Member postings for thomas oliver 2

It is my experience that silver steel apart from being sold in 13in. lengths is always no more than 0.001 ins below size, and mild steel and stainless will normally be 0.002 to 0.003 in smaller at least. Ground stock will usually be spot on for size.

In 1961 the price of the Boxford AUD Gearbox Lathe was £225. The BUD - no gearbox, was £200.

A common misconception is that Myfords offered more accessories than Boxford. This was not the case and Boxfors offered excellent 40 accessories.

Some small diesel engines like the Mills 1.3 have a cast iron piston in a hardened steel liner. I have one which has run for hundreds of hours and still has good compression. Other engines have cast iron pistons in a cast iron sleeves so no expansion problems. Most ofl the diesels I have made have this set -up but I made an Amco 0.87cc with a steel cylinder and it too has had a long life. Some of the latest glowpiugs have plated cylinders and apparently require virtually no running in.

The ETA 15D is a diesel engine which require a very high compression- maybe 15/1. This cannot be obtained with rings fitted due to leakage. The piston must be lapped to fit the cylinder. Glowplug and petrol engine work at a much lower compression and are made with ringed aluminium pistons or can be unringed. Lapping is a black art and you will find that many modellers have had to make two three attempts before achieving desired compresssion. Rings are not too difficult to make with fine grained cast iron but require heat treatment to remove brittleness and to give some springiness.

I have a compartment box in which to keep shim. I measure and mark all the strips with their thickness, When shimming a tool I stick the shim to the bottom of the tool with double sided sticky tape. On my Boxford, I made tool holders for small 3/16th square HSS bits with the tool slot at a small upward angle. The tool was fixed with short Allen grubscrews, set to centre height, then clamped in the normal way. Both methods allow instant tool clamping. LIke John Macnamara, I find that a four way tool post and HSS tools perfectly adequate for all of my work which includes model diesel engines, steam engines and locos, vintage motor-cycles and so on. It must be realised by beginers to modelling that most model parts require sharp shoulders to allow close fitting. TC tools have slightly rounded noses and I find them useless for most of my work and much prefer HSS which is easy to grind. I use TC tools for Cast Iron and tough steels when necessary.. Why go to the bother of buying expensive tangential tooling or having the tedium of making them in profusion when the old 4-way does the job adequately. Can a normal lathe tool be ground to the same angles and produce the same results as a tangential tool? I have not tried. Maybe someone has and can enlarge on it.

Sorry - should mention thickness of plate is 1/8th in.

I have a 10" length x 3/4" wide strip of gauge plate and a 14" one as well. College Engineering cost is about £8 per 1"wide x12". Postage would be about £1.50. I can let you have either length for £4 plus the postage on receipt of cheque for total

At last a common sense comment on the Adept lathe from P.Lousick. Lets have more facts instead of idle speculation. Around 1948, after demob from the RAF in 1947, I happened to work near a small factory producing the "Wizard" lathe whicih is clone of the Adepts, but made from Meehanite. I went to a surplus sale at the factory and bought a set of reject parts for the lathe for a song. I found the leadscrew bearing cast on the bed out of line causing th saddle to jam up. I managed to rectify this,and began a long learning curve with the help mainly of the Model Engineer magazine. I was member of the local model flying club and the then thing was control line flying. The members broke the needle valves with mon,tonous regularity and some cost. I managed to make some 5BA needle valves and sold them at a mininmal cost to members. I could not afford to buy a 3.jaw chuck which were largely unobtainable in the small size needed at that time, so I made 0 MT collets from mild steel to fit the headstock with a drawbar. I needed to make 4BA needle valves but it is a non standard size,so I labouriously bored a collet with a tiny boring bar..I used this lathe over 35 years to make not 101 but more like 1001 different items.. With the advent of Ebay I found a great demand for model diesel engine parts and started making these parts again and have netted maybe £1500 per annum for the last four years, and have sold them all over the world.. Nort bad for a crappy little useless lathe.

There are loads of nasties in the drawings and there is a problem with the fitting of the cross-head pump. You should find a list on Google. If you have a background in engineering It should be a good starter and is a good hauler. Otherwise start with something simpler.

Standard spinning tool end is shaped just like the end of the forefinger. It must be either fully hardened or case hardened and highly polished. A toolrest is fitted into the toolpost consisting of a steel bar drillled with about three holes spaced out near one end and a peg to fit in the holes, against which the tool is levered. The tool needs a longish handle. Lubrication is needed and use of most common oils will result in failure. The secret lubricant used by Spinners in factories is Tallow and I can vouch for its efficacy. A rotating centre with a wooden pressure pad fitted is necessary. The disc of metal is pressed lightly against the former with the tailstock and the disc edge tapped lightly to centralise the disc. Full pressure is then applied. The metal must be fully annealed as suggested and the tool is worked from the centre outwards. It requires a little practice although it.is very quick. However you have chosen the worst possible metal to try out the process, so I would practise on annealed aluminium first.

Instructions from Stuarts -- First set valve for equal port opening. Place piston on top dead centre. Loosen eccentric on shaft and rotate in the direction the engine is to run until the port is just cracked open, then lock up grubscrew.

For a long while I obtained a lot of short ends of steel in the grades that I required from my local Corus depot. The foreman in the warehouse would allow me to select what I wanted from the scrap ends bin. Steel grades are colour coded on the ends by the steel manufacturing industry, and since the short ends were all coded it was easy to select the right grades. Crossing his palm with a few pounds made the foreman happy. Don't know if one would even be allowed in these days with all these 'elf an safety regs.

Nowadays I get my steel and brass from local small engineering firms who usualy carry small stocks and will oblige and cut off short lengths. I bought a large stock of aluminium alloy from the AALCO depot in Gateshead recently at a fraction of what the Ebay model engineering suppliers charge, but in 4 metre lengths, which I split with a friend.

I bought one foot of HE15 ( Twice the tensile strength of the usual HE30) from a supplier at the Harrogate ME Exhibition for £2.20. I was asked £8.80 for a one foot length by another suppier. Needles to say I told him to s----f it.

Thank you Rick for confirming what I posted - that it is possible to be sold dies either unhardened or with no rekief. It seems that since no approaches have given results, it is simply that the die has no relief and will simply not cut under any circumstances. The cure is either to grind in the relief, or to obtain a new die, preferably of British make. It is possible to cut good threads on copper pipe with a sharp die and some lubrication.

I have recently had precisely the same problem with a die of the the same make from the same firm.. On examining the die with an eyeglass I could see that no relief behind the teeth had been ground in, and none of the usual fixes would solve the situation. Rather than waste time returning the die, I ground in the relief with a Dremel tool and a conical burr, when the die cut perfectly. I have had dies stamped CS fro Tracy in the past which were not hardened and tempered, and lost their edges immediately. In fairness to Tracy Tools, they never quible and exchange the goods.

A recent successful published design which fits your requirements is the Alex Whittaker Firefly. He had little previous machining experience. The design is made from bar stock and a good few have been made. I do not think there is a casting kit available now for a similar engine. Bar stock is easier to set up, but as the design is angular, it will probably need a suitable milling machine. HE 3O (6082) Alloy is recommended. I would recommend HE15 for the con-rod as it has twice the tensile strength of HE30. I cannot remember if it has rings, but these are capable of being made and heat treated. I think the drawings are a free download from his website at www.alexwhittaker.com. Alex first published his plans and article in the RCM&E magazine of which he is a regular contributor.

Rik, I am 89. Don't leave it as late as me.

Just as an addition to the lubricant problem, I once had a new Myford ML7 and used the recommended oil in the cups. I needed a regular drip to maintain lubrication. I then once used EP 90 oil instead and found that the lathe would keep going for weeks on end with just an occasional drip or two. I formed a very good impression of this high pressure back axle oil and have used it for threading and other things since. I also had a small open tin of pure turpentine for cleaning small brushes and over time it thickened up a lot. I found it magic for threading aluminium.

The American ASME 16-22 is a 22 TPI thread which should measure 0.268ins. near to your thread. Since male thread are usually a few thou.down on nominal size, could this be it?

A comprehensive reference for thread sizes and types can be obtained from www.watchman.dsl.pipex.com

Over my long modellling life, I have acquired sets of threading gear for every type in common use. Some were boxed. Some not. I decided long ago to make my own boxes from hardwood.and made a rig using a router head mounted on a vertical drill stand clamped to the lathe bed, and provided with a multiple depth stops. I stuck a wooden fence onto the crosslide of the lathe, I scanned some original boxes and printed out the scans, then pasted then to the wood as a guide, and even clamped a vacuum extractor close to the router bit. This all worked fairly well. I set to with a face mask, and finished all the boxes off failry quickly. However,, to my dismay, when I finished, every ledge a cranny of my workshop was covered in fine wood dust, which took as long again to get rid of. So be warned about wood. Anyway I now how two neat piles of boxes and everything readily accessible.

A lot of my taps and dies were bought at the local boot sales, amd I found that some stallholders were not even aware of their value, so I could get them for coppers. Many years ago I was quoted £11 each for 10BA HSS taps by the Presto depot. This made a set £33. I have bought many sets of 3 small HSS BA taps for £1 a set. I have had many collossal bargains at boot sales. One of my first was a new 4in 4-jaw chuck with Boxford backplate to fit My AUD model for £40. Now, at my age, I am busy disposing of all my surplus spares on Ebay.

Bill, I think that maybe you have not tried the strength of a very short length of coat hanger wire or used it to make short studs. It is obviously easy to bend a long length. I have used it quite often and find it adequate, for certain studs. The No 10V has either 7BA screws for the cylinder covers only 3/8th in. long or studs. It is difficult to grip this length firmly to cut the second end, hence my suggestion to use screws.

Stuart No. 10V - their smallest engine, uses mostly 7BA screws and only one 5BA grubscrew. It uses 5/16x 26 tpi ( either CEI or BSB could be used) for the gland. The bigger 7A engine uses 4BA, 5BA and 7BA + the 5/16x26 for the gland. Bigger engines go up to 2BA with some 1/4BSF even. Stuart engine do not appear to be fitted with any 6BA size threads.

The screws supplied by Stuarts have a thick head. Some of the egines illuatrated in their catalogues - have studs and not screws. Making 3/8in long 7BA studs is a real problem, so screws are to be recommended.

If you want to go the metric way here are some close equivalents and remember a someone has stated - BA is a Metric system where each successive size is 9/10ths of the previous size. starting with OBA which is exactly 6mm witha 1mm pitch. Only the angle of 47 1/2deg. is different.

2BA 5mm (Pictch is identical)

4BA 3.5mm

5BA 3 mm

7BA 2.5mm

8BA 2 mm

The half sizes are obtainable from Tracy Tools OK. I have had one or two dicey dies from them in the past - actually unhardened, but they are very good and change them without question

To enhance scale appearance - screws are obtainable with head size one size less.

The 0, 1 and 3BA sizes are little used from a full set of BA taps and dies.

As a fair guide, the tapping drills for BA sizes can usually be used as clearance drills for 2 sizes below, which can save buying a few drills.

Sources of good steel for some small BA, UNF and metric studs are bicycle spokes, umbrella ribs, welding rods and wire coat hangers.

To cut out breakage of the small BA or Metric taps, never use the tap wrench provided in a set as it is to provide torque for the larger sizes. Use chuck type tap wrenches with short tommy bars. This allows you to feel when the tap is tightening up. I rarely use a taper tap on steam engines as they vary in taper from one manufacturer to another. These steam engines have a lot of blind holes to tap and a long taper tap wll bottom out and will not give a good start to the plug tap. I can usually manage with a second, but even these can vary in the amount of taper There is a lot of discussion about tapping and staking set-ups but they are only one more complicated time consumer to make. I always check the tap squareness by eye in two directions at right angles and check frequently until I am satisfied as to the trueness before completing the thread. I can usually get my threads quite square thsi way.

If you go for the Stuart steam engines try and obtain one of the old Stuart Turner kits on say Ebay as the casting quality is far superior to what they are now

Do not obtain the castings and parts as you go along or you will end up paying about twice the price of the kit. which includes the fixings. This is because Stuarts now charge £5 for a tiny piece of brass for the valve nut and corespondingly for the other bits of stock material.

Do not go for a full set of number drills for tapping sizes. 15 of the set do not have any use for tapping, clearance, reaming or interference fits. Buys as you go.

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