How to shape the cutout on the top of amp cabinet?

joulupukki

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I’m looking for a good recommendation on how to cut and shape the little cutout at the top of an amp cabinet I’d like to build. Do I just use a handsaw? I don’t have a jigsaw. I’m concerned that doing it by hand it won’t look that even. I mean, I guess I could do it by hand and then just sand it until it looks right? I’ll be using 3/4” pine.

A number of amps do this and here’s just a couple of reference pictures of a Dr. Z Z-Lux that has this feature…
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LowCaster

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Obviously this (the cut and the rounding) would be very easy to do with a router. But a router is a dangerous power tool. Anyway you‘d need to make a jig to guide the router, and understand a number of things. Since you are asking, I think you should do it by hand, for practice and learning purpose.

Many things can be done by hand, with a ruler 📏 and a pencil ✏️ , a hand saw 🪚 , a wood chisel, a rasp, sandpaper on a block, and half an hour.
 

Paul-T

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I did a few of these with a jigsaw. But ultimately bought a Makita router for £35 and re-did them. Was so much easier and looked so much better. I used a simple mdf jig as a guide.
 

joulupukki

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I did a few of these with a jigsaw. But ultimately bought a Makita router for £35 and re-did them. Was so much easier and looked so much better. I used a simple mdf jig as a guide.
Ah, simple enough, though how to build the jig and get it all perfect? I guess using a 1/4” piece of MDF could be easier to shape for a template. Glad I asked. I hadn’t thought about that. See, this is why I asked. Thank you!
 

pipthepilot

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Obviously this (the cut and the rounding) would be very easy to do with a router. But a router is a dangerous power tool. Anyway you‘d need to make a jig to guide the router, and understand a number of things. Since you are asking, I think you should do it by hand, for practice and learning purpose.

Many things can be done by hand, with a ruler 📏 and a pencil ✏️ , a hand saw 🪚 , a wood chisel, a rasp, sandpaper on a block, and half an hour.
This is a great answer to this question.

100% a router is the best option, well worth learning to use and will give you the best finish but if you've not used one before it take time to get used to. I was scared to death of mine, when I first bought one. 😟
 

LowCaster

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I was scared to death of mine, when I first bought one. 😟
Rightfully so. I worked at the hospital emergency room a long time ago, and you see a few guys like us on sundays. I have a burning memory of what a router bit does to a finger.🥺

I’m concerned that doing it by hand it won’t look that even. I mean, I guess I could do it by hand and then just sand it until it looks right?
Yes
For example this is a pair of rulers and a square, made from raw ebony with a hand saw and a hand plane. Does it look uneven? I’ll admit it took me more than half an hour. 😅
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When I made a cab I bought cheap planed wood planks, cut the dovetails by hand, used a jig to cut the round hole with a router, and 1/4 round router bit for the rounding of all the edges. I would not bother to make this round cut by hand, but if uncomfortable with the router I would make something else, like a square opening.

front
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back
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Lowerleftcoast

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how to build the jig and get it all perfect?
The straight part is easy enough.

I draw or copy curves from circular objects or even an original curve from an amp cabinet. (There are rulers with curves and compasses as well.) When I have made a curve I like in 1/2 MDF, I repeat the curve on one end of my final MDF template, then I flip the curve over for the mirror image curve and route that into the other end. Both sides identical... yep.
 

joulupukki

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Good tips! I do have a router and am comfortable using it. That’s how I made the other amp heads and speaker cabs I own. I just haven’t used/made any templates. I’ll be using the router again to cut out the round hole in the speaker baffle. That worked great last time. I just went to YouTube university and found a couple of examples. This is seeming a lot more doable with that and your guys’ Tips. Thanks!
 

LowCaster

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OK, making your jig should be as simple as gluing two pieces of wood on the straight side of a MDF board. just cut them at the correct angle (30° or so?), round the corner, and use a small radius copying bit.

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dogmeat

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I drill holes at the tangent points, then cut or route the straight lines between the holes. I use large diameter bits so the radius makes a smooth transition. once I have the main cutout I file & smooth as required, then route the roundover
 

2L man

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For soft pine I would use hand saw, then knife and finish using sandpaper block. For plywood first saw and then angle grinder with sandpaper blade.
 

old wrench

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I've built a number of combo cabs like that, mostly the Fender Tweed and Black-face type

I've usually made that cut-out with a jig saw and finished it up with a routed edge round-over

On the Fender-type combo cabs the inside corner always has a radius to it - you can either cut that inside radius with a jig saw or you can drill it with an appropriately sized Forstner drill bit

If you have a hard time following a cut line with a jig saw, simply clamp a straight-edge to the board to serve as a guide for the jig saw


And on the other hand -

You can always put together a simple template and then make that cut-out entirely with a router using a pattern bit and then finish it with a round-over bit

To fabricate a router template that I might use just a single time, I'll often make it up out of individual pieces that I hot-glue together - sometimes it's far easier to do it that way instead of cutting the template out of a single piece of wood

Different ways to skin a cat - you still end up with a skinned cat! ;)

.

.
 

Kev-wilson

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If using a template you’ll need a bearing guided bit to follow the jig and they come either with the bearing top or bottom mounted, if using the router guide bush for the template remember to allow for the bush diameter!

Another way to create a radius is to clamp a sacrificial piece alongside , mark where you want your curve and drill a hole to leave the curve when you remove the clamped bit.
 

Freeman Keller

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I just built a cabinet for a spring reverb and while I didn't take any pictures of the exact process I did make a fronts piece that is kind of similar to yours. First I made the box and the front. I drilled two holes to create the rounded corner, then cut straight in at each end. I used a band saw but that could be done with a jig saw or a hand saw. With the band saw it was a simple mater to turn the piece 90 degrees (motor off of course) and position the rip fence so the blade was sitting at the upper end of the hole.

The other way I would consider doing it would be to make a template out of MDF or plywood and do the actual wood removal on my router table same as making a solid body guitar. With a router you want to remove as much waste wood as possible and just let the router finish it. You will be using a router on your cabinet for the round overs anyway and possible for box joint if that is how you are going to do it.
 

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tubeswell

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If you don’t have a table router and jig, you can do it by hand. measure and draw the cut line with a ruler and solid curve, then use a jigsaw to hand cut 2-3mm inside the waste-cut portion of the plank, then a wood rasp, file, small hand plane (with the grain), and sandpaper block to dress the cut perfectly square, then a hand router with a roll-over bit to make the round edge with a light sand to take out any marks.
 

mountainhick

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If I was making a dozen, I'd make a routing template, but for just one, band saw (Jigsaw works fine too) straighten the cut with a file or sanding stick, round over on the router table and sandpaper. The roundover can also easily be done with a half round file and/or sanding sticks and drums

You can buy a jigsaw very cheaply. You get what you pay for, but even this will do a lot of work for you: https://www.harborfreight.com/power...amp-orbital-variable-speed-jig-saw-69582.html

I've bought a couple similar tools from HF, like a $19 reciprocating saw.YMMV. I am not endorsing them. Just had good luck with these for occasional use.

I also like sanding drums mounted in a drill for shaping rounded contours. These long versions are more user friendly than the shorties:

 

schmee

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I use a hole saw of the proper diameter and draw lines between the holes and to the edge. A jig saw, or table saw finishes the cut out, and then a 3/4” router bit gives the finish!
^ For a deeper cut out, like most tweed amps etc, this is what I do. I normally would use a 1/2" router bit though. (1/2" radius)
 




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