Noob with a few questions

Hello everyone.

I found this project by searching for 3D printed CNC. I’ve been wanting my own CNC for years, as I am a mechanical designer with extensive knowledge of 3D modeling, and I’m always building DIY projects, as well as having access to a 3D printer.

My main questions are…

  1. Is this system able to produce fairly tightly toleranced parts with consistency once set up properly?

  2. Are larger versions any good?

  3. I have watched a lot of videos that show peoples first cuts and such, but I am wondering how many people are regularly producing good CNC parts on this thing, particularly ones with some depth to them, complex carving, etc. I can’t find many examples of this. At most I saw a guy that has made a few picture frames.


Glad to hear it caught your eye.

You didn’t give much info to go on.

  1. What do you consider tight tolerances, and in what material specifically? The shorter you make it the tighter it is. Wood and plastic, It is as good as I could imagine anyone needing in these materials. PCB’s depend on your experience cutting them, Usually better to laser etch the mask, aluminum good enough for the parts I’ve made.
    2)Any Good for what? Larger machines aren’t expected to hold as tight of tolerances as small ones. Kind of a conflict with #1.
    3)I use mine for milling printer frames and printing parts for the kit, all day everyday.

Hi V,

Thanks for the reply. I guess I could rephrase it by asking… What sort of tolerances does the standard sized MPCNC hold compared to a 3D file?

Also thought of another question: Do the CAD files exist in any other format other than STL? I like to model everything in Solidworks before I build something like this, and I may end up with some small tweaks to the files, which is not possible with STLs.


Sorry I don’t release the files in any other format except the tool mount. I strongly urge you to try it as is before making any changes. That is the reason I don’t release other file types. Most people find no tweaks are needed and the ones that do usually are good enough with CAD to replicate my parts with ease.

The tolerance question is not easy to answer for a few reasons. You still haven’t specified a material. Like I said with wood, acrylic, HPDE, ect The tolerances are as high as any decent CNC mill. After that Machine size has a huge effect. I can not give you a number or I will get flooded with emails saying how there machine does better than that or doesn’t and I will quoted with those numbers everywhere. My machine setup well gives me very good numbers but I am also getting really good with feeds and speeds which are much more important in smaller “desktop” cnc’s. If you try and cut to fast or not fast enough your tolerances will suffer.

If you ask something more specific I am comfortable telling you if it is within the machines capabilities if it is set up properly.

No problem. Ill probably just model them up real quick. Even if I don’t make changes, I like to see everything together in an assembly as I build. It will probably be this winter, as I am currently building a sailboat.

Consider the tolerance issue answered. Having you say it is comparable to other mills is satisfactory.

Thanks again for the quick answers. That’s the biggest plus when considering a project like this.



Actually thinking of building one sooner rather than later. I know you mentioned that you don’t give out other file formats, but is there any chance you had the entire assembly in one STL file anywhere so I could spin it around and see how everything goes together? Would also use it to quickly assemble the existing STL files into my own assembly. I’m thinking 3’ x 4’