Summary Easily change spools by just lifting one end of the bar. This works with either an 8mm rod (like the one that comes with the stock spool holder) or a length of 1/2 inch pvc pipe as the spindle. Fits on top of the .75" square tube uprights of the the stock holder. (Print two copies - one for each end of the rod) This is a remix that lets you mount the spool on the back or the front of the ridigbot using the original rod