Re: Saturn 2 4x4 questions.
Reply with QuoteJust to muddy the waters, I'll put in my opinion here.I completely agree with David on the Hitachi VFD. Really nice unit with good options. I really like the fact that it essentially has a built in safety relay (not quite) that allows you to cut power to the motor without killing power to the entire VFD. The configuration can be a little complicated at first, but there are lots of folks on this board that have used them, so help is available.
Where I will contradict David (with all due respect) is on the spindle. I have a Chinese 2.2kW air-cooled spindle and have barely seen it get warm after cutting for a solid 45 minutes. Your point about keeping it cool at low speeds could be a concern, but that will really depend on what you are cutting. I have been cutting with 1/2" flat and ball end 2-flute bits, running at 200 IPM, and it cuts cleanly at 20k RPM without burning (nice chips). If you are cutting mostly wood, then you shouldn't need to run the spindle slow. That said, I also did some (marginally successful) cutting on aluminum with a 1/8" bit running at 9000 RPM for about 30 minutes, and also didn't get the spindle even warm. Alot will depend on how much material you are removing each pass and the feed rate because that will determine how much power you have to put into the spindle.
My biggest concerns with water-cooled were rusting out the spindle and the inevitable leak.
On your previous question about removing the gantry...I had to do this on my 4x2. Its not hard...until it is time to re-square the gantry. I'd love to hear how Nate does that because my method was tedious and difficult to get dialed in. I'm still not convinced I have it perfect. Still...if you have to do it, you have to do it. My machine wasn't going into my shop any other way.
-Robert
Originally Posted by difalkner
