Router bits (UK)

[garry parker]

I need to cut some ventilation slots through 18mm thick wood on the top of a guitar amplifier I'm making. I need a 3mm router bit, but they only seem to have a cutter length of 8mm. Does anyone know where I can find 3mm straight cutters long enough to penetrate 18mm wood?

Thanks a lot Garry

[bridgerfafc]

that's a pretty long skinny bit you're wanting. long skinny bits have a nasty tendency to break off under load, which is probably why you're having a hard time finding one. you might consider cutting a bigger hole and fitting the baffles back in or cutting the slots with a saw....

[Tyke]

I agree that even if you found a router bit of this length, it would likely break.

I think the choices are a saw, as the other poster stated, or go for lots of

3mm drilled holes.

If you want a given open area, you could consider fewer, but larger diameter holes, or fewer but larger slots. If you go with 1cm slots, you should be able to find a router bit long enough. I would use a spiral style for this type of cut.

[deadlock]

If you really really *have* to have 3mm slots, you could rout them out on the reverse side of the panel with a 6mm bit to within say 5mm of the other face, flip it over and finish off with the 3mm on the visible face. Easy enough to get the alignment with a simple jig and a guide bush.

[garry parker]

Thanks for the replies all. I've already drilled about 200 holes in a previous amp, and I don't fancy doing it again! I found a 5mm bit which is long enough, so I'll do a rough piece with a drill bit to see if I like the larger slot width. Deadlock's idea made me think of routing a recess on the top and then slotting it so it looks like a proper vent panel. And yes, I have considered buying a vent panel! Didn't fancy having a plastic square on the top though.

Garry

[Gooey TARBALLS]

Routing it out from the bottom sounds like a winner. And a similar approach might work to allow you to create a proper vent grill out of thin aluminum and fasten it from the inside. The aluminum should work with a carbide router quite nicely while affording a proper grill vent.