We have been using these DC spindles internally for quite a while. We absolutely love them and everyone who sees and/or hears them, loves them too. The first thing to love is the sound level. They are very, very quiet. In a slightly noisy office, workshop or hackerspace you may not even know that it is on.
The second thing to love is the collet. The collet is the part of the spindle that clamps the bit. The collet is a standard ER11-A. It comes with a collet for 1/8" shank bits, but we also sell collets for 3/16" and 1/4" shank bits. We sell additional collet nuts too in case you want to pair your collets with nuts to save time when swapping sizes.
The third thing to love is the power. These have over twice the power of a rotary tool.
Usage
We have an awesome and totally comprehensive blog post about using this spindle on a Shapeoko with spindle control via grbl or TinyG in the works. It should be done shortly after Maker Faire. In the mean time, this quick blog post will go over the basics.
Mounting.
The standard Shapeoko Universal Motor Mounts work very well to mount this spindle, but tends to mount it a little high. It is easy to modify the Z axis to make it work. You can either slide the Z axis MakerSlide down a little or swap the positions of the Z axis lead screw nut and upper mounting bracket to bring the spindle down a little.
We also sell a beefy standard mounting bracket, but these don't have a mounting pattern for a Shapeoko.
We have a custom Shapeoko mounting solution in process, but that won't be available for several weeks.
Powering.
As the name implies, this is a DC powered device. You can power them with 24-48 Volts DC. For best performance you want to be closer to 48VDC. These draw up to 300 Watts which is probably more than you current power supply can deliver. We recommend an a power supply with at least 6 amps, like this one.
Speed Control.
The top speed is about 12,000 RPM. The speed can be controlled by varying the voltage or with a dedicated speed control circuit. We sell this circuit. It comes with a knob and pot to control the speed, but it also can accept a 5V PWM signal to control the speed.
This circuit can accept DC or AC up to 110 Volts. Using AC is for advanced hackers only. It exposes dangerous voltages and the range of the control must be limited to the lower end because it will output too much voltage for the spindle. You could damage the spindle or speed controller.
Circuit
A typical circuit would look like this.
Here are some more instructions.
How Quiet is It?
We don't have professional sound level measuring tools or an anechoic chamber, but for a simple comparison, I used a cell phone sound pressure level meter app. The rotary tool had about 75dB of noise and the DC spindle had about 67dB of noise. The dB scale is a logarithmic scale so each 3dB is about twice the noise level. This means the rotary tool is roughly 7-8 times louder.
Here is a photo of the app measuring the rotary tool.
