X axis pulleys, front or rear?

[routercnc]

Thanks, Clive. I think I'll go for rear pulleys, all being considered. I think the tensioning will be done by just sliding the motor downwards a little, when necessary.

Drilling to the side of a long plate can be awkward, often requiring fixtures. Normally I use a little mill where the head can be swivelled 90 degrees, but it's still a bit of a hassle.

Edward

Do you have a link to the thread where you saw it being discussed?

Other things to think about are:
Position of motors and length of cables back to control box (shorter could be preferable)

If you tend to cut in one location on the machine for most jobs, or at least in one half of the machine, then a pulley mounted at the same end will reduce the amount of twist in the ballscrew on rapid changes of direction. This in turn gives a minor positioning error but I would guess this is very small and could be ignored on DIY machines.