I am a complete novice so please be patient with me.
I am looking to cut holes and grooves in 4mm wood.
The wood pieces will be 246mm x 246mm.
So my questions at this point,
1) Is a S-400 suitable for my needs?
2) Can a beginner work with these machines, are they easy to program?
3) Looking at the pictures of the machine I can't see how pieces of wood are held in position during cutting. Do I need to use a clamp or something?
First - go for S-400/T version. It's faster and more productive.
Second - buy a bigger machine than You need for now. Let's say S-720/T. In most cases as You start with one particular product You shortly face another, but - Your machine table is too small ;-)
1. yes, You can do all You mentioned on respective machine.
2. Together with machine buy VCarve Pro and dont take that ConstruCam they are offering - it's not forth of that. VCarve Pro is VERY easy to get a hands on.
3. You 'll have to build a work table. Most popupal way - 3 sheets of MDF/HDF bolted together and faced flat by machine it self. Fast, sufficient, cheap way.
Manual how to do that is available on manufacturers web.