tool shanks of 1/4” or 1/8” with an
There are dozens of rotary tools of
all shapes and sizes. Most are meant
to be held in your hand and are used
to engrave, cut, grind, and drill various
materials. Unlike routers, they are not
meant for the larger tasks that routers
can handle. Two rotary tools that
represent most variations you will find
at home centers or hobby shops can
be seen in Figure 6. While they are
well suited for handheld use, they are
not suited for CNC use. They have slop
in the bearings and tend to have too
much runout to get an accurate cut.
There are tools that fall into the rotary tool category but are
better suited to CNC use. Let’s talk about three of them.
The first is the Wecheer WE248 shown in Figure 7.
This is the first rotary tool I attached to the KReduCNC that
produced results that were accurate and repeatable. The
tool has no slop and very little runout. It’s powered with an
included AC adapter, and proved to be very easy to make a
spindle mount as shown in Figure 8.
I used this rotary tool, and while I was able to cut
softer materials, I found it to be under-powered. It also has
an auto shutoff if it senses too much load. I did find it
worked very well for PCB (printed circuit board) work.
After playing with the WE248 for about a week, I
realized I was not pushing the KReduCNC as much as I
could. It was time to look for a better suited spindle. I could
probably get a trim router to work, but I would have to
slow down the Z axis due to the weight.
Having good luck with Proxxon products, I selected the
rotary tool shown in Figure 9. It’s the Proxxon Micromot
50/E. It has much more power than the Wecheer, and I
was able to cut deeper and faster. Its size also made it very
easy to mount on the KReduCNC as shown in Figure 10.
The 50/E worked much better than the WE248, but I
still had the following issues:
1. It requires a special 12V power source. While I was
able to make one, it does add some complexity to the build.
2. The speed control can bog down, as it has no
feedback control. It can also shut down if pushed too hard.
3. I still wasn’t pushing the KReduCNC hard enough.
While doing my research, I came across the Proxxon
Micromot IBS/E shown in Figure 11. This is a rotary tool that
costs almost as much as a full-sized router, so I was reluctant
to take the plunge. Then, while cutting some softer material,
the 50/E stalled out when it cut through the stock and hit
the waste board. I ordered the Micromot IBS/E.
Despite the $130 price tag, the IBS/E (Figure 11) is a
remarkable tool. It boasts a 1/8 HP motor, which is plenty
for the KReduCNC. It is designed for continuous use and
has a full electronic speed control with feedback. Its speed
range is 5,000-20,000 RPM. I can honestly say it’s the
smoothest rotary tool I have ever used.
The motor in the IBS/E is the same used on the
Proxxon MF70 (Figure 12) that I incorporated in a CNC
conversion I did a while back.
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