Quote Originally Posted by soyeb View Post
Hi All

Starting on a new project for a 4' x 9' cnc machine. Before i buy all the parts i would like to ask what is the best motor size to go for on this size project?? Also can anyone recommend a nema 23 or any other kit which will include all the electronics which i need?? I have seen some ranging from 22, to 40kg but i do not understand what this means. Thanks in advance
Soyeb,

Welcome. 4' x 9' is a monster machine and one you can spend a lot of money getting nowhere on. Start by deciding and designing the basic structure, dont worry about motor or electronics at this stage. No one can really recommend a motor or drive electronics without knowing a lot more about the machine and its purpose, all they can do is give you their own experiences.

The key issues you will need to deal with are what sort of things you will be making with a machine this size. You have some major tradeoffs betwen speed and cost here. If most of your work could be done on a 4' x 4' or 4' x 6' machine you need to carefully consider the reasons for going to 9'. Similarly are you thinking of production runs or one-offs? Is time to complete (and therefore speed of operation) a critical factor? What sort of accuracies are you looking for and what sort of materials will you be cutting?

All of these factors will influence the overall design, what drive mechanisms (screw, belt, chain, rack, etc.) would be possible and what construction techniques can be used.

Get some ideas together, sketch some drawings, post them here and get feedback.

Good luck!