Hi,George

I believe you are referring to the felt track sweeps/lubricators.
There are 4 on the gantry gussets one on each side of the gusset
that clean and lube the x track. Also there are 2 on the y axis track ,
we spray wd-40 on the top of the felt daily, it works its way thru the felt
to lubricate the track. Not sure if this a shopbot feature as we purchased
this machine from Master Gary C. and he had many special ingenious add ons.
It may pay to contact Gary and ask him but i would be happy to take pictures
of them the next time I'm in the shop.

Best wishes
Buster Pile

By the way Cody is my son and operator and Gary has been a true
blessing to us i can't say enough good things about him