I like the aluminum piece for ease of use and it wont "melt" or deform anytime soon from stepper motor and/or hotend heat. The fan on the left was removed and used for other things, as was the fan on the back of the case. I suppose the left side of that aluminum piece could be cut off but I haven't done so - didn't really see a need to.

At the moment, it is serving as a mounting point for a remote nozzle fan (using one of those 40mm fans I removed for a better purpose) - and no, i am not gonna show it yet...still a work in progress & pretty ugly, lol

http://www.soliforum.com/post/72175/#p72175

Perhaps if  you are using the entire printed extruder assembly (Mk5?) you don't need to drill holes, but I had to in order to fit the stock set up... I will take pics shortly since I have mine torn apart at the moment...

I chose to keep the stock aluminum extruder assembly since it worked fine and it was not the acrylic jigsaw junk from the earlier models.

here ya go... The white parts were just printed yesterday, unmodified, for the 2nd SD4 we have. the purple parts with the aluminum mount attached are from my 1st SD4 - I took it apart because the bearings were getting rather sloppy in the carriages - will be wrapping them with some kapton tape and reinstalling today. 

So.... I guess it all depends on what extruder setup you are using on whether or not you need to drill holes.

what. lawsy's carriages requires no drilling. what are you talking about

+1

(see bold part above)
If you did not drill a hole for that 3rd screw (the centered one) that is where a lot of your problem lies.

Disassemble down to the mounting plate, and drill a hole in the carriage base for that 3rd mounting screw - 7/64" drill bit will work very well

what. lawsy's carriages requires no drilling. what are you talking about

So I rebuilt my SD4 with the Lawsy carriages and the E3DV6 hot-end, and I'm getting supposedly circular items that look like:

Any idea what might be going wrong?  I've checked the belt tension, tightened both X and Y axes to the point where they'll start skipping steps and destroying the print after printing a while, and am getting essentially no change.

The only thing that seems strange to me with the Lawsy carriages and the E3D hot-end is that the original carriage had three hold-down screws for the hot-end/extruder-stepper bracket, two in the front and one in the middle, where the lawsy carriages only have holes for the two in the front, so the hot-end has a bit more freedom to move up and down if the rear of the extruder stepper lifts, if that makes any sense.

or is this result something obvious?

Thanks!

(see bold part above)
If you did not drill a hole for that 3rd screw (the centered one) that is where a lot of your problem lies.

Disassemble down to the mounting plate, and drill a hole in the carriage base for that 3rd mounting screw - 7/64" drill bit will work very well

Any idea what might be going wrong?  I've checked the belt tension, tightened both X and Y axes to the point where they'll start skipping steps and destroying the print after printing a while, and am getting essentially no change.

The only thing that seems strange to me with the Lawsy carriages and the E3D hot-end is that the original carriage had three hold-down screws for the hot-end/extruder-stepper bracket, two in the front and one in the middle, where the lawsy carriages only have holes for the two in the front, so the hot-end has a bit more freedom to move up and down if the rear of the extruder stepper lifts, if that makes any sense.

or is this result something obvious?

Thanks!