Hello. I'm looking to engrave small logo's (2") into 6000 ally using a CNC's X3 mill & ball cutters.

Before I commit to the set up, what sort of quality can I expect from 3500rpm?

Hello,
We are using a CNC SX3 and have just done several engraving samples to submit for bids in aluminum 6061. We did them with a total depth of .030" in 3passes of .010" with very good results at 3500RPM from about 15-23IPM. We don't have our flood coolant system implemented yet so the part and tool were hand brushed with cutting fluid. The burr was so minor in several places that we did not have to clean up the surface. Naturally we could use faster feeds and perhaps less passes if we had a high speed spindle but the quality of the engraving we did at those depths and feeds will be fine for the jobs we have in mind. The bit used is a solid carbide engraving bit with a 60 degree end and 2 flutes. It looks a lot like a 60 degree 2 flute countersink tool.
I am currently looking into a high speed spindle to add to the SX3, but if I have to mount it to the side of the Z-axis I will lose some X-axis travel so a unit to mount in the current spindle would be optimum. Any ideas or suggestions about a high speed spindle alternative to use would be appreciated.
Regards,
Wes

Here are some pictures of our SX3 engraving results. We did these at about 3500RPM with .010" passes to a depth of .030" with a 2 flute carbide 60 degree engraving tool and 15-21IPM feeds.
Wes

http://img444.imageshack.us/img444/9640/sx3partsfx1.th.jpg (http://img444.imageshack.us/my.php?image=sx3partsfx1.jpg)

Thanx. Thats pretty impressive and along the same lines of what I intend doing.

At this stage, I'm happy that I can get the table moving . . . !

What software are you using? I intend sticking with Mach 3 to control the machine but I'm experimenting with various progs to realise the designs.

I am using Dolphin CAD/CAM for the programs(toolpath) engraving etc. I am also an authorized reseller for Dolphin CAD/CAM USA and I have several Levels of the PartMaster software available in my eBay store(Its for Sale). The prices are currently reasonably lower in my eBay store than the website for the Dolphin CAD/CAM software. I too am using Mach3 for the controller and have no plans to change that. I find the Dolphin PartMaster software very easy to use for the engraving and have had good results with it for milling also. Hope you get your SX3 ready to cut some chips soon. I had a lengthy period from getting mine to making chips with it but I am happy with the machines performance. Good luck!
Wes