The checker has six 1mm holes on the curved part. At the top Hole (Hole No.6) the Distance should be 120,5mm. See my professional drawing…
print it, check the length, scale it in your slicer an print again. I had to scale the length to 100,4%
remove the elephant foot from the part
Distances from top to bottom
6 = 120,50 mm lifetime 0% for Steel gears
5 = 120,25 mm lifetime 0% for aluminium gears
4 = 120,00 mm lifetime 25%
3 = 119,75 mm lifetime 50%
2 = 119,5 mm lifetime 75%
1 = 119,25 mm why did you measure, your chain is new
When checking your chain, don't use force, let the tool fall into the chain.
I double checked it with a Caliper an it works.
Sorry for my bad English
The author marked this model as their own original creation.