garry parker wrote:
> 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
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....
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.
"garry parker" <[email protected]> wrote in message
news:[email protected]...
> 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
>
>
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.
Dave Paine.
<[email protected]> wrote in message
news:[email protected]...
>
> garry parker wrote:
>> 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
>
> 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....
>
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
"Tyke" <[email protected]> wrote in message
news:[email protected]...
>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.
>
> Dave Paine.
> <[email protected]> wrote in message
> news:[email protected]...
>>
>> garry parker wrote:
>>> 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
>>
>> 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....
>>
>
>
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.