Best settings for spring loaded diamond drag bit on acrylic?

I just ordered a 1/4 inch spring diamond drag bit to engrave in acrylic. I want to make some light up signs. Does anybody know the best depth and speeds to use?
I saw on other forums a depth of 0.2 and speed is 150 ipm. That seems high to me. Obviously the depth is just going to increase pressure on the spring so deep might be better.

If you’ve used a spring diamond bit please share your experiences.


Just wonder what settings you use, trying this myself but seem to have something off. Thanks

I have been trying out my spring loaded bit on various products like plexiglas, mirror tile, floor and wall

tile to some sucess. First I would make sure the surface is perfectly flat to the bit.

You can check this by drawing a square with an X in the square using a ball point pen. Drop the pen to the paper and see if all lines are plotted.

If you want only one pass, set the cut depth the same as the depth per pass. The diamond tip that I have is supposed to be about .003 in. If you make more passes on same line, the point just engraves deeper. On things like glass or tile, you might want multiple passes to give that frosted look. You probably know the diamond tips come in 60, 90, 120 degrees. 60 for light work, amd 120 for engraving on brass and steel. I have broken two diamond bits already from unknown reasons. Maybe to agressive.

I would practice on some scrap plexiglass until it looks the way you want.

You can play with the pressure on the diamond by turning the hex screw in the bit holder, which changes the pressure on the spring.
The depth per pass can set more pressure by making the spring depress more.

I have tried engraving on plexiglass, mirror tile, floor and wall tiles.

Check back in, as I am curious to see what other people are doing.