Dear @Neilp
In considering that I have 3D modeling of my LowRider v3 in SketchUp, I realized I could import the “printed version” of the XZ plate into the mix and compare side-by-side to see what is up with a stub mod for this swap, in your case.
The printed XZ plate is 13.5mm thick, compared to milled plate’s 6.35mm thickness. However, some of the difference in the printed plate’s extra thickness is absorbed on the outside face of the plate, owing to its 4mm deep “pocketing” of insets for the bearing slides to attach. Thus, instead of having to deal with a 7.15mm difference, it gets reduced to dealing with a 3.15mm difference.
That 3.15mm difference ultimately means your LR Core has that amount of travel lessoned, when compared to a milled plate setup. To use printed plates, you make a tiny sacrifice of 3.15 mm on each side, for a total of 7.3mm less travel in the standard X axis, when compared to a LowRider v3 using milled plates.
This is illustrated in the screen shot below. The left side is with a printed XZ plate. The right side is with a milled plate. The gray on both sides represents a milled aluminum plate, 6.35mm thick, and the yellow on the left side, sticking out on both inside (up) and outside (down) illustrates the placement to accommodate the extra thickness.
However, the 6.35mm milled plate thickness / placement comes back into consideration whenever we turn our attention to the task of modeling a printable XZ plate that has a tab on it for triggering an end stop. Assuming one does not want to use supports to elevate the tab off the print bed to match the position of the tab on a milled plate setup (shown in BLUE in the next illustration), then leaving the tab resting on the print bed positions it 6.35mm away from the original spot (shown in GREEN in the illustration below). Note: the BLUE for tab and switch, was staggered slightly to the right to make it easier to distinguish from the GREEN for new placement of tab and switch. Also note: it’s easy to mistakenly think the difference should be 9.5mm (3.15mm + 6.35mm), but that would fail to take into account the slight loss of travel of the LR Core. I made that mistake while composing this post and had to edit to correct it.
This leads to an issue in which the end stop switch itself, shown in GREEN on the left for the new position), cannot be placed at the same elevation in the Z axis of the LR3 as the original remix, because that space is partially occupied by the LR Core.
Note: Based on real world measurements with calipers, which were a challenge due to limited access (and thus a little bit sloppy), I designed my new end stop switch mount to target placement of its edge 5mm shy of touching the new stop tab. The remainder of the distance was to be covered by the switch itself, as it has a slight protrusion from the mount, plus the trigger finger’s footprint when in its “contracted” / “touching” position. In real world results, that 5mm measurement turned out to be pretty much spot on, as it seems to be stopping right where I wanted it to.
The problem with the planned position of the end stop switch can be addressed in at least two ways: the switch could be raised up to clear the core, or it could be moved toward the plate (moved toward past the outside of the beam). The former approach requires a somewhat more significant remix of the new switch mount part, and extending the “tab” on the plate some more. The latter approach suffers the issue of supports to get the tab moved off the print bed.
I like to help. I’m willing to create a new remix that works for makers with printed XZ plates. The questions regarding that include:
- Is the goal to design for those who have not printed this plate yet (seems to be default approach to help the most makers), or to help those who already printed their plates (which would help you) or both?
- Which approach to take (regarding the above two ways of getting the switch repositioned? (Seems that saving from having to print supports is the better approach.)
All that having been said, your idea about gluing on (with epoxy) an add-on tab, or screwing one on, or both, is perhaps a decent approach. If you decide that route seems desirable, I can help by use of my modeling.
UPDATE
@Neilp
Don’t feel any pressure to use these if you don’t choose to. I modeled up a remix just for those who either have printed, or will be printing, their XZ plates.
https://www.printables.com/model/230531-lowrider-3-cnc-reversal-of-homing-on-short-axis-fo
Here are some details and pics:
This remix seeks to accommodate owners (or potential makers) of a LowRider v3 MPCNC who either have printed, or plan to print, their XZ plates (as opposed to buying or making milled metal XZ plates) and who also desire to flip the homing direction of the short axis, which by default is called X, as they also seek to swap the X and Y axes of the CNC machine, as documented and explained here. If you don’t want to reverse your short axis homing, you don’t need this. If you want to swap your X & Y axes, you probably need to reverse your short axis homing, and this should work for that.
Full disclosure: I did this with milled XY plates, not printed. I made this remix not for myself, but for others. Accordingly, until someone tries this with printed plates, and succeeds, I cannot properly guarantee it has no issues. If you make it, post your make and alert me to any issues.
In the illustrations below, obviously the colorations are only for identification purposes.
For makers who have already 3D-printed their XZ-plate-right
Makers who have already 3D-printed their XZ-plate-right can print a stand-alone addon tab and glue it onto their existing XZ plate. This addon tab serves as the end stop surface for their (relocated) end stop switch to touch for triggering. These makers should print the part highlighted in yellow ( “addon-stop-tab-for-printed-XZ-plate-right-v1.3b.stl” ) and epoxy it onto their existing XZ plate as shown below ( plate shown in orange ). They also should should print the part highlighted in green ( “X end stop mount (for reversal of homing) (for printed XZ plate) v1.3b.stl” ), attach the end stop switch to it, and install it onto their existing X motor mount as shown below. This involves removing the two front screws holding the motor to the mount, which are short M3 screws, and replacing them with two M3 x 30mm screws that go through the new end stop switch mount, through the existing motor mount, and into the stepper motor.
These parts can be printed in PLA, with 30% infill and 3-4 perimeter walls.
For makers who have yet to 3D-print their XZ-plate-right
Makers who have not yet 3D-printed their XZ-plate-right can print the REMIXED XZ-plate-right ( shown in orange ) that has a pre-attached addon tab to serve as the end stop surface for their (relocated) end stop switch to touch for triggering. These makers should print the part highlighted in orange ( “REMIXED_printed_xz-plate-right_with-addon-tab-for-reversal-of-homing.stl” ) and use it as their XZ-plate-right as shown below. They also should should print the part highlighted in green ( “X end stop mount (for reversal of homing) (for printed XZ plate) v1.3b.stl” ), attach the end stop switch to it, and install it onto their existing X motor mount as shown below. This involves removing the two front screws holding the motor to the mount, which are short M3 screws, and replacing them with two M3 x 30mm screws that go through the new end stop switch mount, through the existing motor mount, and into the stepper motor.
These parts can be printed in PLA, with 3-4 perimeter walls. The remixed XZ plate should be printed with 70% infill, while the end stop switch mount can be printed with 30% infill.