cutting a 1 1/8" hole in plastic

[Fritz]

put a BT/USB module on the back end of our '05 Accord radio.
needs a USB extension.
It takes a 1 1/8" hole.
Not gonna drop $25 on a one time use bit.
Besides the fact that 1 1/8" is a 1/2" chuck. I have 1/4".

I was thinking draw the hole and use an 1/8" or so bit to cut the circle out. It's the "storage" bin in the center. Not very thick. < 1/4".

Other ideas?

[cbelt3]

I used a soldering iron to do the same thing to my '02 Civic. Plastic melts handily. If you don't have a soldering iron you can hold a nail in a pair of pliers and heat it up with a butane lighter (or a torch, better)..

I will say that having a cheap set of hole saws (harbor freight) is handy.

[bazookaman]

[Fritz]

yea, solder iron might make it faster even if it ruins the tip.
I'm sure I'm due for a new tip.
Even the cheapies HF hole saw sets are $25

Left my laser beams in my other pants.

[cbelt3]

It won't ruin the tip. Just wipe it while hot on some steel wool or a metal scrubbing pad. Or let it cool and just cut the plastic off with a knife.

https://www.harborfreight.com/34-in-5-in...68115.html

[Fritz]

oooo, those look alright!

[testcase]

Do you have a Dremel tool? Or a circular rasp?

[Fritz]

neither. Stanley knife. wallboard saw.

[apocketfulofwry]

Cut a square hole with the mat knife?

You could use a drill bit to round the corners first if you want it prettier.

[Gareth]

It will take seconds to cut the correct hole with the Harbor Freight hole saw set vs minutes or more of potential aggravation and risk of damaging other trim using another method.

Or, if you don't have a convenient HF, get a proper sized hole saw for $14 from Home Depot: https://www.homedepot.com/p/Milwaukee-1-...327733-_-N&

(Unless your drill literally only takes 1/4 quick change bits? I didn't know they made drills with 1/4" chucks, I thought 3/8" was the smallest chuck size).