2024-04-21

Last modified: 2024-04-21 20:31:08

Base plate

This evening I went out to the garage, removed the clamps from the baseplate, chiseled off the squeeze-out, and laid the uprights next to the baseplate to transfer the hole locations.

I first lined up the bottom forner of the uprights with the back edge of the base plate, by eye:

Sighted along the gantry back supports to see that it is somewhere close:

And laid a straight edge across the fronts of the uprights, so that I could measure the distance to the adjacent rail hole, on the basis that if everything is square then the 2 distances should be the same:

I found that initially one side was 0.5mm further away than the other. I tweaked it by hand until it was within 0.1mm, but I'm not sure how necessary that was because I almost certainly won't drill the holes to within 0.5mm, and I think the bolt holes should give 0.5mm wiggle room anyway.

I've centre-punched and circled the bolt hole centres:

In the event that the gantry when finally bolted up is not perpendicular to the Y rails (which I think is quite likely), I will shim one end and pack out the empty space with "polymer clay" so that it has half a chance of transferring force across the whole surface.

In fact I may need to shim both ends if the gantry does not end up vertical relative to the table. Will have to see. But polymer clay is my ace card if I need to do any shimming, and I'm actually wondering if I should be shimming all the joints on purpose so that I can use polymer clay as a mating material.