Routing brass?

[yetloh]

Anyone know whether it is possible to rout brass with a conventional TCT wood bit, perhaps with the speed reduced to the minimum and light cuts, please?

Jim

 

[9fingers]

On the basis that machining brass in conventional ways requires positive rake on the cutting surfaces, I would think that it should be avoided.

However the only way would be to try on some scrap but do be careful to have everything clamped down firmly and take very very light cuts.

Ideally can you find a local man in a shed with a milling machine who can help you?? 'tis the season of goodwill after all!

Bob

 

[Racers]

Hi,

I have routed 10mm aluminium with a 1/2 slot mill in a router, lots of shallow passes untill I was through, and rounded over the edges with TCT tiped roundover bit.
So brass should be possible.

Pete

 

[9fingers]

Aluminium alloy is a lot softer than brass and only requires normal negative rake cutting angles

Bob

 

[Harbo]

I've successfully chamfered the edges of some brass using my DW625.
Light cuts and slow speed.
Haven't tried routing a groove though?

Rod

 

[Digit]

Yes it can be done, but there are different grades of brass, some harder than others. Hard brass tends not to poduce shavings, rather lots of nasty needle sharp spears!
An 'end mill' does a better job than a router cutter.

Roy.

 

[jasonB]

Aluminium alloy is a lot softer than brass and only requires normal negative rake cutting angles

Bob

Bob, you have got it the wrong way round alloy needs positive rake, brass zero or negative rake, the exception being in a metal chop off saw where negative rake blade is desirable to stop it snatching.

A lot will depend on the grade of brass being routed, the harder brasses (CZ120) will not be a problem but the softer ones (CZ106, 108) will be a bit gummy. HSS slot drill will work better than TCT in both types at your slowest router speed.

J

 

[9fingers]

Aluminium alloy is a lot softer than brass and only requires normal negative rake cutting angles

Bob

Bob, you have got it the wrong way round alloy needs positive rake, brass zero or negative rake, the exception being in a metal chop off saw where negative rake blade is desirable to stop it snatching.

A lot will depend on the grade of brass being routed, the harder brasses (CZ120) will not be a problem but the softer ones (CZ106, 108) will be a bit gummy. HSS slot drill will work better than TCT in both types at your slowest router speed.

J

Yes, I got my positives and negative rakes reversed but the principle holds true, Router cutters fundamentally have the wrong rake for brass.

Bob

 

[Setch]

Aluminium can be easily cut using the same tools you would use for wood. Brass cannot, and using your router on it will likely hurt you, the router, the work piece, or possibly all three.

 

[WoodMangler]

An 'end mill' does a better job than a router cutter.

A 'slot drill' (2 edges) would be better for cutting a housing, 'end mill's (4 edges) are for rebates. Also, you need a really sharp cutter for brass, anything less is likely to jam in the cut.

As somebody already mentioned, some grades of brass can be an absolute b******r to cut at the best of times, and the needle-like swarf gets everywhere and hurts like hell...

 

[Eric The Viking]

Some months back I had to convert some brass plumbing spigots into compression fittings.

I built a jig for the router table, practised on a couple of fittings first, and successfully made a pretty accurate 60deg internal chamfer, to match the compression olives in question, using a 45deg wood V-grooving bit. The new fittings are now in use just below our boiler.

The worst issue was the chippings it produced. They go everywhere, and aren't very amenable to dust extraction. Happily the router's airflow blows them away when it's running, but I was very worried about them damaging the insulation on the motor windings - and they conduct electricity!

It wasn't an ideal method at all, but I have no lathe and the fittings I needed to make are not available commercially. You'd do better with the router over the work rather than underneath it, and heed the advice from metalworkers about cutter angle etc.

Also, it was obvious the cutter was going too fast, at the slowest speed on the router, and the bit wasn't a very large diameter (about 3/8" at the point of contact with the brass).

E.

 

[chunkolini]

What are you after doing?
If it is edge work you can get Tungsten Carbide die grinder bits that do a lovely job and a lot of guys use laminate trimmers as die grinders.
The tiny flakes of swarf are very pretty, it is like working in a glitter storm if the light is right. Top, tip, dont wear a fleece when doing this the stuff sticks to it a treat and works it way to places you would rather it did not go, and have your overalls over your socks.

 

[TheTiddles]

I've routed brass quite successfully, however, that was with 6mm milling cutters in the router. You can get 6mm collets then just use standard milling bits, run them fast and shallow with lots of extraction and do a practice part first.

Aidan

 

[Eric The Viking]

Top, tip, dont wear a fleece when doing this the stuff sticks to it a treat and works it way to places you would rather it did not go, and have your overalls over your socks.

+1

 

[DTR]

An 'end mill' does a better job than a router cutter.

A 'slot drill' (2 edges) would be better for cutting a housing, 'end mill's (4 edges) are for rebates.

Sorry for going off topic(ish) but would you mind explaining why? When I was an apprentice making v-blocks and the like, I seem to remember end mills being used for housings. I could be wrong of course because I seldom used the vertical mills, I mostly worked on a horizontal mill (using a side & face cutter for housings).

 

[Digit]

'End Mills' have four end and face shearing edges, but the end has a hole in the centre so cannot be plunged like a dril.
Slotting cutters have two face and edge shears and can be plunged. To cut slots with an end mill requires a pilot hole.

Roy.

 

[jasonB]

Not strictly true these days as you can get 4 flute endmills with a centre cutting ground flute, quite a few of the "roughing" type endmills are like this. Als two flute cutters without centre cutting.

The other option is to ramp down into the cut.

J

 

[DTR]

To cut slots with an end mill requires a pilot hole.

Only if the slot is not open ended, which goes without saying really. Similarly I couldn't use my trusty side & face cutter for a blind housing. The end mill was our prefered choice (for vertical milling), the slot drills only got used for holes and slots.

 

[WoodMangler]

To cut slots with an end mill requires a pilot hole.

Only if the slot is not open ended, which goes without saying really. Similarly I couldn't use my trusty side & face cutter for a blind housing. The end mill was our prefered choice (for vertical milling), the slot drills only got used for holes and slots.

In my Model Engineering persona, I find end-mills used for cutting slots tend to cut a bit oversize.

 

[yetloh]

Thanks everyone for the very helpful replies. What I wanted to do was make a deepish slot in the head of each of the blade clamping screws on my Veritas mark 2 honing guide so that I could fit flat cross pieces to allow them to be properly tightened without the aid of pliers. The need for this has increased as a result of using pliers on them for some years which has pretty much knackered the knurling. I am conscious that holding these securely during routing might be a problem in itself. I guess it might be easier to make new screws or find a man in a shed with a milling machine.

Has anyone else come up with any mods to solve this design fault in the Veritas honing guide? I have made a jig that enables em to dispense with the horrible little fence thingy that has to be attached and then detached for every blade but this clamping frustration remains.
Any ideas?

Jim