I just converted my Taig from a single spindle machine to a dual flexshaft machine.  The Taig motor turns the Taig spindle to about 10,000 RPM.  The flex shaft tools I grabbed turn to about 15,000.  In aluminum they cut a heck of a lot better.  Also, getting that big heavy motor off of my Z-axis improved performance 3 fold.  I used to have to leave the Z-axis kinda sloppy on the ways, stay under 4 inchess off the table at all times, and turn the stepper down to 10 IPM.  With this improvement I am moving the z-axis at 30 IPM with no problems at all, and I was able to tighten up all the adjustments on it and eliminate all the slop.  

In addition to the picture here is a short video showing it running at 30IPM on all axis, ramping at 15 IPM and taking off .006 at 30 IPM and 50% stepover.  
http://www.youtube.com/watch?v=RfcaT1AB2gM

The second spindle is retracted while I cut a single workpiece, but if you look close I can raise or lower either spindle relative to the other one so I can zero to two seperate work pieces and cut them two at a time.  Yeah it looks kind of Frankenstein, but it works.  The adjsuter clamps are actually modified single spindle clamps that I made a couple days ago for another project.  When I saw how well it worked I decided to setup a dual clamp system and cut pieces two at a time.  

I will be getting a couple other handpieces soon that use collets instead of a chuck and increase the number of end mills I can use.  

cool!

Hi Bob,
that is a great idea, are you still using it and are you still happy?

many thanks,
Stjohn

Hi Bob,
that is a great idea, are you still using it and are you still happy?

many thanks,
Stjohn

Well, I'm not using it at the moment.  The basic idea worked pretty well, but my design needs some refinement.  I cut two sets of mold plates with it, and it worked perfectly, but I discovered when I was cutting my shallow (.003") air vents in the molds that they drift a few thousandths no matter how hard I tighten up the mounting screws.  I am working on a redesigned version with a squaring block bolted in between the two clamps that paired with a tighter fit to the Z-Axis should eliminate that.  Obviously I still need to plan this for my most common since plate size or plan to spend some more time setting spacers and shim to get the pieces square and the right distance when clamping to the table. 

hmm... interesting, thanks...

Stjohn