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Picture of Building your own CNC router/milling machine

Already at the age of 12 I was dreaming of making a machine which could make things! A machine which would give me the opportunity to create products for in and around the house. Two years later I stumbled ont the words 'Computer Numerical Control' or more specifically the CNC milling machine. After I found out people were able to build one themselves in their own shed, I knew it! I had to build one, I yearned to have it!!
For three months I tried to find the proper parts (A dremeltool, drawer slides, pieces of wood, etc.), but I didn't really know how to build a CNC. The idea fell into oblivion.

In August 2013 the idea to build a CNC milling machine captivated me again. I just finished the first year of my bachelor in Industrial Design, so I was confident enough to start a build. The real difference between now and 5 years ago was, I learned to work with metal on manual milling machines and lathes and above all I had the right tools to design a machine.

This Instructable will show you how I built my CNC milling machine. I know a lot of CNC dreamers do not have the knowledge or tools to build a full metal machine. I still think and hope this Instructable inspires you to make your own machine. I include all of the necessary steps I went through in designing and building this CNC milling machine. All of the drawings I used to build my machine will be available.

 
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God, everything is in this tutorial, my friend you are the real MVP

lnr06261 month ago
I'm thinking of using this as a base for my cnc machine, just had a few questions.
What sort of resolution and repeatability have you managed to get on this?

Are there any changes you want to make to the design after a few months of use?

Did you manage to find the time to make a bom?

With this design, how complex would it be to switch out the spindle in the future? On that note, what are you using as a single currently? I'm on mobile, so i may have missed it in your description.

Thanks for posting this, it looks to be a very well made cnc.

@inr0626 just my 2 cents here: It's a pretty ok design. The accuracy depends upon a lot of factors. To name a few. First of all good supported rails get used here for the gantry - that's very positive as majority of DIY gantries and chinese junk are built without supported rails which is a bad idea.

Accuracy of the X-axis is heavily dependant upon just using 1 carriage each side here. They have been designed to use with 4 at the same time whereas here there is just 2. So that's giving a wobble here simply that shouldn't be there if you use 4. With for in fact it's micrometer accurate (under 0.01mm) those hiwin type carriages. In fact smaller rails can be used, pretty huge rails gets used here which can drive hundreds of kilo's and here it's just a few kilo's that are on top of it.

That would be improvement 1.

The weakness of this design is stiffness because of the cardhouse type construction of the bridge. This to large extend gets corrected in this design by using very thick aluminium for the sideplates. 60 mm thick if i read it correctly. That really helps remove the weakness of this design a lot!

Question is whether, especially in Europe, you can find such thick huge plates cheaply. I doubt it. Easy way to use thin aluminium is by constructing a T or U or angle shape. Also simple manner is just put a small thick plate on the 2 carriages (instead of 1 here) and then use some angle iron say 70x70x7 mm for example. Might add some weight yet that's not a problem at all more weight!

For the same stiffness reason the underplate in this design would be interesting to use angle iron or U shaped or T shaped iron/aluminium.

As for the spindel. This entire design has been made for a lightweight spindel. The chinese watercooled spindle as i have got here is 9 kilo. So that would be way way too heavy for this design and as also up to 13 mm (1/2 inch) mills can be put in such watercooled spindel, which generates too much forces - you'd want a far stronger gantry and bridge weighing way more - the heavier the better for that. At least 40 kilo bridge.

So this kress of say 1.5 kilo or so? (never bought one myself as that 90+ decibel it produces is too much for me to nonstop endure) so that's a great weight. Yet there is also a lot of other brands. You want a lightweight nevertheless.

Note that the advantage of such kress would be a great runout. It's made in Germany and under 0.005 mm runout (it really is). For watercooled spindles (which would require a heavier design) to get such or even better runout you'd need to buy from China a GDK series spindel which even in 2.2 kilowatt version is over 600 dollar to get at home. All the spindles in between that are the GDZ's either watercooled or aircooled which have very bad runout.

So overall this is a pretty well designed gantry, especially if we look to the age of its creator, my compliments!

@inr0626 and @Vincent.diepeveen.
Both of you thanks for the comments.
Coming back on the resolution; Vincent gave a very clear story about the stiffness and it's results on the accuracy! Can't make it clearer.
The good thing about making such a machine at a University is that we, as students, are provided with some very good stock material at for reasonable price (both 7075 and 6082 series, 7075 is extremely though and give great results on those gantry sideplates). The sideplates were actually milled from a solid slab of 7075 aluminium, both with a thickness of 20 mm. Partly sponsored by my university, that explains why I was an affordable option for my machine.

Starting on the 4 carriages on the x-axis. What a coincident! I've just started with a redesign for new sideplates to be mounted on 4 carriages. We a started design de machine 2 years ago, I already knew I should have implemented those extra carriages from the beginning. As a student cutting costs on expensive materials and carriages (plus extra length of the machine, because you loose some with 4 carriages) was necessary in those days. I've gathered some money to tune the machine now :)

As for the spindle; same story, just a matter of cutting costs. Would have been a lot nicer for the ears to have a small (german made) watercooled spindle ;)

I didn't manage to find the time to create a BOM so far....sorry

Yeah you finished a job and did well! That's an accomplishment! Now it's interesting to improve upon it and document carefully online what you did do and show lots of pictures and design documents.

I'm designing some stuff here in FreeCAD. The CNC mill and CNC surface grinder i am busy building i probably will put the CAD and design online.

Yet plans are to produce everything from steel. For 4 reasons. Most important reason is cost. Steel even newprice is under 1 euro a kilo (aluminium 6-10 euro a kilo) and the cnc mill will easily weigh 500 kilo or something as CAD seems like now. Secondly steel is 3x stiffer than aluminium whereas it weighs 2.89x less. Third, this is something most overlook - is the expansion. At each celcius higher or lower away from the assembling temperature of the machine, materials expand. Steel expands simply 2x less than aluminium, roughly spoken. Fourth is that i have a very heavy spindel which i bought because i also want to have the option to mill steel - though for robots and 3d printerdesign i mostly will be milling the expensive aluminium. If i want to mill steel and have a spindel because of this of 9 kilo which is watercooled, you simply know for sure you are looking at a heavy steel / concrete / granite type machine where every kilo extra is nice to have, as long as it doesn't disappear through the floor :)

Argument 4 simply implies that for this gantry you CAN keep a much lighter design. Yet redesigning its stiffness and especially torsional problems up to a level that the torsion and stiffness you can expect can rival the quality of the rails.

If we take for example hiwin rails, those are 90 euro a meter for 20 mm rails (excluding 21% tax) and even cheapest offer from China for the carriages is 100 dollar for 4 carriages.

there is not really ALTERNATIVES for this for a good gantry. I'm toying a bit with SBR20 and SBR16's here yet those are horrible toythings.

So the rails you can write down with capitals as something you need for sure, though a bit lighter rail might possible so i guess. You can CALCULATE by math what you need by the way :)

Now accuracy. 4 carriages very optimistically lowest grade hiwin i've seen claims of up to 0.007 millimeter or 7 micrometer error of the carriages. The rails itself at 1 meter distance could have parallellistic error 22 micrometer, which is a lot.

Basically you can get rid of all sorts of errors, the real big issue is HOW STRAIGHT IS THE RAILS if you want higher accuracy. Yet let's not go further there as that's beyond the scope of this project.

Now let's expand upon that 7 micrometer and just note that:

"Paper supports everything"

If we then take a look to the structure of the bridge, i wouldn't be surprised that if i touch it with 1 finger from the left or right that it swings a few millimeter.

Now i've heard different opinions and estimates on how much force a kress at full rpm with the largest size mill it can handle, can generate at its structure, yet let's round it up to about 20 kilo for now.

That means that priority 1 really is to make the gantry stiffer especially the bridge, without adding too much of a cost.

*that* would be very interesting. Like moving back to 10 mm aluminium for it yet introduce ridges that make it a lot stiffer than it is now.


bubbo5 months ago

Hi Trochilidesign,

first of all, great design! I'm thinking of using your design to make my own, i was just wondering: do you think it's possible to use the same dimensions and make the working area bigger? Let's say 60cm x 60cm. Or would i have to change the structure?

If you just mount a lightweight Kress it's not a problem. You do want to make the bridge more stiff though as the current design is not so stiff and have it rest at 4 carriages at the expensive rails rather than at 2.

Easy way make it wider is by using T shaped sideplates for the gantry and the overhang make it a wider U-shaped plate. So the horizontal part you especially want to make wider of the U shape, so instead of [__] it becomes then [_____] which is longer and vertical mounted that's stiffer. Maybe bit thicker as well. Can use steel there as well. More weight is not a problem. If gantry has been positioned level even small motor can move huge weight.

Stiffness of something goes by the power of 3. So U shape of 30 x 60 x 30 mm U length 2 feet versus 30 x 120 x 30 mm length 2 feet, that 30x120x30 U-shape is 8x stiffer when the 120 mm hangs vertical in the bridge.

Trochilidesign (author)  bubbo5 months ago

Hi,

Of course you can, you just need to find the longer guiderails for the gantry and make the whole gantry and the frame wider. So, yes, you would have to change the structure

bubbo5 months ago

can i ask what is the thickness of the Gantry sideplates? Looks like 20mm thick aluminium?

Idea: use something thicker than 20 mm or simpler: make it a T-shaped plate. That's easy to do and adds lots of stiffness to this design and avoids the bridge to get torsional problems.

Trochilidesign (author)  bubbo5 months ago

Indeed, they were milled out of 20mm thick aluminium

Goedenavond,

Ik ben ook van plan een freesmachine te maken en vindt jouw ontwerp erg interressant. Mijn vraag is dan ook of u de solidworks bestanden nog hebt en of ik deze van u mag ontvangen.

Groeten,

Tom

ICareP29 days ago

I love this. I'm a mechanical/manufacturing engineering student in my first year aswell. I think this project is brilliant, but how long did it take to complete the DIY CNC MILLING MACHINE and when did you find the spare time lol. I would like to embark on this project because CNC machines tools and 3D printers are expensive to buy, they make life easier and are a means to and end. Milling, drilling, turning and lathe machine tools haven't been DIY or hand built since World War 2, BECAUSE THEY'RE BEING BUILT BY multinational corporations. But thanks to bringing this revolution back to life

hemant06011 month ago
Can you provide drive nut details of all three axis.

do you have any of the files in a format google sktechup can open?

also I was glad that you included the wiring (most don't) also what did you use as a microcontroller/ computer

crr095251 month ago

Could you post the link to where you got the guide rails and the lead screws?

JohnR322 months ago

I've looked at a few of this type of machine and yours is definitely one of the best designed and presented. I think I'd like to have a go at making one based on your design. I might need to make it a little smaller though (600x400mm workspace).

woodbutcher533 months ago

Very nice machine. I love the clean and simple looks of it. I think you have a design I would like to duplicate. Its beautiful. Thank You.

Trochilidesign (author)  woodbutcher532 months ago

Thanks! I look forward to your version, maybe even and improved one!

jaythenarwhal4 months ago
How much money would this cost to make?

How much money would this cost to make?

Trochilidesign (author)  mosbahbnsad2 months ago

It all depends on your chosen parts and where you buy them. If you manage to source your parts from eBay (second hand), you can keep the costs low

mosbahbnsad4 months ago

Is it possible to know the price of each piece alone

Trochilidesign (author)  mosbahbnsad2 months ago

It all depends on the price you can get on the raw materials, so it's impossible to give you a price of each piece alone

znipe3 months ago

Nice work!

noticed that there are no thickness on sideplate gantry can u specify what you used?

Trochilidesign (author)  znipe2 months ago

I used 20mm 60-series aluminium plate

LazyH2 months ago

Awesome looking build, the only thing is that you have the steppers labeled as spindles where as your spindle would actually be the dremel rotary tool.

Do you have a YouTube video of this running?

th3-1nonly5 months ago

I will make this when the opportunity arises, however, the guide is really comprehensive and thought through. Thank you for the great information, I will post pictures when this project is done :)

Trochilidesign (author)  th3-1nonly5 months ago

Great, I'm looking forward to that!!

phippsy275 months ago

wow thats pretty cool. im just at where you were about 7 years ago, a dreamer. Its amazing to see how far you can come (encouraging actually).

Trochilidesign (author)  phippsy275 months ago
Cool, that's the goal :)
fabiort6 months ago

Awesome proyect I am really interested in built it, but I would like to request to you the cad files

Me too

Too bad bruh

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chessuraya5 months ago

Hey are the cad files for the cnc mill open source? :(

glogothetidis5 months ago

This is an awesome build ! Great job dude ..

parsing6 months ago

Great work!!!!!!! thanks

PiotrM6 months ago

Hi, your project is very interesting, I'm going to do cnc machine, but I'm wondering about several issues:

- the center of gravity axis-z is not raised too high above the y-axis (u-profiles)?
- drive nut Y-axis is mounted to the plate Z-axis backplate - it might be better to mount drive nut to the Z-axis guiderailplate (between guides the Y axis)?
I will be grateful for your answer.

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