How I built myself a CNC router – from WOOD.

This is how it all started for me. This is my first self designed CNC router
I built out of mostly hardware store parts that got me into making, later to 3D printers
and how I finally ended up here on YouTube. In this video I’ll show you that you can
build your own CNC router that can even machine metals out of readily available parts with
no special tools for not much more than 100 bucks and I’ll also tell you what I should
have done differently in retrospect.

Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen. So I am a mechanical engineer by trade and
creating my designs in CAD was always something that I really enjoyed. Converting such a design into real world parts
often was quite challenging for me due to the lack of tools and the lack of patience
to do it with the tools I had available. At some point I started playing around with
Arduinos and some stepper motors I got from an old floppy disk drive and was really intrigued
with the connection of mechanics, electronics and programming. Stepping it up a bit and having heard about
GRBL I noticed that everything for making my own CNC router was already available and
connecting a couple of cables to an Arduino shouldn’t be a challenge, even for a mechanical
engineer. My goal was to make myself a CNC router, reasonably
priced and with the tools I had readily available. I did some research online and did a rough
CAD design with all of the bits and pieces that seemed reasonable at that point. I didn’t have a welder nor the proper tools
to work on metal so I decided to do the whole frame in wood.

The tools I was using at that time were only
a cordless drill, a jigsaw and a cheap drill press with different sized wood drills. I can highly recommend to use some kind of
drill press, because that makes drilling straight holes so much easier. So the main structural parts are 60×80 mm
composite lumber which is really sturdy. I wouldn’t use normal lumber because it
is usually not the straightest and will warp over time due to temperature and humidity
changes. The composite wood consists out of lots of
smaller wood pieces cut in different orientations and glued together which makes the behavior
more uniform and predictable. I pre-drilled all of the pieces and screwed
them together with these long woodscrews. The gantry is also slightly reinforced with
a couple of steel angles. All of the axis carriers are mostly made out
of 18mm multiplex board that is easy to cut on a circular saw or the hardware store, at
least here in Germany, will cut you everything directly to size.

When I build the frame I often just printed
templates, glued them on the wood drilled through them. I don’t regret using wood because it made
the building process very easy is still very rigid and the wood does absorb vibrations
quite a bit! The mechanics are pretty simple because all
of the axis just ride on heavy duty drawer slides. I had also been buying some cheaper ones but
thought they were too flimsy.

If I would have used two in parallel and even
two in series it probably should have worked as well. The lead screws are simple M8 threaded rods
that are supported by 608 roller blade bearings that I actually bought in a sports store at
that time. On one side there is always a fixed bearing
setup with two opposing bearings where the leadscrew is mounted against with counter
nuts, the other side is only a loose bearing.

I later upgraded the led screw nut bearing
blocks to 3D printed ones but in the beginning I simply used a piece of wood with a hole
in the middle in which I mounted drive-in nuts. My X-axis is still working like that with
only little play! The kinematics are a bit different to the
nowadays usual ones where the Z-axis rides on the X-Axis. In my design it’s the other way around and
this has in my opinion the advantage that this is the stiffer setup especially if you
are working on different z-heights. The electronics are also pretty simple and
only consist out of 3 NEMA 17 stepper motors and an Arduino UNO with a stepper motor shield
and stepper motor drivers. At that time, I actually soldered the stepper
motor shield myself but nowadays they are cheaply available also on ebay and Aliexpress. At first I used Polulu A4988 drivers but later
changed to DRV8825 drivers because I had problems with the motors losing steps.

Also the fan helped me to keep the drivers
cool that they don’t overheat and cause problems. The motors are also only mounted on simple
wooden standoffs which I thought were temporary at first but in the end worked out pretty
well. At first I actually only connected the stepper
motors via a piece of hose and cable clamps but later switched aluminum couplings for
more precise movements. In the beginning I used a normal laptop power
brick to run the whole machine but since I wanted to use higher accelerations and my
motors were already at it’s limits I purchased a separate 32V power supply that I mounted
under the table and is probably overkill.

When I first finished the CNC I mounted a
Dremel to the machine which worked okay in soft wood but wasn’t ideal for more and
metals were a no-go. Also the 1/8 inch collet really limits the
tools that you can purchase. I later bought a Kress or now AMB 1050 which
is a 1050W air cooled router that I still use now on my new CNC router. It’s loud but the rpm can be varied between
5000 and 25000 which makes it usable for metals and wood. I could have also made myself another mount
and used normal shop router instead. The 1050 can use collets in different sizes
up to 10mm which gives you a huge selection in tools. If you’re working not only with really soft
wood then don’t bother with high speed steel cutters. If they get too warm once you can throw them
away. For years I have therefor been buying carbide
cutters from Banggood and I haven’t been disappointed so far. Obviously with a wooden router you can’t
really use flood cooling for cutting but low amounts of cutting oil when working on metals
hasn’t harmed my machine during the years.

In the beginning I always mounted sacrificial
pieces of MDF on the machining table in which I screwed in the pieces of wood. Later I machined myself a piece of MDF with
lots of holes that have drive-in nuts in the back that I can use to mount my parts with
clamping claws or even attach a vise to it. The nice thing is, that as soon as you have
this machine working you can design and machine more precise updates on your own to make the
machine better and better. On the software side, I use GRBL on the Arduino
UNO that interprets the G-Code that is being streamed to it and translates it to stepper
motor signals. The GCode, so the instructions how the machine
should move can be created in lots of different tools nowadays with even some browser-based
ones. Since Autodesk provides Fusion 360 for free
to makers and small businesses I’ve switched over to this piece of software for more than
two years now because it has a really powerful CAM module included which should even satisfy
advanced users.

In the beginning I was also thinking about
adding a 3D printing head but dumped that idea at some point because even though it
would definitely be possible the machine is just too slow and unprecise for 3D prints. I even added a simple laser head at some point
which due to safety concerns I rarely used. Now, in retrospect, what should I have done
differently? Even though the use of wood might not please
everyone, I still think it was the perfect choice for me but I probably should have painted
it in order to make it less sensitive to changes in moisture and fluids during use.

The thing that I really had the most problems
with was the torque of the stepper motors. So I used NEMA 17 motors that in some situations
just were too weak and if I would build another one I would definitely go for NEMA 23. Another nice upgrade but that also involves
spending a bit more money is replacing the drawer slides with real linear rails to make
the axes sturdier. The M8 threaded rods as lead screws worked
okay for me and with the use of two nuts don’t have that much play but trapezoidal lead screws
or cheep ball screws could increase the accuracy. Only keep in mind that the pitch should be
kept quite low because with a CNC router you are aiming more for force than for speed.

So I had been mounting the roller blade bearings
directly in the composite wood. The problem is that if they are not 100% aligned
your lead screw might lock up. So today I would rather mount the bearings
in a separate piece of wood that I can then slightly move to align everything. This was an overview about my hardware store
CNC router that has served me well for years and even more importantly has taught me so
many things about mechanics, electronics, machining and so much more. Of course, it is not the most accurate machine
and you might reach its limits at some point but machining wood and even aluminum wasn’t
a huge deal. I even used it in the past to make my own
PCBs. The design is very simple and even if you
are no pro in CAD at the moment the whole machine can be planned on a piece of paper. Depending on your needs the dimensions of
my design might not be 100% suitable for you so if you are planning to build something
similar maybe change them accordingly. The investment is not very high but I promise
that you will learn a lot during the process and still have a usable machine in the end.

A couple of years ago I purchased all of the
parts in town or in local online shops and one reason was that I was impatient and wanted
to get the parts as soon as possible. If you want to approach this project there
is also the possibility to source the parts from China but this process can sometimes
take 3 months or more. So I would really like to know from you what
you think about this project I did quite some years in the past. There are links to the design, tools I used
and some of the hardware down in the description for you to check out. Please leave a thumbs if you enjoyed this
video and if you are new to the channel than hit the subscribe button and take a look at
the other videos on my channel. If you want to support the making of these
videos consider becoming a Patreon! Thanks for watching, auf wiedersehen and I
hope to see you guys in the next one..

As found on YouTube

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