Member postings for john jennings 1

Judging by the prices this gear is made of platinum!

Is this a first?

John

A sharp tool with the correct geometry and at the right height should ensure success even at "LOWER" speeds.

If it still gives a poor finish I would suspect the material. So called "HARD" brass is required for a good finish.

Some brass is very chewy, particularly sheet that is intended for bending or forming : round rod is less likely to be like this but bending rod is a possible requirement in manufacture (although unlikely above 1/2" diameter) and hence soft material is required. This soft brass will turn as badly steel reinforcement rods do if you are foolish enough to try!

The simple solution is I am afraid to buy material of known specification.

If using unknown material any hexagon rod is almost certainly OK as it is intended for turning nuts and hexagon headed bolts.

John

Must agree with Michael.

John Wilding is a very practical clock maker (a sort of Horological LBSC ) and made to his designs a timepiece or clock should tick away, no problem. Re-reading some of John Wilding's books the construction instructions occasionally drift off to being a little obscure (just like LBSC) which I tend to think is partly down to the assumption that you will have read all his books. His books on clock repairs are particularly valuable for the techniques described and for the construction notes for a variety of specialist tools.

John

Browsing the bookshelves I chanced upon BONDS O’EUSTON ROAD “Light Engineering Catalogue” dated 1964. It portrays a lost world of limited choices and a catalogue amazingly thin in detail.

In particular it features the Adept Lathe the subject of this thread.

The model offered was the version without leadscrew retailing at £9.12 .A four jaw chuck (no size specified!) added £3.10 and a 0-¼” drill chuck a slightly extraordinary £ 2.45.

Motorisation was available a “Foot Motor” (some form of treadle?) and Countershaft totalling £6.35 and Six lathe tools £ 0.65 .

To give a context a Myford ML7 was £70.75 and a Super 7 at £102.35 , both as bare lathes (but probably including an electric motor).

The Unimat SL at £33.50 pointed to the future being complete with a 3 jaw chuck, drill chuck and motor.

Interesting there are no fewer than five hand shapers starting with the Adept No 1 at £16.00

(All prices decimalised.)

John

I too use the bandsaw route for sheet metal cutting, both with a B&D equivalent of the Burgess and a bigger ELU wood cutting saw. A 32 dpi blade is needed and for brass will need to be sharp (new?), alloy cut by this method will tolerate a blunter blade.

My usual technique is to use 3 to 4 mm ply wood as a carriage, this damps the blade and reduces the noise.

Correctly positioned (and with a well set up bandsaw) you can run the carriage plywood edge down the fence and get very reasonable straight edges.

I must confess to having abused the B&D in the past , cutting steel blocks 1-1/2" thick and alloy blocks even thicker.

John.

My first set of taps was BA in a wooden box although mixed in manufacture. This was sixty years ago from a shop in Farringdon Road (London) which didn't seem to sell other tools. Looking back I suspect they had had a good war and were of varying sharpness. Since then I have bought as required (Not many of these), some I thought would be useful such as some ME. When I lived closer a visit to Tracy tools was always expensive but Very Good Value.

I have also bought random taps and dies from end of lines in shops and stalls - usually HSS was on offer.

Result is a three decker collection of all sorts from 14BA to 1/2 whitworth.

John

You may have explored all below to the point of insanity - apologies if so!

"Given that the fusee does not accurately compensate for the varying output torque of the main spring"

In principal that is what fusees do,

If your drive force is varying so as to affect the rate of the timepiece there are two likely causes.

One.: The profile of the fusee helix is wrong or does not match the properties of the spring. Is the profile you used a published one or is it made up or derived in some way? Trying another profile may be an answer but would involve much time and effort.

Two: The fusee is suitable/correct but the mainspring and fusee need setting up. Basically this involves altering the amount of spring still wound when the stop work is in its fully down position. This tuning should get a better fusee action and constancy of torque.

You also conclude that the escapement is very sensitive to driving force. This worries me as the escapement is supposed to ration the unwinding of the mainspring with a time dependent element. .

Now an increase in driving force by a well positioned finger on the driving train will cause a speed change. It shouldn't cause the train to free wheel. If your train is seriously sensitive it would appear to be effectively a freewheeling set up and not a time latched/unlatched process.

Is your escape wheel and its pallets adequately depthed ? Does the escape wheel bounce (recoil) or stop (deadbeat) or dribble round ? This may be difficult to observe with a lever escape which appears to be used.

John

A very posh and quite large rise and fall light system , lacking a light fitting and shade.

I remember smaller ones with porcelain pear shaped bit in a dental mechanics work shop in about 1950, but I think not new then.

The idea was you could push the light up out of the way or pull it down for an intense local light.

The pear shaped bit is a container that you filled as required with lead shot to balance the light fitting shade and bulb.

John

I fear that part of the education and training course that you are on is to think of an idea for yourself.

What you can then do is to use entrenched wisdom of this forum to suggest how practical a project you have decided on and if it it likely to be completed within your time allowance.

Again, I guess that solving the problems is essentially down to you with the guidance of your tutors.

Sorry to appear a bit negative but you can only benefit from your own learning experience.

John

Bikepete beat me to it.

I looked for the new title of MEW , ''Zen and the art of Model Engineering'' , but not to be found.

Seriously , I accept that "a better deal" may be out there but an approximate price guide is part of a review.

Again although the general costs of many things in articles may be difficult, as the reserve store or junk box may be the source of much material, some items will have been purchased within living memory . So I guess for example the cost of the Hacksaw castings in the current issue is known and might be useful in deciding if to embarque on construction.

By contrast the cost of a surplus motor bought 25 years ago, even if known, is nor particularly relevant although the type/sort/source of the motor might be.

John

I don't know if you have a clear idea of what you want or an existing tool. If so you can ignore most of below!

Wearing my woodworking hat the term ''scratch stock'' conveys the idea of a cabinet scraper with a particular profile (which might be quite complex), also the blade would probably be sandwiched between two pieces of timber to provide a grip/handle and some sort of guide/fence.

The blade will cut because, like a cabinet scraper, it has a turned over (hooked)edge mad by burnishing a sharpened edge.

For the blade I would think 1 mm adequate and some sort of carbon steel. Short of buying something (horror horror) an old woodworking panel saw would provide a life time source. An ordinary resharpenable saw is probably easier to cut and shape than a hard point, Blunt saws at a car boot ought to be cheap enough to try both. A dremel or clone with cutting wheels/pioints would be my choice to cut and shape. The resharpenable saw may be best if you go down the soften-shape-harden-temper route.

John

Using Firefox, the right hand column is 'behind' the list of forum posts on the right side of the screen.

The pdf downloads fine

A lathe/workshop in the house is quite practical within limitations. If hidden away in a cellar or accessible loft a fairly large set up is possible - say ML7 size.

On an 'open' site as proposed I would suggest we need to keep feet firmly on the ground and fitting as big a lathe as will fit in and fill the space will lead to conflict and frustration. Working space is required round machine tools and many other tasks have to be done round 'lathing'.

As is always true the size of the proposed work governs machine size as does the landing location.

From experience if a smaller size is practicable an EMCO UNIMAT 3 (4) or Compact 5 could fit the bill. Both can be fitted with a mill drill and the latter a combined drip tray splash guard. The Unimat is also cupboard storable. Both were well built in Austria (although at a price - but not a lot else was available 30 years ago). The Compact 5 is one man handleable

I have not had experience of the later more or less clones which are I guess far Eastern (but much cheaper).

Once set up dirt control is the big problem swarf flies , sticks and moves. No answers!

JOHN

Our egg supply used to be from a local butcher (now closed) who sourced his eggs locally and were generally large and often double yolked. An occasion of note was a generous scrambled egg for 3 - Four eggs Eight yolks!.

john

If you have already tried apologies , but I think that you may be unduly pessimistic concerning spares.

I had the same problem with a ten/twelve (??) year old machine finding the top wheels were disintegrating.

As a typical practical (tightwad?) model engineer I checked through what I had in the way of plastic bits.

Although I found possible material its boiling water resistance was unknown , it also on reflection seemed a lot of tricky machining that might end in melt down.

A bit of webbing and I found http://www.espares.co.uk that had pages of BASKET WHEEL spares (not manufacturers originals but manufacturer seem not to care for the older spare! ) and after a lot of gazing I picked a set that worked, if not an exact match, and gave another two years before another terminal illness intervened.

Alternatively a midway course of cannibalising a near match could be tried.

The only caution is that the wheels are relatively expensive ( with post c.£20 for four ) and buying a hat full to try is not really practical unless you employ a buy/try/return strategy

happy searching

JOHN

Posted by john jennings 1 on 13/09/2014 17:09:56:

Citric acid is so soluble that a saturated solution at room temperature will consume vast quantities of acid and the resulting syrup will be very messy and difficult to handle.

What a load of claptrap.

Sorry I'm not sure what the claptrap is.

Using Muzzers figures a pint of warm (30 C) saturated citric acid solution would need over 2lb of solid acid.

This seems a really awful lot and if the solution evaporates or cools it will deposit excess solid acid.

The action of citric acid is quite complex partly due to the acidity of the solution (which at higher concentrations won't be proportional to the concentration) and partly forming soluble citrate complexes with, in this case ,copper atoms/ions.

End of chemistry tutorial for today!

However I guess it is a matter of experiment : I would still begin with weaker solutions.

John

Citric acid is so soluble that a saturated solution at room temperature will consume vast quantities of acid and the resulting syrup will be very messy and difficult to handle.

I would have thought that 5% solution i.e. 50g per litre ( or 1 ounce per pint ) would be quite strong enough for purpose and If you want a large volume to totally immerse the boiler you would probably find a more dilute pickle would work if hot. Although citric acid won't give off an acid vapour - leading to mega rust on steel - I would prefer not to store the solution which is another reason for making it over strong.

John

OK, so it is possible to cut " granite" sheet in the home workshop particularly so if the material is a loaded plastic composite. I am less clear about is why one would want to use the material in the first place. Certainly real granite would add weight ( and stiffness) to a bench but might also add to problems coping with the weight of machinery and its desire to migrate to Australia by the direct route (from UK that is). It is also hard and cold with a poor bounce index. The composite material may have less problem with hardness and be a tad flexible but the "plastic" bit may not like all the oily messy stuff that we slop round our workshops.

A bit puzzled

John

As a kid I lived along the road from ‘Bonds o’ Euston Road ‘ and to enter the shop you went through a tunnel of display windows. Although mainly models and kits some tools were displayed including a Super Adept Lathe, I thought then, as a nine year old, what an odd bit of kit it was with a relatively giant chuck and no driving motor. I reckoned that no way could I get it to function : I’m afraid that’s what I think over sixty years later. Compared with today’s market this part of the Euston Road was some sort of heaven as in addition to Bonds, Buck and Ryan had a huge branch particularly stocking hand tools for the metal and woodworking trades and the Showroom of F J Edwards that sold really heavy machine tools.

John

Both headstock and tailstock are located/clamped onto the v bed.

Hence if there is a mis-alignment it might be bad news. However I cannot imagine it is possible for the unimat to abuse it self to this extent, so short of dropping on to a hard surface not likely.

I would not think that the error described is normal and would cause difficulty (unimat3's were made in a proper factory! and when I bought mine over thirty years ago were quite pricey)

The sockets on the unimat are (more or less parallel) and my experience was that they did loosen after a lot of use and I made fractionally larger replacements.

I think other respondents are right in that it is the holding arrangments at either end that are to blame, and as Ian says use pointy bits to make a judgment.

John