Recommend a mill file?

[horizon]

I would like to buy a mill file for cleaning up the end of brake cable housing. But I would like to buy the right size, the right type, of a reasonable quality at a reasonable price. This should be very simple but there must be thousands out there from dozens of suppliers as well as various sets and I still wouldn't know which is best for cable housing. £8 - £10 would seem about right for a good one.

Any pointers? I don't have a favourite general tool supplier.

[123ttam]

If you need a file then.

http://uk.rs-online.com/web/p/engineers-files/2390030/

but i've got a Park tools cable cutter

http://tinyurl.com/p6nhxmn

so you don't need a file.

[simonineaston]

Might seem a bit over the top, but I bought a modestly priced bench grinder a few years ago and now use it for a wide variety of jobs, including finishing the ends of cable outers, a job which it does perfectly and extremely quickly. I wasn't sure that I should spend that sort of money (about £30) at the time but ten years later it has now done the job of many files.

[Brucey]

brake cable housing is different to index gear cable housing. The former is spiral wound in soft steel and the latter has paralell strands of much harder steel.

It doesn't matter what cutters you use IMHO; you rarely get a perfect cut with either type of housing, so if you are doing a job that has to be 'just so' then I agree some cleaning up is desirable.

Cutters can produce a slant cut through brake cable spiral wire that is up to ~2.5mm long. Under load this can cock in the ferrule and in a few cases I have seen it move and start to bind on the cable. It also has a burr on it (that usually faces outwards) which can also help to push the cut end inwards slightly. Both faults can be rectified with a file quite easily.

Really good quality cutters can make nice cuts in gear cable housing, but because the wires are hard it quickly knocks the wotsits out of cheaper cutters. It is best to cut the housing end once the housing is curved into something close to its final shape; the ends (unlike brake cable ends) tend to become angled otherwise, and the uneven loading that results from this can cause trouble, especially with plastic ferrules.

If you are just cleaning up brake cable housing then pretty much any medium cut file will do the job OK. I bought one that would do the job in the pound shop recently, so you don't have to spend lots.

Gear cable housing is a different matter; I think that it is hard enough to take the edge off any file eventually.

I often use an ultra-thin cutting disc in an angle grinder for prepping housing; a bit like using a sledgehammer to crack a nut I suppose, but when used correctly it quickly makes (plastic parts aside) virtually burr-free cuts in any housing, perfectly square, first time.

cheers

[horizon]

Thanks all for the very speedy replies. I do have good cable cutters and always assumed they solved the problem, but as Brucey says, they don't quite do the job. I'm going to pick up a generic file locally (on the basis that gear housing might eat good ones for breakfast) and see how I get on.

[horizon]

Might seem a bit over the top, but I bought a modestly priced bench grinder a few years ago and now use it for a wide variety of jobs, including finishing the ends of cable outers, a job which it does perfectly and extremely quickly. I wasn't sure that I should spend that sort of money (about £30) at the time but ten years later it has now done the job of many files.

I looked at this:

http://www.screwfix.com/p/scheppach-bgs ... 230v/69533

It may be an indulgence too far (compared to a £1 file!) but I don't really have the knowledge/competence to make much use of it - maybe one of the consequences of going to a grammar school and learning Latin. But who knows ....

(I do want to be able to do most bike jobs at home and lack of the right tools is a pointless barrier to this.)

[531colin]

I got one of these...http://www.axminster.co.uk/axminster-awbgdl-wide-stone-grinder....a few years back. Its one of the "how did I manage without it" tools.

[The Bat]

I've found the following methods work the best for me:

For brake outer (spiral-wound):
1. Place onto a flat worktop, hold a Stanley-type knife on the top of the outer, and then 'roll' the outer while cutting increasingly deeper with the knife. Watch that you keep the cut at 90 degrees, it's easy to go off and end up with a helter-skelter. You should be able to tell when you are through as you can feel the blade pressing against the inner metal spiral - you only want to cut through the outer plastic at this point.

2. A bit of 'feel' is required for the next point: keep the blade in the cut you have just made and apply a bit of pressure at the same time as rolling the outer again, but you are aiming to get the blade to separate the metal spiral and cut through the inner sleeve. There is a sweet-spot where the cut you have made in the outer will align with a gap in the inner spiral and the blade will just drop through and neatly cut the inner - it takes a bit of experience but you end up knowing what to feel for.

3. You should now be left with just a piece of spiral inner connecting the two lengths of outer. It should now be fairly easy to cut this almost flush with the end of the rest of the outer. I find a good pair of side-cutters (I use Knipex) are more suited to this than cable-cutters as you are cutting a flat piece of metal, not stranded cable.

4. All that is left to do is open-up the inner (I use an engineer's scriber) and just file the end of the metal spiral - with practise you will have cut this neatly so not much filing will be required. I find it easiest to file with the cable outer held flat on the worktop with its end just over the table edge. I use a smoothing file, about 1" wide, I'm not sure what make it is.

This sounds long-winded but with practice should not take long at all; overall it is probably a lot quicker than chopping through the cable quickly but then spending an age tidying up the mangled end.

For gear outer (with parallel stranded inner): just use a good stranded-cable cutter (I have Park and Knipex) and, because good cutters produce a neat cut, you should only need to open the inner with a quick podge of a scriber and you're ready to go.

[horizon]

Thanks very much for that Bat and welcome to the forum!

I'm still chewing it over but it's great to have more input on what is an apparently minor but actually important process.

[horizon]

Thanks to all again. I have now purchased (from our local ironmongers) a Faithful Tools brand 200 mm Second Cut Engineer's Hand File at £5.19. I certainly wasn't going to have one of those "[rude word removed]" tools that they suggested .