Ok, where to start.

I seem to have run into a problem that I think can only be solved by filtering the output from a DC Regen drive that I bought new, to replace the original Westamp analog Spindle drive that my mill originally came with.
The old drive was circa 1979 and finally became too unstable and unreliable, so I decided to replace it.
Things didn't go quite as planned though.
The DC drive I bought is a KBRG-255. 5hp 180Vdc. Seemed like a perfect match for the 5hp,180VDC Peerless motor and in fact it does work quite well. But, I'm not too happy with the resulting harmonics and potential for rapid or increased brush wear on the motor. When the motor spools up, it starts with a low growl and at full motor speed, 3600 rpm, it sounds like a jet engine at half throttle. A very high pitched, whinny sound.
Some may find this cool, but it's not for me. If I wanted the squeal, I would of kept the old drive, as it was quite loud.

So in any case, I came to the conclusion after reading many posts and doing some research, that SCR drives although reliable and affordable, have some draw backs. Their outputs ( form factor ), is not quite pure DC and they draw more on the incoming AC line then fully filtered drives. They wear brushes out quicker and create more heat in the motor when not running at full rpm.

My question to all this is, can I use the big capacitors that came with the analog drive and it's inductor coils, and make my own filter.
If I take the output from the SCR drive and pass it through two Capacitors in parallel with an inductor in series between them, would it smooth out any left over ripples?(thus reducing noise)
How would this affect reversing the motor?
Has anybody tried this or am I the only one with this issue?
Any constructive input is welcome.
Thanks.