Jazzmaster build: thimble question

[Glimmer]

As I've mentioned on a few threads here and there, I've embarked on a JM build and have actually begun doing some preliminary work while waiting for all of the parts (most crucially the neck) to come in. Thus far, in a discreet homage to Cagey, I've lined the pup and control routs with copper foil  :icon_jokercolor: and have begun enlarging the holes for the bridge thimbles. My question is: how difficult / easy should it be to get the thimbles in? In one thread I've seen here the builder widened the holes slightly and, using a bit of lubricant, tapped the bridge thimbles in with a rubber mallet; in another the builder said he contacted Warmoth who told him to enlarge the holes to the point that the thimbles fall out when the body is turned upside down. Is there a proper way of doing this and, if so, what is it?

FTR, the un-enlarged holes measured approx. .343" wide. I have a Mastery bridge and am using their thimbles as well; they measure .375". Using 150-grit sandpaper and a series of dowels I've enlarged the holes to measure approx. .360", and at this point the thimbles just barely begin to enter the holes.

Any thoughts?

 

[Cagey]

You want those thimbles to be tighter than dammit. Whoever suggested they be able to fall out should be smacked silly. A loose bridge eats tone and sustain like a pack of wolves on a kitten. That's why some folks won't even consider installing a vibrato, even though they're not the debilitating things some consider them to be.

The other thing is Mastery bridges/thimbles are machined very, very close. You start messing with the holes, and you're liable to have problems getting the two to match up. The few that I've done have always amazed me that they work, considering the tight tolerances.

The thimbles will seem to not fit, but that's because they're a press fit. You need a press to get them in because they're supposed to be tight. Ideally, you'd want an arbor press, but a large-ish drill press will work. For almost anything else, I'd say you could pull it off with a hammer, cushion and care, but not the Mastery parts.