Drilling holes in head cab for chassis mounting

[Big Jim]

My idea worked perfectly. Of course this only works if you are building your own cab. Using the bottom plate as my template, I drilled the holes in the wood before I even glued the cab up. The bolts go through the feet, then into the cabinet and chassis. Way easier than drilling them after the fact.

[Richie]

Pretty much what others have done or tried. It is best after getting the correct position holes drilled. make sure it fits, and like mentioned oversize a little to have some room for movement or placement.
One reason i never drilled the bottom when i sold some cabs for a friend, was becasue you never know what chassis they are going to use,or faceplate.
Some peoples chassis had different mounting measurments.
Also the difference in what faceplate thickness they might use. And also be sure when building your amp, the power transformer sets back ,and is not flush to the front. If it is you won't be able to slide the chassis under the front panel. Be sure to look at the build sheets if your new to building for things like this to watch out for.
Mostly if you build them all the same, then you can use a template. Or measure,measure, measure, before drilling.

[xtian]

I did my two Rocket Dogs with the method I described, but I didn't reverse the bolts. I just screwed them in to the chassis, screwing them all the way in so just the rounded heads protruded. Slipped the chassis gently into the cab to avoid gouging, and pressed down once positioned to make the bolt heads mark the cab. Then I used calipers to measure the inside marks, transferred to the outside of the cab, and drilled from the outside. Success.

[keithshapiro]

Not sure I have the tools to do this, but I was thinking I could sharpen to points the ends of the mounting bolts, reverse them and screw them into the chassis, so that the points are just barely sticking out from the bottom of the chassis, then place the chassis in the head cab, and push down to indent the wood with the pointed bolts.

Any simpler ideas? Careful measurements with my digital caliper?

I did this, it worked however measuring works and its easier