Help with Stars

Hello, I just had a few questions about making stars on my X-Carve. I build rustic wood flags and enjoy it. For longest I did them by hand or used my friend laser engraver. I wanted to start doing them for yourself and have watched YouTube videos and get the idea down. But my issue is that they come out with a around look to them and the points aren’t coming out right. I used my 90 degree bit, set my depth to about 0.17 and the area are 1in. Also I noticed that my top row of stars are smaller than the rest. Any idea what I maybe missing or doing wrong.

Can you post a photo of what you’re getting, and if you’re using Easel can you share your project (File > Share with link > Share, and paste the link here)?

Yes I can do that once I’m off of work.

Thanks. That will help us to see the problem and hopefully offer solutions.

Misalignment of V-geometry (most V-bits have a flat spot and not all 90deg bits are true 90deg, material thickness variations, uneven spoil board are some factors that can cause this.

If the star points are “round” => the bit is to deep down. Consider the profile of a V-bit with a true point vs a V-bit with a very small flat spot. The latter will go deeper as the Z zero reference is slightly off.

  • Your spoil board is not even in height relative to Z.
    Solution is to add a 2nd spoil board and perform a skim cut, making the height relative to Z equal across the board.

  • Material to be carved isnt unifrom in thickness (thinner at the top row) so the bit have less material to engage with.
    Solution is to plane material prior to carving - or do a skim cut of the surface after the V-bit, this will bring the design layer to a uniform thickness.

Just posted a picture of what I did for my first cut.

Could you explain that a little more. I’m new but open to learning

The link is

Uneven spoil board - or uneven material thickness (relative to Z) will reach higher or lower surface level and consequently enter deeper or shallower, causing thickening/thinning of design:

For height critical work it is recommended to perform a skim cut of the spoil board surface (either the original Xcarve board or an added 2nd sacrifiscal board. Draw a large rectangle in Easel, covering the 2nd layer and use a large diameter bit/shallow depth per pass and set path to Fill. This will take the top of the 2nd layer and make it uniform in height, relative to the bit.
For skim cut operations I also recommend you increase stepover from 40% to 80-90%.

  • Check for height variations on your main board surface, adjust some if possible, then:
  • Go shallow untill entire surface is carved.

Now any cut depth variations will come from material thickness alone, assuming otherwise healthy machine.

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So I can place a second board on top of my spoil board, then perform a skim cut to make that board even. Then if there is anything wrong it would be in the wood I’m using. I only have a 60 and 90 degree bit would that work. Where will I have the way to increase the stepover

Under machine advanced. The default is 40%. That works fine. I use a 3/4 flat bit

Ok sorry for all the questions. Is there a size the second board should be. I have 3/4 in plywood that is flat and square

That will work

As long as its bigger than the part that is getting carved.
Carve time for skim cut will decrease with larger stepover percentage, I also use a 3/4"flat bit.

Taking it all one step further, a large diameter bit with a large step over will show any misalignment of the perpendicularity of your z-axis as ridges will form if the end mill isnt truly perpendicular to the X/Y plane.

so I went out and got this bit to do the skim on my second board.

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That is the same bit that I use

Question what do I set the v-bit detail step over to. Right now it’s at 1% and when I simulate it’s telling me it will take 43hr

Ok I have everything set up. But not sure about these settings. Right now it is saying it will take 43hrs that can’t be right

You bit setting is set fro .75mm. That is not correct. It should be .75 inch. That will reduce the time. Your step over is 80%. I would use 40%. The 1% you mentioned is for vbits