My first "useful" thing made with my mpcnc

I’ve thought about the RGB possibilities too. Started simple with a length of RGB strip LEDs and a SP3T switch to select Red, Green, or Blue.

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To get some dynamic display options I got this kit:

Worked fine, but I wanted something with an RF remote that was small enough to mount inside my base. Ended up using these:

Works well.

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On the other hand, getting a consistently clean cut in acrylic has proved challenging. It requires a well surfaced spoil board, and well dialed-in tool and travel speeds. I’ve wanted to try drag engraving, but couldn’t justify the ~$170 for one of the spring loaded diamond bits commonly used. So, I bought a Dremel diamond bit to play with:

It’s meant for their vibratory engraver, but seemed a good candidate for drag engraving. For me, it’s proven more consistent for fine line engraving than a rotating bit.

The last 1/4" or so of the bit tapers towards the point, so making the bit mount exit hole smaller than the bit shaft diameter allows the point to protrude, yet be captured. A spring and set screw behind the bit compensates for an imperfectly leveled engraving surface. I intended the set screw to run through a threaded insert, but screwed up the prototype and put the insert in without installing the bit and spring (Ever soldered a wired connection and forget to slip heatshrink on first? Kinda like that). I drilled out the 6-32 insert, and then just tapped for an 8-32 set screw - works, but I’ll use an insert if I make another.

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FWIW - With sufficient infill, I’ve found threaded inserts useful in situations where a nut pocket isn’t ideal. I have inserts in my main tool mount plate, and they’ve worked great so far - no pushed out nuts or three handed tool changes req’d.

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Sorry, meant to attach the zipped .stl, not the gcode. (240 KB)