Mounting a chassis in a tweed cab

[tele_savales]

I’m a little sketched about this and need some advice. The mounting holes are almost kinda exactly 13.5 inches on center (actually 9/16 or 14mm in from the edge, not 1/2”, sadly) and the chassis is 14.5.

It looks wayyyy to close to the round over to even think about drilling there, much less will it even hold the chassis? I emailed the guy’s at Mojo but im pretty much ok with, and pretty much decided upon, redrilling the chassis at 1 5/8ths up (instead of 1” which is where the hole is now) and 3/8 in from the edge of the chassis, just enough room to get the keps nut on. That will get me away from my existing hole and a possible breakthrough, and give me enough cabinet not to crack it apart.
Any advice at all would be super helpful. I’m not big on asking for help because I usually can figure thing out w enough tinkering, but extra holes in the cab are just not happening here. Can’t let it happen. Even tho I can patch it perfectly w a dowel and some spare tweed from inside the cab. Extra hole on the chassis I can live with, they’ll never be seen.
The last pic is where the new holes might go.

 

[schmee]

I once mounted one with studs inside, so no screw shows on the outside. It was a PITA way to do it though, and I always worried they would pull out.
I think you are ok there. Leave yourself room to use a countersunk style oval head screw and no finish washer.

 

[Powdog]

I build a lot of tweed style cabs and always use a #8 stainless bolt with a chrome finishing washer on top, and a #10 washer and locking nut on the inside. It does get close to the edge sometimes.

 

[tele_savales]

View attachment 985837 I build a lot of tweed style cabs and always use a #8 stainless bolt with a chrome finishing washer on top, and a #10 washer and locking nut on the inside. It does get close to the edge sometimes.

Looks pretty good!

 

[chas.wahl]

Theoretically, the Tweed Deluxe cab has a 12-1/4" wide x 2-1/2" deep controls cutout, with a 1-1/4" radius to the interior corners. The mounting holes for a standard chassis are, indeed, 13-1/2" on center. That leaves a 5/8" distance for each hole from the cutout. I may be wrong, but I think that the standard roundover is 3/8", leaving 1/4" of "flat" to the mounting bolt. I believe that the standard mounting bolt spec is #10-32 with an oval (countersunk) head but no finishing washer, which will make the encroachment problem worse.

Here's a vintage one. It's pretty close, but should work out OK:

 

[tele_savales]

And so add 5/16th's to whatever measurement to you mounting holes to accommodate the back door plus the tweed covering?

 

[tele_savales]

HANDLED. Man, that was nerve wracking. That right side bolt, the nut holds itself in place against the chassis, hee hee.