Woodworking advice - best way to add large radius to sharp corners?

Hi,

Woodwork novice here! >_<
I have done the basic woodwork induction, but haven’t made anything in the workshop yet.

I want to make a speaker cabinet, thinking glued 20mm thick MDF or birch plywood.
I’m looking for a smooth overall look, no sharp corners. Fillet of 20 mm radius on all edges. Does anyone have advice on best way to achieve this?

I saw people do it by filing by hand (https://www.youtube.com/watch?v=53t_EgW48Dk), use a hand plane to chamfer 45 degrees and then file? (How to Round Over Edges by Hand | The Literary Workshop Blog). I also want to round internal edges so some parts not very accessible with tools.

Thinking it’s best to do this after the box is assembled?

Pre fillet

Post fillet

Thanks!

Would suggest the the router with the appropriate radius cutter would the tool for the profile you picture shows.

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If you wanted to stick to hand tools, you could use a half-round rasp to do the internal edges, and finish off with sand paper. It will be hard to make it perfect, but you can get something reasonable.

Hand plane isn’t going to work well with MDF or plywood. The rasp is probably okay on these.

Otherwise the handheld electrical router as mentioned by @crafty_creator would work well in any of these material and would give you the most consistent results.

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thank you both! the handheld router seems like a great option, haven’t used that specific router bit before, seems very useful

The bit(s) you need are called ‘rounding over’ such as these…Sinoprotools Roundover&Beading Router Bits,6Bits Edge Forming Router Bit Set,Corner Rounding Router Bits 1/4 Inch Shank with 6pcs Beading Bearings, Radius - 1/16" 1/8" 3/16" 1/4" 3/8" 1/2" Sinoprotools Roundover&Beading Router Bits,6Bits Edge Forming Router Bit Set,Corner Rounding Router Bits 1/4 Inch Shank with 6pcs Beading Bearings, Radius - 1/16" 1/8" 3/16" 1/4" 3/8" 1/2" : Amazon.co.uk: DIY & Tools.
Work great on mdf but try and use local extraction effectively…

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