Generate toolpath for convex shapes

[tder]

How would you generate the toolpath to mill the outside of the 2 cylinders from the picture? Z is the small side of the part. Of course I'm expecting this to be a 2 operation process by flipping the part .

path_trouble.png (184.83 KiB) Viewed 2411 times

[M4x]

Please add your FreeCAD information (have a look at my signature) and an example file.

[GeneFC]

How would you generate the toolpath to mill the outside of the 2 cylinders from the picture?

Unless you have a very fancy and expensive multi-axis VMC I cannot think of any practical way to mill those hose barbs. You could probably create a special cutter, but it is hard to imagine someone actually doing that.

The "cylinders" are an ordinary lathe job. Add the pipes and hose barbs to the rest of the object using your preferred attachment method.

Gene

[bmsaus4ax]

How would you generate the toolpath to mill the outside of the 2 cylinders from the picture? Z is the small side of the part. Of course I'm expecting this to be a 2 operation process by flipping the part . path_trouble.png

If you upgrade to version 0.19 or the development version 0.20 you could use the 3D Surface Operation.

Using the smallest ball endmill that will reach more than it's radius beyond the centreline, it could be done in two stages. It will create radiused corners behind the saw tooth peaks and at the shoulder to the plate, but since the peaks are what do the work it can be effective. It would involve a high number of passes to achieve a good finish but can be done if time is not too critical.
Presumably you have a specific reason for making them integral to the plate rather than drilling and tapping the plate for machined nipples. ?

Version info:

OS: Ubuntu 20.04.2 LTS (ubuntu:GNOME/ubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.19.2)
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.8
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/Australia (en_AU)

[GeneFC]

Using the smallest ball endmill that will reach more than it's radius beyond the centreline, it could be done in two stages. It will create radiused corners behind the saw tooth peaks and at the shoulder to the plate, but since the peaks are what do the work it can be effective. It would involve a high number of passes to achieve a good finish but can be done if time is not too critical.

Those shapes need to be quite sharp for maximum effectiveness. How would you do that with a ballend mill?

Gene

[bmsaus4ax]

Those shapes need to be quite sharp for maximum effectiveness. How would you do that with a ballend mill?

Gene

Attaching an image for general illustration. This is not based on an actual fitting !
Using a ( 3mm ball endmill ) 1.5mm radius for a radial step differential of 2mm produces a sharp edge which will obviously improve if the cutter radius can be reduced.
The cutter step over can also be coarser for the parallel section as further grip aid since this is a custom situation.
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barb_path.png (89.15 KiB) Viewed 2123 times

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Unfortunately ".FCStd" file too big to attach even with Operation deleted.
General dimensions : Cone max 5mm radius, Cone min 3mm radius. cone height 4mm.
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Edited: Sorry I can actually attach freecad file just had to remove "Cut Material"
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barb_fitting.FCStd

(91.96 KiB) Downloaded 41 times

[GeneFC]

Have fun!

Gene

[JoshM]

I’d weigh carefully the consequences of them breaking versus the ease of drilling and threading a hole and inserting a standard fitting first. You could in theory make them yourself on a lathe, or by CNC, but why bother.

[JoshM]

One other thing about that--there's no point in milling those from the two flipped sides because the inner hole requires drilling on the barbed hose fittings. Once you mount it to drill, you can also mill out the barbs and external contours using circles...