What are folks using for spindles in CNC routers?

Considerations of course are voltage (110V NA, 220V EU, 220V at 30 or 50 amps) diameter/mounting system, and budget.

(ob. discl., I work for Carbide 3D which makes and imports a couple of options)

Inexpensive options seem to all be based on the Makita RT0701(NA) and RT0700(EU) with a new European-saftety-standards mandated option, the RT0702 which adds a “No auto restart” feature (which interferes w/ using it in a CNC w/ a relay) — note that those are 65mm in diameter) or other trim routers such as the DeWalt DWP611 and D26200 (69mm) or Bosch Colt PR20 (though that fell out of favour Precision Bosch-Colt Collet Kits (precisebits.com)). There are various collet systems, with ER-11 being offered on variants of some where the originals had a proprietary system. Note that comparing these to others is difficult since their rating seems to be given as their peak draw.

There are myriad VFD spindles, which are divided by diameter (65 and 80mm), Wattage (300, 800, 1.5KW, and 2.2KW) and collet system, usually ER, sized from ER-11, through ER-16, up to ER-20, though there are systems which will support an ATC.

Bridging the gap in-between are “milling motors” such as are offered by AMB/Kress, Mafell, and Sauter — usually from 800 to 1,000 Watts. These usually have a proprietary collet system, though sometimes there are adapters to other industry-standard collet systems such as ER-16, ATC is an option, and some units will have a “quick-change” mechanism where a lever will open up an 8mm diameter tool holder (note that rather than collets, such systems use reducing sleeves for other diameters) for changing tools.

Ages ago, there were other options/ideas, but they all seem to have dropped out (glad to have seen the last of the Dremel/rotary tools) — one which was striking was a motor which used a series of brass reducing pulleys for torque.

As certain forums joke, “This thread is worthless without pics!”, so here’s my Mafell FM 1000 WS which I finally got around to mounting on my Shapeoko 5 Pro:

This is the spindle that came delivered with my small CNC kit:

This is the ubiquitous 775 DC spindle that comes in many small machines; my mini tablesaw also uses one too. For my CNC it came with the ER-11 collet system pre-installed.

I run from a 32V DC supply; assuming my spindle is a standard spec that gives me 12,000rpm unloaded. It’s a ‘standard’ design with a lot of different suppliers, so there are plenty of substandard units etc, a few years back I found some interesting YT videos reviewing these and their clones.

From my perspective it cuts well, so long as you dont ask too much from it. I got this machine for PCB making and it does that with ease. I have also done some light wood engraving with good results. And some acryllic engraving and cutting, which went well once I got feeds, speeds and toolbits sorted out.

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I’m using a generic 240V ER11 water cooled three phase spindle with VFD that I bought from @funinthefalls before he passed. :cry:


My frustration with the VFD spindles is they mostly all seem to be ER with a solid spindle, and I’d sure like the option of a spindle tube so I could hold things in with a drawbar. But this may just be because I’m so used to milling machine operation.

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You have a sherline lathe, right? Could you gun drill one of these spindles and turn it for an 8m WW collet and interchange them?

I’m building a DIY CNC mill and have repeatedly failed to make sense of the spindles available in the $500 to $1500 range. I would like a spindle with a path to adding ATC that can run on US household 240V split phase power without a terribly expensive or noisy converter.
I’d prefer something with enough torque at low speeds to cut mild steel and enough speed to make smallish holes but at this point I’m willing to work with almost any speed range.
There’s a boatload of badly made spindles on the usual sites and I’m having trouble separating them from the reasonably good ones.

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I’m running an off-brand 65mm 240V ER11 air cooled 3P 1.5kW / 24k RPM spindle driven by a Teco L510-101-H1 (120V1P in, 240V3P out) VFD.

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One interesting thing is that the design of the 1/8" reducing collet for my Mafell markedly changed since I first purchased mine, becoming markedly longer, but oddly, not increasing the actual length involved in holding the tool — that remains scaled to match the typical shaft length of such small tooling.

I’ll probably have to order all the other sizes so that I can have the complete set, and see if the 6mm design changed.

I wish that there was a 5/16" (or 8mm) to 1/8" reducing collet option like to the 1/4" offered by IDC Woodcraft:

(and that 8mm (or 5/16") tooling in general would become more popular)