The Part Store now offers a full kit for the Sphinx. The one thing that stood out to me was the limit switch placement shown in the instructional guide. I built my own variant of the Sphinx a while ago, and here is what I did. Going this route allows your Z axis c beam to move from end to end (minus 2mm). This also allows you to use a larger cable chain.
I used acrylic for everything, except the limit switch mount. It was some odd size at around 5.5mm, but anything stiff enough should work. The thickness of the material will only change your hardware length.
Everything is pretty self explanatory, but feel free to ask any questions.
Cable Chain Accessories
To complete this mod, all you need is some material that is stiff enough and a few extra bits of hardware. This mod allows for the use of a wider 30mm inner width cable chain.
Use two 10mm bolts to mount one L bracket to the outside opposite of the X axis stepper. The other L bracket simply hooks into the overhang from the stepper mounting bolts. Insert one tee nut in each slot of the 2040. Use four 10mm bolts to mount your 2040 to the L brackets. The lower end of the cable chain will mount to the tee nuts with two 8mm bolts.
- 10x M5 lock nuts
- 8x tee nuts
- 2x corner brackets
- 4x M5x8 bolts
- 6x M5x10 bolts
- 6x M5x? depends on the thickness of your material, but 12mm should be fine
- 2040 with a length equal to your gantry
For the upper assembly, you will need to insert two tee nuts into the outer slots of the Z axis C Beam. These will allow you to mount your corner brackets to the C Beam. Leave the brackets loose. Using two ?mm bolts and nuts, mount your upper chain bracket to the corner brackets. Using two more ?mm bolts and nuts, mount the upper end of the cable chain to the upper bracket.
From there, we continue onto the Y cable chain. I think you get the idea by now. The file has two different designs for the Y axis lower chain supports. The short one will fit withing a 12" strip of material and requires less mounting hardware. The longer one is exactly what you see in the picture.
The major focus here is the Z axis limit switch, but here are other possible options for X and Y. These were made from 1/8" aluminum and tapped to an m2.5 thread. The micro switches come standard with a 2.5mm mounting hole.
For the Z axis, I made this nifty little bracket that bolts to the C Beam gantry plate. I made mine with counter bores for the screw heads, but that is entirely optional. This can be made from pretty much any material with decent stiffness. This particular piece was made with ~5.5mm acrylic. To complete this mod, you will need an M3 standoff (easiest to find) with a length of 20mm or longer. You will also need an M3 bolt. The length of this bolt depends on the thickness of your material, but you want at least 4mm of thread into the standoff.
After completing the Z limit mod, you will be able to use ALL but the last millimeter of gap on the C Beam. (The grub screw on the lock collar actually hits the gantry plate.)
Sphinx Cable Chain and Limit Switch Accessory Set 2018-09-26
Limit Switch and Cable Chain Mount Upgrade