Engraving Acrylic - Best End Mills?

Hey all. I am making these little items out of clear acrylic that have a motion activated fluid inside of them. Long story short I am getting requests to get logo’s and words engraved on them and I haven’t had the pleasure of doing that just yet. Does anyone have experience with what types of end mills that give the best results? Here is a pic of what I am making:

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Those look great! What size engraving are you looking at?

For acrylic, I would think you just need to scratch the surface for the engraving to be visible, correct? Maybe 0.05 mm deep or less? For that, I don’t think you would need specific end mills (like 1-fluted plastic cutting end mills). Depending on the font, size, and thickness of the letters, a tiny square end mill of any type should work. Maybe a 0.4mm end mill (or larger, if you font size is larger). For logos, it would depend on the clarity you are searching for, and the sharpness of any turns. Possibly use a v-bit for any sharp corners, and use the square end mill to ‘hog’ out the center parts of the logo. You might want to consider Diamond Dragging Engraving bit for the logos, but I found that very small items that need to be filled in don’t work as well with that.

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Hey thanks boss! Yeah I think for this I am going to start simple with things like outlines. I am going to do an experiment later where one is using a small ball nose, one a v-bit and another a square. The smallest I have in stock for end mills is 1 mm diameter and the smallest ball nose is .063". We shall see, I just figured I would ask because I don’t see many articles out there showing best results for things like outline vs fill in and such.

Look into Diamond Drag Bits. They are pretty forgiving and you can get some pretty good detail with them. They essentially scratch the surface but do a pretty good job on acrylic. I have something similar to this: https://www.ebay.com/itm/1-4-CNC-45-90-DEGREE-DRAG-ENGRAVING-TOOL-BIT-WITH-SPRING-LOADED-DIAMOND/192479839073?hash=item2cd0b14361:g:yF4AAOSw8oxaqyRH

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I have that exact bit from same seller and it works fantastic on acrylic.

Dan

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Awesome this is good to hear! And thanks @DanoInTx as well. Do you all have any recommendation on how to use it? I.e. feeds and speeds and such?

There is no speed on a drag bit, as you don’t turn on the router. Your feeds can be pretty fast, I think I ran mine close to full speed, but it depends on how small an area you are engraving. For smaller areas, you want to back off a bit. This is another one you will have to test yourself, but the drag bit is very forgiving.

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What Adam said. For most engraving sizes 75-100ipm is plenty fast. Acrylic is pretty forgiving compared to metals like brass or aluminum. It is also a little dependent on how deep/how much pressure you put on the bit.

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That is what I assumed but I wanted to be sure. With a name like “drag bit” it makes sense it would be used that way :smiley:

http://community.carbide3d.com/uploads/default/original/2X/5/5716c0747d5fc03be42bb388f756d12b0c6623c5.JPG

Done with that bit and Carbide Create

Dan

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That… Is… Amazing! I definitely look forward to playing with this in the future!

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