This is a rear mounted stepper version of my XY Axis parts that can be found at https://www.thingiverse.com/thing:3483883.
I wanted to use a rear mounted stepper setup mostly to move the steppers outside of the frame for when I enclose the print area. This design only requires an extra two Gates smooth idlers.
There are no changes to the X or Y Carriage parts so get those from the link above.
This setup is designed to use only genuine Gates idlers and pulleys and has only been tested with those parts.
No supports required for any parts. Print in the orientation provided.
Feel free to leave any comments or suggestions. If you use any of this please post a make and/or remix. Step files provided for all files.
Uses a 20mm length of 5mm diameter brass rod for the Gates smooth idler that is sandwiched between the Idler Cover, spacer and stepper mount. Three M3x25mm screws and M3 square nuts hold the Idler Cover in place. Install by first installing the Rear XY Idler mount and then aligning the bottom of the stepper mount with the bottom of the XY idler mount.
There are slots in the stepper mounts for belt tension adjustment. I was hoping I'd be able to remove the adjustment setup from the X Carriage but it turns out that setup is really nice for fine adjustment. I left the slots in the stepper mounts so you can set your belt length with the steppers all the way back, move the steppers all the way forward for belt installation, then move them back for tension and then adjust final tension with the X carriage. This combination should make maintenance easier.
XY Idler Mounts
Uses 30mm lengths of 5mm diameter brass rod for each XY idler mount. Use a M3x6mm (max 10mm) screw to capture the rod in place. M3x20mm screws and square nuts secure the Y Rod Caps in place. These caps allow you to install the XY Idler mounts before installing the 10mm Y linear rod which should make printer maintenance and changes much nicer. Use one Gates 20 tooth idler for each XY Idler Mount.
You can use any material 5mm rod stock. The Aluminum rod stock I purchased from Amazon was slightly oversized so I chucked it up in a drill bit and sanded it until it was just under 5mm. All of the 5mm brass rod stock I've purchased so far is already just under 5mm actual size and usable as is.
This section is to list some basic facts about my build. This is important because many of my design decisions are based around the specific parts I've selected for my build.
Frame: 8020 Inc. 3030 extrusions.
Heatbed Frame: Zyltech 2020 extrusions.
Linear Rods: X 8mm, Y 10mm, Z 12mm
Controller: Duet3D Duet2 Wifi
Z Probe: BLTouch
Hotend: E3D Chimera+
Extruders: Zesty Nimble
Power Supply: Meanwell LRS-350-24 350W PS
Heatbed: 713 Makers Mic-6 build plate w/Keenovo 120V 750W Silicone heatpad