What size router bit for marshall roundovers?

[kamanda]

Hey guys, I swear this will be one of my last quesitons

As you know, I'm building a 2x12 cab based on the marshall 1936. I bought marshall corners and I need to know what size router bit I need to do the edges, I've heard 7/8" or 1"...your opinion?

Thanks!

[steveh]

1" is a 25mm roundover?!

IME most cabs have a 10-12mm round over, but maybe the cab you're discussing is different.

[Keith2112]

Yeah, 1" is huge! You would most likely need a router with a 1/2" shank capability for a bit that large. Most cabinet corners that suppliers sell use a 1/2" radius, which is about the largest roundover bit that still comes in a 1/4" shank size, and it sounds like a reasonable radius even if you opt to not use corners. I have used that radius on the cabs that I have built. Since you have the corners, why not trace them out on paper and estimate the size of the roundover by measiring the trace? You could also take one to the hardware store and see what size dowell fits the best in the corner and halve the dowell diameter to get the radius.

[jaysg]

I measured a JCM900 1936 with some radius gauges. Oddly, the front roundovers measured between 7/8" and 1". Maybe it's metric.

[sub]

I measured a JCM900 1936 with some radius gauges. Oddly, the front roundovers measured between 7/8" and 1". Maybe it's metric.

7/8"=0.875"=22.225mm
1"=25.4mm
between two = 23,8125mm ....... maybe 24mm (two dozen )

[clobo]

Hi

I measured a few Marshall cabs, older ones had smaller radius (1/2 to 5/8 in) but they got larger from 70, on (7/8 to 1 in.).

For my own builds, I use 5/8 for heads and combos, but 3/4 for larger cabs (4x10 and 4x12).

Also doing the front edge with a hand router is tricky, I use a temporary baffle (shimmed flush to the cab edge) to support router base.

Claude