[Dougl]

I want to cut a semi circle out of the lower winglet spoiler to allow fitment over the OEM engine bars. BMW marks the cutout on the inside. What’s the best tool for doing this?

 

[Dougl]

Think Dremel would work.

Grinder, cutter, or sander?

 

[Dougl]

Imunna try a diamond hole saw. Can’ find fine easily and my standard coarse is, well, too coarse. Thanks!

 

[Dougl]

I think they are known as "Aviation shears". They come in straight cut, left cut, right cut models. View attachment 119062

Have those. Loathe to take it to rigid plastic.

 

[Dougl]

You could always do it like the shop would - a pair of curved snips. Rough enough is good enough. 😄

Already butchered one set of these.

 

[Dougl]

If you used this method, you would want to screw the part to the wood using some self tapping screws around the periphery of the waste piece.

This is a good idea.

 

[Dougl]

It’s comical reading all these ideas and it shows virtually no one actually works with tools these days! 🙄 Proper tool would be an air belt linisher as you have perfect control and it puts a perfect curve in. Failing that and you could heat up a knackered screwdriver and burn the basic shape out.

What’s an air belt finisher? I asked a metal shop if they could do it. No dice. Also couldn’t suggests a tool. Then I asked here and voila! Thanks all for the advice