Thanks Paul! I have 2 bars like that sitting in the corner. I was going to use them for a home made CNC 5 years ago but I fried my electronic (controller) on first start up; that took the power supply with it too (:-
It turned out I had shorted the pin on the driver during soldering.
Thanks L/W. Steel ruler with cork on the bottom are available at Michaels a block away from work. I bought one sometimes ago for drafting. I also saw they had shorter ones while I was looking for the big fat ruler.
I have experienced the knife jump few times but luckily no harm.
This is a new field for me and I am pretty excited.
Abbas, Castro Valley, CA