What's the best way to round or "scallop" a control panel top?

[Numbski]

So I'm finally getting around to re-doing my control panel this weekend.  Making some tweaks to the box, and completely re-doing the top.

One of the things I screwed up badly the first time around was the corners.  I just took a glass, traced the bottom around the corners where they intersected, and cut.  Not the most scientific way to do it, and the results were *terrible*.

The only thing I can thing to do is drill a small pilot hole, and I have a circle cutting attachment for my roto-zip rotary saw, and just use that as though I were cutting a full circle, but just cut the rounded edges.  Is there a better way to attack this?

[javeryh]

How big of a curve? 

I would draw the arc out on a piece of MDF, cut it and sand to the line and then use that piece as a template with my router for all of the corners.

[Numbski]

Not sure how big I want to do.  Here's a shot of the last attempt (early shot, ignore the fugly wannabe CPO):

[ChadTower]

How big of a curve? 

I would draw the arc out on a piece of MDF, cut it and sand to the line and then use that piece as a template with my router for all of the corners.

That's the way to go right there.

[Numbski]

So get an extra big flush-trim bit then?  Take a scrap piece of 5/8" board, cut my curve there, then clamp or screw that to the work piece, and flush-trim bit the thing?

[Franco B]

If you can find a vegetable/processed food can with the right radius you could cut around the side of the can about 3/4" from the bottom and then screw that to the CP top to use as a template for your router to follow. Should give you a perfect curve.


 

[shiloh]

How big of a curve? 

I would draw the arc out on a piece of MDF, cut it and sand to the line and then use that piece as a template with my router for all of the corners.

I am redoing my CP and that's how I plan to do it too.

One question: is worth getting a belt sander to sand the curves or elbow grease will do it?

[ChadTower]

If you want to be that exact I wouldn't use a belt sander... one moment leaning too hard and now you have to fill it.  They eat stuff fast.  I'd cut it close and use a palm sander with like 80 grit.

[javeryh]

If you can find a vegetable/processed food can with the right radius you could cut around the side of the can about 3/4" from the bottom and then screw that to the CP top to use as a template for your router to follow. Should give you a perfect curve.

That's a great idea too - or at least use it to make the template.

I would NOT use a belt sander.  MDF sands super easy by hand.

[Numbski]

I like the can idea.  I think I'll give that a shot!

[fjl]

My mom told me that pointing is rude.