Trying to teach myself surfaces and solids.

[Nbdy]

I'm attending tech school and we have Mastercam. This summer we did work with basic print geometry and aplying tool paths to it(primarily mill and wire programs).

This semester I'm back to hand-coding. However as fast as I can complete my assignments I try to get back to the MasterCAM program. I think that this will be worth more money to me. I've got about three years in machining.

As a drawing problem I have set myself half a nautilus shell. I've built a wireframe of splines and spirals. This was surfaced with automatic Coons.

But I have a few probably basic questions.

1. What is Coon? Apparently not the furry kind.

2. What is Nurb?

3. What is a lofted surface?

4. What is the advantage of solid over a surface and what are the differences?

5. Can I enter a geometric equation into Mastercam like a graphing calculator?

I appreciate any help.

[mishikwest]

1. A mathamatical surface invented by a fellow named Coons (I kid you not). Replaced by the net surface in version X, however I don't thing there is a Mr. Net behind it.

2. Non Uniform Rational B-spline

3. a smooth surface created by a minimum of 2 chains

4. With a solid you have a "history", automatic trimming of planes, generally are quicker to build than surface models, associativty of geometry (meaning they are generally easier to edit and modify than surfaces), and some toolpath pluses and minuses. Surface is a "sheet", analogus to a nurbs spline. Lots of flexibilty and fun things you can do with surfaces, however they generally more time and care to create.

5. yes, limited to + - * /

[cadcam]

To follow the Last question you can do all kinds of math with in MC including Pie and otheres.
When I teach class my students are told not to bring a calculator as mastercam will take care of all the math for you.

Mishikwest has answered the other questions well.

Just adding that surfaces do not contain Mass were solids do.
Also Solids are a single enitity unless it's an assembly.

This counts for a water tight model and a cleaner model.

[bpmufx]

Just to elaborate on the solid def: As Cadcam has said, solids have mass properties imbedded into the part. What this means is that for engineering purposes a functional machine can be designed and tested. This can be done because a material like 1018 steel or 2024 aluminum can be assigned to a part and from this info like Weight, and Center of mass can be easily recalled. And even cooler is when you add up all the parts in an assembly and change one thing and watch the whole thing update. This was not possible without making physical prototypes just a few years ago. Also with solids the data can be used with other apps like FEA (Finite Element Analysis), and the accuracy allows mfgr models to be shared online. In a matter of minutes get the real thing from vendors allover the web. Lastly, Neutral file formats are hugely powerful with solids. Very little goes wrong these days when using STEP, SAT files.

Hope this gives an idea of why solids are the current rave.