3d Modeling - Bevel Question

[Travisty]

I'll explain this to the best of my abilities, and attach a picture so hopefully you guys can see what I mean.

I'm drawing up one of my newest prints; it's a rectangular object that has 3d steps. It's basically tiered. The upper section is largest, middle section is in fact mid-sized, and the bottom is the smallest. The mid section has a 20* bevel throughout. How do I tell MasterCAM to do a 3d bevel joining two pieces? Or can I assign faces individually?

Another one of my problems is the simple fact that I can't see how to do with my CNC what the drawing is asking of me.

The upper section gets .375" radius around the corners while the mid and lower section gets .750" radii. How am I supposed to maintain a 20* bevel between those two? I can do a 20* bevel along the edges of the piece because they stay a consistent size, and the step between the upper and lower equals 20*, but at the corner where the two radii are different the mid-section grows in length and doesn't stay at 20*; in fact, it changes its bevel throughout the length of that corner... I'm lost guys, little help please?

Pics to hopefully aid in what I'm asking of you to help with..

Top wireframe

Front Wireframe

Isometric Wireframe

Front 3d

[ObrienDave]

In order to make the beveled surfaces, I would use, in V9, Create-Surface-Ruled-Single.
Selecting the individual lines or arcs for EACH section of the wall.
You are correct stating you cannot maintain a constant 20 degree bevel with the current wireframe geometry.
This is the time you call the engineer and ask for a model for clarification or a detail view at the 45 degree point in the corners.
Don't be afraid to ask the engineer.
It's easier to deal with dumb questions than dumb mistakes.

[Travisty]

Thanks Dave! The Single Surface trick worked perfectly all the way around!

According to the customers rep., "Engineering is swamped, you'll have to do the best you can!"... Hooray.

[ObrienDave]

And then again there are swamped engineers....

Glad to be of assistance.

[Travisty]

Alright... New part, same basic problem. I have a leg that has two angled faces. The leg has a square upper body, goes to a length, then starts a taper to the bottom. How do I create a 3d model of this that allows me to "machine" the faces? Doing a Create Surface does in fact create a surface, but projecting an extruded procedure through it doesn't cut the body like I'm instructing it to.

What's the easiest way? I wish I had more time to go through MasterCAMu, but I've already gone through the 3d modeling section and I don't seem to remember seeing anything about it.

[ObrienDave]

If you can save what you have so far in V9 format, I will try to help you.

[ObrienDave]

OK, received your file.
Email on the way

[Travisty]

Maybe I'm just daft, but how do I turn on solid model? I've tried the "Shaded" button and switching back to wireframe, but nothing changes. Looks to me like it's blue now with cut-body extrusions through the part, but nothing appears to be solid? I don't really need the part to be solid, just wanted it more for visual confirmation.

Thanks again Dave. I owe ya a !

[ObrienDave]

Level 1 is your original geometry.
Level 2 is surfaces for the outside of the bar only.
Level 3 is the actual solid.
Level 4 is a cut boundry to create the second taper.
I used the front face with the first taper to create the bar.
Level 5 is the finished wireframe imported fron a SAT file that I exported from the level 3 solid.

I sent it to you with Level 5 visible.
That is why shading had no effect.
You are looking at wireframe, color coded by entity.
Light Blue Lines, Dark Blue Arcs, Red Splines.
You will have to make level 3 visible for the shading to work.
Alt-S will toggle shading.
A solid appears to be a single color wireframe when not shaded.

Sorry if I sound cranky, I just got done driving 660 miles in 11 hours.

[Travisty]

I didn't perceive it as cranky at all, but like I said I think I'm just daft.

I don't know why I didn't bother to look down at the levels... I see it now. Thanks again for the help!

Now, to bother you some more, care to explain how you went about adding the tapers (or cutting the solid to the taped would be more accurate it seems? Was it a boolean remove?

[ObrienDave]

I avoid boolean operations like the plague!
I don't know about McamX versions, but V9 can get really confused when there are bunches of boolean operations.
It has a tendency to corrupt the database eventually.
Others might disagree, but that is my opinion based on past experience.

Always using YOUR geometry, I set the construction plane to one of the wireframe faces that already has the taper edge established.
Using that profile, I extruded the profile to the farthest endpoint of the large square base, thus establishing the basic block and one taper.
Then, on level 4, after setting the construction plane to the second taper face, I copied the second taper edge and added a horozontal and vertical line to make a triangle that would cut the second taper from the block.
The faces I'm refering to are the ones that already have one edge of the taper established.
After that it was a simple matter to cut the slots from the block in separate operations.

There are many different ways of obtaining the same result.
The easiest way to start doing solids is to plan it just like you would cut it in a machine.
Start with a basic block and remove material to get the part.

Just for fun, I will resend you the file with the slots extruded into bosses.
Glad to have helped

[ObrienDave]

Ok, file for fun on the way.