Making a Plastic Valve Body (with Crenellations)

as requested on support…

Given the need to make something like to:

one would need to work up a file which has:

  • the highest elements as one set of geometry
  • a pair of circles for the body
  • another pair of circles for the base
  • surrounding geometry for cutting things away

First, a size estimate — 3" for the diameter and 1" for the height, so we set up a 4" square for the Stock in Job Setup:

and then begin drawing…

To make things easier, we set the origin to the Center:

(this can be changed later)

First, a 3" circle:

We estimate 1/4" thickness, so another circle inside:

and it looks as if the inner lip/body is 1/8" thicker than that, so we create another circle which has a radius 1/8" less than the middle one:

We need a series of lines to set the upper geometry, so we draw one in:


and use the Circular Array tool to make a suitable number of duplicate appropriately spaced:

First thing to do is to adjust the center by clicking “Select Center in Window”, then clicking at the center:

Since half of the circle stays intact, we work with a 180 degree arc:

and then we increase the number of lines until we have lines which seem to be placed where the features should be:


We then deselect the lines which will be wanted by shift-clicking on them:

leaving selected the elements which we wish to delete:

Select the two outer circles:

copy-paste them in place by moving the cursor out of the drawing area:

then add the lines to the selection:

and use the Trim Vectors tool:

to allow you to click on what is not wanted:

until one arrives at:



Join Vectors:


For previewing’s sake we draw in geometry surrounding everything:

(with dogbones so that the corners won’t be left behind)

Then add the elements for the highest portion of the part to the selection by shift-clicking on them:

We then go to Toolpaths and make a Pocket toolpath with this selection to the desired depth:

Then we select the two outer circles and the other geometry:

and assign a toolpath which starts at the bottom of the previous one and cuts down as deeply as is desired:

Lastly, we select the inner and outer circles and the outer geometry:

and make a toolpath to remove the balance of the material:

which previews as:

Attached as a v7 file.

plastic_valve_body_v7.c2d (116 KB)

I have made it to the part where I draw in the “geometry”, I tried clicking on everything and do not understand how that was created

Never mind… I found it…

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Thanks for your help, I picked an interesting project for my first… I am understanding that this has to be looked at in layers and paths…

Using Layers for organization will probably help, but it’s not necessary (we did a bunch of complex projects before that feature was added).

Note that once you have this all drawn up, to actually cut you’ll want to remove the outer rectangle and replace it in the toolpaths w/ a circle which has a radius which is larger than the largest circle by endmill diameter plus 10%.