Mercury One.1 Inside Frame Double Shear Stepper Towers

Part of my ongoing series of models to enclose my Mercury One.1

These stepper mounts do three things:

• They are contained entirely within the frame of the printer so that the printer can be easily enclosed using large, flat panels.
• They are double shear meaning they utilise an F695 bearing to support the end of the motor shaft. This helps prevent shearing forces that could bend the shaft or shorten the life of the motor. If your motor has enough torque it also means you can run tighter tensions.
• I found that both the standard mounts as well as other models I'd used tended to lift on the unsupported corner. These use three mounting points for increased rigidity. Furthermore, if your extrusion has a 5mm through hole at the end you can run a longer bolt through the corner hole and bolt it into the upright extrusion for even more rigidity.

Print Settings

Print out of ASA/ABS using standard Mercury One.1 print settings. No supports required.

BOM

• 6 * M5 x 50mm SSCH
  • Alternatively; 4 * M5 x 50 SSCH & 2 * M5 x 70 SSCH if you plan to run bolts through the corners and down into the vertical extrusions.
• 6 * M5 T Nuts
  • Alternatively: 4 * M5 T Nuts if you plan to run bolts through the corners and down into the vertical extrusions.
• Min. 6 * M5 Washers to pack out the heads of the M5 SSCH to prevent them from bottoming out on the extrusions. I used one spring washer and one flat washer per bolt, but you can stack flat washers or even print washers if you'd like.
• 8 * M3 x 20 SSCH
• 2 * F695-2rs bearings
• Recycle the bearing stacks from original steppers towers (12 * F695-2rs bearings and 16 * M5 flat washers)

Assembly

1. Insert an F695-2rs bearing into the base of each Tower Lower.
2. Thread a Bearing Holder into the base of each Tower Lower using a 4mm Allen Key. It should be firm, but be careful to not overtighten it to prevent splitting the bearing holder or rounding out the hex hole
3. Use the printed alignment tool to align the pulleys onto the stepper motors
4. Place the T Nuts into the extrusions
5. Stack the washer/s behind the head of the M5 SSCS bolts
6. Slide the 6 * M5 SSCH bolts through both Tower Uppers. If you are using longer bolts to bolt down into the extrusion; ensure they are in the corner holes.
7. Slide your bearing and washer stacks onto the bolts
8. Slide the two halves of each tower together
9. Place the stepper motor into the Tower Uppers. Rotate it until the plug is facing to the rear of the tower on the side with the zip tie mount
10. Place 4 * M3 x 20 SSCH through the bottom of each tower and screw them into the stepper motor
11. Bolt the assemblies to the frame using the T Nuts