Snap depth gauge for adjusting plate perimeter lag screws

According to the instructions for WNG’s plate perimeter bolts, it’s best if you use a magnetic base dial indicator to register exactly when you’ve raised a given bolt up enough to contact the plate.  I happened to have on hand an inexpensive (~$20) digital snap gauge that I thought could handle the job, but clamping it directly to the rim was fiddly at best.  Fortunately it has a conveniently placed hole in the back that makes it pretty easy to screw anything you like to it.  Grabbed a scrap block of pine and voila:


Note that I knocked down the edges to avoid marring the rim, even though it’s already protected by thin cardboard.  And here it is clamped in place:


(Actually it would have been a little better to clamp the gauge on the other side so I could get it as close to the bolt hole as possible.  But I believe even this distance to be perfectly adequate given that none of the machine bolts were installed — if the plate is getting raised up it’s going to register just about anywhere nearby.)

I love it when a cheap, thrown-together tool modification works perfectly 🙂  I wouldn’t necessarily suggest going out and buying one of these particular gauges by the way.  The annoying thing I’ve found about these cheap digital measurement tools is that they seem to eat batteries even when they’re off.  So I have to pull the battery out or flip it around… kind of a pain in the neck.  If I had it to do over again I’d probably at least try to get a dial gauge of some sort.

Filling in oversized plate bolt holes – Part I

Working on the rebuild of a 1911 6’2” J&C Fischer, I ran into a small dilemma – some of the plate bolt holes had been re-drilled at the factory (as far as I can tell), probably because the original holes were too far from the outer rim – i.e. the original bolt when drilled would have been too close to the edge of the inner rim, or stuck out altogether.

All in all not a big deal, but I’m replacing the original bolts with the WNG plate suspension bolts and the washer is a little smaller than the originals, so the enlarged holes were going to show. (They’re really nice washers, so I wanted to use them instead of the old ones.)

Unfortunately I had already drilled for and installed the WNG bolts before I realized this.  I wasn’t too keen on trying to plug a stepped hole, so the question became how do I fill these guys in without losing the proper location for the hole? Since the washers are quite snug around the bolts, I could draw circles around the washers with them installed, like so:


I used a pencil here – not the most visible marking, but it showed up well enough. A black permanent marker would have been more obvious, but I didn’t feel like dealing with cleaning it off the washers…

I also had an idea that I could use dowels as mould so I wouldn’t even have to re-drill anything. All I had to work out was a way to get them in the right place…

The original unmodified plate holes were 7/16” and that dimension seemed to work well, so I glued some 7/16” dowel into some plywood cutoffs, making sure to keep them square to the base:


Continued in part II.