I noticed that the bed would shake and I figure that's really not good for prints. I "field tested" this a LOT to make sure I didn't loose any z height. It rolls along the frame perfectly. There are only 2 parts you need to buy which I've linked. I tried to design this with as little fabrication as possible. All you need is a hack saw and mayme some sand paper to smooth the edges of the rods. http://www.homedepot.com/p/Unbranded-1-4-in-x-36-in-Plain-Steel-Cold-Rolled-Square-Rod-801197/204273977 http://www.amazon.com/VXB-Skateboard-Bearings-Double-Shielded/dp/B002BBGTK6/ref=sr_1_5?ie=UTF8&qid=1416070512&sr=8-5&keywords=skateboard+bearings Video of it in action http://vid5.photobucket.com/albums/y180/Masurrao/3d%20Printing/20141115%20181406.mp4I designed windows into the sides so you can see if the rods are inserted all the way. Cut them to 142 mm exactly and it should be slightly snug inside the frame of the printer. It wedges onto the end of the aluminum bed.