FFCP travel off in X axis

[DaveyG]

So... finally got my FFCP functioning again, making a small test part, and my test part is supposed to be a 1" x 1" square block, .5" tall, with a countersink style void in the bottom, 45 degree build angle, meeting in the center of the part at approximately .375" height... The parts I've made since getting my heat to stay consistent, I first noticed the conical bottom void is actually almost football shaped... which led me to more closely examine the part overall, and it is quite noticeably short in the Y axis of movement. The portion that is supposed to be square measures 1.009" x .935" compared to the same test part I created some time ago, which measures .995 x .996, only off from square by .001" which I find perfectly acceptable. Has anyone had a similar problem with their FFCP? Also of note, the latest part has a quite acceptable texture on three sides, the back, right and left, but the front face is terrible. I've tried slowing down the travel speeds, with no improvement. Is there possibly some kind of offset or stepper calibration that is out of whack?

[DaveyG]

Found the culprit! The little bracket on the stepper motor is made of injection molded plastic, with brass threaded inserts where the bolts go. The plastic around the threaded inserts were cracked, both top and bottom. The bottom was broken completely off, and the top was just hanging by a thread. Either it broke when I was cleaning the nozzles, or perhaps the screws were over-torqued from the factory. In any case, I fixed it by machining a new bracket from 6061 bar stock. Problem solved. Took some pictures but I don't know how to upload them.

[DaveyG]

There, figured out the photo upload. But posted in reverse, the broken one is second, the new 6061 bracket is in the machine, posted first.
FFCP New bracket.jpgFFCP Broken bracket.jpg