Super-PID or Go Back to Quiet Cut Spindle?

I currently have the DeWalt DWP611 on my X-Carve, which I primarily built to carve wood (including MDF), plastic, and copper clad boards. The DeWalt DWP611 is nice - I wouldn’t mind having one not permanently attached to my X-Carve :grinning: - but its spindle speed control is not automated.

I was thinking of getting a Super-PID, but by the time I pay for a trackable level of shipping to the states, I’m looking at $200. Plus I have to modify the DWP611 and figure out a way to feed the Super-PID a spindle enable signal (since both the gShield and the X-Controler mangle enable and speed into one output).

My concern with the Super-PID is that it only gets 120 chances a second to adjust the spindle speed, is that enough for effective closed loop control of the spindle.

Or for that same $200, I could get a 48V power supply, Quiet Cut Spindle, and a fast Solid State Relay (like one of these). And yes, a ultrafast diode to put across the terminals of the spindle so I don’t blow out my SSR. [Yes, I realize that this costs more than $200, but I’m giving some credit to the value of parts removed.]

The drawbacks of the Quiet Cut Spindle is that it is only 300W (if I buy from Inventables) or 400W (if I buy a more powerful one elsewhere)… and with the simple control method I describe above, it is not a closed loop control. However, I could make my own closed loop controller for the Quiet Cut Spindle (since we’re talking about low voltage DC) whereas I would not be comfortable doing this for an AC spindle.

So long post short, am I crazy for wanting to downgrade to a Quiet Cut Spindle? Or will I be happier with the Super-PID than I currently fear?

Personally, I’ve just made up a chart for where each tool performs the best for me, and I just put that setting on the dial when I swap the tool in. If you are concerned about live control, perhaps one of the water-cooled spindles?

The superPID creation was not hard, although I am doing my X-controller upgrade at the same time, so will soon know how well that works. The big thing it adds is not just closed-loop control but also much lower cutting speeds (it will hold 5000rpm all day for me - and it can go lower but haven’t really tested that extensively)