I just bought a cheap plotter to do odd jobs ,, today the carriage hit the vinyl and and really messed up,, it is making a noise like the belt wants to strip the gear, but it seems the carriage fell off the roller part, i am not sure how this carriage sits on with the 3 wheels ,does it go inside as if it sits outside it seems to loose and there are 2 wheels at the bottom and one on top with the belt pulling from side to side,, do these wheels go inside as it doesnt seeem to fit and if just rolls on the outside it seems to loose to me ,, i should of looked at it a little better ,i am new to this stuff so be gentle with me and i appreciate the help ..