Y End Stop (Adjustable and Corrected)

On my Ender 3, the Y end stop was about 6 mm too far to the rear; this meant that when the bed homed to Y, the nozzle was about 6 mm too far forward of the edge of the bed.

I designed and printed two different solutions for this issue:

  • Corrected Y End Stop
  • Adjustable Y End Stop

Note that for both solutions you'll need to tap a pair of holes for the existing M3 fasteners used to mount the limit switch PCB to the printed end stop.

 

corr f3d   adj f3d

 

Corrected Y End Stop

This is essentially identical to the stock Y end stop, except that the mounting holes and cavity for the microswitch PCB are moved 6 mm toward the front. The existing M4 fasteners are reused and mate with the existing threaded holes in the 4020 extrusion.

Note that, different from the original molded part, my design added a guide rail to the rear surface to establish perpendicular aligment.

Fusion 360 Model User Parameter(s):

Name Value Desc
YAdj 6 mm sets the Y offset (available if your printer's Y offset differs from ~6 mm)

 

Adjustable Y End Stop

I assumed that the 6 mm Y offset on my Ender 3 occured because of engineering and/or manufacturing changes that occured subsequent to the open sourcing of the mechanical drawings. So, further assuming that other Ender 3s might have yet a different offset, I designed the adjustable version.

Rather than design a slot-type adjustment for use with the existing M4 fasteners (and therefore limiting the total available adjustment to some arbitrary value), I chose to eliminate them completely and use standard T-nuts with M5 fasterners instead. In this way, the Y end stop can move over a much larger range and yet keep the overall bracket small, simply by using the slot already in the 4020 extrusion. (And why not, we get it for free...)

Like the corrected version (above), the design added a guide rail to the rear surface to establish perpendicular aligment, but requires only a single M5 fasterner and T-nut.

Fusion 360 Model User Parameter(s):

Name Value Desc
Thk 6 mm sets the thickness of the adjustable Y end stop
TnutHoleDia 5.5 mm sets the hole diameter for the T-nut fastener

Download Corrected Y End Stop STL model and Fusion 360 Archive as a single zip file.

Download Adjustable Y End Stop STL model and Fusion 360 Archive as a single zip file.

 

3D view each model:

Corrected Y End Stop
Adjustable Y End Stop


Corrected Y End Stop

CYES 1Fig. 1

Shown here is the Corrected Y end stop (left). When compared to the stock Y end stop (right) you can see the PCB cavity has been offset toward the front of the printer.

The Y offset can be changed in the Fusion 360 model by means of the YAdj user parameter.

 

CYES 2Fig. 2

Shown here is the guide rail on the back surface.

 

CYES 3Fig. 3

Shown here is the Corrected Y End Stop in place on my Ender 3. If the Y offset after homing is ~6 mm too far forward, then the STL file is usable as is; otherwise, you'll need to change the YAdj user parameter  in the Fusion 360 model and then regenerate the STL file.

The existing M4 fasteners are reused and the through holes in the end stop align with the existing tapped holes in the Y extrustion.


Adjustable Y End Stop

CYES 1Fig. 4

Shown here is the Adjustable Y end stop. The PCB cavity is in the same position as the stock bracket.

Since a standard M5 fastener and T-nut are used to hold it in place, the end stop can be moved to nearly any position along the Y extrusion.

 

 

CYES 2Fig. 5

Shown here is the guide rail on the back surface.

 

CYES 3Fig. 6

You'll need to tap the pair of M3 holes used to mount the PCB to the end stop.

 

AYES 4Fig. 7

Needed parts for assembly: the PCB and M3 fasteners (stock) and the M5 fastener and T-nut.

AYES 5Fig. 8

The PCB mounted on the adjustable end stop.

AYES 6Fig. 9

Back view of the assembly.

AYES 7Fig. 10

Shown here is the Adjustable Y End Stop in place on my Ender 3, moved forward enough to correct for the ~6mm Y offset.