AndyUK's Build - 1.2x1.0m Gantry

[Zeeflyboy]

My plan for the motors was, as you point out, cut some ventilation holes in the rails, and to try and mount a fan inside the rail (assuming the vibration isn't too much) - I'm not massively set on having them there, whilst its aesthetically pleasing I can see that placement causing all sorts of headaches while I'm trying to diagnose things!

If motor heat is a concern (and generally they are designed to run hot without a problem, worth a quick check of the specs) you could always plumb them into the water-cooling loop you will have anyway for the spindle. Just a generic water block attached to the motors enough to pull away a good amount of heat - i've seen similar done for 3d printers where the motors are inside of the heated enclosure.

Overall design looks very nice, you've clearly done a good deal of reading and research. I'm sure it'll be a good machine!

End machining will be different re pulley or direct coupling. That is not to say you couldn't make a direct drive coupling end work with a pulley, you'll just be making your life more complicated.... go with best angular contact bearings you can afford.