Hi Tony,

> I think you called them 3D model codes???

I'm sorry I don't really know what that's referring to... Maybe just 3D modeling techniques like sweeps and lofts?

Some of those construction techniques like sweeping are covered in the introductory tutorials, have you had a chance to watch those? :
http://moi3d.com/2.0/docs/tutorials.htm

- Michael

Hi Tony,
Here's a quick example of going from model to code:



You'll see me model a part in MoI then save it to an STL. I load the STL into my CAM package (for you, cut3d) Then generate a toolpath. Towards the end you will see me "POST" code (I dont know what it's called in cut3d, maybe something like generate). The gcode is the text you see at the end, where i load it in a backplot simulator and simulate the machine cutting with the gcode.

I hope this helps the process a bit.

@Bur : do you kow a free prog like your Bob CAD CAM ?

Hi Frenchy,
This one will do simple raster toolpaths.

http://www.mecsoft.com/freemill.shtml

It will be a bit more limited than what you saw in BobCad. The paid version of visual mill can be very powerful, but will cost a bit also. They are partnered with several CAD companies, Like "Alibre" and others.

Many Thx
Its just for see see how works this sort of prog : just in virtual ;)

Ellipse help.

I am trying to draw a ellipse in a rectangle like in a upper post, when I do it, the ellipse makes a full circle and does not stop 1/2 around. I am having no luck figuring out how to do this step. Help is appreciated.

Tony

Hi Tony, yup that is normal when you draw an ellipse that it goes all the way around.

If you only want to keep a part of an Ellipse, you need to cut the ellipse up into pieces - for that draw in a line that divides the ellipse and then use the Edit > Trim tool to cut the ellipse with the line.

See here for some more details about how the Trim command works:
http://moi3d.com/2.0/docs/moi_command_reference4.htm#trim

Let me know if you are still stuck using it - basically all you do is draw in a line that goes through the ellipse, then select your ellipse and run the Trim command, then pick which piece of the ellipse you want to discard.

- Michael

Thanks. I will try that tonight. I am going to focus tonight on drawing a solid shape and getting it to move to cut3D and practice on their part in this process. Having trouble getting the arc/ellipse (like in the other mans post) to extrude and stay as a solid. Getting the rails to converge as the "tube" goes away is also a stumbling block.

Thanks

Tony

Hi Tony,

> Having trouble getting the arc/ellipse (like in the other mans post)
> to extrude and stay as a solid.

An extrusion will only be a solid with end caps if the curves you are extruding form a totally closed loop.

If you have some space between the ends of the pieces that you are extruding then that could be the problem.

Can you please post the 3DM file with the ellipse that you are having problems extruding so I can take a look at it? It helps a lot to be able to see the actual file you are working with to be able to give you better feedback.

- Michael

i will try to get a 3dm file posted later toght or early in the am.

We have a few things to try to see where our stumbling block is,

Tony

Ok, I am really messed up now. How do I post a picture of what I have drawn on my screen, when it is in the open format and it wont save in a stl file????

Tony

In windows 7, I use the snipping scissor tool...Saves as PNG.

A smaller version of the butt end profile at the far end of the sweep helps...

maybe this will work.we could not get the screen picture to send so we took a picture and sent it.

Tony

ok, the picture came thru. Ignore the middle drawing.
We are thinking of concentrating our efforts from the area where the arcs were used to the left (rear). We could use a tab to stop the machining farther forward than the arc used region??
The original pictures posted earlier will help show what our end result should look like.

Thanks again very much.

Tony

Hi Tony,

> Ok, I am really messed up now. How do I post a picture of
> what I have drawn on my screen, when it is in the open
> format and it wont save in a stl file????

Actually the best way is for you to save what you have in MoI as a 3DM file (which can contain anything you can create in MoI), and then post that as a file attachment here.

That way I can examine your actual geometry and see if you've got pieces not touching each other or stuff on different z levels or things like that which require a kind of close examination of your geometry which I'm not able to really do just from a screenshot alone.

- Michael

Hi Tony,

> ok, the picture came thru. Ignore the middle drawing.

Ok, thanks for posting that screenshot.

So I'm a little bit lost as far as what your particular problem is right now - are you not able to save an STL file of that? But that screenshot appears to be of your CAM program isn't it? Didn't you have to export to STL in order to get it into there?

Is it possible for you post your 3DM file which contains your actual geometry instead of just a screenshot?

Is your problem still that you can't generate an STL or that you need help with making a different shape for your object?

- Michael

Hi Tony, so from what I can see from your screenshot it looks like you're currently trying to construct it by using a 2D curve that is extruded. That method works fine for shapes that are fundamentally straight in one direction, stuff like gears or pipes or things of that nature.

The kind of tapered and curved result that you want is not really suited for using that particular command though - your final shape is not gear-like and does not resemble a cookie-cutter type punched out shape. So probably for your particular case Extrude is not going to be the right approach.

You're probably going to need to use more freeform surface construction commands like Loft and Sweep, and since you are going to be trying to make a kind of seamless sculpted looking type result it's really a quite difficult model that you're attempting to create, pretty much in an advanced surfacing type level of sophistication. You can probably expect to spend many months of practicing and honing techniques before you will be able to actually make it happen. The particular style of model that you're trying to do just tends to be quite difficult, it's not really well defined just by 2d profile curves alone.

So anyway with Loft for example you can create a tapered shape by drawing 2 profiles where one is larger than the other something like this:



Then run Construct > Loft and that will build a tapered object between those 2 profiles like this:


Sweep works by taking one or more profile curves and then a kind of spine-like path curve like this:






You are not likely to be able to construct a final shape like you want there just out of one single command, it has enough variation and kind of branching within it that you are going to need to build it out of separate pieces and then work to try to connect those pieces together. That's an advanced style of NURBS modeling and that's why your project is going to have a high level of difficulty.

Really when you get to a shape like you're trying to do here where it's got a lot of sculpted type blending between different pieces in it, you may be better off using a much different modeling technique called subdivision surface modeling to do that, rather than using a CAD program like MoI to do it.

CAD programs are stronger at building things that are actually defined by 2D blueprints.

Although you can make a 2D silhouette outline of your shape, it is not actually "defined" by that silhouette, any more than just a single silhouette of a person's face captures the entire complex construction of their features.

- Michael

Is the wood going to be strong enough in the handle area?

On my shotguns, there is a metal rod that runs right through the stock, fastened to the gun at one end and with a nut and washer at the other end. I assume something like that will be used here.

Thank you very much. I will be having fun trying this morning. I will post how the profile with the new tool attempt goes later this am. I recall seeing those tool but don't recall ever seeing what they looked like.

Michael, thank you for answering on the wkend when my friend is here to help me learn this art form.

The stock does have a grip bolt going slanted thru the grip region. This region will not need much for details, just rough shape, as it gets custom shaped for the persons hand size with belt/spindle sander type stuff.

Tony