Mill size different than drawing size

[maudvandeveire]

Hello, I'm new to Fusion. I want to create a figure in wood. I made a 2D contour of all parts. The problem is that when milled some parts are smaller (or have a different size) than the drawing in Fusion. For instance, the part on the upper left (one of the legs of the figure) and the part that looks similar (but has an extra torso and arm) in the middle on the left. The foot/leg of the middle figure is smaller than the upper leg while they were drawn in the same size. It seems like one time the tool mills on the inside of the contour and the other time on the outside, I'm not sure. The only difference that I can see is that when I select the 2DContour and the image turns green the contour of the upper part is black (or blue depending on the view) and that of the middle one is grey. I don't know what this means. Could anyone help me out?

[seth.madore · Accepted solution]

I'm guessing you have selected sketch entities, rather than the model? If sketches are turned on, the selection tool will favor the sketch over the model. When Sketch is selected, it's a crap shoot as to whether it's going to be an inside or outside result.

If this doesn't help, can you share your Fusion file?
File > Export > Save to local folder, return to thread and attach the .f3d file in your reply

[maudvandeveire]

Hello,

Thanks for your reply. Your solution has worked. I don't know if you can help me with some additional questions.

1) Does it make a difference if you select the contour at the top or the bottom of the model?

2) The machine doesn't cut away the spaces between the fingers of the hands I'v drawn, is this because my tool's diameter is too wide? ( it's 0,9mm, but if I take a tool of 0,5mm it stays the same)

3) Maybe the major problem that I have: When I run the machine the mill doesn't go through the wood it stays on surface level, while I selected a 2,5 mm thickness of the material and the simulation runs fine.

I'll add the fusion file.

Thanks so far!

[seth.madore]

1) Top or Bottom selection doesn't matter. However, you will need to make sure that your Heights are set proper. For example, if you select the top contour, but your Bottom Height is set to "Selected Contours", the tool will remain at the height of the....Selected Contour. Thus, you need to change your Bottom Height to "Selection" and manually select the edge you want to go to. Or, you can leave it at Selected Contours and input an offset value if you happen to have that at hand.

2) The width between the "fingers" is .50mm. You are using a .9mm. You need to change it to something smaller than .50, a .499mm would work. Fusion can't send a tool down a slot with the tool of the same size as the slot

3) Your WCS is set to the bottom of the stock. How are you establishing the length of the tool? If you are setting it to the top of your stock, that's likely your issue.

[maudvandeveire]

Hello Seth,

Thank you for all the information!

With my third question I'm not sure what you mean with "establishing the length of the tool" and where you do this. Do you mean I have to change soùe info about my tool in the tool library?

[seth.madore]

No, this is done at the machine. When loading a tool into a CNC, you need to teach the CNC how long the tool is. This can be done with a touch-plate, a tool setter, or the old school method of bringing the tool close to the part, place a piece of paper under it and slowly lower the tool until it just starts to drag on the paper. Set your length in the control and subtract another .003-.004"

[maudvandeveire]

Hello seth,

I do lower the tool and use a piece of paper . So I don't think that's the problem.