Member postings for Max Tolerance

Depends on whether you know how to use it. Does it have any tooling etc. and what state the bearing etc. are in.

If it is a tool room grinder like a J&S or similar it will be heavy and large. It may have air bearings (good clean air supply needed) or not(bearing wear problems)

With no tooling they are useless. The cost of buying and keeping a decent one will probably be more than you spend on new cutters of the standard type, end mills etc. in a decade.

However if you know how to use one it does give you the ability to make your own special tooling and sharpen pretty much anything. So it is horses for courses can you justify the cost for your workshop. Have you the knowledge, space and time to use one properly. Do you have a need to make or sharpen special tooling.

Only you can answer the above questions but if any are in the negative don't bother.

Before asking why the imperial system is so illogical it should be remembered where it came from. Originally before the nineteenth century standards as we know them did not exist. The English system of weights and measures were conceived to make trade etc. easy for a largely illiterate population. So each trade had its own system and each district or town had a local "standard" that could be used to check any suspicious weights or measures.

From the Roman mile (one thousand steps for soldiers on the march) to the sheep's fleece (7 pounds) the barrel, hogs head etc. all meant something to the people who used them. Some still remain with us even today Carat (used for gem stone measurement) Hand's used for horses height, Timber measures to show how much useful timber can be taken from a round log all these were devised to suit a specific purpose. The Acre used for land measure (the amount of land needed to produce a given quantity of crop) etc. etc.

Then engineers and philosophers started to look for a standard that could be used for their work and that is when things get interesting. In Britain Joseph Whitworth was responsible for the first truly scientific definition of the inch. He applied this to the threads that still bear his name. The thread angle and pitch was carefully chosen to suit the iron or steel materials available in his day. He did not have access to the high tensile steels we are used to.

The French were responsible for the metric system which was devised on a "scientific" principal involving one degree of arc of the earth at the latitude of Paris. This attempt which was somewhat better than previous systems but even this was not perfect. All that remains of this standard are the names. The current metre was defined by the International Standards Organisation and was applied through out the world, even the "metric" countries had to revise their systems to comply since they all had slight variations in their previous standards.

It may be interesting when talking of logic that the French also tried the decimal week consisting of ten days. It was not a success.

Curiously enough even the metric French still cling to their old measures for wine. Think Magnum, demi-john etc.

A die hard refusal to accept any thing new like the metric system? I was taught the metric system whilst at school in the sixties. I have used it all trough my engineering career as have most if not all of my contemporaries. The BA screw system is metric based. I don't remember a single instance of any professional engineer refusing to use it.

Old issues of Model Engineer from before the first world war contain designs using metric dimensions. Many, many, questions have been asked about cutting metric threads with imperial lead screws in books ,magazines and engineering works all through the twentieth century. In locomotive works engines have been executed in metric dimensions. I.C engines, especially motor bikes have always had metric pistons and been expressed as so many c.c. from the very early twentieth century.

Much of this before the ISO standards were put in place. The main obstacle to the adoption of the metric system generally, came from the usual place......... POLITICIANS, not engineers.

I can remember as a young lad in the late fifties early sixties going down to our local library in the evenings to watch films. I am talking real films here, shown on old fashioned projectors. These featured many old crafts and skills such as clog making, Coopering, Fitting steel tyres on wooden cart wheels etc. One in particular showed a huge stationary engine flywheel being cast. It included footage of the moulders preparing the mould, the molten metal being prepared and poured and finally the removal of the fly wheel from the sand. There was another showing ships propellers and one of a large naval gun being erected and tested.

I don't know where these films came from or who was responsible for their production or even why they were shown but I never missed a one. Looking back I must have had free admission because I certainly didn't have any money for tickets or anything. I often wonder where those films went. Maybe they will surface on the net one day.

Just for interest. Electric cars outnumbered I.C. cars at the end of the 19th century. Dime in the slot charging stations where installed in large American cities. The "experts" of the day laughed at the thought of I.C. engines ever being any good. Come the 1st WW Britain and France built thousands of I.C. engine wagons etc. Aircraft engines I.C again, developed at a tremendous rate, in Britain, France, Germany and Italy. Why?

In a Model Engineer editorial it was discussed that oil and coal where running out. Everyone would be driving electric cars within a few years. The power would come from small wind mills and a tidal barrier in the Bristol channel. Sound familiar? The date was December 1920.

The "experts" were wrong. Politicians lie for a living.

The biggest promoters of the electric car are the ones who will make the biggest profit from the tax payer subsidies.

Just a few reasons why I am sceptical.

Edited By Neil Wyatt on 27/07/2017 08:32:53

You don't state which end bearing you fitted. Normally on a motor the shaft end bearing if fixed and locked in place usually with an end cap, or on some cheaper versions a circlip. The other end of the armature is allowed end clearance to allow expansion in the armature shaft during running and is normally fitted with a wavy type spring washer.

If the front bearing housing has worn then you need to make a better repair than centre punched dots and lock tight especially given that the housing will likely be some type of die cast aluminium / zinc type metal. The best way is to bore out the housing true to the flange and fit a bush to give total support to the bearing outer ring. There are available ready made bearing shims made to suit popular sizes of metric bearings. These are made of steel and are a top hat section complete ring (not split or joined) normally about .25mm thick. maybe one of these would work for you. I don't know where they are sold but your local bearing supplier should be able to point you in the right direction.

All hard hacksaw blades are still available from good tool suppliers. I never use anything else!

The modern bi-metal blades are widely sold and many people seem to think they are the only type in town. Even some sales reps. deny the existence of all hard blades.But if you persist and are willing to pay the extra then you can still get hold of them. As the previous poster mentioned they don't like bending and will shatter if not used correctly (hence the popularity of the bi-metal ones) Unfortunately many users have never been shown the correct way to use a hacksaw and would find it an expensive learning experience.

At work I can leave my hacksaw out on the bench and no-one will use it because they hate the blades snapping. .......BUT I am the only one who can cut a straight line and the younger lads think it is some kind of magic secret that only I know. They will confidently state that it is impossible to do this with a hacksaw even when I demonstrate that it isn't.

Another source of good HSS is machine hacksaw blades, the old fashioned reciprocating donkey type saws.Not the modern band type. These make excellent tools and because they are quite wide there is a lot more strength in them.

It is as mentioned Herbert 2D capstan. One of the older models although they didn't change much over the years, mainly detail changes. The lathe would normally take 2047 collets and these are specific to the lathe you cannot use Ward collets or other similar types due to the included angle of the head and also slight differences in the diameter. It is possible to fit these machines with a new collet closer and nut so you can use Burnerd or Crawford multisize collets since the metric versions of the 2047 are quite rare (they do exist but many must have gone to the scrapper years ago) the imperial versions turn up occasionally on certain auction sites.

The main problem for anyone trying to fit one of these lathes in a home workshop is the motor. It is a hefty three phase unit designed for rough industrial use. they are almost indestructible and extremely heavy so the current drain on start up and reversing peaks at high levels. You can go from full speed forward to full speed reverse with a flick of a handle and the motor will do this all day as often as you like without complaint. Whether an inverter would stand the strain is debatable and I would imagine rewiring to delta would be very difficult and very expensive even if it could be done.

How do I know all this? Well I have one in use in my shop. I have a three phase supply which helps and I make numbers of parts on a fairly regular basis. However as per previous posts you need to understand how capstans operate and have the necessary specialist cutter holders, die boxes exc. to make the best use of it. Once set it can be operated by a complete novice and produce massive numbers of identical parts all day every day hence their popularity in the days when Britain made things. Now superseded by CNC these machines are a relic of our industrial past and many thousands of them must have gone to the great scrap yard in the sky since the sixties/seventies

I have a three phase supply fitted for "free" by the old NWEB. My house was built around the turn of the century (1901). In those days electricity was a new thing for houses and if a new house wanted to be connected to the mains as it was called then, they used the tram supply generated by the local authority. The only problem was that this was usually D.C. When the national grid was set up later then of course the supply changed to A.C. and voltages where standardised.

In my street when the national grid was connected they decided to use the original two core D.C. supply cables so one phase went down one side of the street and a different phase went down the other. Later a three phase cable was laid to supply the street lights, however they left the houses as they were. Around twenty years ago the supply cable to my house failed (after all it was approaching 100 years old) it was a lead and paper insulated cable and very light by modern standards. The electric board were very busy at the time so In exchange for me digging the trench across my front lawn they kindly agreed to fit three phase power for "free". Happy days!

I only pay one standing charge and standard tariff, the only down side is finding a supply company who will accept three meter readings instead of one since most of them unbelievably can't cope with it for domestic customers. But if you want to fill your cellar with machinery you can't beat it.

I would just ban the politicians and dodgy lawyers. Then there would be no-one left to ban anything.......................

It is a Crawford multisize collet. it is complete as is since these didn't have the "leaves" that Bernard (and others) used.

If the correct collet chuck is with it then no problem it can be used, that particular one will hold between 1/4 and 3/8 as indicated. From the photo it is difficult to say which series of collets it is from since there were five different series, B going through to F the largest went up to 3 1/8 inches but the B series stopped at 1 1/8. All were available in light duty with plain bores (as sample) or heavy duty with serrated bores. They are not interchangeable with Bernard collets since they have a different included angle on the body and various other dimensional differences.

They do turn up occasionally on a certain auction site in round, hexagonal and square bores and I own a full set of all the "B" range however I seldom use them because I find the Bernard type to be superior for my applications and also because my Bernard set has a lever operated chuck rather than the scroll type which I find too slow for repetition work.

Try Lee springs (no connection) They have an excellent site with downloads that list springs in size order with a separate column showing loads/ length etc. really easy to pick what is wanted. each spring is classed with a group letter as well as a reference number. All springs in the same group cost the same so easy to work out costs as well.

Max

Hello Douglas,

I should be able to manage this on my big Colchester. It can go as course as 6mm or 4 TPI. If the tap is for wood what sort of thread form is used? also what material would you be looking to make it from? i.e is it just a high grade steel or does it need heat treatment etc.

Regards Max

I agree with the other posters about the problems of using TIG. I used to have a full set up, HF strike, trigger control, the lot, and could make a decent weld, no problems. However I sold the kit because I only really used it for stainless steel fabbing and the cost of the gas got too much to justify keeping it. I suggest before you go down the route of buying a welder you check out the cost of the shielding gas. I used Argo shield from a large industrial gas supplier, it was only available in the larger sizes and although the cost of the gas may have been justifiable the rent on the cylinder made it very expensive. Too expensive for the amount of use I made of the kit. Now I just drop into the local sheet metal works when I need stainless welded. I still have a MIG set since the Co2 is not so expensive and small cylinders can be bought quite easily. This will do most of my needs in other metals and IMHO is the better buy.

I am also a sinister. However it has never really bothered me I use most tools as well as any ordinary right hander and since all the machines I have ever used are all designed the way they are I simply learnt to use them as they were. There are however two area's where things can be awkward. Scissors oddly enough are a pain in the butt, if I use them for any length of time they dig into my thumbs. Hence I didn't become a tailor!!!!

The other item which I find very poor and in-fact a danger to all left handers is that the manufacturers of power tools ALWAYS assume everyone is right handed and they fit those annoying trigger locks on the drills etc. THEY think the operators will press them in with their thumbs but us poor lefty's tend to push them in with our palm when we grip the handle. If you have ever had a drill powered up and been unable to stop it when you let go of the trigger you will realise what a dangerous idea the trigger locks are. The first thing I do with any power tool I buy ( or am asked to use at work or anywhere else) is to rip the annoying little buttons out and destroy them. I have written in the past to various tool manufacturers pointing out this obvious H&S issue but I have never received a reply. It seems odd to me that in all the risk assessments etc. required by law no-one has ever pointed out this one. There is a similar though less dangerous problem with battery operated drills where the forward / reverse button always seems to be designed so that a left hander will accidentally push it in and the chuck will revolve backwards ARRRRRRRRRG.

The reason for fitting taper keys to flywheels or any other highly stressed part was because the fit had to be well nigh perfect. A parallel key should be fitted leaving a slight gap on the top and it should only bear on the side of the keyway. This is fine for small pulleys etc where the shear stresses are relatively low. However if you have a 30 tonne or more flywheel whizzing round at 60 RPM the stresses in the hub are huge therefore a taper key was fitted and would be fully scraped so as to touch on all four sides all over. This is only possible using a taper. As an apprentice (and after) I regularly used to fit taper keys to paper machine cylinders, brakes etc. we also fitted them to line shafting pulleys. Not many people had the patience or ability to fit them correctly so I used to be selected almost every time. The trust that the foreman had in me was such that in my last year as an apprentice I was asked to fit the keys into the brakes on the fifty tonne overhead cranes. I spent a week up there with a file, a tin of marking blue, a slide hammer and my trusty scraper. Afterwards the crane was put to some pretty severe testing involving large concrete blocks and sudden application of the brakes after fast down. The whole building shook, the supports bounced and banged, the cables groaned and the brakes got rather warm.................. but the keys stayed where they were.

Obviously in a model there is only a requirement to copy full size and the stresses do not require quite such a good fit. But that was the reason for the different keys in days gone by.

Ian. You are quite right in your assessment of the radial needle bearings involving sliding and slip. ALL bearings have this problem. The bearings you mention are only used in very low stress areas and tend to be of a small size typically they are found on the end of feed screws etc. This problem has existed since the first bearings were developed and the manufacturers have spent millions on designing and building bearings to try to mitigate it. One approach involves tapering the rollers, another is to use barrel shaped rollers with corresponding radii in the tracks. In ball bearings they use different contact angles or again radiused inner and outer tracks. The solutions and types of bearings vary according to the use the bearing is intended for. Thus the special types used in lathe mandrels (see other thread)

A look into any catalogue from a bearing manufacturer will show the differing types available. However all bearing will suffer to some extent the sliding and slip referred to. This is the reason for the finish imparted to the balls/ rollers housings etc. it also explains the use of plastic brass and metal cages. All carefully matched and machined to tight tolerance . This leads to the obvious need for lubrication and the reasons for oil or grease, again dependent on loading /duty. It must be the correct type, viscosity and quantity if you want the best from the bearing.

If foreign matter gets in or the lubrication is incorrect metal to metal contact will take place and the bearing will wear. The wear will accelerate exponentially until the bearing ultimately fails completely and seizes. Normally before complete failure the noise becomes more noticeable and if you are sensible you will investigate and replace the bearing .

Hope this helps Max.

I agree with Nick above. If you are not intending to replace the bearing do not attempt to remove it, you will almost certainly damage it if you do. Taper bearings come in a number of types and not all can be disassembled. However I would use something a more volatile than paraffin, perhaps ethyl alcohol or electrical solvent. I would then allow the bearing to dry naturally, perhaps with a gentle heat such as a central heating radiator (check with household authorities first !!!). I would definitely advise against using compressed air anywhere near an exposed bearing.

The reason for the shelf life is because the bearings are shipped in a preservative oil or coating in cardboard boxes usually. This coating is intended to protect the bearing from corrosion due to the atmosphere and acids from the cardboard and general storage conditions. If the surface of the bearing is allowed to oxidise or become pitted from corrosion then the bearing service life is severely shortened . Reputable bearing factors rotate their stock constantly and will return unsold out of date stock to the manufacturer (or sell it to bargain suppliers) The problem comes when the preservative has aged and becomes unreliable allowing for the deterioration above. One of the problems with early far eastern cars was the corrosion caused by the long sea journey in salt laden atmospheres. This also is the reason for minimal handling of bearings before use, your skin is salty and corrosive.

Bearings unfortunately are often unwittingly abused by ignorance and misunderstanding. As for whether the cost is justified I cannot comment, not having seen your lathe. However these older machines were usually very solid rather over engineered pieces of kit and if the slides and lead screws are good then they are far superior to the modern budget machines in every way. If however the slides are very worn or damaged and you are not able to get them back to good order then maybe you do need to decide how best to spend your money.

I currently have about fifteen different lathes (I lost count a while ago and it pays to be hazy when the wife enquires where her house keeping has gone !!!!) All of them are older ex industrial machines ranging from tiny 6mm watchmakers up to a Colchester triumph long bed and all of them have been lovingly restored where needed. They are a privilege and a pleasure to use and the work produced is first class and accurate. That is what I need in order to produce my models to the standard I want. Not everyone needs to work to the tolerances I do and many find the modern machines well up to the demands they need. As the old adage goes you pays your money and take your choice. I should add that I am referring specifically to the budget machines, the better industrial type machines produced in the far east can be as good as any but you will find the price matches!!

Depends entirely on how accurate you want your lathe to run. I would never even consider mixing old and new bearing parts. Bearings usually wear because of either bad fitting or lack of lubrication/ingress of contaminants and if yours are worn then they are worn all over. When the lathe was first manufactured the Timken bearings were fitted because they are specially designed for machine tool spindles. The design of these bearings is very specialised and there is a massive difference between them and the "common" taper roller. Timken normally sold these bearings as pairs or sets and they were designed to run with a certain amount of preload. If fitted correctly they would run as sweet as a nut as long as the lubrication was adequate and of the correct grade and quality. Fitting commercial quality bearings would be o.k. but don't expect super fine surface finish, chatter free machining etc.

Colchester and Harrison among others changed to using Gamet (pronounced Gamay) bearings and even put a plate on the outside of their lathes to advertise the fact. These are also a very high quality unit often manufactured to special order (and odd sizes !!). It is worth remembering that as a previous poster noted the price reflects the quality. Unfortunately machine tool bearings are usually the best quality for the reasons given above.

It is still possible to buy matched sets of bearings to order but obviously this is reflected in the price. Many of the far eastern manufacturers at the budget end of the market use the lower quality type in order to keep prices down (and this can be heard and felt if you choose to do so).

It is also worth noting that bearings have a shelf life if unused. Often the lower priced bearings offered for sale have exceeded this and have been sold off cheaply hence the "bargain" price.