Spherical Surf

[88Matt]

Basically i am cutting half of the inside of a sphere. Trying a few different paths like waterline and scallop, I can't get arc output. I have tried changing my tols to no avail. Any suggestions?

 

Basic 3 axis mill using 3/4 ball. Ø approx 8in.

 

Thanks

[pip]

Think you should look at the filter option

[88Matt]

I opened up arc tol and it did nothing.

[Mike S @ S4A]

how about a simple 2d swept?

[jeff]

flowline spiral?

[JDowe]

Create a series of concentric circles above the part create contour toolpaths on thes circles

- they are easy to select using window - then

use toopath project to project the cuts onto the surface

[Craig Madsen from CM3D]

Use the wireframe toolpaths. If it really is a sphere, that is.

 

Create an arc for the along contour, and another connecting to that for the 'across' contour. you will get arc output.

[MotorCityMinion]

Try changing your stock to leave at -.0001.

[RandleXX]

If you are cutting a true half sphere the toolpath will not be an arc. A ball mill will use the tangency of the tool along the path. Side of the tool at the side and tip at the bottom. It's always changing along the path.

[Millertime]

88matt check youre email.

[ken wong]

offset centre instead of tip

[Superman]

quote:

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offset centre instead of tip

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+1

 

another senario where you don't get arcs

-Cut a tube in 1/2 and lay along the X axis

 

A toolpath going at 90° to the radius axis will give an arc thru the centre of the ballnose only.

 

but

 

If cutting in any other angle ( eg. 91° or 45° ), then the tool tip or tool centre will never give an arc, filtering will put in a few arcs, but never to the extent that you would be expecting.

[88Matt]

Robert,

 

That is similar except the sweep is a full 360. I can get arcs as well with flowline but not with waterline or scallop in the HSTs. I should be able to get arcs in the xy-plane with waterline as in good ole flowline. If I can't get it by the time comes to cut it, I'll use flowline. Otherwise I would like to use waterline ideally.

 

Thanks for all the input guys. You're the best.

[Richard Thomas - Mastercam UK]

Try Surface Finish Contour and... (I'm sure you have checked this in Waterline already) make sure that you have switched on XY arcs in either the Total Tolerance page or Refine Toolpath page (name changes depending on whether you chose to try the Refine Toolpath feature).

 

If you get arcs with Finish Countour but not Waterline with the same Total Tol/Refine settings, then go to the Windows Control Panel, find and select the Mastercam X icon. Select X4 at the top of the window and the look for "Toolpath Support".

There is a section there for "HMM kernel arcs" - I wonder if your arcs have been disabled from there for the HMM (including Waterline) toolpaths?

 

By the way, with Finish Contour you'll probably need a tool boundry around the top of the sphere, to stop the toolpath running down the outside of the job!

[88Matt]

I finally got waterline the way I want it. I had to get the tols "just right" to meet spec and still kick out arcs. Thanks guys.