Creating the 30 deg angle for a Fender princton Rev chassis

[pjd3]

Hello,

I was curious to see if I could get any comments from those who have built a Fender type cabinet for a Fender chassis.

Specifically, I'd be curious on the starting steps for creating the 30deg angle for chassis with the ubiquitous 30 degree angled 1.75" H chassis.

Over the weekend I glued/clamped up a 20" x 27" pine cabinet for a 18.5" Princeton Reverb chassis and a single 12" speaker. Yeah, I know its a little big for just a 12" speaker but, I did want a good amount of wood and space (hopefully full tone). Also, I beveled the 27" H front of cab 1.25". I measured in 1.25" on the top of each side and drew lines from the very bottom corners and carefully cut out the angled front with a good wide hand saw. It came out very well, I'll just need to make a long board with sandpaper on the ends to true up the entire perimeter of the pine on the front edge.

After that, the next step will be to create the 30deg angle to match the angle on the front of the Princeton Reverb chassis.

What I'm slightly stumped about is how to establish the starting points for drawing the lines that will be cut on. And mostly, will going with 1.75 inches from the inside bottom of the top board down 1.75" get me where I want to be, or, is it better to do some kind of compensation by extending measurements to leave room for the chassis to sit properly? There will still be the need for a bit of space for the guide rack sliders, and also a tad bit of space for the speaker baffle? That's what I'm ruminating about and can't quite relegate it in my head. My instincts tell me to extend every measurement I make by 1/16" to an 1/8" of an inch to leave some breathing room for what ever else may need to happed.

Have you done this and found an approach that got you where you wanted to be?

Thanks, sure would like to get this right. I don't want to end up painting myself into a tight corner or, leave silly spaces that look cheesy.

Thank you!
Best,
Phil D (pjd3)

[Phil_S]

I can't quite picture what you need to do but I'll take a stab at it. In general, it is better to work with the piece than to go by calculated measurements.

Get a bevel gauge. If you don't have one, the cheap Harbor Freight one is adequate. Use this to find the 30 degree angle from the chassis. It might be 29.5 or 30.3. Using the gauge means you don't need to know the measurement. The gauge is exact. Transfer the angle to the cabinet. If you need some extra breathing room, just move the gauge in or out to compensate and you can just eyeball it.

Use the same basic procedure to determine the height. Use a square this time. Mark it with a thin Sharpie. Sharpie cleans off with alcohol.

If you have the skill to cut to the line, mark the cab and cut. If you skill level is not so good, cut away from the line. Either way, sneak up on it using PSA sandpaper on a known flat piece of wood or metal. A hand plane is better than PSA sandpaper, but only in the hands of an experienced user.

This is simpler and more accurate than calculating it.

[nuke]

A relatively decent table saw with a really good mitre gauge will cut those. It's more important for the cuts to be equal left and right side than perfect. Get it set up, make the angled cuts without adjusting anything in between. Start with a piece of scrap to setup the saw first, then cut the actual work pieces.

Sort of recently taught myself cabinet making with a table saw when I made a reproduction cabinet for a 1959 Magnatone 260A amplifier.

[martin manning]

Why not build the cab without the chamfer and then cut it on a table saw afterward?