Hi guys,
Recently built my first printer after using a Wanhao i3 for a while. Decided on a D-Bot and it's been a great experience building it.
I recently replaced the lead screws with some high quality ones that were slightly longer as the previous ones meant when the bed was near the nozzle it was at the limits of the threads. I also use anti backlash nuts.
Since putting the machine back together I've had a weird problem where a calibration cube prints out (seemingly) perfectly at 20mm +-0.02 in all axis, however when I printed a benchy it was a not unsubstantial 2mm shorter than one printed before the upgrade and had some ugly diagonal banding on it. The thread of the rods is the same, and I've checked that if I command the bed to move 1mm it only moves 1mm. As a result the layer height I've been using has stayed the same.. I found this thread but noticed it was for a delta machine, however it seems similar to what I am seeing
http://forums.reprap.org/read.php?178,763881 I'm using a Duet WiFi with the default stepper drivers.
Here is an example of a good benchy from before the upgrade, a bad one from now and a cube from now:
https://imgur.com/a/Lswkz
Any feedback would be welcome.