013)

No. But it does it make it nicer. I have done lots of 3D design in 2D CAD, but since I have learned 3D CAD I find that I like doing things in 3D CAD. Probably even some things that would be just as well done in 2D. The initial learning curve was just as steep, or maybe steeper, than the learning curve for 2D CAD.

I do my 3D CAD with AutoCAD and have also done the same type of drawings using ProgeCAD. Functions are just the same, cost is different. Actually like the rendering tools better in ProgeCAD. Cost is a bit less also. Macro stuff had to be written a bit differently.


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## Dave Sohlstrom (Jan 19, 2013)

I'm also a Alibre user form day one. Found a big error in the Holt 75 paper drawings I have. Would of found it when I build the engine but maybe not until I had made a rather costly mistake machining.

Dave


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## Niceonetidy (Jan 20, 2013)

Hello,

I used Cad too both 2d and 3D. I recently upgraded to a new 64 bit pc and my Autocad2007 will not work. And to hell paying again for a new version. I have since been using Draughtsight. It is supplied free from the Solidworks company, and apart from 2 icons, it looks and operates just like AutoCAD.  Give it a try, it's amazing,. . . . . . . . .


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## Niceonetidy (Jan 20, 2013)

http://www.3ds.com/products/draftsight/overview/

Is a link to the softwware


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## abby (Jan 20, 2013)

I agree with Dave , the ability to build a model in 3D cad before cutting metal  highlights any drawing errors , limiting expensive re-working , especially useful where multi-part asemblies are involved .
Adding another dimension to a drawing also adds another dimension to thinking.
The ability to see a 3D part often leads to changes and simplifications that would not have been apparent looking at a 2D drawing.
Machining set-ups and solutions can often be resolved at the computer rather than the mill or lathe.
Not a necessity by any means but for me a huge timesaver , like any tool that is not essential but makes the job much easier it needs to be priced to allow occasional use and not be the most expensive piece of equipment I possess.
I came to using 3D CAD later in life than many model engineers and have  found 2D/3D ViaCad to be a good choice , cheap and very easy to learn and use  which is important as I want to spend my time producing models not  drawings.
It doesn't have the frills of the industry leaders but does the job at a fraction of their price.
I will also add that as a G5 Mac user the majority of 3D cad software is unavailable to me.


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## ausdier (Jan 20, 2013)

Finding drawing errors.
Finding missing dimensions.
Visual referance.
making sure things fit.
It's all great to be able to do this with CAD and it seems that about 90% of plans that I get have problems.
I use either Inventor 2012 Pro or Solidworks 2012 Premium in either Metric or Imperial.


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## Tin Falcon (Jan 20, 2013)

I am a registered Alirbre PE  user. 
Tin


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## canadianhorsepower (Jan 20, 2013)

robcas631 said:


> I learned Acad 12 for win. Back at that time it wasn't that hard to learn! Right now I am looking to obtain a student version of acad for win 7. Can't find it yet!


Hi Rob, what is ACD software???????????

I know that you can get CAD from Autodesk as a student version,
this is what I get my students to download

cheers


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## canadianhorsepower (Jan 20, 2013)

this is also a free link and does work well

http://www.emachineshop.com/machine-shop/Upgrade-Success/page218.html


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## vascon2196 (Jan 20, 2013)

Great responses...It is nice to see the differences and simmilarities between all of us.

I was fortunate to have learned board drafting, then 2D Autocad, then Mechanical Desktop, then SolidWorks, then Pro-E, and now back to SolidWorks. I did use Alibre for a little while when I was doing contract work on the side.

Personally I like SolidWorks and enjoy teaching it. Even though there are a lot of Wizards and built in functions of the software that make it great when designing I find it necessary to bring back all of the old drafting rules I was taught. Like, what does Hole Wizard do when you select "Clearance for a 1/4" SHCS"? Most students don't care...and I have them search through the Machinery's handbook to find it.

Anyway...I wanted to see how many Model Engineers use 3D CAD for their designs and what you all thought of it. Just because I can design something using pencil and paper does not mean I am in a hurry to go back and do it!

Either way, I enjoy all of it...2D & 3D CAD...and model engineering.

For those of you still thinking about moving over to 3D CAD just try it once. When you get your first mechanism moving in an assembly you will be hooked!!!


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## camm-1 (Jan 20, 2013)

I have Solid Works and have try draw some tutorials for some ours
but when I try do somthing myselfe I dont remember anything how it
was done.
I realy want to learn it but I dont know if I ever will.:wall:
Right now I started to transform another engine from a drawing to
another shape but I do that on simple paper sketches.:fan:


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## canadianhorsepower (Jan 20, 2013)

camm-1 said:


> I have Solid Works and have try draw some tutorials for some ours
> but when I try do somthing myselfe I dont remember anything how it
> was done.
> I realy want to learn it but I dont know if I ever will.:wall:
> ...


try this one compltely free ans easy to use
http://www.emachineshop.com/


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## Lew Hartswick (Jan 20, 2013)

Does anyone have a suggestion for a SIMPLE pgm. that can do what I needed to in this dwg.? I DON'T want a full blown CAD pgm.
I probably could do it with geometry but I think it would have to be an iterative process and take ages. The drafting I need to do is 
usually simple enough to do on a board with straight edge and triangle with a circle template occasionally.  But finding the location of
an arc center is the catch. (when the lines are not at right angles). 
  Thanks for any suggestions.
   ...Lew...


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## camm-1 (Jan 20, 2013)

Well, it looks to be much simplier.
Do you now the price?


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## canadianhorsepower (Jan 20, 2013)

camm-1 said:


> Well, it looks to be much simplier.
> Do you now the price?


free, gratos, nothing, oooooo
before I get my students to jump in CAD I give them a smell at this
to build confidence


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## canadianhorsepower (Jan 20, 2013)

Lew Hartswick said:


> Does anyone have a suggestion for a SIMPLE pgm. that can do what I needed to in this dwg.? I DON'T want a full blown CAD pgm.
> I probably could do it with geometry but I think it would have to be an iterative process and take ages. The drafting I need to do is
> usually simple enough to do on a board with straight edge and triangle with a circle template occasionally.  But finding the location of
> an arc center is the catch. (when the lines are not at right angles).
> ...


look at answer number19 there is a link posted


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## stevehuckss396 (Jan 20, 2013)

vascon2196 said:


> Howdy folks...just wondering...
> 
> For those of you who have used 3D CAD (like SolidWorks) for your model engine builds...what has been your overal experience? Is 3D CAD a must-have when designing and building a new engine? Was it hard to learn?
> 
> ...


 

3D cad has helped me out. I'm not saying I couldn't do it without the program but it saves a ton of time. I have designed a half a dozen engines to the point where they were complete before I cut the first part. In the end there were very few changes and no "do over's" on making parts. It's a big help.


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## Lew Hartswick (Jan 20, 2013)

OK downloaded emachineshop. and am trying it. got the circles drawn and the two
tangents but now can't figure out how to "move" the last circle to MAKE it tangent
to the two lines, and then read the coordinates of center.
   ...lew...


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## canadianhorsepower (Jan 20, 2013)

Lew Hartswick said:


> OK downloaded emachineshop. and am trying it. got the circles drawn and the two
> tangents but now can't figure out how to "move" the last circle to MAKE it tangent
> to the two lines, and then read the coordinates of center.
> ...lew...


when it's red like the picture and the square around it
put your pointer over the line and you will see the 4 arrows coming upuse lh mouse and drag it.
you can also use help or tutorial. They also offer online help for free


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## vascon2196 (Jan 20, 2013)

camm-1 said:


> I have Solid Works and have try draw some tutorials for some ours
> but when I try do somthing myselfe I dont remember anything how it
> was done.
> I realy want to learn it but I dont know if I ever will.:wall:
> ...


 
It does take some time to get the learning curve...that is for sure.

Best thing to do is practice. I started by taking old 1970's drafting books and putting them into SolidWorks...very challenging and lots of fun.


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## pgp001 (Jan 20, 2013)

Another big plus for Solidworks from me.
I use it all day everyday in my paid job as a mechanical design engineer.

Then I come home and use it regularly at home for my model engineering designs. I have a golden rule to never trust any published design until I have modelled it in Solidworks myself to make sure it will work out OK.

I started with pencil and drawing board, then Autocad 2D and since 2005 I have been on Solidworks.
Would I go back to 2D ??.........Not on your Nellie.

Phil


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## aonemarine (Jan 20, 2013)

My biggest complaint with solidworks is the cost of it. Since I'm just using the 3D Cad as a hobby I can't justify the expense, so I went with what I could afford (Alibre) and have no complaints. Having used turbocad for a few years the learning curve was next to none. Heck just playing with it and thinking I want this to do this was enough to get going for me.


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## Dave Sohlstrom (Jan 20, 2013)

Here is you drawing done in Solid Edge that is free.

Dave


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## Lew Hartswick (Jan 20, 2013)

Dave Sohlstrom said:


> Here is you drawing done in Solid Edge that is free.
> 
> Dave



OK I'll have to give it a try. Does it show the dimensions on the drawing like you showed? 
   Thanks. 
   ...lew...


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## canadianhorsepower (Jan 20, 2013)

Dave Sohlstrom said:


> Here is you drawing done in Solid Edge that is free.
> 
> Dave


show the link for a free program pls


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## Walsheng (Jan 21, 2013)

Just starting back in the hobby in the last couple of months and after pouring over the plans for the Stuart No.9 I decided to model it in Solidworks both as a double check and also to be capable of dimensioning things the way I want them dimensioned for ease of settup.

It took approximately 6 hours to model it this far.  The castings are not dead accurate but I was more interested in the machined surfaces.

I know it's not necessary but it sure is a nice luxury to have.  I have Solidworks for my business and I am quite sure if I was a basket-maker or a tailor I would make do without.

John


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## Dave Sohlstrom (Jan 21, 2013)

You can find Solid Edge here http://www.plm.automation.siemens.com/en_us/products/velocity/solidedge/free2d/

When you are drawing lines and circle you use the reference grid. Once you are happy you go to the Dim tools and Dim the drawing. I don't use this program a lot because I mostly model in 3D using Alibre. Alibre is about 25 times less expensive than solidworks.
Dave


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## vascon2196 (Jan 21, 2013)

Walsheng said:


> Just starting back in the hobby in the last couple of months and after pouring over the plans for the Stuart No.9 I decided to model it in Solidworks both as a double check and also to be capable of dimensioning things the way I want them dimensioned for ease of settup.
> 
> It took approximately 6 hours to model it this far.  The castings are not dead accurate but I was more interested in the machined surfaces.
> 
> ...


 
Great looking model...it is always nice to see it "work" on the screen before it "works" in reality. Also great for double checking form fit and function of mating parts. Also good for setup purposes too!

Unfortunately some people still think 3D CAD is only good for making cartoons....


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## Lew Hartswick (Jan 21, 2013)

Dave Sohlstrom said:


> You can find Solid Edge here http://www.plm.automation.siemens.com/en_us/products/velocity/solidedge/free2d/
> 
> When you are drawing lines and circle you use the reference grid. Once you are happy you go to the Dim tools and Dim the drawing. I don't use this program a lot because I mostly model in 3D using Alibre. Alibre is about 25 times less expensive than solidworks.
> Dave


UN-fortunately it needs Vista or Win 7 .:-( I am using XP and no plans on changing.
Thanks 
   ...lew...


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## mrehmus (Jan 21, 2013)

Alibre works just fine under XP 32 bit.

I switched from AutoCAD to Alibre after the second issue of my magazine. I could not do the drawings if I had to use a 2D drafting tool to make them. Alibre is about 10 x faster than 2D and being able to put all the parts together and check clearances, etc., is incredibly important. Motion capabilities really allow analysis of designs, etc. Especially when tab A hits tab B and it should have hit tab C. Really keeps the errata notifications to a minimum.

It is also a major design tool where I feel 2D is just a drafting tool.


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## Dave Sohlstrom (Jan 21, 2013)

Mike is correct that Alibre will run on XP machines. The personal edition is $199.00 and well worth the money if you are designing model IC or steam engines. It will do most of what solid works does for less money. Here is an example of what can be done. This has been rendered with Key Shot 3. It is a model Z drive for RC model tug boats we are designing and building.

Dave


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## aonemarine (Jan 21, 2013)

Dave, love the Z drive!!!  How did you make the prop??


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## Dave Sohlstrom (Jan 21, 2013)

All the cast parts of the drive have been designed in alibre. Shapeways did several of the RPs and I built molds for lost wax investment casting. The castings I have now were cast in the UK or NZ. I have waxes at the foundry in Tacoma WA right now.
The molds for the props were a pain with the development of the parting line.

Dave


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## aonemarine (Jan 21, 2013)

I need to work on my rendering skills......


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## Dave Sohlstrom (Jan 21, 2013)

I've only been playing with Key Shot 3 for a short time. I find it fairly easy to use and as you can see it adds to the 3D model 100%.
It did cost me a few bucks when I went from PE to Pro.

Dave


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## aonemarine (Jan 21, 2013)

Ive played a bit with the keyshots as well,  there are still some things I need to learn about it, mostly the lighting.


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## RichD (Jan 22, 2013)

Lew Hartswick said:


> Does anyone have a suggestion for a SIMPLE pgm. that can do what I needed to in this dwg.? I DON'T want a full blown CAD pgm.
> I probably could do it with geometry but I think it would have to be an iterative process and take ages. The drafting I need to do is
> usually simple enough to do on a board with straight edge and triangle with a circle template occasionally.  But finding the location of
> an arc center is the catch. (when the lines are not at right angles).
> ...


Lew,
Not sure if this helps, but if you offset each of the tangent lines by the  known radius of that third arc...the intersection of the two new lines will be the center of the third circle.

In AutoCad built in tools let you place all these items and identify center points, intersections etc.
Rich


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## kvom (Jan 22, 2013)

I don't have the skills or interest to design an engine, so I work with plans that are already drawn.  For 2.5D CNC, I need to draw the parts (Draftsight) and export as DXF.  For 3D milling, I would need to be able to draw as a 3D part and export as STL.  3D CNC milling is much slower than 2.5D, so I have avoided it until now.

Having said the above, it would have been nice to have modeled the Kozo A3 loco as a total assembly, as that would have show up several problems that I have encountered after making the parts.  Most of these problems were in scaling up to the 7.5" gauge version.


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## vascon2196 (Jan 22, 2013)

FYI

The student edition of SolidWorks is under $100 (some sell it as low as $60) and it offers all of the features "we" need for model engineering including part modeling, assembly modeling, detail & assembly drawings, and animations.

http://www.solidworks.com/sw/education/buy-student-edition-software.htm

Something to think about.


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## RonGinger (Jan 22, 2013)

The solidworks student program is a bit limited. This quote is from their web site 


> A &#8220;degree-seeking student&#8221; is defined as a student who can confirm  enrollment in a degree-granting program, or who can confirm full-time  enrollment in a certificate-granting program. Do not purchase this  software if you're not a degree-seeking student or a full-time faculty  member. Commercial and institutional use is prohibited.
> *Please note:*
> 
> 
> ...



So you must be registered in some school, and the program will stop working in one year.

I will never be able to afford solidworks for my hobby use, so I went with Alibre. Why invest your learning time is something you can never really own? I believe Alibre can do everything needed for 3D design


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## mrehmus (Jan 23, 2013)

And Alibre doesn't die at the end of 12 months like SolidWorks.


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## aonemarine (Jan 23, 2013)

Im a big fan of alibre thats for sure, cant beat it for the money.


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## camm-1 (Jan 23, 2013)

mrehmus said:


> And Alibre doesn't die at the end of 12 months like SolidWorks.


 
Checked my licence on SW 2013 now.
It say activation expires Never, Maintenence 2020Thm:


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## Dave Sohlstrom (Jan 23, 2013)

Camm1

Yes but what is the cost of one seat of Solidworks. You can install Alibre on 2 computers. 1 in the computer room in the house and 1 in the shop. All for $199.00

Dave


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## edan (Jan 23, 2013)

[FONT=Arial, sans-serif]Hello,[/FONT]


 [FONT=Arial, sans-serif]First, I am an Alibre fan and support the software whenever I can.  I have used other software and my best experiences has, so far, been with Alibre.[/FONT]


 [FONT=Arial, sans-serif]I started a project in the early 90's designing a one-third scale working model of a 1937 Norton motorcycle.  The design was first on paper then transferred to Cadkey. Over the years the project has been re-done in AutoCad, KeyCreator, Solidworks, and then Alibre. [/FONT] 


 [FONT=Arial, sans-serif]Alibre has enabled me to create this project to a point where I am finally comfortable with my design and I feel the inevitable mistakes will be minor.  My goal was to have a design that looked as close to the original as possible and still have a working model.  Being able to render the model and seeing a somewhat realistic picture has caused me to change/modify a number of features that I could not visualize before.  I have also found a few areas where I needed to open up some clearances to cancel any possible contact that could happen with operational wear. Its great being able to see what goes on inside the engine as the crankshaft is rotated. [/FONT] 


 [FONT=Arial, sans-serif]The learning curve is steep if you have not used a program like this in the past, but after you get a grasp on the basic concept, you will not want to go back to paper.  [/FONT]


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## Dave Sohlstrom (Jan 23, 2013)

Edan

Very nice looking engine. You will have to do a build log so we can follow the change from drawings to working engine.

Dave


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## MrMetric (Jan 23, 2013)

I used AutoCAD for years but eventually sold it and went to DraftSight.  It works extremely well (and is free) but is limited to 2D.  Around Thanksgiving time (November, for you non US folks) Alibre always has a sale.  Last year I bought Alibre and I have been playing with it.  I can't say it is the most intuitive thing in the world but it isn't bad.  I'm still amazed at what some of the people here can model with it though. They are clearly far more advanced than I.

Alibre solves a real problem.  SolidWorks just doesn't "get it" if you ask me.  They are losing low end customers who may well end up being professional users at some point.  But if those users learned Alibre then that is what they'll buy when they can afford something other than the PE version.  

The biggest limitation with all the systems is affordable CAM.  CNC is common in the home shop now and as we've discussed, there are good number of affordable CAD systems out there.  But CAM is another matter.  The choices are much more limited there.  Fortunately, however, there do appear to be some decent choices, from MeshCAM, to FreeCAM and CNCViewer.  You can expect to pay up to about $200 or so.  That is acceptable.  Sadly, this will probably not cover lathe and mill applications though.  You may need a separate expenditure for each


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## robcas631 (Jan 23, 2013)

I'll try it.


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## camm-1 (Jan 24, 2013)

I only want to tell,,you can find SW 2013 free download
whith some googleing.


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## idahoan (Jan 24, 2013)

I prefer to use software that I own; so Alibre Pro and Bob CAD are my choices for my home shop. I do get to useSolid Works and Master CAM at work though.


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## ozzie46 (Jan 24, 2013)

camm-1 said:


> I only want to tell,,you can find SW 2013 free download
> whith some googleing.




   My virus program flagged this download as a virus as I thought it would.

  Be WARNED!!!

 Ron


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## ozzie46 (Jan 24, 2013)

Are you sure it's not a pirated copy?

 Solid Works for free just sounds to good to be true.

Ron


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## Dave Sohlstrom (Jan 24, 2013)

Looks like you are saying it is OK to steal softeware.  That could get you banned from this forum I'm thinking.

Dave


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## camm-1 (Jan 24, 2013)

Dave
I was a bit afraid to tell the link ,sorry.
I deleted it so do so you to


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## keith5700 (Jan 24, 2013)

Hmmm, interesting. I never thought there were so many fellow modellers using 3D CAD systems.
Looks like it might be time to drag myself into the world of 3D. I always assumed it would take a lot longer to design stuff in 3D than 2D Autocad.


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## vascon2196 (Jan 24, 2013)

Folks....all CAD programs are a great addition to this hobby wether they are 2D or 3D based. I am just happy to see so many of you using CAD for your model engine designs. For me, there is nothing more fun than modeling an old antique engine from old blueprints to see how it "runs" on the screen.

I teach SolidWorks and I am a CSWE (Certified SolidWorks Expert) so of course I always push for SolidWorks whenever I can.

Alibre is a fantastic program for the price and if I did not have the capability of getting SolidWorks for free through the college I would choose a program that fits my budget...

Let me do a little more research to see if a seat of the student edition or educational edition can be aquired the right way...in other words not a pirated copy or a license from some random company. It probablty does not exist but SolidWorks just does not realize the market they could get from great people like all of you!

Take care folks...


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## Tin Falcon (Jan 24, 2013)

keith5700 said:


> Hmmm, interesting. I never thought there were so many fellow modellers using 3D CAD systems.
> Looks like it might be time to drag myself into the world of 3D. I always assumed it would take a lot longer to design stuff in 3D than 2D Autocad.




Once you get past the learning curve the 3-d stuff is imho easier than 2-D. once a part is modeled in 3-D it only takes a few minutes  create a 2-D drawing. A bit more time to create the tile blocks. 


IIRC Alibre still offers a try before you buy download. 
Tin


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## jgedde (Jan 24, 2013)

I'd be lost without my 3D CAD.  I use Alibre (personal edition). It's a bit buggy at times, but it's one hell of a bang for the buck.

I'm currently building the J.E. Howell Farm Boy.  Here's the Farm Boy engine as a 3D model that I put together using Alibre from Mr. Howell's prints.  Having the parts modeled really helps me to visualize the parts before making chips (and mistakes).

I have a 3D PDF of this where you can pan, rotate and zoom, but I need a way of uploading a 8 MB PDF file to share it with you guys.

John


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## Brian Rupnow (Jan 24, 2013)

Thats a funny thing. When I worked on a drafting board, I really dreaded having to learn Autocad. Then when I did learn, I thought "Well Sir---That wasn't all that terribly hard. Just lines, arcs, and circles, same as on paper." Then I moved on to 3D and was amazed at how easy it was. You start out just like Autocad--draw a sketch to scale. Then hit the "extrude" button and type in a value of how far you want your 2D part to extrude into the third dimension to make a 3D solid model. Of course, like all things, you learn more every time you use it. Its not the big things that are difficult. Its keeping track of the ten thousand little things that make you crazy. I've been designing in 3D cad now for about 11 or 12 years, and I don't even have to think about what commands I'm using.----Brian


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## vascon2196 (Jan 26, 2013)

I did speak to my contact at SolidWorks to see if there was anything SolidWorks can do for "us"...and there is not. There is no basic seat of SW that even comes close to the cost of Alibre.

The nice thing is that every 3D CAD program works about the same..if you can use one then you can certainly pick up another. The rules that govern sketch geometry are about the same and the feature functions as well.

One last attempt and it is only temporary is you can purchase some SW books that contain a code to use SW legitimatly for just under a year...then it runs out. Probably not worth it but I just wanted you to be aware. The book I use for my CAD-1 class comes with that free code..."Engineering Graphics with SolidWorks".

I have also enjoyed viewing the 3D models some of you have posted...some extremely great looking work!

Maybe I will see some of you at the 17th annual NEMES show in February in Waltham, Massachusetts!


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## Walsheng (Jan 26, 2013)

I am in the process of building the Stuart No. 9 and part of the process has been to model it in Solidworks (picture in a previous post.)
I have been mulling over weather I should make the parts on my 3-D printer just because...
The printer holds pretty good tolerances and I am thinking I could get away with minimal machining. Probably use steel shafts and brass inserts for threaded holes  I'm thinking it just might work (on compressed air anyway.)
Anybody tried to do this yet?

John


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## vascon2196 (Jan 27, 2013)

I have not tried personally but have know a few people that have. It all depends upon the plastic that the rapid prototyper uses. The one we have at work is rather old and the material is very pourous...its only good for static parts and assemblys.

Can't think of the material off hand but I believe *Zcorp* makes a 3D printer that can print fully functional interchangeable parts that with a little clean-up can be used to run an engine.


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## Tin Falcon (Jan 27, 2013)

> Anybody tried to do this yet?



I have not personalty done this but I do know a guy that has. I have an aquantance that teaches in a neighboring county at the High school and college level. One of his schools has a decent 3-D printer. The printer manufacturer said that it could not be done. This guy did build a working steam engine with a 3-d printer. the trick is to dip the cylinder and any other part that has to be air tight in acetone. . just enough to seal the plastic. the 3-d printing process leaves the plastic porous and air will leak though if the surfaces are not sealed.
Tin


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## Walsheng (Jan 27, 2013)

We have made working pumps and valves for air mattresess, low pressure but absolutely cannot leak, and a bunch of other stuff from bird feeders to amunition chutes for machine guns.
The material we use is ABS and it has some pretty good properties and pretty accurate.  I think most of the parts would hold up well.
Now the downside.  I just looked at making the sole plate, cylinder, flywheel and steam chest and it is a 30 hour build.  The rest of the parts would take another 10-15 hours. I'm guessing 10-20 hours to finish parts, put threaded inserts in and make the shafts and small parts.
I don't know, might be fun.

John

PS, I am planning to attend the NEMES show in February.


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## BobsModels (Jan 27, 2013)

Hi

I thought I would chime in. About 4 years ago I started building a 1/8 scale Galloway and found some issues with the drawings. I decided that after 35 some years of hand drawing everything I should get a 3D system. I purchased Alibre and all its tutorials. I spent a month as if in school learning the tool. I felt that if I did not invest in the tool it would never be used effectively. I then used the Galloway as a further learning tool by modeling the entire project and using my drawings only to build the engine. As you can see from the attacments I did finish the engine, the only difference from the model you see is I put a working Lunk type mixer on the engine as was on the Galloway. I have some actual photos over in the building from castings section.
I have found learning the 3D system has changed the way I approach projects I just start with a very rough sketch and I am off an running with everything fitting and most "mistakes" done on the PC. I have done engine parts, cabinets, a quilt rack, an entire room addition, a pc desk, layout for vac sustem for the wood shop, etc. 
For anyone hesitating just get a system and jump in, take the time to learn. It is no different than taking the time to learn a machining skill like single point threading.

I bundled up the Galloway prints in a nice package and transferred them to the current owners - Ministeam. They use them for there current sales.

Bob


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## vascon2196 (Jan 27, 2013)

Tin Falcon said:


> I have not personalty done this but I do know a guy that has. I have an aquantance that teaches in a neighboring county at the High school and college level. One of his schools has a decent 3-D printer. The printer manufacturer said that it could not be done. This guy did build a working steam engine with a 3-d printer. the trick is to dip the cylinder and any other part that has to be air tight in acetone. . just enough to seal the plastic. the 3-d printing process leaves the plastic porous and air will leak though if the surfaces are not sealed.
> Tin


 
Thanks Tin...that is nice to know. Our students often try to paint over the plastic but it only makes a mess.


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## vascon2196 (Jan 27, 2013)

Walsheng said:


> We have made working pumps and valves for air mattresess, low pressure but absolutely cannot leak, and a bunch of other stuff from bird feeders to amunition chutes for machine guns.
> The material we use is ABS and it has some pretty good properties and pretty accurate.  I think most of the parts would hold up well.
> Now the downside.  I just looked at making the sole plate, cylinder, flywheel and steam chest and it is a 30 hour build.  The rest of the parts would take another 10-15 hours. I'm guessing 10-20 hours to finish parts, put threaded inserts in and make the shafts and small parts.
> I don't know, might be fun.
> ...


 
If you build it on your 3D printer...and get it running, it will attract a lot of attention!


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## vascon2196 (Jan 27, 2013)

Great CAD assembly!

Is the engine "operational"? Does it move in CAD as it would in reality?

Very impressive!


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## BobsModels (Jan 27, 2013)

Hi

Thanks I spent a lot of time on it so I could see how everything fit OK. I feel that the assembly feature of 3D modeling is what sold me on the time spent to learn. If it fits in the assembly, I am really confident that it will work when I machine it. I have also found that by making the model I have in effect gone through a mock machining sequence. I have used intermediate steps in making the model to create jigs for holding the parts. Mount the part on the jig and get all the reference demensions from the jig rather than the part. So it just goes on and on.

Now back to your question:

Well it does move yes and no. I do not have the real expensive version of Alibre so I do not have the motion feature with lots of bells and whistles. I am also not the best at setting up the alignments, mates etc. Sometimes I just do not get it.

Now here is what does move, the crank, Flywheels, rod, piston all move if I "grab" it and move the mouse in a circle so to speak. If I grab the cam timing gear then the cam and push rod move together along with the rocker arm so I could verify the trip position, rod length etc. Many other parts move individually or in concert with one other to see how things fit and for cleareance. I am sure I could get a lot more moving together if I wanted to but there was a limit as to how much time to spend on the "fun" vs getting drawings done and machining parts.

I needed to keep the real goal in mind learn Alibre to - produce a set of drawings that produced a working model. That was accomplished now on to the next one.

I am in the shop drilling the centers for the Gade crank, hope to get the crank done Monday.

So break is over now back to fun and ignoring the ice storm outside.

Bob


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## Tin Falcon (Jan 27, 2013)

> Thanks Tin...that is nice to know. Our students often try to paint over the plastic but it only makes a mess.


__________________

when I worked at the model shop in the days before 3-d modeling we made some high end plastic models and painted them. I would think krylon plastic paint should work fine. Should be easy but on the other hand I have had three jobs involving spray on coatings and a couple years of experience and training. 
tin


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## vascon2196 (Jan 27, 2013)

BobsModels said:


> Hi
> 
> 
> Bob


 
Cool!

Thanks for sharing Bob! Keep practicing with those assembly mates...you will be surprised what you can do with the basics.


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## Walsheng (Jan 27, 2013)

Tin Falcon said:


> I have not personalty done this but I do know a guy that has. I have an aquantance that teaches in a neighboring county at the High school and college level. One of his schools has a decent 3-D printer. The printer manufacturer said that it could not be done. This guy did build a working steam engine with a 3-d printer. the trick is to dip the cylinder and any other part that has to be air tight in acetone. . just enough to seal the plastic. the 3-d printing process leaves the plastic porous and air will leak though if the surfaces are not sealed.
> Tin


We don't use acetone but a different solvent. Works much faster than acetone and seems to wick in further. But you are correct the parts come out pretty porous but the solvent seals it up nicely.

John


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## Walsheng (Jan 27, 2013)

vascon2196 said:


> If you build it on your 3D printer...and get it running, it will attract a lot of attention!


 
Hey, maybe I'll do a build thread.  Bet that would be a first.

John


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## idahoan (Jan 27, 2013)

I haven't tried to build a complete engine but I have used our rapid prototype machines at work to check the fit of some of the parts on my Pacific.

The first is the valve lifter that I modeled in Solid Works and machined from brass. The printed part allowed me to check the fit before I spent all the time to machine it. It is printed with ABS and painted as white parts are hard to photograph.





The second picture is of the crossover cam and follower shoe made on the SLA (stereo lithography) machine. One of our MEs at work helped me with modeling the parts. These were mated and animated in SW before the protos were made. Here they are installed on my friends engine and worked perfectly.






The more I use the FDM (fuseable deposition modeling) and SLA tools I can really see the benefits to the technology.

Dave


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## vascon2196 (Mar 15, 2013)

I just downloaded this software from the SolidWorks website. I needed a 2D CAD package to grade DWG files. I was the chair for our local SkillsUSA (VICA) Drafting contest but all of the students use AutoCAD.

Anyway...it's called DraftSight and it is FREE. You only need to register with a valid email address and re-register each year. No strings attached and it "feels" just like AutoCAD.

http://www.solidworks.com/sw/products/free-cad-software-downloads.htm


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## rleete (Mar 16, 2013)

I use Draftsight at work for 2D layout stuff (plant layouts) that doesn't need 3D.  It is functionally the same as AutoCAD.  Very nice package for those that don't need 3D.


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## doc1955 (Mar 16, 2013)

I use Catia, NX6,and Auto cad at work and have also used Solid Works which is similar to NX6 but in my opinion is dumbed down a little. I prefer NX6 and second would be Catia but both are spendy for a home shop. For CAM side I use either NX6 or FeatureCam and I prefer FeatureCam we have had that where I work for at least 15 years ore more. I design tools for a living mostly Cargo systems tools and some military things. I have been doing CAD in one form or another for a long time seems like forever. If we have any other NX users and they are attending the UG World Conference in Dallas we could meet up I have been asked to attend for our company.
  I did start out designing tools on the drafting board many years ago I had the pleasure of designing tools and then building them in the sho back then. Would I go back no but I do believe beginners should learn on the board anyway to understand how a view is created through fold lines and such then Cad will come even easier when you know whats going on behind the scenes.


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## mikegw1961 (Mar 16, 2013)

I have been trying to teach myself Alibre for the last couple of weeks. Taking the time to learn this as I cannot get into my Worksop (shed) as i am having to look after my mum at the moment.

I have finally finished drawing and assembling the Vega V Twin

This could be the next project if I ever finish the Nemett Lynx I have started.

This was drawn 2x scale and I think I have it correct now. There were some missing dimensions in the original article.







Need a another project to draw now. Thinking of a straight 4 IC engine. Need to find some drawings


Mike


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## popnrattle (Mar 26, 2013)

I prefer 2-D because it is faster for me, although I can draw fairly well in 3-D and do so because it makes my 2-D parts look cool and sometimes I need to make my parts in the prototype machine. 
	

	
	
		
		

		
		
	


	




 I guess its hard to break old habits I been using since '73(high school drafting board and T-square). 
	

	
	
		
		

		
		
	


	




 The youtube link is for the parts of the 6 cyl. rotary air engine. 

[ame="http://www.youtube.com/watch?v=JqfgLoUedkM"]http://www.youtube.com/watch?v=JqfgLoUedkM[/ame]

The sectioned head of the 2.22 cu. in. mini hit-n-miss engine is the attachment. Later, Rick.


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## lohring (Mar 26, 2013)

I'm finally starting to learn Alibre. It's far from intuitive and very difficult for the kinds of shapes I need to model.  I think I can model the various important characteristics of surface piercing propellers, but two stroke engine transfer passages are a lot harder.  The first picture shows a propeller.  The cylinder I'd like to model is the other pictures. The 3D model of the transfers may be a scan of the core patterns. Some type of lofting procedure through a series of sections set at a series of angles along the passage is the only way I can think of to draw the passages.  Any other suggestions?

Lohring Miller


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## mrehmus (Mar 26, 2013)

Lohring,
Alibre isn't really great at modeling complex contours. It can be done but there is a 'sister' program you should take a look at, MOI or Moment Of Inspiration. www.moi3d.com should get you there. I bought in to it when it was first introduced but haven't had time to play with it much. Another program (more expensive) is Rhino that should do some bits a pieces for you.

I suggest you look at making complex passages in a slightly different way. First make the engine cylinder, leaving the bypass passage area as a solid. Then make a negative of the passage (separate model). Then use Boolean subtract to create the passage in your cylinder. Somehow, looking at the passage as a negative of the final bit is easier than working in the cylinder model (for me). Of course, a Boolean subtract object is actually a lump that looks like a solid of the passage.

Contact me off line if you have questions about this process. We've used the Boolean technique on models of V-8 blocks, complex engine bases, etc.


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## Tin Falcon (Mar 26, 2013)

Mike interesting program look more like a computer sculpture program than for machine design. 

I have alibre. 
Tin


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## lohring (Mar 27, 2013)

I looked at MOI, but decided to try Bonzai3D.  All these programs have a steep learning curve.  The method I used to generate propellers in Alibre doesn't seem to work with Bonzai.  However, the main reason for something new was transfer passages, so I'll start working on that.  I'll try subtracting the passages from a solid.  The way I was planning to make the cylinder with conventional methods was to build the passages and cover them with sheet wax.  That way I could make the outside mold.  A mold of the passages could be used to generate the cores.  See the picture for the sand cast core molds a commercial foundry uses.

The main reason for 3D modeling is the promise of 3D printing.  So far even commercial methods haven't been good enough for propellers.  I plan to have a test propeller laser sintered in stainless steel to see how that works.  I keep hoping that something like PLA from a low cost printer could be burned out, but the consensus seems to be that its expansion would damage the investment.  I'm sure commercial manufacturers could make a good casting, but the cost will be high.  In any case, I need a 3D model first.

Lohring Miller


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