Double Headed Double Threaded Bolt

Same thing as the double threaded bolt except this one's also double headed!

Note this is based off Wout's “two way screw” model, not the “two way screw long” model, both from the remixed object. If requested I can throw that long one together as well.

Note if you want to put the threaded nuts onto this bolt (which you do) it will require pausing and resuming the print as quickly as possible. I was only able to do this by leaving a small seam, which I did just before the start of the top head, but I can share tips on how to pause/resume if you do not know how. Unfortunately I cannot share my gcode file, as Printables rejects it on the basis of it having a pause M0 command. 

Just like the original, the nuts should smoothly glide up and down the bolt. Even the thin nuts, and in both directions. Print straight up and down, head in the air, and the print pause should be as late as possible before the top head starts so you can get the nuts on.