PierreB, thanks for pointing out that they were missing from the BOM. I've just updated the BOM. In my case I used two M3 x 50 screws. I had to push against the springs to get the screws started, so they're perhaps a little short. I haven't tried 60mm screws--I'll have to see if I can get some to try them out.
As to the smooth or threaded rod, I just looked at noticed that I didn't use one--my bearing is held in as a press fit. I suspect this isn't the best solution, so I'm going to see if I can get a pin or rod to put in there. It's been printing fine without it, interestingly enough.
Also, I'm wondering if I need to add another 3/4" spring to the BOM, as I believe the Printrbot Simple only comes with one, and this extruder requires two. I've just updated Part I to include your link to the MakerFarm hardware-only kit, as this seems like the best way to get all the hardware required for the extruder. Thanks for the link!
Also, there are no end stop adjustments because they don't really have an effect on the hot end staying level--that's controlled by other values like the radius and rod lengths. If your rod lengths are slightly different, it can lead to all sorts of problems. I tried some other rods at one point and had a lot of calibration issues until I measured the rods and discovered they weren't all the same length.
RTurnock, I'm a big fan of the T nuts that you can install after the fact. Here are the ones I use: [us.misumi-ec.com]
As to the smooth or threaded rod, I just looked at noticed that I didn't use one--my bearing is held in as a press fit. I suspect this isn't the best solution, so I'm going to see if I can get a pin or rod to put in there. It's been printing fine without it, interestingly enough.
Also, I'm wondering if I need to add another 3/4" spring to the BOM, as I believe the Printrbot Simple only comes with one, and this extruder requires two. I've just updated Part I to include your link to the MakerFarm hardware-only kit, as this seems like the best way to get all the hardware required for the extruder. Thanks for the link!
Also, there are no end stop adjustments because they don't really have an effect on the hot end staying level--that's controlled by other values like the radius and rod lengths. If your rod lengths are slightly different, it can lead to all sorts of problems. I tried some other rods at one point and had a lot of calibration issues until I measured the rods and discovered they weren't all the same length.
RTurnock, I'm a big fan of the T nuts that you can install after the fact. Here are the ones I use: [us.misumi-ec.com]