hi everyone,

I an creating this thread to get some advice from experts in this forum for the selection of various parts for the new CNC build that I am planning to start for pro-hobby and basic professional work. The design is heavily based on following work:


I've started the design of base using Fusion 360. See the attachment.


In order to finish the cad model for the base, I need to select servos, ball screw and related components like end supports, couplings.
Since this is mostly for hobby type work, the amount I can spend is limited, but it does not need to be super cheap. (I already have a 6040 CNC and the reason I am making this machine is to have better stability and accuracy).

Some questions that I currently have regarding above selections are:

1. Which servos are more suited to this? AC or DC servos? The total weight of the machine would be around 800KG at the end.
2. In this thread, JMC brand is recommended for servos for this build. I think they are reasonably priced and also seem to have good quality. I also checked DMM and their pricing is too high. Also checked Delta servos and those are also too expensive. Apart from JMC, I would like to see if there are any other Chineese good quality brands with reasonable prices. Also what are your thoughts on various servo motor options listed in AliExpress? Such as this one.
3. Which accuracy level is required for ballscrews of this machine? C3? C5? C7? And which manufacturing process is more suited (ground screws, rolled screws, etc)? Which nut (internal circulation, etc)? Preloaded or not? If preloaded which type? any specific recommendations for fixed and floating end supports?
4. Based on above what are some of my options for brands and suppliers for ball screws? I have already looked at brands like tbimotion and terry-machinery. Hiwin seem to be too expensive. (However I will be using Hiwin for linear rails/guides). What about various suppliers/brands from Aliexpress? For example this one?

I will be having more questions on base later in this same thread (for example on how to machine various critical surfaces, how to make the mould, etc), but above are most important at the moment.

Any help is really appreciated.

Thank you
S