how do i cut a bowl with bob-cad

[jrslick22]

Hi, I’m new to all of this stuff but am pleased to say I have built my first CNC milling machine.

I am using bod-cad cam and mach3 to run the mill.

I was wondering if anyone could point me in the right direction as to how to go about cutting a bowl (half ball) shape using this software.

I have drawn what I want in bob-cad but am unsure where to go from here.

Regards.

[tikka308]

JR - check out Sorin's video's on CAD CAM trainer (http://cadcamtrainer.com/forums/index.php). Sign up and you'll see the link to his demo video's.

I also have some video's on my CNC blog - www.nyccnc.com

It sounds like you've got the shape done. If it's a bowl, you'll need to use 3-axis milling. Right click on "Milling Stock" and choose "Slice Spiral". Select your part, right click OK. Then right click "slice spiral" and click "edit" to choose your milling settings. Let me know if you need more from here.

[tobyaxis]

Originally Posted by jrslick22 Hi, I’m new to all of this stuff but am pleased to say I have built my first CNC milling machine. I am using bod-cad cam and mach3 to run the mill. I was wondering if anyone could point me in the right direction as to how to go about cutting a bowl (half ball) shape using this software. I have drawn what I want in bob-cad but am unsure where to go from here. Regards.

What Version of BCC are you currently using??

[jrslick22]

Originally Posted by tobyaxis What Version of BCC are you currently using??

V21

[jrslick22]

Originally Posted by tikka308 JR - check out Sorin's video's on CAD CAM trainer (http://cadcamtrainer.com/forums/index.php). Sign up and you'll see the link to his demo video's. I also have some video's on my CNC blog - www.nyccnc.com It sounds like you've got the shape done. If it's a bowl, you'll need to use 3-axis milling. Right click on "Milling Stock" and choose "Slice Spiral". Select your part, right click OK. Then right click "slice spiral" and click "edit" to choose your milling settings. Let me know if you need more from here.

Sorins videos are great, they have helped me so much! _ BTW thanks so much Sorin
Ill check your vids out now.

Im not sure the milling stock option is mate?

[jrslick22]

Here is my geometry, I’m not sure if its drawn right but it will give you an idea of what i want the pocket to look like.

http://www.skynetnz.com/bobcad/

Thanks

[jrslick22]

Is my geometry really that bad?

[The One]

Your geometry was fine, but you did have to break it so that you could get a usable path on it.

Take a look at the file I have attached. To generate the path use the following directions:

Select the Blue arc so that the arrow on it points down.
Then select the other arcs, either Clockwise or Counter-Clockwise this order determines the direction of the cutter, making sure that the arrows also point down toward the smaller shape.
When all of the arcs are selected, click on 3D => Set Path.
Input the step over distance you wish to use for the "Max Length of Division" and click OK.
Then hide the arc segments, so that they don't interfere with the next step.
Holding the Shift key click on the top shape, close to the point, so that the arrows go the same direction you selected the other arc segments.
Do the same for the bottom shape.
Then go to 3D => Skin.
Input your values for the Skin operation and click OK.
the system will then generate a toolpath.

Hope this helps.

Regards

[jrslick22]

Under the set path option what do Max length of division, Max number of divisions and max error for arcs mean? and what would some typical settings for this project.

I was with you up to the 3d => skin part, after selecting the top and bottom circles and ensuring the arrows go in the same direction it will not let me choose skin as an option.

thanks

[The One]

OK, that might have been a little over the top. Try this. Use the newly attached file. I have created a surface from your wire frame using the revolve surface function.

Select the Surface(s).
Click on Solids => Generate Toolpath.
Choose the spiral option and click OK.
Input the values for the toolpath, you have two dialogs to work with and the input fields are labelled so it should be relatively simple.
Then click OK to generate the toolpath.

Hope this helps a little better than the previous post. If I left any room for confusion let me know.

Regards

[jrslick22]

Ok that has done a great job of it.

1. How do I reverse the direction if there are like a billion segments? Hold shift to select than?

2. Would you please talk me though what you did to change my wire frame into the new drawing?

thanks alot