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Hi All

I'm trying to learn some engineering skills by making a small clock hand removing tool out of 5mm silver steel rod. I'm following some instructions taken from a sample paper. I am not used to working with files nor working to exact measurements. I have reached stage 8

8) File a small chamfer all round this end. To do this, clamp a block of wood in the vice with the top protruding above the vice jaws. Hold the rod against the block at an angle of 45 degrees and file a small flat at this angle. Then turn the rod through about an eighth of a circle (rotation) and file another similar flat. Continue by turning the rod and filing another flat after each movement. The result will be eight flats which should all be at the same angle. Now with a combined filing and turning action blend the flats into a smooth chamfered surface that is even all around the end; it may help if a notch is cut in the wooden block to locate the rod. The chamfered edge should be 0.8 mm (1 /32 in.) measured both along the rod from its extremity and, if truly filed at 45 degrees, inwards from the outside surface.

 

My question please is how would I mark 0.8 mm around the top of the rod in order to get this so precise? Is there a special tool I need? I think I am going to need some digital calipers as I only have an old set marked in single millimetres. It may be simple to some people out there but I am trying to learn so I would be grateful for any tips please or better still a YouTube video. I have searched but I can't find one. Maybe I'm not typing the correct term. Another problem is each time I need something it adds another week to the project time as I wait for delivery as the shops are shut but would like to order any special tools I need.

 

Thanks in advance Richard

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Hi Richard,

you appear to be having fun.

You could do your 0.8mm by eye.  Get it to the correct dimension over a short area and then spread along keeping it even.

Or you could use a cheap digital vernier  https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=digital+calipers&_sacat=0

These have sharp nibs that would easily scribe the line to work to.

Are you using marking out 'blue' This will give a surface that gives good contrast bewteen the scribed line and its background

.

 

Roger

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As per Roger's tip, instead of marking blue you can use a dark permanent-marker pen.

AlternativelyI think I would wrap some thin sticky tape - e.g. parcel tape - around the rod leaving the 1/32 " at the end clear, to act as the guide and to give some protection to the bit you don't want to file. 

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Hi Richard,

 you can definitely see the variation between 0.8 and 0.9mm  (that is a whole 0.004")  but you would need to measure it to see that is is 0.9mm

 

And always remember the old adage - 'Measure twice, cut once'  

I tend to remember this just on the other side of the nick of time.

 

Roger

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Thanks for the replies. I think I may be over thinking this but the further I get in to building my tool the more worried I am about making a mistake and having to start again and I am acutely aware that I cant add any material if I take to much off......... 

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In reality if the dimension was actually important you wouldn't file it free-hand unless you had no other means of doing it. This sounds like the sort of filing exercise given to apprentices, learning the hard way by trial and error.

You have to be prepared to make scrap while you practice - you probably will not get it right the first time. Best to have a few goes first on an oddment of material, to get the feel of it.

 

 

 

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13 minutes ago, Richmac said:

Thanks for the replies. I think I may be over thinking this but the further I get in to building my tool the more worried I am about making a mistake and having to start again and I am acutely aware that I cant add any material if I take to much off......... 

Nope ! I served a 4 year toolmaking apprenticeship and the amount of scrap I turned out (along with about 10 others) was heroic ! Working with your hands and developing a skill in benchwork can ONLY be achieved by working material, that means sometimes...you get it wrong.

As Roger and others have pointed out, use engineers blue or as Rob suggests a dark fibre tip indelible pen scribbled over the material and scribe a line to work to, the digital calliper method suggested by Roger works surprisingly well.

 However you have chosen a difficult end of the scale to work with, our engineering test pieces for all disciplines, lathe, milling, jig boring and benchwork were all at least 4 or 5 inches in scale, easier to measure and work with. Engineering at such a small scale at 5mm means your work has to be very precise and is the sort of work established engineers will do after a few years working on large scale pieces with easier to manipulate surfaces. Have a go at this clock tool and use small delicate hand movements, try slow file strokes and feel the file teeth engaging with the material and vary the pressure applied to the file to enhance or reduce material removed, one stroke of the file and inspect the angle and result. Think what you next need your hands to do, a tilt of the file... less or more acute ? how much material was removed ? does it need more or less hand pressure ? if you scrap it, no recriminations just bin it and get another piece to work on, just remember what you did wrong and next time do it differently and preferably better.

Our world in the 1950s was made by such methods and men in brown engineering coats who sucked Victory V and pipes in equal abandon, welcome to their world.

Mick Richards      

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Here's a good example,... under the Knurling Tool posting 

 "My first parts went straight to the scrap, I think I need some practice to make nice diamonds. Ciao, Marco "

Marco is an excellent engineer with first class reasoning and machining skills and he also sometimes scraps pieces as do we all, you are learning skills which will enhance your lifetime, they are won with application and perseverance, try again...and again.

Mick Richards

 

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You do know that you can buy clock hand removers on eBay (I bought one a while ago) I usually use a pair of fine tweezers, with a piece of card under to protect the dial then lever the hand off. 

If you want an engineering starter project, why not try rebuilding a TR engine :ph34r:

Seriously though you have chosen a tough one to start with

Bob

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Mick - when I was a graduate apprentice in the Model Shop at Evershed & Vignoles in the 1950s, we wore WHITE cotton coats (no man-made materials back then).  The fluid used when machining on lathe and milling machine used to cause the cotton to disintegrate.   What it did to one's nether regions, I know not.

My last coat and cotton overall (also 1950s) were recently consigned to the bin as SWMBO demanded what  was the purpose of an overall which had split in a number of places and had to be secured using string.  Fortunately, over the years, I have purchased more overalls at autojumbles so am able to work on the TR.

I used to be able to sharpen quite small diameter drills on my grinding wheel, but eyesight now means that the drills need to be larger for this.

Ian Cornish

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10 minutes ago, ianc said:

Mick - when I was a graduate apprentice in the Model Shop at Evershed & Vignoles in the 1950s, we wore WHITE cotton coats (no man-made materials back then).  The fluid used when machining on lathe and milling machine used to cause the cotton to disintegrate.   What it did to one's nether regions, I know not.

My last coat and cotton overall (also 1950s) were recently consigned to the bin as SWMBO demanded what  was the purpose of an overall which had split in a number of places and had to be secured using string.  Fortunately, over the years, I have purchased more overalls at autojumbles so am able to work on the TR.

I used to be able to sharpen quite small diameter drills on my grinding wheel, but eyesight now means that the drills need to be larger for this.

Ian Cornish

Quite agree Ian, our toolmaker Miller "master" started us off by selecting a 2" dia drill and attacking it on a grinder on it's central web and destroying the cutting edges. Then he gave it back to us and demanded it be represented with in 10 mins reground and tested on a large pillar drill where he expected it to cut a hole within 5 thou of it's cutting flange diameter (checking the eyeballing of the cutting edge lengths). As we progressed in a couple of weeks we reground drills of ever smaller dia until a 1/64th dia was reached when we realised that even young eyes meant a calculated 1 touch at a cutting angle was all that could be achieved, there not being enough material on the flanges to allow manoeuvring of the drill for it's benefit.

Mick Richards  

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4 hours ago, Motorsport Mickey said:

Here's a good example,... under the Knurling Tool posting 

 "My first parts went straight to the scrap, I think I need some practice to make nice diamonds. Ciao, Marco "

Marco is an excellent engineer with first class reasoning and machining skills and he also sometimes scraps pieces as do we all, you are learning skills which will enhance your lifetime, they are won with application and perseverance, try again...and again.

Mick Richards

 

He is better than that Mick his aspirations stretch to making Diamonds. And knowing Marco from this forum he will probably succeed.

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Wow I envy you guys with the skills you have developed and can now use to your own devices throughout your life. All I can do is boss and weld lead and that has limited uses. However your never to old as they say. So I thank you for your comments especially Mick for his wise words I'm going to practice on a scrap piece first.

Thanks again Richard

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Hi Rich,

so that we can help you can you give us some information.

What tools have you got.  Tatty tools are not good. Files, drills, scribers etc etc need to be sharp.

Steel rule - 12" and 7" (see RDG Tools)   Engineers set square.

The list goes on. These help to make life easier.   But as mentioned above, practice o0n scrap what it is for your next move.

One of my BEA apprentice pieces was a mind bender -

the first step was to make a plate about 2" x 4" and into this we cut three holes -

a round hole (1/2" Dia)

A square hole 1/2" square

A triangle 1/2" high with a 1/2" base.

Having done that you had to think of a single piece that would fit into the three holes.  (we did have help)

 

Basically from 1/2" round bar stock the end was filed into a two sided wedge, The was then cut off the round bar.

So it comprised of a circle in the plan view a triangle (1/2" base x 1/2" high) and a square at 90 degrees to the triangle. 

I think I still have it hidden on the garage somewhere

 

Roger

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Three items I made while doing my engineering apprenticeship with Decca are still in use,  a tin plate folded box with a sliding lid, a three pronged puller, & a ½" drive ratchet.

I also made a steel toolbox, but that rusted away !

Bob.

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The first year of my five-year apprenticeship was spent in the mechanical shop learning basic use of files, drills and chisels and machine-tool use ( shaper, horizontal mill, lathe, grinder), before I converted to the electronics trade. During that year each apprentice made a toolkit including a pair of calipers, an engineer's square, a toolmakers vice, a scribing block and two vee blocks and when finished we could buy them at nominal cost.  I still use them all in my home workshop though they are a little the worse for wear now.  We also made a sine-bar but I have never found a use for that !

 

 

Edited by RobH
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On 1/12/2021 at 8:12 PM, RogerH said:

Hi Rich,

so that we can help you can you give us some information.

What tools have you got.  Tatty tools are not good. Files, drills, scribers etc etc need to be sharp.

Steel rule - 12" and 7" (see RDG Tools)   Engineers set square.

The list goes on. These help to make life easier.   But as mentioned above, practice o0n scrap what it is for your next move.

One of my BEA apprentice pieces was a mind bender -

the first step was to make a plate about 2" x 4" and into this we cut three holes -

a round hole (1/2" Dia)

A square hole 1/2" square

A triangle 1/2" high with a 1/2" base.

Having done that you had to think of a single piece that would fit into the three holes.  (we did have help)

 

Basically from 1/2" round bar stock the end was filed into a two sided wedge, The was then cut off the round bar.

So it comprised of a circle in the plan view a triangle (1/2" base x 1/2" high) and a square at 90 degrees to the triangle. 

I think I still have it hidden on the garage somewhere

 

Roger

Rodger the sum total of my engineering tools are files that I bought new for my project and a couple of old tools hidden in my tool box

Files.jpg

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Hi Rich,

files are good and as old as the hills.  Everything that is cut usually needs some sort of filing/smoothing.

Dozens of different types of file from the very coarse roughest devils to the smoothest.

If you have a 6" smooth file and want something smoother turn it around 90 degrees and use it that way. This puts the teeth away from the cut and smooths things down a treat.I think t is called draw filing.

Another useful knack is to hacksaw in a straight line. Not that easy to start with. Make sure the blade is very tight in the frame.

Well done. keep it up.

 

Roger

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"t.I think t is called draw filing."

It is, as you say the file is layed on across the workpiece and you draw the file towards you and then push it away from you, very useful for fairly narrow plate maybe 1/4"  or slightly more where you'll find it easier to control the angle of the file and keep it at 90 deg to the material for a flat surface, it being easier to control both ends of the file and keep it level. It's sometimes used with a drop of oil on the file where the oil lubricates and minimises the cutting action of the file and "burnishes" off the material polishing the surface on the workpiece, very small tolerances can be achieved this way...down to 1/10s of a thou.

You'll find job lots of files and hand tools on e bay, the detritus of thousands of engineering firms who have closed or been driven under. Much of it can be bought for £20-£30 where you'll get a job lot for maybe 30 items, if half is scrap the new price for much of the remainder is probably £10 a piece so you won't lose out for a relatively small investment. See if you can find an engineering set square amongst them, about 6" long very useful for checking for flat or square when working. Like wise Micrometres in all sizes are to be had very cheap and can be recalibrated easily yourself if out of adjustment, I'm envious of the fun you'll have learning to create with them.

Mick Richards     

Edited by Motorsport Mickey
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1 minute ago, stillp said:

Chalk on the blade is a good trick when filing aluminium, to stop the file getting choked.

Pete

Yes that would be it.  I was at BEA when draw filing and they were noted for their Aluminium aircraft (very popular)

 

Roger

 

 

 

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