I’ve had my converted Sieg X3 for four years now. I used an off-the-shelf kit for the mechanicals of the initial conversion, sourced from the now-defunct ProMiCA in Australia. I did this primarily to focus on getting a machine running ASAP. My formal background is electronics and software engineering, so it was a natural fit to do those things myself. I have a thread over in the CNCZone X3 forum that describes some of the details, including some links to videos that give an overview of the conversion and some of the unique things I did in my build. You can also read posts right here on this blog from the very beginning of my interest.

It has been a reasonably good machine for me and I’ve learned a lot in the process. I’ve been a life-long tinkerer and maker and it’s been awesome to finally have a tool to help me realize the ideas in my head. So far I’ve mostly used the machine to make functional prototypes for ideas relating to my various other hobbies and interests. I’ve made motorcycle parts, mountain bike parts, photography/videography related parts, etc.

Lately I’ve felt like a new machine might be nice, to overcome some of the limitations of the X3 (and simply to have a new toy to play with and learn). Tormach/Novakon/IH/etc. seems like the logical step, but once you’re talking about $10K+, a used commercial machine starts to look appealing as well. I am operating out of my walkout basement shop with a 36″ wide door, and no 3 phase available on my street. Moving a 3 ton machine into my basement just doesn’t seem like it’s in the cards any time soon. Moving a Tormach or any of the other hobby class machines would be easy, but ultimately I decided waiting at least another year might be a good idea to see if the market offerings change.

By chance, I ran into this awesome build thread on the CNCZone forum. The really interesting discovery to me was that Tormach actually sells their spindle heads as complete units. They’re not exactly cheap, but once I discovered that they’re very close in size to the X3 head, got really interested in the idea of grafting one onto my X3. This would get me a 10K RPM spindle and a 3 phase AC motor with belt drive. Having 5 times the spindle speed and getting rid of that rattle-trap gearbox on the X3 seems really appealing.

I did some measuring and modeling, and it seemed like it was possible with some work. The main part that needs work is the mounting to the Z slide. The slide on the X3 is a bit too narrow, but it’s actually the same height as the Tormach spindle head. Sometimes I just can’t let go of an idea, even if it’s a bit outlandish. So, I’m aware that this is a pretty silly project, but I think it will be entertaining and educational.

Maybe it’s a bit like this?