3" highball trackball mounting hole in lexan...

[ahofle]

Has anyone mounted a highball trackball in a wood CP with lexan over it?  The trackball itself is 3", but there is a little plastic lip around it that is about 3 1/4".  I don't know of any hole saws that size, so my options are to either drill a 3" hole and dremel it down to fit (sounds like a bad idea),  go with 3 1/2" hole and just live with the extra spacing, or just go with the 3" hole and let the lexan sit on top of that lip.  Is there another option I'm missing?  Any suggestions would be appreciated.

[JesterDEV]

I bought a 3"...  Round saw looking thing that fits on a drill. Sorry my mind went blank, and I dont remember what it's called.. Anyway, I cut out the shape of the football and in the wood. Then drilled the 3" hole into the lexan.  

The bit can be had for around $16 at home depot.  There was just a thread about this not to long ago. I'll see if I can find it.

Edit:
Here's the link Click Here

[u_rebelscum]

I suggest the 3" hole, and round the top of the hole.  Easiest with a router with a round bit, like this guy did.

If you want to gain another ~1/16" and have a router anyway, you might be able to route the 3 1/4" hole, using the mounting plate as your template (maybe transfered to some spare wood first for a thicker template).   Your are using a mounting plate, right?

[ahofle]

I suggest the 3" hole, and round the top of the hole.  Easiest with a router with a round bit, like this guy did.

But rounding the hole isn't enough.  The highball trackball lip actually pokes up through the mounting plate and into the  lexan (barely, maybe 1/16 - 1/8") and is slightly wider than the 3" hole.  I actually looked at another thread where you posted a great illustration... http://www.arcadecontrols.org/yabbse/index.php?board=1;action=display;threadid=7749;start=msg56076
but the highball illustration doesn't seem to be correct, at least with the Happ mounting plate.  The highball lip actually rises above/into the lexan and looks more like the 'high lip' illustration.  Hence my dilema with the hole needing to be a tad bigger than 3".

If you want to gain another ~1/16" and have a router anyway, you might be able to route the 3 1/4" hole, using the mounting plate as your template (maybe transfered to some spare wood first for a thicker template).

Hmm, now this sounds promising.  But how can I do this without scratching up the mounting plate with the router bit?  Or do you mean just drawing the circle and then freehanding?  Forgive my router ignorance, I'm sure there is a better way to do this.

Thx,
Andy