Easy to Build Desk Top 3 Axis CNC Milling Machine

Step 1 The Frame

The frame needs to be a flat base that you can mount everything on horizontally and a goose neck of some kind to hold the Z axis (the up and down part with the motor tool)firmly in place. I used one inch pipe just for fun but as it turned out it was pretty handy too. When I needed to make adjustments I could just tap it with a hammer. As you can see the post that holds the Z axis doesn't have to be in the center. It just needs to be firm and the water pipe does a good job of that. Later, after you are sure all the pipe joints are in the right place, you can add a drop of thread sealer to the joints and it will be a good solid structure.

Comments

[yosoytamez2]

¿Donde puedo conseguir el cuello de ganzo? ó ¿con que otro nombre lo encuentro?

[blade z51]

Todas son partes de tuberia. El cuello de ganzo es nada mas que una "L" de 90° y un "nipple" (parece de 3" de largo). La piecza con los 4 huecos se llama "flange" y tanbien es pieza de tuberia. Todas las piezas del marco son partes de tuberia de fierro estandard.

[shadowkiller]

I am usnig 1/2 inch copper piping, when I try to add the Z-axis mount, the goose neck fell down, should I use thicker piping or shorten the goose neck?? Or would sweating the pipes work??? thanks,

[prosi9]

What is the length of x, y and z axis pipes?

[Davetech]

The length's are not critical. They will; however, affect the amount of working space you have. I guessed and bought 1" ID pipe, the two legs (y) are 10", the parts that join the Z-"T" (x) are 8" and 3" and the Z pipe is 10". I guessed wrong about the 1" ID because the thing turned out bigger than Tom's but I'm happy. It is Sturdy!

[slider388]

Better sturdy than weak. What cutting area do you have? I'm thinking of scaling this up a bit to get a 12"x12"x3"ish cutting area.

[Davetech]

My work area is X-12", Y-8" and Z-5"

[slider388]

wow thats pretty good. The Y in this design is kinda limited by how far out from its support you mount the z module, but I'm aiming for you area or a bit bigger.

[Davetech]

Yes, you are quite correct. If you try to extend the Y out too far, when the stage traverses very far from the X rails, it will tend to tip. I overcame that problem by pouring a 6 pound lead counterwieght that rides on the X stage. I was worried that the lead weight would make it hard for the rails to slide but since I used channel steel riding on steel conduit for rails, the additional friction was minimal.

[Davetech]

The easier approach, of course, would be to use longer black pipe "legs" to make the X stage wider, but I was past that point by then and just made the counterweight instead.

[slider388]

Thanks for the heads up, I think I'll go with some 18" legs. When you say you used 10" pipe for the Z, do you mean that you put the z module 10" above the rest of the frame or do you mean you extended it out 10" over everything else? If not, how high up did you put it and how far out? Thanks!

[Davetech]

Upon re-reading I realized that my response missed the gist of your comment... I answered about extending the Y axis, but you commented about the placement of the Z axis upright. Here's how I built mine. But if I were to use a little longer extension than the 3" nipple. I'd get more useable workspace. I might do that. With this size pipe, it might even be a good idea to point the "T" towards the rear and put a pipe and elbow so that the Z upright is further away. I constantly have to be on guard against my Y stage colliding with the upright. In the picture you can see the counterweight. The rubber bands keep it from walking around due to vibration. I used rigid 1/2" copper rails for the Y stage because I ran out of steel conduit. It works well too. What looks like blown fuses are actually ballast lamps. Looks like I may be running them a bit hot.

[slider388]

Thanks for the help man! I have my frame set up, and now I need to build the platforms. It looks like plexiglass will be too bendy for my size machine, what did you use? I need to find something relatively cheap and strong that will do the trick and not sag under its weight for its size.

[Jii Dee]

Do you know what the effects of backlash are on this thing? I see you're just using a normal nut on the screw to move the x and y plates. I would be tempted to use preloaded double nuts to keep the plates from moving when they shouldn't. Aside from that i really like this. i may just do one for cutting sheet styrene.

[Tom McWire]

I had a backlash of about .010 at one time but I think it was cause my drill motor wasn't firmly mounted. Double nuts would be good but be ware of the additional friction and torq on the motor.

[fgleich]

would you get so much backlash if you used a printer stepper motor with it's screw and acompanying nut ?

[Jii Dee]

Thats much better than i would have expected for such an easy to make design. Impressive. Personally i would still want to go with the anti-backlash nuts and maybe do away with the metal-to-metal sliding action and replace that with bearings of some kind, but thats just me. The good thing is this design, with being so simple, makes it really easy to modify. kudos!

[JuniorEng]

Would PVC Piping be OK, or must it be metal?

[fgleich]

If you DO use pvc, use at least schedule 80, since this frame needs to be quite a ridgid structure

[jallenmorris]

I've not made one of these, but depending on how much tolerance you have for bending, shaking, etc, you probably do not want to use PVC. It seems strong and stable to us, but it doesn't take much bend to get the cut off by a few hundredths of an inch. If you don't need that kind of accuracy, then do it. Besides, if you try PVC and it doesn't work out, how much money have you lost? Very little and you've learned something too.

[allegfede]

Could you tell me what is the normal name/use of the flat circular piece of metal (the one with the treaded hole in the center and 4 holes on the side) you used for holding the Z axis? I found the tubes in my plumbing store, but cannot explain to the shop guys what kind of stuff is that piece of metal :( .... so I need to know how it's used ... int the plumbing word :D Thanks

[fgleich]

It's a pipe floor circular support

[Galway]

allegfede, It is a flange or mounting flange. Galway

[allegfede]

thank you guys :D

[disturbedreaper]

print out the picture and bring it there i think it is used to mount something when runing a pipe throught the wall but i dont know just bring a picture

[josheeg]

I think the pipes and correctly drilling a hole through them is a difficult part for a beginner. I wonder if this could be done with angle or I beam type pieces to make it more modular.

[bluumax]

Use a piece of shelving instead of pipes. It will also be absolutely flat. Pipes are hard to get the whole thing flat & not torqued / warped.

[snowpenguin]

You don't have to drill. Just use self-tapping screws.

[snowpenguin]

Oh, yes, you drill before you put in the screws... Still, it should be simple enough even for beginners. snow

[twhaley]

very nice, i've decide to put something together similar to this. I can't think of an easy way to write a program for it though. I use vb and can interface to microcontrollers but i could use some advice, or if possible, code samples for turning a drawing into numerical instructions for the servo's. Thanks!

[landru]

what are those black circles acting as "feet," and how did they get there?

[brandonmiller21]

they look like the little screw in feet that come with furniture...I am using the extra ones that came with my computer desk...they look like checkers with a threaded rod coming out one end.

[brandonmiller21]

they look like the little screw in feet that come with furniture...I am using the extra ones that came with my computer desk...they look like checkers with a threaded rod coming out one end.