3D CAD and Model Engineering

[vascon2196]

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...

 

[Tin Falcon]

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

 

[jgedde]

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

 

[Brian Rupnow]

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

 

[vascon2196]

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!

 

[Walsheng]

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

 

[vascon2196]

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.

 

[Tin Falcon]

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

 

[Walsheng]

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.

 

[BobsModels]

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

 

[vascon2196]

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.

 

[vascon2196]

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.

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

 

[vascon2196]

Great CAD assembly!

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

Very impressive!

 

[BobsModels]

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

 

[Tin Falcon]

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

 

[vascon2196]

Hi


Bob

Cool!

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

 

[Walsheng]

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

 

[Walsheng]

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

 

[idahoan]

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

 

[vascon2196]

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