Low Cost Z Axis Coupler for Prusa i3 and other 3D printers

thingiverse

This is simplified shaft coupler engineered for precision in 3D printing applications, where a substantial amount of torque isn't required to drive the Z-axis smoothly. A sturdy construction proves suitable when your 3D printer operates with relatively little vibration and stays straight and true.\nPlease consult the instructions on how to create this item from scratch or acquire ready-made couplers:\n5 to 5 mm:http://www.ebay.com/itm/-/221611355801\n5 to 8 mm:http://www.ebay.com/itm/321498700056 Instructions for manufacturing are outlined below. Hobby lathes come in handy when making this piece. Examine the drawing closely before proceeding. For the coupler spanning from 5mm to 5mm: *Use inch-sized material with a diameter of 0.4375" (11mm), cut from aluminum bar that's 6061-T651 alloy with a cold finish round bar.\nYou can either drill 4.9mm and then ream to 5mm, or drill straight for the precise 5mm measurement. On both sides where M4 screws are to be used, apply caution by firmly gripping the workpiece while using a vise attached to your drill press. Use a drill bit that's 3.3mm in diameter and insert the necessary threads by running the tap in one full stroke. Be certain you obtain a solid grip by choosing parts that fit perfectly together. As required, have on hand two M4x4 set screws per coupler available for assembly. Obtain part number 91390A110 from McMaster to meet your requirements.\n For couplers going from 5mm to 8 mm: \Use the specified diameter of material in inch format, namely: 6061-T651 aluminum with cold finish round bar with a size that measures 0.5625 inches or exactly (14.2 mm).\nThe precise sequence starts off by first boring a hole into it - this needs an exact precision, using either lathe's operation of 4.9mm and subsequent reaming up to the needed dimensions at a perfect circle shape for one precise placement followed lastly in one pass, making two sets total. Use appropriate materials while keeping proper care so as you have best suited fit on M4 thread.\nWhen manufacturing coupler of diameter varying from five mm and eight millimeters then drill three 5 mm using either side - for left-right pairs; apply similar set screws which match perfectly fitting together ensuring they line properly.