Solids / Surfaces question

[DonW]

I'm pretty new to the whole solids and surfaces thing. So forgive me if this is a really elementary question...

If you made a cube out of lines, and then created surfaces on all the sides, then did a Boolean add to the sides, is this the same thing as a solid? I'm trying to get a handle on this stuff, to see how I want to progress when trying to create a 3d part. If it's the same thing, then I know how I want to progress, otherwise I have to come at it differently.

Thanks...

[dewme5]

no, it wouldn't be the same thing. What you want to do, is create a square, and then extrude in the direction you want, but the amount you want.

[DonW]

Ah...that becomes a horse of a different color then. Ok, then a stupid question would be:

For machining then, does the CAM portion treat a solid object the same as it would if it were built in a wireframe? Or, is a wireframe not truly a 3D object that can be machined?

Sounds like I need to creat a flat shape, then extrude it to the desired depth, and that will give me a solid, no? Do I have to create a surface before doing that, or will it automatically create the solid for me?

I know...a newbie question. Sorry...

[DonW]

Oh, dewme5.... thanks for the response. Much appreciated.

[dewme5]

I'm not a bob-cad user, and the way different CAM software treats 3d can make a world of difference.

For the most part, you can create just a 2d image, and then choose the depth of machining on each separate operation. This will start you off in the right direction, and then start building with solids as you become more comfortable with the software. eg. if you select a square, and then choose a depth of cut that is -.5", you will essentially do the same thing as creating a cube, and then creating a cut of -.5". Once you get further into machining, and you are actually machining all six sides (or at least two), instead of just the top, solids will become important!

There are some excellent training videos for bobcad out there, and some free ones at that. I highly suggest you search for them, and make good use. CAD/CAM is so feature rich that if you don't know there is another way to do something, you can become quite frustrated with the ineffectiveness of the one way you do know.

[DonW]

Here's my fist solids part...thanks for the help....

[dewme5]

good deal. I can even tell it's for a guitar. Just don't ask me to name that part.

[DonW]

Originally Posted by dewme5 good deal. I can even tell it's for a guitar. Just don't ask me to name that part.

It's a pyramid bridge...or at least it's my take on a pyramid bridge.

The spacing on the bridge pin holes is 2-5/26". The nice thing with something like this is I can save a version without the through-holes, and add the holes at whatever spacing I need to use based on customer preference. Players often like different spacing at the bridge, as well as different width at the nut up by the headstock.

Thanks again for your help dewme5... next, I may tackle a guitar neck!

Happy Holidays...

[dewme5]

you can also use math to set up the holes. I use edgecam, and instead of just putting a hole in the right place, I put a hole dimensioned off of a fixed location. I can then name that dimension, and us it to other dimensions. On an example of the thru hole spacing. Hole 1 / 2 =.25 and we name it spacing_one. I would then draw holes 3-6, and for a spacing dimension (in edgecam, look up bobcad) ={spacing_one}. Now, whenever I need to adjust something. I can just click on the dimension for spacing_one, and change the size. When I rebuild the object, the spacing will automatically be fixed. you can also fix the spacing for the outsides in the same matter using math.

I know it seems like a good amount of extra work, but the first time you need to readjust an item, it's really just clicking on one dimension and changing it, followed by a rebuild, and all the work is done for you.

Think of doing a headstock with out this type of convenience. Now, you customer wants an exact match for his 9 year old. Redraw and recreate everything, or just change one dimension and rebuild. Adding these parameters will be a great help for you.

[DonW]

That sounds smart. I'll keep that in mind for the future!

Thanks...