Thought you guys might like this.

[rlockwood]

950rpm/8.5ipm is about .004" advance per tooth with a two-flute (which is what I would call a center drill) which may be a bit much. For instance, we engrave aluminum .01 deep with a carbide #1 center drill at 6000rpm/10ipm, or .001" advance per tooth (with coolant)

to get the same ratio at 950rpm, though.. you would need to be going 1.9ipm, and i'm guessing that cut would take awhile

now, thats incredibly conservative, ive never once broken a tool at that rate, and the finish is great.

[twisted]

I am thinking of selling some of these to help justify to the wife all of the time out in the shop, and to help keep me in tooling...

i want

[Jacampb2]

950rpm/8.5ipm is about .004" advance per tooth with a two-flute (which is what I would call a center drill) which may be a bit much. For instance, we engrave aluminum .01 deep with a carbide #1 center drill at 6000rpm/10ipm, or .001" advance per tooth (with coolant)

to get the same ratio at 950rpm, though.. you would need to be going 1.9ipm, and i'm guessing that cut would take awhile

now, thats incredibly conservative, ive never once broken a tool at that rate, and the finish is great.

I corrected my original post, it was 2100 RPM, I am not sure what I was thinking. I believe the calculations put it at about .002 chip load per tooth.

I spent some time tuning the machine tonight. I got the acceleration up about 3x where it was. Time to cut the logo is down to about 5 minutes. I did the new one with a #2 CD, and .04 inches deep. It looks good, but is to deep I think. The surface is almost dangerous to touch. I got my feeds up to about 20Ipm now. Much better. In the end I went with a even lower RPM. From what I am reading, acrylic is funny that way, it likes lots of feed and relatively low cutter speed. Too much and it melts, too little and it chips. I am going to look around and see if I can find a shop with polycarbonate drops. I priced some small pieces of .375" polycarbonate, and the price if fuckin' ridiculous.

Seriously though, if any one wants one of these, PM me with size and lighting, and I will see what I can do. When I feel comfortable with the finished product, I will write and make sure you are still interested and we will work things out.

Later,
Jason

[denim]

Jason, I might have to see if I can get you do to one with my company logo.