[noeyedeer (Matt)]

hi Darren, the screw closest to the scope will prevent the focuser from moving using the knobs, and the second one will prevent the focuser from sliding in and out. I've been caught out a few times. best bet is to have he one furthest away from the scope secure, so the tube doesn't slide without having to turn the knobs.
the one closest to the scope can be not so tight as to allow the knobs to move the focusing tube.

so the one closest to the scope is the locking screw, and the other one is the tensioner. honestly ivdont know what the deal is with those, but I usually have it set like how I've described. .. tensioner tight (tight enough that my heaviest eyepiece doesn't make the tube slide when the scope at low altitude), and locking loose.(loose enough so the knobs move the focuser in and out)

nice stuff indeed for the kids!

matt

ps .. my version of the knobs is the actual focuser things, not the screws.

word of warning .. never over tighten anything either with the thumbscrews. enough pressure to prevent it from sliding at its minimum tightness with the weight involved is ample. you still want a smooth slide when adjusting focus, not a gluggy movement. like Malcolm mentioned play around and you will work it out what best suits you.