Hi Julie,

Welcome to the forum.

Only advice I can give is:

Know what you want to make beforehand and size your machine accordingly. It's pointless having an 8X4 router and then having it only making 18" long house signs.

CNC is really, REALLY good at multi-run jobs, but not for one-offs unless you can price it right. It ISN'T just another tool like a drill or a planer, it is a manufacturing system that can do the jobs of all your machinery in you workshop but I bet 90% of the time you will use the drill or the planer or whatever simply because it is easier and quicker to do than writing the program or generating the CAD/CAM. WHen I first built mine and I wanted to say cut a 20mm groove across a sheet for a shelf to fit into, I would clamp it down and zero the machine, then type in a move to the appropriate distance up the sheet, lower the Z to the required depth and then simply zip the cnc across the sheet, job done. I don't do that anymore, I just clamp a straight edge across the sheet and run my triton router across it by hand like I used to, quicker and easier.

If you want to get into 8x4 size machines and cutting the likes of oak etc. think of getting into welding classes and build it from steel with supported rail on all axes, rack and pinion on the 8' axis and ballscrew on the other two. IMHO an 8x4 from MDF or baltic birch can't hold a candle to a steel or aluminium framed machine for rigidity, Irving will be able to fill you in on the deflection of wood vs steel. If you are thinking of doing this professionally, i.e. to earn a living from, then you really need to be building in longevity and accuracy IMO only a steel framed design will give you that on the scale of machine you are looking at.

You are looking at splashing £2,500+ to get a half decent machine up and running, 8x4 really is getting into commercial territory size-wise and it might be cheaper or more sensible to look at a second hand commercial machine. If you want to build one for the experience, knock yourself out, that's why I built mine and I can honestly say it's the best thing I've ever made and the most fascinating hobby I've ever had.

I don't want you to think I'm trying to put you off but do yourself a favour and decide in the first place what you want to actually DO with the machine and stick to it!

All the above my own humble opinion as always but good luck whatever you do and don't forget if you start to build one, we want to see pictures!

Jeff