Machining Small Lettering

[Rob Holowack]

I am working on a project that involves pocketing lettering using blue machinable wax. I am using a .01" flat end mill to pocket letters which are .08" to .10" in height. Depth is set to .018 I am having trouble with some of the inner portions of the letters breaking off.

Any ideas on how to prevent this, either during the design or machining process.

[Chips Ahoy]

Try slowing down your spindle speed and blow an airhose on it while you are cutting your part. You are probably getting a built-up edge on your tool and it is pushing the material instead of cutting it. Just an idea. Switch material? Rick

[bryan.davis]

Do you have to use a square cutter, for engraving a 60 degree engraving cutter is normally best.

maybe using a font that has larger islands

at all times be aware of islands, sharp corners, cutting direction and breakout places, you may find that some places where you get breakage,will machine perfectly ok if you do that particular cut from the opposite direction

[Rob Holowack]

Thanks for the ideas.

I changed the font slightly to create larger islands, reduced the spindle speed, set all cut directions for climb milling and used compressed air.

I am not sure which change solved the problem but the lettering cut fine.