Articles


NOT JUST ANOTHER STANLEY BLOCK PLANE....

posted Mar 1, 2019, 3:40 PM by Geoff Emms   [ updated Mar 1, 2019, 8:38 PM ]

The No 60 series of low Angle Block Plane, were primary designed, for freely planing end and cross grains, hence the low angle, and the sharpening degree of the blades 20° for the No’s 60 & 61 and 12° for the No 60½.

                                          

 

Now just a little diversion, but I will get to the point.

My knowledge of block planes, was very limited, that is besides using them.

So I decided to give my brain a bit of exercise, and do a full Case Study on the No’s 9½ series block planes, these cover the No’s 9¼ & 9¾ tailed version. But soon came to the conclusion, that it also covers the No’s 15, 15½ , 16 , 16½ , & 17, so the first production date, doesn’t necessarily become type -1- .

These planes pick up the Types as on the No 9½ case study.

But this wasn’t the case with the No 60 series of block plane, they pick up the Type No’s from production date, but the ’’ years ‘’ are, as per the ’’ chart.’’

Back to No 60 series............the No 60 Type -1-1898 has a ‘’Non Adjustable Throat’’, and a Rosewood Finger Knob.

The No 60 Type -2-1903 and following types all with ‘’Adjustable Throat‘’ but have a Brass/Nickel plated finger Knob, ceased production in 1950, but in the mean time in 1902 Stanley introduced a new block plane as No 60½ “Adjustable Throat’’. The only difference with this plane was it had a wider throat opening to accommodate the12° Blade Angle.

Confusion! With that slight alteration, you would wonder, why didn’t Stanley just add it to No 60 Block plane and add a new Type ‘’ say ‘’ Type -4-

Not to be: this block lasted till 1982.

Remember 1902/03 Stanley dropped the No 60 type -1- ‘’Non Adjustable’’ plane, and introduction of the Adjustable Throat, that were more popular and only for a few extra  dollars, became obvious customer choice.

 

So one wonders why. 1911 Stanley introduced yet another ‘’non adjustable throat‘’ .......................well this is it ........... ‘’ Not just another, Block Plane ‘’..............

This is a No 61 Type -1- ‘’ Non Adjustable Throat ‘’ Low Angle Block plane, has a Rosewood Finger Knob and the central longitude rib missing. It was only made for a few years and followed by Type -2- up till 1935, only [2] productions were ever made.

So why did American Collector Bill [Pop] Wilkins call this,’’ PERHAPS THE RAREST STANLEY’S 20 CENTURY BLOCK PLANE, IN MY FORTY PLUS YEARS IN COLLECTING, THIS IS EASILY THE BEST FIND ‘’?

 

                                                                                
      

 It may well be identical to No 60 TYPE -1- except...

No 61 Type -1- has what no other No 60 Series has, raised Casted No 61 on the Heel of the Plane and a Missing Horizontal Rib ...

This is my story /  and bringing old tools to their original glory.

Gerry G.

Notes on Restoring a Plane.

posted May 1, 2018, 4:23 PM by Geoff Emms   [ updated May 5, 2018, 1:53 PM ]

                                                                                 
Figure 1. The Plane as Found. Plenty of Surface Rust and Minor Damage to The Wood.

Among tools being auctioned by the club from the estate of former HTPSWA chairman and founding member, the late Bob Shoosmith, was a derelict rusty Spiers infill plane.
It would have attracted a lot of interest except for some major damage to its rear, where a long past former owner had cut away a section of wood in a most unprofessional and unattractive manner.


Figure 2. Major Damage at Rear of plane

I could, and perhaps should have avoided it, but I am a sucker for a challenge, so I bid for it with little opposition and won.
It was not at all clear to me how to deal with the plane. This is indeed a challenging restoration job.

To Restore or Not?
I don’t want to imply that restoration is always the best thing to do. Hand tool enthusiasts hold a wide range of views; from people who happily repaint black japanning, or polish with Brasso, to people who oppose ANY changes being made. Then there are pure collectors, and people who decry perfectly good tools being put on a shelf, and not used as originally intended. We as members need to respect such views, some of which can be held with a great deal of passion.
If you are thinking about restoring a tool, you would do well to be aware that there will not be universal agreement that it is the correct thing to do. The decision to restore is not one to take lightly.
I far prefer not to restore or repair tools, but I see little choice in this case. The plane would likely end up in a skip if no-one recovers it, so I am not compromising a valuable bit of heritage.

 Exploratory Surgery
At this stage the main task was to explore the situation as fully as necessary to reach an informed decision on the best way forward.
Before we go further, a note about how these planes were originally built is appropriate.
If you have ever considered making your own infill smoothing plane you will have come up against the difficulty of shaping and fitting the rear infill. It is an odd-shaped part with very few reference surfaces to measure from.
The commercial makers, Spiers, Mathieson, Preston and probably Norris all made this job easier by building the rear infill of their smoothing planes in two pieces (see Fig 3):
- A lower section with its top surface flush with the tops of the metal sides of the plane, and
- A top section glued to it that extends over the metal sides to be flush with the outer plane surfaces. If you look closely at any of these planes you will see the join by sighting down the blade bed, or at the rear, where you might see an abrupt change in grain pattern instead.

Figure 3. The Rear Infill is Made of Two Pieces of Rosewood Glued Together.

Close inspection revealed the top part of the infill to be slightly misaligned, in a way that would have prevented the plane working properly. With this being the case, it was necessary to separate the two parts of the rear infill. This was achieved by tapping a carefully-placed chisel, to reveal the original joint surface with its toothing marks and animal glue bond.
I learned something new about the original construction after doing this. The top infill has thin rosewood fillets glued to its sides. This is how the outer wood surfaces were made flush with the metal sides of the plane. The fillets are cut from the same bit of rosewood as the central bit. They are fitted so neatly that the joins are not detectable on the dressed outer faces.

Figure 4. Detail Showing Side Fillets Glued to The Main Part of The Rear Infill.

Having explored the situation in sufficient depth it was time to set the job aside and carefully think about the next step.

Cleaning the metal sides.
With the plane disassembled as far as it is going to be (see Part 1), this is the best time to tackle the metal parts of the plane.
The orange live rust was wire-brushed away to reveal shallow rust pits surrounded by unattractive dark blotches amid patches of clean metal. This is not great news because anything done to remedy the situation will irreversibly alter the surface.
Avoid this step if you can, but I draw-filed the sides until most rust pits disappeared, then used abrasive cloth down to 400 grit, to reduce the inevitable scratch marks. I used various holding methods to keep the scratches parallel to the sole and cleaned the file frequently with a file card to reduce the risk of pinned bits of steel cutting deep scratches. The steel ends up brighter than I am happy with and has coarser tooling marks than were originally present, but my experience is that these settle down over time.
I treated the sole similarly but left more rust pits than on the sides for fear of widening the mouth by taking too much metal off the sole.
This might be controversial, but I find draw-filing to be the most accurate way to flatten a plane’s sole to the standard needed for high performance planes. Sanding as suggested by the books may be simpler but is prone to rounding the sole in my experience. Although draw-filing leaves deep scratches on the sole, careful finer abrasion
can make smooth flat areas between the scratches, achieving a suitably flat and smooth surface overall.

Cleaning the Blade Assembly.
The parallel blade (or iron) is made by fellow Scottish maker; Mathieson and has an early serrated-border brand mark consistent with the early age of the plane itself. It is a composite of soft iron forge-welded to a tool-steel cutting edge. The soft iron part of the blade has a rough stippled surface with areas of dark oxide scale. These must be original features acquired from the blacksmith’s forge. In view of this I did little more than to wire brush the orange rust away. I doubt these early blades were ever bright metal, except at the cutting edge.

Cleaning the Gunmetal Lever.
My observations of well-preserved gunmetal screw-levers suggest their front faces were originally dressed sufficient to remove all tooling marks, before being coated by French-polish. Often the metal and polish have mellowed to give an attractive warm gold colour. This cannot be replicated successfully as you cannot abrade away all the little dents and scratches with their oxidised bottoms that the tool has acquired over its life. Polishing them as is would look like an amateur job.
The screw-lever had a few speckles of original polish surrounded by unattractive oxide patches in some parts and abraded scratched metal in other parts. I went for the minimum cleaning needed to make a more even surface. I used a worn bit of Scotch Pad with a salt and vinegar mixture which works well on brass and gunmetal and does not leave an unduly bright polished surface. One note of caution; salt and vinegar will be highly corrosive on the adjacent steel parts, so neutralise it with baking soda and wash & dry the area thoroughly. A final burnish with 0000 grade steel wool softened the finish.


Figure 5. Cleaned Gunmetal Lever and Blade

Repairing the Rear infill.
The top part of the rear infill was the most difficult part of the job, as it had a missing chunk sawn off by a previous owner. I cleaned the sawn rear face and planed it flat. Then I replaced the missing chunk of wood in four steps. First was a rosewood core fixed to the original piece with a sliding dovetail joint (see Fig 6). It extends to the back of the plane but does not extend to the top or sides. I then carefully fitted chamfered fillets to the top and sides of that core (Fig 7). The chamfered joins are much tighter than the end-to-end-grain joint in
the core piece.

                                                    
Figure 6. Sliding Dovetail Core.                                                                          Figure 7. Chamfered Fillets Attached to Rosewood Core.

As the top and bottom halves of the infill were originally held together with animal glue, I used similar glue to reattach them.
This unhandled plane model presents a simple shaping job. There are enough photographs of similar planes on dealer websites to give a clear picture of the correct shape to copy. The vertical rear face of the plane is simply curved to the same profile as the curved heel of the steel sole. The radiused top edges are then continued around the back of the plane. These were achieved by sawing, rasping and sanding to shape.

You Can’t Get Rosewood Any More.
Prior to the Second World War the commercial plane makers, Spiers, Mathieson, Preston and Norris, mostly used Brazilian Rosewood for their planes, as did most tool manufacturers in general.
Since then, Brazilian Rosewood has become an endangered species, and was protected by the UN Convention on International Trade in Endangered Species (CITES) in 1992. Most countries prohibit export or import of rosewood blanks and manufactured items because of this protected status.
I used Indian Rosewood for this repair, having bought a few pieces from a Sydney specialty wood supplier many years ago. I don’t have enough left to do many more repairs like this.
Indian Rosewood and all other rosewood species were afforded CITES protection in 2017.
You will not be able to get rosewood for repairs like this in future.

 Finishing.
I avoid refinishing if possible.
My preferred approach is to clean wood parts with one of the many cleaning mixtures available. I have used this one for many years: 3-parts turpentine, 3-parts raw linseed oil, 3-parts vinegar, and 1-part methylated spirits. I got this recipe from an article in HTPAA's Toolchest journal. There are similar recipes published in various furniture restoration books. Rub this mixture on and off with rags. Then remove stubborn spots of house paint etc. with finger nails and harder implements as needed.
Even if the resulting surface doesn’t look to have any preserved French-polish, it is worth trying this next step. It is an old French-polishers’ method for rejuvenating polished surfaces. It was first described to me by Ray Bellinger who used to give French-polishing talks at the Perth Wood Shows.
Thoroughly mix 2-parts raw linseed oil with 1-part methylated spirits. You only need a few drops of this mixture for a typical hand tool but be absolutely certain to have more oil than metho. Rub this on the wood with your fingers until the surface feels very slightly tacky. Then rub off with a clean cloth. This can brighten polish you didn't think was there. Any polish you could see beforehand, will look brilliant after this
treatment. The method does not add any new polish and does no harm to the patina of scratches and dents on old tools. I have found this to work wonders on japanned metal surfaces also.
For the present project, the repairs necessarily left bare wood, so the above methods are not applicable.
Up until about the 1930’s commercially made infill planes were French-polished. Later Norris planes are finished with some sort of varnish, similar to our modern polyurethane finishes.
The trouble with refinishing is that unless you sand so deep that you risk compromising the shape of the work piece, you still have dents, scratches etc that form part of the aged patina. Shellac or varnish sink into these depressions. Each little indentation ends up with shiny edges that are the hallmarks of an amateur refinishing job.
I solve this by filling the dents with hard stopping-wax before applying the first coats of shellac. This is a conventional French polishing technique. Once the French-polish is fully cured, you can either leave the filled dents, or pick the wax out of them with a none-too-sharp awl. This leaves the dents and scratches unpolished, more in keeping with their original state.
With only a few bits of rosewood to choose from, I could not get a really good colour match between new and old wood. Application of wood stain prior to polishing partly corrected this, and addition of spirit-based stain during the skinning stage of the French-polishing process further reduced the visual impact of the new pieces.
The repaired surfaces look too new for my liking and lack any patina. This was always going to be the case, however I prefer to leave them like this rather than attempt to forge an artificial patina.
 
The End of the Journey.
After tuning up the blade assembly, properly mating the cap iron to the blade and bedding it solidly on the blade bed, the plane now works superbly.

                       

Figure 8. The Completed Plane Cutting Fine Shavings
This project has transformed the plane from an ugly duckling that attracted little interest, and did not work properly, to a presentable, fully operational item. The repair joints are very tight but are still visible to anyone who looks closely, and the market devalues repaired items. Nonetheless this work must have added value to the plane somehow. I am under no illusions that the days I spent on it can ever be reflected in the value of the plane, but that was never my purpose.
This has been about skill, historical knowledge, learning, and their preservation, values that go way beyond the object itself.
Or I could have avoided buying the plane in the first place….



Thanks to Vic for this interesting article.

Bailey Pre Type 1 Vertical Post Plane.

posted Feb 10, 2018, 7:45 PM by Geoff Emms   [ updated Feb 11, 2018, 2:20 PM ]

ACQUISITION TO MY COLLECTION 
No 3 Pre Type 1 Bailey Vertical Post Plane. 



Leonard Bailey (1855-1905) was an inventor and manufacturer. Working as a cabinet maker approximately 1839-1849, he began messing around improving the wooden planes he worked with. Although iron planes have known recordings as far back as 400AD in Roman days, their blades were more in a position for scraping. Much later, around 1827, a man called Hazard Knowles ( a carriage maker ) came out with an iron plane but with a wooden locking wedge and a quarter of a century later in 1854, a Birdsville Holly obtained a patent on a jointer plane, which was twenty and a half inch long iron plane but it had a fixed back to house the blade. It also had a corrugated bottom with no frog.
Then along came Thomas Worrall of Boston in 1855, a maker of wooden planes but in a transitional form which he called a “Multiform Plane”. It had a wooden bottom and iron top section ( to house the blade ). His TRANSITIONAL PLANES are the most impressive type I have ever come across. 

Now this is where Bailey made his first mistake. His mind set stayed with the successful transition plane, but he wanted an all iron plane. Bailey applied for a patent, as we know now as the “Split Frame Plane” (Two separate castings ). In 1858 he introduced his Split Frame Planes - “Problem Plane” ( Metal on metal ) which again gave him grief over the control of movement of steel, the “rocking blade” and the main thing, tension. Bailey experimented with coil springs and spring steel, double springs, thumb screws and under front knobs.

There were too many moving parts. In 1859 he introduced the new version of these planes but stuck with spring coils but did add a pivoting frog and a solid cast lever cap. In the meantime, in 1861 Bailey moved to new premises in Boston and needed to make money. He decided to drop the production of the split frame. It was to costly to manufacture because it had to have numbered parts, sophisticated castings and filings.       

                                      
  
Hence the birth of what I call- Pre Type 1 Vertical Post Plane. No more split frame, but a one cast body but still staying with the pivoting frog ( a mistake because there was no gain ). The plane has limited adjustments, and on the face of it, the pivoting frog only gave the blade angle adjustment and no up and down movement. The pre - Type 1 Vertical Post plane was made from numbers 1 - 3, though mainly 3 - 8. Maybe only six Number Ones were made. Bailey Pre Type 1 was definitely the front runner of all the Bailey planes.

Thanks to Gerry G. for this interesting and informative article.

Hert Varken. (pre 1740)

posted Apr 12, 2017, 3:38 PM by Geoff Emms   [ updated Apr 13, 2017, 3:19 PM ]

This is a Dutch plane which gave difficulties for the English translator for it is called “The Pig”. The reference book ‘Four Centuries of Dutch Planes and Planemakers’ has illustrations of the pre 1740 plane. One can see small holes front and back which were for depth pins, the horn at the front is for someone to pull the plane as is the hole at the toe which allows a rope to be used. This is thought to be a non adjustable plane because the single skate appears to need a locating track.


             




The illustration of the post 1740 Varken shows an adjustable depth stop. Also two holes which are for the posts of the adjustable fenceThis is the plane bought at the club auction and cleaned.  In the process one of the posts which had bowed was cut and re glued. No markings were found but because it had some features, such as a skate on the fence, a more detailed search was made and the Dutch option was  tried.

 

        

As to why Het Varken was called a pig is interesting. One thought is that it was a difficult plane to use hence in the colloquial language of the tradesman it was a pig of a plane. Also it may have been seen to make a trough through the timber as would a pig in dirt. If it took two to work the plane it may well have had a poor reputation with the tradesman.

Two friends - Wim asked Jaap could he give him a hand working this monstrosity [ it can cut up to 6 1/2 cm deep ] and after a while Jaap stopped for a breather and says to Wim looking at the Varken [ this stage unnamed ] “dit varken is moeilijk werk.’ in our phrase we might say, “ this monster is bloody hard work.”  ```` so the name Het Varken came about ```` true story, maybe, I think, could be .

There are many club members with skill to use the tools they collect. Gerry is one of them. He also has the research techniques which enables him to see the small differences in the progressive history of  Stanley tools and clearly identify each ’Type’. His collection of Stanley planes and shaves is of tools which  have been restored to original condition and with his cabinet making skills he has them displayed in fine Jarrah cabinets. His story is one of bringing tools to their original glory.


 

Editor: Thanks Gerry for your insight  and research into one of the most interesting tools to pass through the Club auction.

 

Heritage.

posted Oct 28, 2016, 2:47 PM by Geoff Emms

It’s All In The Story

How many times do we wonder if only the tools could talk. Recently we were donated some very plain well used and mostly ordinary every day tools that belonged to their Grandfather-Frazer Paterson Henderson 1894 to 1963

Frazer, from Scottish parents was an apprentice carpenter in Kalgoorlie/ Boulder before enlisting with the AIF in October 1915 and served with the 4th and 15th Field engineers. Whilst fighting in Marseilles he was wounded  and returned to battle on two occasions ,was returned to England  and repatriated with” debility” in 1918 and discharged in 1919.

He returned to WA and worked on a family orchard , was married in 1920 ,Worked for DJ Chipper and Son as a coffin maker and eventually joined his brother in partnership as a contract builder  where they went on to build many Gov't buildings and  houses . When the depression hit he returned to Kalgoorlie and worked for the North Kalgurlie Mine as a carpenter whilst endeavouring to repay loans for business debts. After 4 years he returned to Perth and continued his coffin making trade but now for CH Smith And Co in Newcastle street. Suffering from financial hardships, still repaying loans , they relocated several times around Perth to rental houses, eventually settling and building the family home in Daglish. He also made much of the family furniture for the immediate and extended family. This was one of his favourite pastimes.


Having experienced two of the most significant events in our history being WW1 and the depression  no doubt took its toll as he had his fair share of financial and medical hardships. He passed away in in 1963 and his tools remained and were no doubt used by Frazer’s family until now.

Are the tools of collectible significance –Not Really

 Should they be preserved –YES!!      because----- what a story they can tell!

(This brief history was written  by Nigel with information  from papers and documents supplied by the  family )

The Pin Stapling Tool.

posted Jul 4, 2016, 5:51 PM by Geoff Emms   [ updated Jul 5, 2016, 2:43 AM ]

 The Pin Stapling Tool is a pair of pliers that cuts the ends off an ordinary brass or copper pin, bends it into a U shape then allows you to staple 
your papers together in the normal manner.

                                                                       

                                                                        
 Patented in the USA on July 14th 1896 (563970) by James Keyes and Herman Lee of New York, the instructions with the tool are that steel pins are not
 to be used. This example, purchased locally, has suffered a slight amount of damage to one side of the jaw where the pin is inserted. Regardless of this
 damage the tool still works perfectly. 


                                                                       
                                 Pin is inserted in the hole in the bottom jaw, across and out the hole on the other side.  The  flat slider in the middle of the bottom jaw 
                                 is locked in the out position.



                                                                        
                                 The handles are squeezed together, the locked bottom slider causes the top jaw to extend out cutting the ends off the pin and forming 
                                  it into a staple.



                                                                          
                                The paperwork to be stapled is inserted between the jaws. The bottom slider, now not locked by the pin, is able to retract which leaves
                                 the top jaw unextended. The handles are squeezed again, the staple is pressed through the paper and the ends folded in. The result, a 
                                 perfectly formed brass staple holding your valuable papers together.

                                Thanks to Molly E. for her assistance.
                                





 

Slide Rules.

posted Jun 1, 2016, 4:20 PM by Geoff Emms

Sliderules: The What and How.

 

A slide rule recently rescued from the tip as reported at a recent meeting begs the questions – what are slide rules, and how do they work?

 

Mankind on the Moon: Slide rules were used for space program calculations, indeed some were  actually taken on the missions – in case calculations needed to be made (all of the astronauts were slide rule literate), in the photo, the astronaut is wearing a slide rule watch.

 

Lord Merchiston (John Napier 1550 - 1617) was concerned with the time it took to perform calculations – they had to be done using pen and paper, long division and multiplication – a very time consuming business. Extracting square and cube roots were a real trial. It was the 1600s, and calculations were essential for the emerging fields of engineering and navigation, as well as the increasing interest in science and astronomy. Merchiston, in a brilliant stroke, invented logarithms.  With these, any numbers could be multiplied by merely adding the logarithms of the numbers, and then looking up the anti-log of the result to get the answer. (so, the log of 100 is 2, and the log of 1000 is 3, so to calculate 100 times 1000 , add 2 + 3 = 5, the antilog of 5 is 100000, which is the answer). Division is achieved by subtracting the logarithms. This was an astonishing advance in calculation, indeed, and extracting square and cube roots is achieved by diving the logarithm by 2 and 3 respectively. (Merchiston also invented the decimal point). Tables of logarithms were published and advanced calculation immensely.  Of course, the results were limited to 4 figure accuracy, using 4 place logs.

 

Within a few decades, William Oughtred, an Anglican vicar, arranged two logarithmic scales face to face, which could be used directly for calculation, without having to use logarithmic tables – Oughtred had invented the slide rule. (Usual rules have linear scales – equal distance between the numbers, however  in logarithmic scales the numbers are squashed closer at the large end, as in the photo). By the mid 1800s, a young French artillery officer had developed the layout of the slide rule as we know it now – it was found to be so useful for artillery calculations it was adopted by the Military, then spread to the world of science and engineering.

 

The slide rule meant that complex calculations could be done immediately,  and they became icons in movies and photos. It was usual to have photos of people such as Franck Whittle (inventor of the British jet engine) and Edward Teller (inventor of the Hydrogen bomb) with slide rules to show they were at work. The use of logarithmic tables for multiplication and division was taught in schools, and those students studying physics and chemistry also learned to use slide rules. All university engineering courses included a section on the use of slide rules. Slide rules for specific purposes (bomb aiming, navigation, space travel, pressure pipe calculations etc) were developed.

 

The beginning of the end for slide rule use occurred in the mid 60s, when an engineer developed the first electronic calculator – indeed, he had performed all the calculations necessary for the invention using a slide rule! It was the introduction of the HP calculator in 1972 that tolled the end of slide rule use, and early electronic calculators were called “electronic slide rules”. Slide rule production ceased in 1976, however there are still large numbers of slide rules extant, and batches of 'new old stock' are unearthed periodically. One Japanese manufacturer still has for sale (on their web site) their circular slide rule as sold in the 1970s.

 

Enthusiasts still collect and use slide rules, there are still annual slide rule competitions. The benefits of using a slide rule are real – use combines physical and mental skills. For example, from the photo, it can be seen that the decimal point is not shown. It is the same process to multiply each of the following:  218 x 325 or 0.218 x 0.0325. For each, the slide rule will yield the same answer,  that is, 710 as in the photo. In order to get the right decimal point in the answer, it is necessary for the person to mentally estimate the answer and insert the decimal appropriately., thus requiring a level of mental arithmetic.

 

Of course, a slide rule does not rely on batteries! In the mid 1980s I recall that a person teaching navigation for solo yachtsmen insisted on each student learning to use both calculator and slide rule use in the course, arguing that no-one knew when they may be mid-ocean with dead batteries....... I cant imagine that such courses insist on slide rule use now, however I was recently interested to hear a Master Mariner, whose job it is to test and certify magnetic compasses on commercial ships in Australia waters (it is an annual requirement) say that the compass is required to be accurate, being the fall back navigational aide should the GPS system for some reason become unavailable. However, he also said he expects that it wont be many more years before the requirement will fall away, if for no other reason than sailors themselves will no longer be skilled enough to adequately use it.

 

The point about accuracy also indicates the fundamental limitation of the slide rule – the usual 10 inch rule will yield 3 figure accuracy. There were special slide rules (40 inch long) that would yield 4 figures, and cylindrical slide rules (the scales being spirally etched on the cylinder) that had scales equivalent to 80 feet would yield 5 figure accuracy. The first electronic calculator mentioned above itself had 12 figures, undreamed of on an analogue system. The use of 3 figure accuracy in engineering meant that engineers needed to be conservative in their designs – panels were made of thicker materials than actually necessary, etc, to avoid failure. Since the introduction of calculation to 12 figure accuracy, devices are more precisely designed –  lighter and more reliable. 

 

The slide rule was indeed a great step forward for mankind when it arrived, it is very pleasing to use (if you like puzzles, crosswords etc – I periodically take my slide rule, retained from my school days (!), dust it off and work through some textbook problems – just to keep my hand in). (Mind you, I still also use the RPN logic  calculator I had as a uni student – although it is a virtual one, the original device alas ceased to function a decade ago).

 

There is a large amount of material on slide rules, how to use them, example problems to solve etc on the internet – just search for the Oughtred Society, whose web site has a wealth of material, including virtual slide rules that can be downloaded onto your laptop or tablet – work just like the real thing! Slide rules are plentifully available for purchase on ebay type platforms, and there are slide rule societies in existence, too.

 

My regret: There was a teaching slide rule (about 6 foot long, large scale, to be visible from the back of the class) at one of the educational institutions I worked at a decade or two ago – of course it hadn't been used since the 1970s, and languished in a store room. The lab assistant, noting my interest, asked if I wanted to have it. I declined (it wasn't, after all, mine). Alas, some years later, it was taken to the tip............

      The Pickett 160 slide rule.

Slide rules have ABCD scales, where C and D are the usual scales used, giving the interval 1 to 10 (and often called “X”). A and B are indeed merely C and D squared – that is, they range from 1 to 100 (ie, X2). There is often a K scale, which is the cube (so ranges from 1 to 1000, that is,  X3). The inverse of the C scale is usually given in the centre scale , called CI, (ie, 1/X). Also, usually given at the bottom is a linear scale (called L), which yields the logarithm of the number (so, in the photo, the cursor shows that the logarithm of 710 is 850).

 

To multiply, say 218 by 325, as in the photo, set the 1 of scale C to the first number (218) on scale D, then using the cursor, find the second number (325) on C (so that is actually adding the second number to the first one), The answer (710) appears on the D scale, under the cursor. Note that you have to estimate the position of the “8” in 218, to be somewhere between the marks for 215 and 220. Likewise, close inspection will show that the cursor is just a shade below 710. The actual answer is of course 7085, which would round up to 709 to three figures. Given the thickness of the scales' lines (and the Pickett 160 was in fact a 6” slide rule, not the usual 10” model), the answer of 710 is close. To get the decimal point, one has to mentally do an approximate calculation, so 218 is close to 200, the estimate might be, 100 x 325 is 32 thousand, so twice that is close to 70 thousand, so the decimal in the answer is 71 000, not 710 as given by the three figures.  Older engineers, brought up using slide rules and so having to mentally estimate the size of the answer to get the decimal point right would say that this mental exercise gives the person a feel for the size of the answer – ie, an idea of the actual physical entity being described by the number – an invaluable insight that only use of a such an analogue device can give.

 

 The Tachymeter scale on an analogue watch,   solves 1/T (where T is time in seconds) to give the speed. The scale is on a rotatable bezel. Place the zero on the scale on the second hand when passing a milestone, then when passing the next milestone, the bezel will give the speed (in Km per hour, if using Km pegs on the road).  This isn't a slide rule, really, as it doesn't involve logarithms, it is really a nomogram solving the expression 1/T. For example, if it took 30s between Km pegs, then the bezel would yield 120 km/hr. Although these are still readily available now, they are of limited use as most roads do not have Km pegs any more.

 

Credits: Images come from the Oughtred website, the Tachymeter image from the web, and the slide rule example from the virtual Picket 160 slide rule. 

 

 

 

 

 

 

Nuts and Bolts.

posted May 25, 2016, 7:09 PM by Geoff Emms   [ updated May 25, 2016, 7:11 PM ]

What you always wanted to know about Nuts and Bolts

By Bob Wallis (non-engineer)

June 2016

NUTS & BOLTS

Once upon a time I was fascinated with the history of how nuts and bolts evolved along with threads, yes, Joseph Whitworth sorted the threads out, but the profile of the bolt heads got me.

I believed the square nuts were replaced by the hexagonal about 1900 – Wrong!

The hex head was developed as far back as the very early 1830’s (James Nasmith) , and the square continued mainly in the production of agricultural implements.  In Australia the implement manufacturers bought square mild steel bars and made their own, say into the 30’s (Depression).  1/4" Gutter bolts with square nuts are still available.

The common rule was that Square was used where the fastening was not required near the vertical member, or with tension, and then hexagonal were used so as to get closer to the vertical member. If you needed to get even closer, then an Octagonal nut was used – however I have not seen an octagonal but I’m assured that some of the early steam engines used octagonal nuts, again in the early 1800’s.

Today we often see a variety of nut heads used mainly as ‘security’ to ensure you ‘keep out’! – but now you can buy the kits to remove them. During 1974 Rolls Royce had square nuts right down to small. 3BA that held the pipe clips were also square. Also some railways still use square nuts in fixing rails to sleepers etc.

Joseph Whitworth (1803 -1887) During 1841 devised the ‘British Standard Whitworth’ system of standard threads and more so the pitch (55 O) to ensure the greatest strength in the nut and bolt. Before this revolution each manufacturer made his own proprietary thread which in turn meant only he could replace them!

On my “ARAB” platen printing press, patented 1872, (and sold in pack form) it has mostly numbered Whitworth nuts and bolts after 1841, but one set of four bolts  is definitely proprietary thread. On restoration of the platen one bolt was missing and it had to be remade.



James Hall Nasmith (1808-1890) patented a machine for milling hexagon by 1829.  It was tooled to mill the six sides of a hex nut that was mounted in a six-way indexing machine.  Nasmith did not suggest that hexagons were anything new, and he refers to the tediousness of the filing process in making them.

Back a little further, innovator and inventor, Henry Maudslay [1771-1831] Nasmith worked in his early years for his partner after Maudslay died, as a Draughtsman, in the Illustrated Table Engine of 1807, hexagon nuts were found to be used. (Again, proprietary) and as used by Maudslay.  

In conclusion, on the shape of the nuts we find that two of the  differing heads, hexagon and octagon were both developed during the early 1800’s, or even before,  and the square head would perhaps be some 100’s of years before, at the time foundries commenced and threading devised. Some consider that the screw thread was invented in 400 BC by Archytas of Tarentum (428 BC – 350 BC) one of the first screws principle to be used was in a press to extract oils from olives and juices from grapes. Archimedes (287 BC-212 BC) developed the screw principle and used it to construct devises to raise water.



LOCK-NUTS

The original concept was that the thinner nut went on the bottom, and the thicker went on top. Then two 3/4 nuts were introduced. This was widely believed as far back as 1893. Then the world went upside down and said the thick went on the bottom and the thin on top, for convenience, then science .

It is now proven that the thick nut goes on the bottom, and the thin locking nut on top. The argument is that when the load nut (thick) is tightened, it butts on the threads and sends the strain down the bolt and actually thins the bolt by that pressure by use of the wedge of the thread. The locking nut only does that, it locks the pressure being applied down the bolt. However, the strain can only be applied to the tensile strength of the bolt. (Below is a diagram showing the forces of the tension)


It is said that in backlash even a precision class 4 bolt, (lower the number the smaller the tolerance) with selected nut, will have some, whilst a class 1 course tolerance bolt it could be as much as ten thou.

For example a class 3 bolt with a quality fit – lying in the middle of the tolerance range, the clearance will be about 3 thou. If the bolt were 4” long in mild steel a stress of no less than 22,500 p.s.i. to take up the clearance, and then a bit more to get the locking action. Remember that by tensioning the bolt it stretches and the nut compresses, the effect here is that the pitch of the thread changes.






On applying the locking nut it now compresses the expanded load nut. If the small nut was on the bottom then the pressure applied to the thinner nut is greater than a thicker nut. The manufacturers of engineering nuts and bolt advise the maximum tension that should apply. If exceeded the bolt will either stretch or break – there is more science applied to the tension under more stressful situations, but for normal use the manufacturer’s details will suffice. (Source 1)

ROLLED THREAD

Up to about 1941 the Aero Engine Industry thought rolled threads were cheap and nasty and they only tried them as a war-time experiment. Now they are accepted as being much superior to threads formed in any other way. (Source 2)

Conclusion: Today, we find that many of the old threads are gone including BSW and most now used are either Metric, or Unified (USA), however there are still many applications where BSW and BSF  are still used. The shape of the nut-head now has many profiles, and differing uses.

References:

Source 1. “Model Engineer” November 1974 – Article by Tubal Cain page 1069 - 1073

Source 2.  “Model Engineer” December 1974 – Article by R.G. Markham page 1239

 Bolt Science. info@boltscience.com 

END.






Darex Wad Punch.

posted Apr 1, 2016, 3:54 PM by Geoff Emms

The Darex wad punch set has 10 punches from 2 mm to 20 mm. The smaller 5 sizes are threaded to screw into the centre of the handle while the larger 5 use a bayonet fitting to connect to the handle. This allows the tool to be used  with a single punch for cutting wads or two punches together to cut a washer.

                                                                
OD 12 - 20 mm, ID 2 - 10 mm. 35 combinations.                                                                                 Contained in a metal box.                                

Mitchells Brace Jaws.

posted Jul 27, 2015, 11:22 PM by Geoff Emms   [ updated Jul 28, 2015, 5:13 PM ]

Stanley Australia  A144- 10IN Uses Mitchell Jaws.

At a recent meeting one of our members had a query about an interesting pair of jaws in an old brace. The jaws are the type commonly known as "alligator" because of the teeth on their two mating surfaces, but these teeth were in two groups separated in the middle by a short land or toothless section.
This style of jaw was patented by Charles Mitchell, an employee of the Stanley Rule and Level Company of new Britain, Connecticut, USA.

                                                    
Toothless Plain Jaws.                                                                                                                       Alligator Jaws.

Braces, originally, were designed to grip the square tapered tang of the standard auger bit by various means. as new shapes of tang, round straight, round tapered (Morse) became common, efforts were made to design a jaw that could accommodate them all. In this regard many could be filed in the "Jack of all trades, master of none" department. 
The recognised breakthrough came in 1864 with William Barber of Greenfield Massachusetts patent (42,827) for a brace chuck as we recognise it, with two jaws clamped by a threaded "nut". This was improved upon in 1868 by Charles Amidon ( 73,279) the rights eventually owned by the Millers Falls Company of Millers Falls, Massachusetts, and eventually became the standard, widely used by other manufactures.
Two very similar patentees, John S Fray and Co  of Bridgeport, Connecticut in 1888 (395222)  and Joseph P Bartholomew in 1904 ( 777,657) designed a pair of jaws connected by a U shaped spring running through a hole in the base and running up the back of each jaw. These jaws were available both plain and toothed. Joseph Bartholomew was an employee of the Stanley Rule and Level Company which is where, on December 12th 1911, Charles Mitchell came into the picture. 
In his patent description Mitchell drew attention to the failure and breakage, in the middle section, of current alligator jaws, usually from over tightening, and proposed that his design would result in jaws having more strength in the central area.

Mitchell's  Jaws, US Pat 1,011,227, Dec. 12th 1911.

Mitchell's design called for a raised, toothless section between two sets of teeth to substantially strengthen the central section of the jaw. 
This new style of jaw was used by Stanley, not only in the USA and Canada, but also in England ie No's 73, 75 and 144 and here in Australia, No's A78 and A144. This style, also, has been adopted by manufacturers world wide.
There are a number of different modern jaw types and in the Stanley Catalogue No 34 of 1927 no less than 81 braces are listed and of five jaw types available Mitchell's is used in about 22 of them.
Many hardware merchants offered replacement jaws for braces and for this reason attempting to date a brace from its style of jaw is quite risky.
 

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