What drives do you have that will handle 2.5MHZ??? That's crazy! It seems i don't really have a choice. Like you said if i did a multiplier of 1 (instead of 4) that would absolutely kill my speed and require a lot of bandwidth (4 times more). The machine works really well how it is, so i can't complain at all!! The resolution is amazing, and i cant complain about the speed cause for how big it is, its speedy!!

I have these servos:
http://www.kelinginc.net/KL34-180-90.pdf

According to this cnc machinery building manual by Siemens, many power supply builders will go 10-15% higher voltage to accommodate like you said for lack of efficiency, voltage drop over long wire runs, etc. I do however have the amperage below the maximum.

Let me know what drives you have. They sound expensive haha.

There may be an advantage  to going quite high on the encoder counts and using electronic gearing when comparing a max input step/dir like your drives have. Waht I am meaning is really you have a min resolution you can really get due to the limitation so going with a higher encoder count and using a higher electronic gearing would get you the same resolution. The advantage may be is with the drive itself as it can then read the ungeared encoder input and thus compensate better within its tuning thus reducing the error.

The drives I use would be expensive if bought new, the 22KW one I have on the lathes spindle comes in at around £4700 ($7500 ? ) but I paid £180 for it and also picked a spare up for the same price and both were new, well one had been powered up for 15 mins, I think, it said in the drives software.
They are Allen Bradley DSD AC drives and I use various Allen Bradley AC servos. As said the most I have paid is £180 for a drive and the most I have paid is £250 for  new 12.5KW motor that I use on the lathes spindle, it too has a retail of about the £4500 mark, isn't ebay wonderful



Hood

WOW! Awesome Ebay Find Hood!

So you use the smooth stepper with that sucker? Wow i bet it really flys!!!

I use the SS on all my machines although presently redoing the Bridgeport and I am going to be using it with some new control although cant say too much yet and to be honest I have a few options.

The lathe is big so I have limited it to 10m/min rapid although I could crank it to 20m/min. Likewise my Beaver mill I have at 8m/min but could theoretically get 40m/min but 8 is plenty fast for that type of machine.
Heres the progress so far on the Bridgeports panel.


Hood

Hood, that work is just sooo neat    (why does all my stuff look like a rat's nest ?)

Tweakie.

I dont really know how I manage as I am a very untidy person, just need to see my workshop
Hood

holy cow that is a very very clean install!! Got a picture of this lathe? Must be equally impressive!

Sadly my workshop is narrow so getting a good pic of things is difficult but heres the lathe thread http://www.machsupport.com/forum/index.php/topic,1234.0.html

Hood