Just designed a helping guide to drill holes on my MK3S frog so I can properly tighten the MGN12C blocks to use linear rails on Y axis.
I printed it in PETG and use a modifier to print 100% infill in all the "join together" holes to join both parts of it, recommended but maybe not necessary. 4 perimeters, 50% infil and 5 top and bottom layers at 0.2 layer height.
The author hasn't provided the model origin yet.