[abdelmonamaz]

Hello,
I am trying to build new CNC plasma cutting machine (3000x1500 mm ) with average performance, I want to know how to choose the best linear guide (Y and X Axis) for my application in term of cost/service life /

[rodw]

MIne's roughly 1200 x 1300.
For the X, I used 2 x HGR15 linear rails, 3:1 rack and pinion drive, NEMA 23
For the Y, I used 1 x HGR25 linear rail each side of the table, 5:1 helical rack and pinion drive, NEMA34
If I did it again, I'd just use 1 x HGR25 on the X as well

[Pat535]

The Best to use is PMI, they have worked the best for me i use the SL kit with double seals and metal scrapers the blocks are fully sealed and work well in dirty environments I also use oil instead of grease helps prevent plasma BB's from building up around the blocks, If you use them in an exposed to weather situation keep them sprayed with phosphate type lube like royal purple Max film. as for gear boxes i keep them all the same if something goes wrong (and it will) it make diagnostics easier and you can swap motors around for testing