My name is Sy. I am a mechanical engineer by qualification but have spent the last 12 years working as an aerodynamicist for various Formula 1 teams both in this country and abroad. As such my general mechanical knowledge is quite rusty!

My CNC experience to date is solely in the work environment and consists of watching the guys in the model shop route stuff out for wind tunnel models. I have also had numerous dealings with CNC shops who manufacture bits for us.

I am always in the middle of one project or another and would like the ability to accurately fabricate my own parts hence I want to build my own CNC router. I envision a machine that can tackle engineering plastics up to 15mm thick. Sheet aluminium up to 2mm thick and also potentially 3D work making tooling for CFRP parts out of epoxy pattern-board. I'm pretty sure that whatever I end up with will be obsoleted by one idea or another so I am keen to put something together that can tackle most things.

My plans to date currently have me redrawing the, from what I can see, excellent machine by Boyan Silyavski. I believe this will allow me to tackle most things. I am redrawing for a few reasons. One, I have no experience in Sketchup and am not confident releasing parts for manufacture out of this package. Two, I think drawing from scratch will help me understand the machine better which can't be a bad thing. Three, There may be tweaks I can make based on my own individual needs and other peoples suggestions. For reference his build log is below.


I will start my own development thread soon but I am not far enough into the design yet and already I have some questions regarding ballscrews. From reading other threads I get the general impression that I can't go too far wrong with the bearings and ballscrews from Hiwin.

For my rails and linear bearings I have arrived at the following which are from their 20mm series parts. I am pretty happy with these selections?

Rail: HGR20R
Bearings: HGW20HC

However, I am afraid I don't know enough about ballscrews to select what I need and I am keen to narrow down the part now so I can model it properly in CAD. I am assuming a 16mm diameter, 10mm pitch (from previous comments in Boyan's thread) but I don't really know what else I should be looking for. For example:

Precision Ground or Rolled?
Nut Type?
Number of Turns?
Screw Hand (Left or Right?
Lead Deviation?
Screw End Machining styel both on Motor Side and the Other Side?

I also am unsure about what support units I need also. AK, AF, BK, BF, EK, EF LK, LF...?

Assuming I am going with Hiwin, if someone could help with some part codes it would be really useful (with the obvious caveats about length etc although if I am working based on Boyan's machine then 1200mm length)

Anyway, I hope I have a chance to chat with all of you soon.

Thanks for reading!