I am wanting to buy/build a cnc router, primarily for wood working (birch ply) but with the option to machine small non ferrous metallic components infrequently.


A specific job I have for the cnc router will be to machine audio horns – see attached picture. Click image for larger version.  Name: iwatahorn.jpg  Views: 209  Size: 69.1 KB  ID: 18230 I will profile layers and glue them together. The maximum size I will be making is around 700 mm x 500 mm. I don’t expect to 3D machine them but to 2 ½ D machine them with 1-2mm steps, which will be sanded post assembly.



I have been looking at a number of posts on this website and others and estimate that a cnc machine is going to be £1500 plus just for the parts. I have no real desire to build the machine, so I had been looking at commercially marketed machines too.

What is the general opinion about Chinese steel framed machines in the £3K sector, as I feel that this is the level I would want to compare too? Buying may be cheaper as a couple of hundred quid can be lost with a few errors. I am also time poor currently.



I have little NC experience – last time I was involved it was on punch tape! I am a professional design/stress engineer with a varied past, from designing complicated handling delivery systems to designing large fabrications for the aero industry. No machine/fixture design experience unfortunately.


If I am to build, ( deep down the engineer in me wants too) I feel comfortable with the mechanical side of designing the gantry and rails – after following a number of the build threads on this site, I am starting to understand the pro’s and cons of different arrangements.

I think I have decided on a few things.


Machine Size - obviously it would be nice to be able to nest and machine a full 8 x 4 sheet. I cannot fit it in my workshop, and for the once a year job – I could not justify it. To build the largest wooden horn I will ever get asked for a 900mm x 600mm bed will be adequate. In the z axis I was going to stick with around 150mm, anymore than this and the work piece will vibrate, never mind the machine.

For the X Y & Z slideways, I was thinking profiled rails. 20mm Hiwin or similar.

I just have a concern with accumulating dust/debris on the rails – are the wiper seals on the carriages – that good? (The answer to this will decide on whether I mount the rails on the top of the frame – or protected down on the side)
I have been looking into how to purchase the Hiwin rails and carriages economically – I see you can get the carriages from BST in china for a good price – but its not really economic to ship the rails. Is there any reason why I could not have the carriages shipped and purchase the rails in the UK? (Different standards/specs etc)

It also seems to be cheaper to buy single longer rails. I was also thinking I would get a couple of longer rails and cut them into my 3 lengths – I assume they can be cut with a disc?



The frame I was going to use aluminium profile sectioning – having used it for a couple of “work” jobs it seems to allow a robust construction without the need for a full fab/machine shop. (Obviously if I had a 2 metre bed machining centre I would fabricate and have the rail pads machined – post fabrication). I am hoping if necessary I could fill the profile rails with sand (concrete maybe) to damp out vibrations – reduce cutter chatter.






I was thinking of using 80mm x 160mm profile for the Y carriage. With similar for the x axis support structure ( twin x axis ball screws).


I am waiting on some info back from a friend who is a HGV coach builder– to see what aluminium sections he can get me for free.



What I don’t have a clue about is the electronics and what is current and is best for this application and what is OTT. From reading threads on this forum, it seems like this bit I sort out after I have finished the mechanical side, I would like an idea of the cost of a “good” 4 motor & controller system.

Sorry for the epic first post……

Steve