found setting stickout of end mills, drill bits etc on my er11 collet spindle to be a pain, so designed tool to allow quick and repeatable setting of bit stickout
designed in fusion360. there are two parameters in the design (bit_diameter and bit_stickout) which allow it to be quicly modified to suit a range of bits. the hex section at the top is sized for an er11 collet nut
allows bit, collet and collet nut to be threaded onto spindle (or removed from spindle) as a single unit with one hand while other hand holds spindle axle. as long as bit pushed to end of pocket in stickout tool, will always be inserted with the same repeatable stickout.
buying a good number of collet nuts (approx 2 euro each on ebay) along with appropriate collets means can have most used bits, end mills etc always ready to use. tool also keeps bits safe when not in spindle, prevents cutting injuries from having to hold sharp edges while inserting or removing bits, and with some oil in central pocket, helps prevent corrosion