y-rod-holder.stl  

y-rod-holder.stl

Firstly - Thanks for all the hard work on a great product. I ordered three MK3 kits and they arrived a day early - what's more, it was the very same day that the official MK3S announcement was made. At first I was a little miffed that the 3S was released the very day I received my three MK3 kits - until I cut open that black plastic wrap and found three MK3s boxes. Kudos on the foresight there guys and gals. And thank you.

To the meat of this post - and forgive me if this has been brought up before. I'm in the midst of assembling my third Prusa printer (and the second of the three that I took delivery of last week) and I've noticed that insertion of the square nuts into the Y rod holders always requires getting the nut started with a pair of pliers, where all of the other square nut holes in the assembly tend to go in fairly easily without the use of any tools (except to push them in).

So I had a look at the STL file and compared the size of the holes - other parts have the square nut recess fully open with a measurement of 5.8mm x 2.1mm - which gives .3mm of clearance in one direction and .3mm of clearance in the other direction assuming we're using standard DIN 562 M3 square nuts. This seems to be enough clearance that the printed parts will hold the nut in place once it's seated and is consistent with the DIN 562 standard.

On the y rod holders, there is a lip - the cavity for the nut is large enough but the opening at the surface of the printed part is is reduced in both directions to 5.6mm x 1.5mm - and once you consider material shrinkage post-print it starts to become clear that these dimensions will require a much greater amount of force to insert the square nuts.

To be clear - this is in no way a show stopper for me nor a complaint - but it seems that assembly of the Y axis would be much easier if these holes were made consistent with the sizing of the other square nut recesses. To be fair, I could make the change myself and print up some new Y rod holders but I'm having nothing but trouble trying to print anything with PETG, though presumably I could print them in PLA. At any rate, I thought you folks should know.

Keep up the great work. I'm extremely happy with my printers from Prusa Research, and I've decided I'm gonna be like Jo when I grow up (no telling when that will be though)