Gantry leveling tool/jig

I noticed that the upper VSLOT wheels on my gantry had different tension than the bottom ones when the gantry was square, meaning the wheel assembly was not mounted square. The printer will work fine like this, but it will cause much more stress on half the wheels, making them wear down.

Primary features

• Designed to break safely if accidentally left installed in the printer during a print instead of causing damage to the gantry. Learned from experience!
• 4020 v-slot notches to keep the tool perfectly upright and straight.
• Minimal use of filament while strong enough to maintain precision.
• Finger catch to make it easy to remove.

PRINT SETTINGS

• Print with the model lying down on it's back, no supports. 
• Any material is fine.
• 0.1mm - 0.2mm layer height (though any should be fine)
• Infill: 10%

NOTE: Do not go crazy with infill or perimeter count. It should be kept low to ensure this tool breaks if accidentally left installed in the printer during a print. This prevents damage to the gantry by allowing the top ledge to snap off and the tower to bend and eject itself (with some velocity I might add!). It will still be PLENTY sturdy to align your gantry. I accidentally tested this after printing it in BLACK and later forgetting it was under the gantry.

STEPS

1. Slide these under each end of the gantry and manually turn the lead screw until both sides of the gantry are snug on the tools. 
2. Loosen the 4 bolts that attach the wheel carriages to the gantry (2 on each side). The wheel carriages should now be able to move slightly separate from the gantry.
3. Tighten the eccentric nuts on each side of the gantry until all 3 wheels on each side are tight. We are going to temporarily tighten them more than they should be normally to help align the gantry. Try to turn the wheels without allowing the gantry to move up or down (ie. letting them “slip” against the vslot). You should barely be able to spin them. Then tighten a little bit more, but not so much that you crush the wheel. The goal here is to have the wheels tight enough to “pull” the wheel carriages into alignment.
4. Your carriages should now be held in their proper alignment. Tighten the 4 bolts on the wheel carriages to lock the alignment in.
5. Your wheel carriages should now stay aligned permanently. Remove the tools and loosen/adjust the eccentric nuts back to their normal tension so you don't cause added wear on the wheels.

CHECK CURRENT ALIGNMENT

With the tools in place and the gantry resting on them, try to slip the 2 outer wheels on each of the wheel carriages. The top wheel should barely be able to slip, and the bottom one should require the same force to slip as the top one.