3mm aluminium possible to cut a slot with a router

[Lazurus]

as the title says I have some 3mm thick aluminum bar which I need to cut a slot in some 300mm long and around 6mm wide, would this be possible with a router, or is it going to be a hand saw and file job.
I thought about drilling a series of holes then tidying up with a router, is this a safe a satisfactory method or should I get it machined?

 

[Dalboy]

There are router bits that are designed for cutting ali but whether you can do it in a hand held router I don't know

 

[sunnybob]

its all down to using the correct bit

https://www.scosarg.com/tooling/router- ... outer-bits

easy to do on a router table with a solid fence and end stops, slightly trickier with a hand held but not impossible.

 

[Racers]

I cut a 1/2" slot in 10mm ally with a slot drill in a hand held router just doing shallow passes, and did a 1/4" round over with a 1/4" router hand held in the same ally.
Both where easy when using the slowest speed.

Starfish preamp by Pete Maddex, on Flickr

Pete

 

[Sideways]

Seconding Pete.

I've edge trimmed 18mm thick ally plate using a cheap B&Q 1/2" router with a carbide wood bit. Slotting is fine too. Just use guides to stop you biting in too far and take many light cuts with the speed dialled down.
I don't make a habit of it but as TC is far harder than aluminium I see no problem with the judicious use of woodworking tools and blades to cut aluminium. I sized the same ally plate first with a circular saw (dialled down to minimum speed) again taking it nice and easy but keeping it moving.

 

[chaoticbob]

The aluminium-cutting router bits sunnybob links to are single flute - personally I'd worry about using that geometry for slot cutting. As Pete says, a slot drill should work fine - if you're OK with 1/4" then an imperial slot drills with 1/4" shanks are readily available, so would fit a standard router collet.
Something to bear in mind is that these are 'upcut' bits, so tend to draw the work into the bit. This can be a problem with thin materials . You need to make sure that the work is held securely. Sandwiching between sheets of ply can be helpful.
Personally I wouldn't bother chain drilling before making the slot. My own experience is that doing so actually makes it harder to get a nice parallel slot.
Robin.