making cutouts in the chassis of my blues jr. rebuild

[steve-o]

Hi all, this is my first build. Today, I took the circuit out of my blues Jr. I'm using the chassis for my new circuit (an 18 watt tmb sort of thing). I'm replacing the stock PT and OT with a pair I got from GDS/Heyboer. But, they're both substantially bigger than the old trannies. What should I be using to widen the opening for the bigger tranny? What should I be using to make holes for attaching my turret strips? I have some metal files...
Thanks all for your help.
P.S. Anyone interested in buying the OT/PT trannies off me...or trading for a Celestion G12H anniversary?

[David Root]

This is a steel chassis, so I would try to find a sheet steel "nibbling" tool that is rated for the chassis thickness, I'm guessing about 18 ga., in order to open up that PT hole. I have used that technique a time or two myself. Klein Tools make them, so do lots of others. (Used to have a Blues Junior myself, nice tone but could use a better speaker and a much better reverb!).

Alternative is a coping saw or a small bandsaw with a steel cutting blade. Drill small holes at the edge of your new rectangle and cut between them. Clean up with files.

As to drilling holes in steel chassis for turret strips, any smaller electric hand drill with a decent (ideally cobalt) drillbit should work fine. A Plato flush cutter will take off the burrs on the exit side of the hole, or you can grind an old screwdriver blade to an edge and chip them off using a small hammer. Again, final cleanup with files. Done both, both work.

[dehughes]

Ahhh Steve! You're in for a treat! So cool.... David Root's ideas are fantastic, BTW.

[RJ Guitars]

SteveO lemme know what your asking for the old iron... I've had decent luck putting new guts into the Pro Juniors and using the existing iron...

rj

[steve-o]

Hey, thanks for the help! As of tonight, all major cutting on my chassis is done. In addition to the trannies, I had to put in another hole for a recto tube, power amp filtering switch, bayonet lamp, IEC power socket.
I ended up using a combination of diamond tipped drillbits, a steel nibbler, and files, like you recommended, David.
Thanks!
p.s. RJ, I sent you a message in response. $50?

[dehughes]

Kinda makes you wish you had a chassis punch, eh?

[lastwinj]

As to drilling holes in steel chassis for turret strips, any smaller electric hand drill with a decent (ideally cobalt) drillbit should work fine. A Plato flush cutter will take off the burrs on the exit side of the hole, or you can grind an old screwdriver blade to an edge and chip them off using a small hammer. Again, final cleanup with files. Done both, both work.

a larger diameter drill bit, spun by hand in the hole removes burrs just as well. a dull one can be used with the drill at slow speed, too. for larger holes, a deburring tool is a must. faster too.


germ

[David Root]

Good tip. I never thought of that. Anything over 3/4" the deburring tool I guess is fine, I didn't like the price though!