Files- best bang per buck

I think thats mainly what they mean by not applying force to a backward stroke, presumably given enough time it will start to wear the teeth down and make each successive stroke that much harder. I've not actually seen this demonstrated however.

Like you said, theatrically moving the file off the workpiece to show you're doing it is going to make it much longer to finish the job, i was once told about 50 strokes per minute was a reasonable average, and that a decent fitter could use the same file every day for 3 months and still be in good nick with care. 

Michael W

Edited By Michael Walters on 13/07/2016 12:14:24

I'd say 3 months easily with correct use and a lot of metal removal. Some people reckon that they need a bit of use to cut cleanly and efficiently. I wouldn't argue about that at all.

Filing flat and accurately is an odd process in some ways. Work needs to be at the correct height. At the 10 and 12" size the usual style of flat file with a safe edge should have a curve to it which tends to flattened in use. I reckon for truly accurate work purposefully lifting the file well off the work would mess it all up. There is also the point that a little bit of drag on the return stroke probably helps keep them sharp and maybe has something to do with them breaking in. Just a theory messed up by the curve but given that the pressure goes on after the stroke starts maybe not. Once people have the hang of say on a cube they check the error and then more or less change the angle of the file / play around the pressure on the file depending on the magnitude of the error. Done properly even with a large 2nd cut file the results will stand checking with blue, even the angles. Needs something smoother for a high quality finish.

I'd guess there are other people on here that made the infamous square within a square and fitted an odd shaped template to a hole in a block of steel. In these cases for perfect results people are working to extremely fine limits. I'd guess that even a couple of 1/10,000" will mess the square within a square up. Mine was a 1 inch square. Aim being to get a firmish fit that is exactly the same when the square is rotated. Also when it's put in sideways anywhere. Mine was a very very slightly firmer in one orientation. Wish I could still do it at times When I fit a set of soft jaws to a chuck I cheat and sometimes move the jaw rather than the file.

John

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Edited By Ajohnw on 13/07/2016 13:25:33

Edited By Ajohnw on 13/07/2016 13:26:47

"I'd guess there are other people on here that made the infamous square within a square "

When i was an apprentice those sadists gave me a piece of plate and asked me to get it square in all planes, it was a travesty to sort out and had the chief engineers scrutinizing every aspect of it, despite the fact they wouldn't imagine having to do these things themselves. As far as i could see i was the only one fiddling with metal to accurate sizes by hand whilst they're pushing buttons on their fancy machining centres.

If they really made all their workers do this in the 19th century as a test i'm surprised nobody stuck two fingers up at them, i bet it happened, you're essentially asking someone to make an extremely awkward thing for it's own sake and then blaming them when it goes wrong, they can't seem to understand why someone would get angry? It might be a useful exercise but borderline construed antagonizing. 

I only wish i could see the look on their faces if i asked one of them to get a plate all nice and square for me, oh and by the way, it's going to have the full works of inspection, i'd analyse it to hell, not because it's important just because i want them to. Would show them the picture beyond their mirror maybe? Sounds ridiculous. 

I'd suspect that maybe during those days, there wasn't a separation between "basic" skills(i'd call good filing an art form) and proffesional demands. I think the top engineers then would be expected to do filing but these days you're not so they no longer practice what they preach. 

Michael W

Edited By Michael Walters on 13/07/2016 16:15:43

Agree there Michael but that was when there were proper engineers employed who made this country great. All gone now anything will do.

50 strokes a miniute with a file and lifting off, top whack looking 20-25 with a 12" bastard which will generate heat quick in the part and file.
Bri they might teach you something! I still cringe today at newbies/apprentices purposefully lifting off, taking an eternity to line up again, then push forward each stroke rounding job over.
Theres plenty of reasons not to lift off especially working to microns or end up with a scrap job after 6hrs work!

After reading about Tomé from Dias Costas post, I asked him about them, discussed with our John S, and we decided to pay them a visit last Thursday. Here is a link with pictures and some factory footage of our day trip to Lisbon.

Arc is hoping to carry a range of their products soon. Thank you Dias Costa for introducing us to Tomé.

Ketan at ARC.

Fantastic News, Ketan

Thanks to all concerned.

MichaelG.

How intriguing, I look forward to it.

Michael W

I bought a couple of the files on ebay that I mentioned. They are very sharp. A bit heavily built for flat precision work but I suspect that is down to the style of file.

I'll keep one for use on wood but they are too thick to fit in a groove in a piece of timber to straighten them for working thin edges straight.

John

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Hello Ketan,

Ketan: Arc is hoping to carry a range of their products soon. Thank you Dias Costa for introducing us to Tomé.

I was very happy to help you.
And by extension I also helped a Portuguese company that makes good products.

Dias Costa

During my apprenticeship we were always instructed to break in new files and brass components or scrap brass before using them on cast iron or steel.

I remember a fiendish test where we had to file out a 1" square hole in a plate and then file up a 1" cube so that it would fit without rattling in every possible way of fitting it.

How long before someone makes a model file cutting machine and demonstrates at a show how needle files are made?

Cheers, Tim

I wonder how many times this "Leonardo da Vinci" design has been mindlessly reproduced on the web by people who have not looked in the lower right hand corner

Brass. Lucky you. I was given rather large chunk of steel, a new 10" 2nd cut file, a surface plate, an angle plate, raddle and told to make a dice. Perfect 1.690" cube with the spots positioned by eye to 0.001" via boxes scribed with a height gauge. I can't remember how big the chunk of steel was really but I suspect 4" a side. It took some blisters and months to make it. From memory it was around 1 3/4 per side when they told us to finish it to size. The sizes used were historic and left people reasonably capable of fairly accurate work with a file.

Then came the 1" square within a square that was about 3/8" thick followed by a bit of press tool work. Making a curiously shaped template on a shadow graph and then fitting that to a hole in a hefty block of steel. Also a number of oddments. Cold chisel, screw driver blade, odd leg callipers, a tap wrench and a tool makers cabinet out of folded sheet steel.

Raddle is very fine red lead oxide mixed with a very light oil. They did tell us to wash our hands carefully before eating. It's better stuff to use than blue. Cleaner as well.

John

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Is that your Mondayo Neil ?

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Nay Sir, 'tis an eckerplopter.

MichaelG.

Finally put into stock this evening at ARC.

Ketan at ARC.

Looking closer at that pic again, there's a rocket at top right and try reading the text backwards

Neil

But when will they appear on the website so we can buy them?

Ian P

Hi Ian,

They are on the website in the cutting tools section, link

Ketan at ARC