Getting started

Hi all
I was given a small Stirling model engine to build for a birthday, and am trying to get going on it. I have discovered (or rather re-discovered) that
I cannot file to save my life.
So I bought some round bar to file into a cube (I read this somewhere on the net as an exercise in filing), but I can foresee that I will have a pile of iron filings and nothing else before I manage to get even a single surface flat.
Suggestions please?
Rich
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wrote:
| So I bought some round bar to file into a cube (I read this somewhere on the | net as an exercise in filing), but I can foresee that I will have a pile of | iron filings and nothing else before I manage to get even a single surface | flat.
Shades of the Apprentice School <mumble> years ago. We were given 1 inch bar and had to get all dimensions within 1/1000 inch. Almost everyone achieved that, though some ended up with a very small cube.
Do not rock the file.
--
Dave F

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On Wed, 19 Jan 2005 09:18:31 -0000, "John Smith"

Practice, practice and more practice. There's no easy way to acquire hand fitting skills, like welding and other things which require hand/eye coordination, the more you do it, the better you get (until you get to my age where your eyes start to go...)
There are a few short-cuts, like machining all over instead of filing, and starting with square bar so you only have to worry about two faces and so on.
Sadly, many of these skills, like bearing scraping are being lost as modern machining resources do away with the need for hand fitting.
Peter -- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk http://www.prepair.co.uk
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File that cube!
Once you have done it, you will find that good-quality filing is second-nature and not a daunting prospect.
Don't do it all at once.
5 minutes (and no more!) before breakfast.
5 minutes (and no more!) at lunch time.
5 minutes (and no more!) in the evening.
The "and no more!" is important for two reasons; firstly because it prevents you from becoming bored and frustrated, and secondly, because you can immediately correlate the effect you see on the metal in front of you with whatever wrist and arm action has brought about that effect.
Don't rush in being too eager to complete your engine, because once it is complete and you have more time on your hands than you ever allowed yourself to make it, you'll regret having been in such a hurry.

that
the
of
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am
surface
Buy a really decent file and save it for use on steel only, guard its edge(s) as you would a honed wood chisel. Don't try to remove too much metal but dont let it rub, make sure the vice is at the exact height for your forearm to be horizontal, only work in excellent light with clean specs if you need them, Treat each stroke as a new event I used to rotate the workpiece so I could observe the pattern to ensure I was cutting in the centre without rocking. Do not be in a hurry the fun is the journey not the destination (as they say)
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On Wed, 19 Jan 2005 16:47:57 -0000, "Chris R"
| Buy a really decent file
Several really decent files, coarse and fine
| and save it for use on steel only, guard its | edge(s) as you would a honed wood chisel. Don't try to remove too much | metal but dont let it rub, make sure the vice is at the exact height for | your forearm to be horizontal, only work in excellent light with clean specs | if you need them, Treat each stroke as a new event I used to rotate the | workpiece so I could observe the pattern to ensure I was cutting in the | centre without rocking. Do not be in a hurry the fun is the journey not the | destination (as they say)
Thinking back <mumble> years to the Apprentice School. When you get a cube side *almost* flat, I was taught to turn a fine file at right angles to the normal way, hold it with two hands one on each side of the work, and then work carefully in the bump
/\ Movement of file \/
| | | | | | | | | | hands ___________________________________________ ___________________________________________ file | | | | work
Hope this is understandable
--
Dave F

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Yes I was told about new files for brass and old for ferrous as an apprentice but my wages were lower than the cost of files then. A decent file doesn't require much down force so the fatigue factor is far less and you can concentrate on what you are doing more. I cant believe how much easier it is now than in the old days. We were taught to chalk the file first to help release clogging filings but now I believe it only helps diull the file and I think incorrect down force and speed is much to blame. I agree that clearing frequently is important but I am not keen on file cards whcih could dull the file and a gentle tap seems effective. Orherwise I brush the file before it gets clogged
Anyone tried using teflon spray as a release agents on files?
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On Thu, 20 Jan 2005 10:26:34 +0000 (UTC), Neil Ellwood

We always used a piece of ali or brass sheet, as wide as the file, rubbed diagonally into the file face which eventually gives you a 'comb' which cleans out the swarf and any other gunge as well.
Our metalwork teacher (J.J.Jefferies) always reckoned that file cards blunted the file teeth as the steel wires were relatively hard. Peter -- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk http://www.prepair.co.uk
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On Thu, 20 Jan 2005 11:06:06 +0000, Prepair Ltd wrote:

Having re-plumbed the house I have lots of copper pipe. I cut a nine inch length of curved half-inch diameter stuff and pinched one end flat, and I "scrape" that diagonally across files; it develops a comb edge which is perfect for cleaning. Now have three pieces to accomodate different pitches.
Ken.
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On Thu, 20 Jan 2005 11:06:06 +0000, Prepair Ltd wrote:

We were taught that the file card had to be used across the file at the same angle as the teeth, the file card should not be used so much as to make a lot of difference to the life of the file.
--
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Neil
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On Wed, 19 Jan 2005 09:18:31 -0000, "John Smith"

I'd suggest you start off with a square bar - saw a lump off and practice getting the end faces square first. The existing square faces will give you a reference to work to - it's all too easy to end up going round in circles with the round bar ( excuse pun ).
Always use a decent file - and make sure you only cut on the forward stroke...don't drag the file back over the work.
Once you feel you've got the gist of it, try the round bar.
Happy filing!
--
Stephen Howard - Woodwind repairs & period restorations
www.shwoodwind.co.uk
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On Wed, 19 Jan 2005 12:40:17 +0000, Stephen Howard wrote:

This reminds me of one of the trade tests on national service, they called it a square fit.
Basically a block of mild steel with a square hole scraped to fit a square block that you had made first, then a drilled hole and a tapped hole: both ends filed, one long edge chiselled and the other edge scraped. The only tools were Files, scraper, blue, Hand brace, drills, tap, rule and firm joint calipers.
Time allowed was something like 4 hours.
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A common problem for starters is the rocking motion as the file is pushed forward and back. Concentrate on keeping the movement parallel with the floor and not bother about the amount of metal being taken off by pushing down hard on the file. Apprentices used to be taught to take the file away from the work on the return stroke, and this encouraged the placing of the feet so that the body was balanced when doing the file stroke, i.e not rocking all over the place. (not sure about its validity ..... might be just the whim of the apprentice foreman!!) The work needs to be at the correct height for you, i.e so you are not lifting or dropping the elbow uncomfortably.
Second problem... do not keep filing in the same place .. you will get a hollow ..... also try to vary the angle of the file up to 90 degrees if necessary when attempting a flat face.
Get the right cut file for the job. Too fine and it will skim across the surface too rough and it will grab or bounce. Unfortunately the right file will vary from metal to metal as well as experienced use.
Not a treatise on how to file but might give you some insight......
Alan
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... and use the full length of the file. The longer the filing stroke the easier it is to detect (and correct) any rocking in your technique.
BTW, the easiest way to get a true and square end to a piece of bar stock is to use the lathe. If you have not already got one, a four jaw chuck should be pretty high on your list of desirable lathe accessories.
--
Mike Hopkins
CSME <http://goto/cheltsme>
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