Member postings for Tony Martyr

Since everyone in my school had one of those little brown books of log and trig tables I felt sure that eBay etc would be awash with copies - wrong!

I've been trying to buy a set and all Amazon etc have are expensive tomes of historical reprints. Did we all throw them away?

anyone know of a source, preferably of 7 figure log and antilog tables (I know you can download limited versions but they are not user friendly )

Tony

John,

I think the answer to your last question is No.

The marginal thermal efficiencies important in full sized designs including degrees of super-heat and compounding through 3 or 4 cylinders is not significant to most model engineers. I think that even those involved with efficiency competitions find that good driving technique is far more important than scaled down multi-cylinder design.

Your first question has no real meaning for me; not that it is a bad question; because it is the building process that involves my interest rather than the long-term or fuel efficient performance of the finished engine. I can't see that two cylinder, double acting multi-drive-wheel engines are any less smooth, in the delivery of power to the wheels than 3 cylinder engines smoother take off at start perhaps?). Most complications in loco design have been induced by the drive for high pulling capacity and the efficient use of fuel in a well balanced boiler/engine combination - smoothness perceived by drivers and passengers is probably well down the list.

Tony

I've just completed a Bolton design triple expansion engine. The valve timing of which is a bit of a pain - "if I ever made another I would do things differently etc"

As I thought I can't get it to run on compressed air, probably due to the very early cut-off required on the HP cylinder so I'm about to build the boiler and ancillaries system. To save some time I'm considering buying a Blackgates boiler kit but can't find an image of one on line. I could build a 4.5 or 5 inch dia vertical fire tube unit that would provide saturated steam at about 50 psi but I would like to hear from anyone who has steam run this or similar triples before I start

suggestions most welcome

Tony

As part of an Engineering in schools demo I ran a Stirling engine from the heat of a bowl of water and asked the children to trace where the energy came from:

We went kettle - electricity - power station - ( here I had intended to go coal - fossilised sunlight ) but none of the 9 to 11 year olds had ever seen coal and only 2 out of 22 had heard of it

we live in rural south Shropshire where heating is either oil or wood-burning stoves.

Tony

I looks like a Millwrights alignment jack. The ones I used, to align large engine before final chocking and grouting were not of such a complex design but we used tree similar units together with non-slewing wedge lifts plus shim plates - was the original owner involved in factory installation?

Tony

Thanks to all

Wellseal it is - but I do remember blue Hylomar from working on dynamometers at Froude

Tony

I'm doing the final build of my triple expansion steam engine and need to seal the six joints between the valve chests and cylinders plus the HP and LP chest covers. This is not suitable for gasket paper (that would be a horrible job) and I'm not sure I could even get the ingredients for the red-lead goo of my apprenticeship - so what is the recommended modern product?

I would hope I don't have to dismantle the engine but I would prefer something that allows that without resorting to violence and it has to handle steam at 180psi and some superheat.

Just in case anyone has an interest in the combination of waiting train and master clock combinations I have put on YouTube a short film of my set-up (finally) working.

The dial hands and mechanism came from the old IMI explosives factory in Birmingham and were all heading for the skip, the central glass of the dial had already been hammer out. With the exception of the worm all the mechanism, including the coils, pendulum and shafting are original and were cleaned up; the worm had to be made anew and was a very strange TPI. The Hipps toggle anvil is a bit worn and very occasionally get chaotic and stops the pendulum so I may have to do a bit of reverse engineering.

It was only recently that I managed to get a Master clock. A 12v caravan battery didn't run the whole set-up (for a reason I still haven't worked out, so that battery just runs the WT pendulum and a small 12v battery runs the master/WT circuit. It keeps very good time in my workshop although I tend to switch it off because it make me too aware that its rhythm marks my life being decremented!

See it at: **LINK**

Thanks for this John,

It is nice to hear that a group of experienced folk like the SBA have to deal with this problem and will direct future queries in that direction even if I can't afford to build a hull!

I intend to use dry superheated steam so the HP and IP pistons would seem to need a lubrication, the LP should be exhausting at lower than atmospheric (if the condenser manages to pull a partial vacuum) so should be OK anyway. I had considered a centrifuge like the Alfa Laval units we used to get water out of bunker C fuel oil but that is a considerable development task!

Your hot-well modifications sound a sensible (cheap!) option - I was just about to start its construction and as I haven't yet designed the cooling water system I can provide for a condenser flush branch.

Tony

Having worked on steam turbine ships I know a bit about boiler water chemistry therefore I'm a little puzzled about the condensate system supporting the triple expansion engine I've built. If I add oil injection into the steam the condensate is going to be a water/oil emulsion that will coat tubes etc and I'm not sure what will happen in the boiler. This dilemma has occurred to me a little late in the day and I would be interested to hear of experience of others

Tony

Just the other side of the border in Clun. I'll be looking at the contacts listed

Tony

I have worked with 'real' engines of all sizes for all my working life and have modelled some for many years but working on these 'industrial' clocks has been very different.

When an engine first runs it is a success - Wow! - but when you start a WT and Gents Master clock they create a rhythm that you realise is decrementing your life with each swing of their pendulums - very spooky!!

For Mark: the WT clock solved the problem of getting several clocks in a factory or, for example on 14 railway platforms synchronised. The WT units have very heavy but short pendulums needed to drive large, open-air hands against wind load. They drive through a worm wheel to prevent the wind stalling or reversing the hands.
They all run (imprecisely) a few seconds fast and then wait for the pulse from the Master (transmitter) clock and so all synchronise every 30 seconds. The Hipps toggle is used to energise two big solenoids that give the pendulum a kick when its arc falls to a minimum.

The master clock works with a pendulum (1metre) that is given a push every 30 seconds coincidentally with sending a pulse to its own and 'slave' WT units that are 'waiting' - just loverly pieces of engineering and the only things I have met that use 1 and 3 BA threads!

I will post some more photos on my album

Tony

Thanks to Michael for send more information that I can absorb today!

The full story: 3 years ago my daughter was project managing the redevelopment of the site of an explosives factory in Birmingham and wanted to save the cast iron clock face that was in the tower above the entrance from the skip. She asked me if I could make a dining room table from it by covering if glass etc!

When it was delivered it came with a wooden box of 'bits' which I later found out was the WT mechanism and the Hooks Joint shafts etc. it was all covered in dust a debris. It has no serial number but the factory was built during WW1 so must be at least 96 years old.

I can see why so few of the WT units have survived whereas the transmitter (master) clocks look valuable the WT units, to the untrained eye, look insignificant and like scrap.

to demolition gangs. I have very carefully re-built the unit (see photos in my album) but not touched the coils which all work when powered up. I now need to know exactly how to wire both units together with a suitable 12-20v power supply and without burning out any of the original parts!

Tony

A couple of years ago I was asked to refurbish and old (1915?) tower clock with a Gents waiting train mechanism - I did that but could no find or afford a master clock to run with it. I have now obtained a master clock (1954) but i'm at a loss as to how to wire the system up - do we have any readers who have experience of these mechanisms?

Tony

My workshop, like many of yours, contains tools, cabinets and machines built up from 1960 when I started my apprenticeship. I have no living relative or friend who has an interest in miniature engineering and, living in rural Shropshire, I know of no local model engineering club.

So how should I deal with the contents of my workshop (to my relations 'my stuff' in my Will?

I don't want it all to sit and rust or get casually misused; this sounds silly as I shall be past caring!

Are there recommended (honest) dealers who do this type of 'house clearance?

Years ago I took over the job of an area Engineer based in New Zealand. He had dropped dead unexpectedly and I had to travel from the UK to sort things out. I knew he had been a keen model engineer with a large workshop but I got there 2 days too late. His wife had sold the lot to a scrap merchant for almost nothing - I have never forgotten looking at that empty workshop.

fizzy

Not an answer to your query I fear but a fellow seeker!

I have exactly the same problem although I would want to fit a ceramic gas burner rather than struggle with coal firing again.

Since moving to deepest southern Shropshire I haven't found any of the model engineering fraternity within a days march of home so I will have to use this forum for advice.

Tony

Thanks to all - I'm going the fibreglass string (from wood-burning stove seal) plus the paster of Paris. Since this is going to be a working model I wanted to avoid heat discolouration of the insulation on the feed to the stop-valve and the IP to LP leg. The LP to Condenser pipe can remain unlagged since it should run cool if I can pull a part vacuum.

I remember how much easier and dangerous it was to find a steam pressure leak than a vacuum leak - nowadays I presume its done with a cleaver microphone device

Tony

I need to insulate the steam transfer pipes on a triple expansion engine. Full scale practice I remember from long ago was to wind asbestos rope tightly round the pipe and then use an asbestos-chna clay (?) plaster to give a smooth surface that was later painted. I used to blow the dried plaster off my overalls with an air-line!

I have used an automotive insulating tape on track cars but it is not suitable for 3/8 and 1/4 inch copper tube.

Any ideas?

Tony

Jens,

Yes you are correct, I guess you could make life easier by drilling and tapping through with 7 BA then you have more tolerance with you split the sheave. I would find that spitting job to be quite difficult using a thin saw in a vertical mill - but holding seems difficult.
You could open up the clearance holes in the larger section after turning. I have never made these things from cast iron and I found the 7 BA hole location to be absolutly critical and not easy to get right

Good luck!

Tony

Jens

A split eccentric is made from two pieces of rectanglular steel section of identical width (a little wider than the maximum diameter) but different height that are screwed together. Their juction is the split face through which the crank shaft runs. You need to cut off sufficient lengths so you can hold it in a 4 jaw chuck and still have enough lenth to tun the cams and part them off.

Clamp the two sections together and mark out the final postion of the 7 BA screws in the top of the 'thick' section. Drill through with 7BA tapping drill then open up the thick section holes with a clearance drill and counter sink. Then screw the sections together (these screws will be machined so are sacrificial, put in a 4 jaw chuck and 'face off' so you can acuratly mark out the position of both the crank shaft bore, which must be EXACTLY on the split joint between the sections, and the (off-set) rotational centre. Set the steel to run on the rotational centre and turn the OD to size (it is best to rough off the corners with a file to reduce the shock loading while turning a two piece square section, then reset the chuck so that the (now offset) shaft bore is centred and drill and ream the bore then part off and finish the face and width. If you have been clever with your marking out and the drilling of the 7 BA screws you could counter-boore the holes so the screw heads are untouched - I had to modify my holes after turning and before I took them out of the chuck

I hope this makes sense!

Tony