Comments sought on new build: A CNC Router for RC Gliders and Planes

[JAZZCNC]

Couple of questions now...

1. I'm going to use 1 stepper and belt (T5, 15mm wide) and pulleys to drive the X axis, what number teeth pulleys would you recommend? I take it that it's worth getting spare pulleys and belts so that the option of 1:1 and 1:2 (stepper to ballscrew) is available?
2. For the belt idlers/tensioners I was going to use skate bearings (as I've got sh*t loads of them) and penny washers, I couldn't see any specific idlers for the belts?

Depends on how your having belt system.? My machine is setup with 2 pulleys bolted together on one screw with a single pulley on other. A short belt goes from motor to first pulley then connecting belt goes between screws. The ratio is 1:2 motor with 40T and first pulley 20T Connecting pulleys are 36T. I then have 2 spare pulleys for 1:1 or 1:3 ratio 20T & 60T.
Connecting pulleys could easily be 20T for simplicity sake but I just happened to have spare 36T so used them.

Don't go smaller than 20T other wise you don't get good tooth engagement and the belts wear quicker or worse they can jump. I'd also use HTD belts/pulleys not T5 has thou they are very similar the HTD just seem better fitting belt.

Yep skate bearings and large Penny washers work fine for idlers.!!