Introduction: $20 CNC Machine
I got inspired for this instructable when I viewed the Easy To Build Stepper Controller
instructable .When I read the instructable I knew I could make a decent looking and functioning cnc machine for under 20 dollars with a recycled twist, Not to mention I did this in under a week.
I expect you to have basic knowledge on power tools and hand tools
and of course this instructable requires you to have a rotary tool such as a dremel.
Even if you don't have knowledge on power tools or hand tools I advise you to try this instructable because you will learn a lot about hand and power tools and you can build this for less then 20 dollars
so if you mess up it's no biggie and it would not cost to much to replace a part.
Let's Build!
Update 02/01/10
{Hi everyone just thought I would give you an update on this instructable since Ive been getting
a lot of emails and messages and such.
I'm getting really close to completing the electronics for the CNC,
as stated in a comment the steppers I found in the printer were bi-polar stepper motors which the circuit
would cost quite a bit more if you went this route. If you were lucky to find some Unipolar stepper motors
then you could build the electronics for under 3 bucks however unipolar motors have less torque. I will be selling CNC kits soon and they will be of better build quality as well as a cheap price tag because I know how it is to be on a budget and not have the tools I need to create simple things and even complex things and this world needs more DIY builders.
The CNC kits will be available roughly 1 to 2 weeks after the electronics Instructable has been released
their will actually be a video showing this CNC working when the electronics Instructable is completed}
Step 1: Find Recycled Material
Now this is the most enjoyable part of building the cnc machine
which is trying to find garbage that people want to throw away.
Here's what you need to locate
Flat bed scanner
Old printer
These two items are going to have your juicy stepper motors and the
beautiful harden steel rods, that's not the only thing you can get out of these green machines.
You will find gears, bushings, cold cathodes, capacitors, buttons, parallel ports and there is
so much more.
Step 2: Tools
Now I tried to build this with the bare necessities so I could show you that it is possible to
make a cnc machine with very little.
Required Tools:
Drill
Screw drivers
Tap and Die set
Rotary tool
Hack saw
Vise or some form of clamping device
Pliers
Drill bits
File
Center punch
Recommended Tools:
Band saw
Table saw
Lathe
Bench grinder
Bolt cutters
Step 3: Linear Slides of Fun
The center core of your cnc machine is your tables
so read carefully and follow the instructable.
Required materials
Quantity Type Cost
4 2"x6"x1/2" Expanded PVC 2.00
2 2"x4"x1/2" Expanded PVC 1.00
2 10" 3/8" Aluminum rod 0.75
2 12" 3/8 Aluminum rod 0.75
2 8" 3/8" Aluminum rod 0.50
1 11 1/4" 5/8"-24 threaded rod 1.00
1 9 1/4" 5/8"-24 threaded rod 0.75
1 7 1/4" 5/8"-24 threaded rod 0.50
Now this is just the run down of everything
I of course cut everything up, you can purchase everything you see here from your local
hardware store and plastic store for really cheap.
First step
Stack 2 of the expanded pvc pieces that are the same size and drill a whole in the center
and two holes each three quarters of an inch from the edge from the center line.
Now cut your aluminum rods to size and stick them through,
now you should have a comparable piece down below
Repeat for all Axis
Step 4: X,Y,Z Tables for Your Brunch
Alright now here comes the most time consuming part
making the tables for the slides but once they are made it really feels like the project
is taking off.
Required Materials
Quantity Type Cost
1 6"x12"x1/4" Acrylic sheet Scrap
1 6"x10"1/4" Acrylic sheet Scrap
1 5 1/2"x5"x1/4" Acrylic sheet Scrap
15 1 1/2"x1 3/4"x1/2" Acrylic sheet Scrap
Now what you are going to want to do is stack 4 pieces of the 1 1/2"x1 3/4"x1/2"
and drill dead center with a 3/8 drill bit
After you have done so feed 2 pieces on each rod
and line them up and place your sheet on top and flip it over now glue.
Repeat for each axis
For your Y axis
now would be a good time to drill your holes so you can mount things you wish to cut.
Step 5: Motor Mount Time
Now depending on where you get your motor from
they are all going to be different so they will require special mounts
I recommend printer stepper motors because they are easy to mount but scanner steppers motors will work just fine.
Now in step three you should have drilled the motor hole and now all you have to do is mount it in
The coupler that attaches from your stepper to your threaded rod is going to be different based on
stepper you have.
I made one out of aluminum but you can make one out of plastic just as long as it is wide enough.
All you have to do is drill in the center of a little piece of rod
to the size of the stepper then on the other side drill 5/16 for the threaded rod.
After that tap the 5/16 side
And glue
Step 6: Thread Me Please
Now once you have made your coupler it's time
to attach the threaded rod and glue a threaded coupler to one of the 1 1/2"x1 3/4"x1/2" square blocks
You have to make sure that the center on the threaded coupler matches the center of the threaded rod.
After you should get something like down below
Required Materials
Quantity Type Cost
3 5/8"-24x1" threaded coupler 0.60
Repeat for each axis
Step 7: Gluing Time
So now you should have all three axis completed and now it's time to line them up and glue.
The base I used was a 20"x12"x1/4" piece of white acrylic I found at the plastic store
You could use smaller but I wouldn't recommend it
Once you have found a base, glue your x axis to it and then your y axis to your x axis acrylic top,
then you should have something like down below.
use acrylic glue
for this step
it will glue expanded pvc as well if your wondering
After that Glue your z axis to a piece of
8"x4"x1/4" acrylic sheet.
Required materials:
Quantity Type Cost
1 20"x12"x1/4" Acrylic sheet scrap
1 8"x4"x1/4" Acrylic sheet scrap
Step 8: Where's the Z Axis :(
Don't worry I didn't forget about that
Moving along
Now we want to add a mount for are rotary tool to the acrylic sheet on the z axis
I used a pipe holder and a screw clamp, you can buy both these items at a local hardware store for really cheap.
You have to cut a little lip to attach to the acrylic sheet because the pipe mount isn't going to be flat once you slide the rotary tool in because it expands.
Place the pipe mount on top of the acrylic lip and glue.
Required Materials
Quantity Type Cost
1 Pipe mount 0.40
1 Screw clamp Free
Step 9: A Piece From the Heaven's
Now that you made your z axis rotary mount it's time to set up
the posts and the acrylic sheet that connects them.
You need a square hole in the center of the 10"x16"x5/16" acrylic sheet to feed your z axis through
After you have cut that out it's time to attach a thick piece of a acrylic
to support the z axis on.
After you have done that you should attach you z axis to it and make sure the acrylic piece is sticking out at least 1/16" off the edge so you can have a flat side.
Required materials:
Quantity Type Cost
1 10"x16"x5/16" Acrylic Sheet Scrap
1 1 1/2"x5"x1" Acrylic Sheet Scrap
(aka thick piece)
Step 10: Tall Posts Oh My!
Now it's time to glue
the 1 1/2"x16"x1" posts to the z axis acrylic top
and then after your done with that, you then glue it to the base.
Required Materials:
Quantity Type Cost
4 1 1/2"x16"x1" Scrap
Step 11: Are We Done Yet!
The answer is no but we do happen to be mechanical done
now because of the short amount of time I had I could not add the electronics part to this instructable,
so I am going dedicate an entire instructable just to the electronics part some time this week as well as a video.
So turn that frown upside down
Word of advise this is quite a bit of work even though it may not look like it
so by the time you have this finished the electronics instructable will be beyond finished.
I will most likely add it on Tuesday or Wednesday of this week.
Part list:
Quantity Type Cost
4 2"x6"x1/2" Expanded PVC 2.00
2 2"x4"x1/2" Expanded PVC 1.00
2 10" 3/8" Aluminum rod 0.75
2 12" 3/8 Aluminum rod 0.75
2 8" 3/8" Aluminum rod 0.50
1 11 1/4" 5/8"-40 threaded rod 1.00
1 9 1/4" 5/8"-40 threaded rod 0.50
1 7 1/4" 5/8"-40 threaded rod 0.25
1 6"x12"x1/4" Acrylic sheet Scrap
1 6"x10"1/4" Acrylic sheet Scrap
1 5 1/2"x5"x1/4" Acrylic sheet Scrap
15 1 1/2"x1 3/4"x1/2" Acrylic sheet Scrap
3 5/8"-24x1" threaded coupler 0.60
1 20"x12"x1/4" Acrylic sheet scrap
1 8"x4"x1/4" Acrylic sheet scrap
1 Pipe mount 0.40
1 Screw clamp Free
4 1 1/2"x16"x1" Scrap
? Scrap from Tap Plastics 12.00
Total= 19.50
I got all my plastic from tap plastics scrap bin and I got the rest of the pieces from home depot
and a local metal supply shop.
Step 12: Recommendations
Now the stepper motors you find in a printer would do just fine
but after a while I would highly recommend to upgrade to some bigger stepper motors.
As for the expanded pvc I would replace that with Acrylic but do to the fact that I had a budget and the short amount of time I had no choice but to go with expanded pvc but I would really recommend you use acrylic.

Participated in the
Epilog Challenge
191 Comments
Question 1 year ago
Hello, I have found this interesting topic today but I feel it still miss the electronic part 11 years after writing this wonderfull project. Do you know wre I should find this missing part if this instructable, please?
6 years ago on Introduction
Great tutorial! Just wish the electronics section was finished...
I found a cheap controller on a Chinese site: http://www.banggood.com/5-Axis-CNC-Breakout-Interf...
I have no idea how to make it work though...
Reply 6 years ago on Introduction
You don't want that. You want something like this: http://www.ebay.com/itm/Arduino-CNC-Shield-V3-03-G...
You can order all the individual parts and save about $10 if you want, or just buy that kit-type-thing with all the parts. I have one I use on a laser engraver, and it works great.
Reply 2 years ago
Personally I'm using something like this:
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F382986266190
This is because that way I can use it to build a 3d printer, and if I want more functionality in terms of laser engraving or millin it's easy to take the output of d9 (typically used as a fan output) and routing that to either my Dremel input (if it's a voltage matched DC motor Dremel) or voltage divide to the input of my laser controller to make a laser engraver work which I got here:
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F332810623708
Still assembling so we'll see how it goes.
6 years ago
So, I've read all of the comments on here and can't figure out why Bipolar Stepper motors would not be better than Unipolar stepper motors since most people said they wanted more speed and power. Why are Unipolar stepper motors recommended by you Techbuilder? Is it just the increase in circuit board complexity and price?
Reply 2 years ago
I was wondering the same thing, especially since it's so easy and cheap to buy stepper drivers specifically for bipolar stepper motors rather than trying to mess around with a unipolar setup and building your own drivers.
4 years ago
what type of software would you need?
7 years ago on Introduction
Good idea trying with this material. I think it would work best for small machines as it is flexible.
With this in mind, the drill stand frame is poor design. First its poles are way too high. The link between the drill stand and the frame of the machine should be as short, strong and direct as possible.
The other axis seem to be less fragile but could be improved.
Gluing : Not good for precision and stops you from dissassembling if you need to transport or repair the machine.
Lastly, nothing is said on how things are aligned perpendicular and parallel.
Reply 5 years ago
As for transporting the machine, it is pretty small and would be able to be transported easily. As you said, taking it apart is probably the only problem.
5 years ago
This is a great tutorial and the result is a beautiful looking CNC that ooks like a piece of art.
However, 7 years is a very long time to make those electronics. Sort of a letdown.
I'd recommend the followers of this project to look into an Arduino controlled CNC. Perhaps use this design but adapt the electronics from one of the other diy CNC projects because the aesthetic of this CNC machine is really quite beautiful.
5 years ago
Do i need both a scanner and a printer or just one
5 years ago
I'm really interested in doing this, but I think I'm missing something. Where is the electronic companion Instructable?
5 years ago
Just chucked my old flat bed scanner away.aaarh.
That looks cool....
5 years ago
This is a really cool take on a DIY CNC. Thank you for making this!
5 years ago
Hi, I've added your project to "The Ultimate Collection of DIY Workshop Tools" Collection
Here is the link If you are interested:
https://www.instructables.com/id/The-Ultimate-Colle...
6 years ago
So I was wondering what type of step motors do you recommend (nema 23 or 17)? And with that being said how many? Plus with the step motor drivers, which do you recommend? I'm trying to get the electronics first then build the rest and I'm new to this and any help would be great!
6 years ago
I asked for help for the electronic circuit to continue assembling a CNC machine from the old scanner
Thank you, my respect
Darmawan
Bali Indonesia
dmd190259@yahoo.com
6 years ago
so do anyone have the electronical part? would be so good if anyone can make it
6 years ago
Can we use this information to build a 3d printer?
Reply 6 years ago
sure, if you have the right technical skills you could definitely do this, just modify the place where the dremel is supposed to go with an extruder and a few other 3D printer related parts!