This is a modification to Lawsy's X carriage top (http://www.thingiverse.com/thing:104059) that allows the use of the stock SD4 extruder, hot end, and default X end stop switch location. Why on Earth would I do such a thing? Two reasons. One, because someone asked about it on the unofficial Solidoodle forum. Two, because I can't afford another E3D hot end this paycheck and I still wanted to go full-bearings on a second SD4 I've managed to acquire. The end result loses a few millimeters off of X (although it's still above 190, which is a miracle on the SD4!) NOTE: This design only works for later design Solidoodle 4 printers whose extruder has two holes facing downward toward the hot end, not the earlier design where the screws aren't immediately visible. UPDATExaqaria also made a remix of Lawsy's carriage that you can find here.It works perfectly well for early revision SD4 users. You'll need to use 12/16mm long M3 screws (even cap screws fit in there, don't worry!) to attach the extruder bracket to the carriage. Because of how the early revision SD4s work, the hot end will sit about 10-15mm further out than normal.Printer Brand: SolidoodleSolidoodlePrinter: Solidoodle 4Solidoodle 4Rafts: NoNoSupports: NoNoResolution: 0.2mm0.2mmInfill: 60%60%Printing is as straightforward as with Lawsy's standard X carriage top. The X carriage bottom pieces fit the same way with no surprises. You'll have fun with the X end stop switch wiring when it comes time to assemble the extruder onto the carriage but it does fit and it works fine. NOTE: If you end up using the bolts from the original end stop switch, the X movement may grind and stick if you're at Y=0. This is due to using the original bolts, and them hitting the bed.To assemble a full X carriage, you'll need the two other carriage pieces from Lawsy's original, new_carriage_centre_rear_2.stl and new_carriage_centre_front_2.stl. His instructions are straightfoward and show how everything is to go together.