Member postings for Paul Kemp

Gary,

I did the same as Paul on my last block also 6" - shrink fit. It's kinder to everything and it doesn't take any force to assemble. Unlike Paul I used the same rule of thumb as yourself 0.001" per inch diameter.. Heated the block on top of a wood burner checking temp with a infra red gun and put the liner in the freezer. It fell in although I did have it set up under the press just in case! I know it's not coming out again as the bore nipped in about half a thou at both ends, quick lick with a home sorted that.

Paul.

Maybe try to imagine it as the form being tilted back so as you grind back the cutting face the form remains the same but the cutter OD diminishes, the actual OD of the cutter is unimportant, the relief is provided by the tilt in the form. Not sure if I explained that very well!

Paul.

Now correct me if I am wrong but I thought most members of this "happy" group were "model engineers" or amateur metal bashers (and no that is not being derogatory as there are some very talented people on here producing some fantastic stuff!). The point of my comment is we are doing this in garages and garden sheds or even back rooms, some on very limited budgets or resources and others with less limits and some pretty fancy kit but the common theme is doing this stuff for fun, personal education or amusement at HOME and not for profit.

Why then do we get this constant insistence of imposing industrial standards, insistence on compliance with every obscure British and European standard that may be front and centre or lurking in a dusty file somewhere? We are all grown ups and surely capable of making our own risk assessments, we do not have employees, I doubt many of us conduct tours for the public of our facilities, all we are doing is amusing ourselves and putting only ourselves at risk.

By all means people should feel free to comment on things they see that they perceive to be dangerous but some of the judgmental willy waving comments quoting professional qualifications and high flying positions are starting to get a little boring. I have letters after my name too and also spent years travelling internationally fixing problems, so what? If I see my neighbour doing something daft I might pass a mild comment or give freindly advice but certainly wouldn't be shouting my professional qualifications over the garden fence! If he wants to kill himself in his own back yard who am I to judge as long as I have flagged the issue?

So let's just have a little reset here, please. This is one of the most heavily moderated forums I frequent but interestingly one of the ones with the poorest attitudes when it comes to this type of issue! Let's leave the day job at the office, that's the whole purpose of a hobby!

Paul.

That last anecdote by Rod is brilliant and says to me everything that is wrong with children's development today. He was given a tool that most parents now wouldn't know what it was let alone consider giving little Johnny something he could amputate his digits with. With it he and his mates were able to build boats and learn to use them too. How many kids today would have that opportunity? Having the means and the determination allowed them to succeed. how times have changed in 50 years!

Paul.

Steve,

Fot it and replied. Can't remember if I included my email so I will send you one then you will have it.

Paul.

Ha, deleted, just managed my first double post!

Paul.

Edited By Paul Kemp on 17/07/2020 22:07:16

I used to work on Countax mowers many moons ago, probably about the same vintage of your mower!! I seem to remember the transmissions were Eaton units and probably still available? Just did a quick search that showed up several current models that look vaguely familiar to me. That probably won't help much as I don't think they ever sold parts for them but.... If you can identify the marque you may find a used one that you could either use or rob for bits if it doesn't work.

Doesnt answer your question I know but it may be another route worth looking at.

Paul.

I would think for Chris's application (clocks) a tapping and staking tool would be the go to tool. However with the general trend in these threads to buck traditional methods in favour of more modern approaches there are loads of alternates. Really depends how many holes you need to tap, the tapmatic or similar auto tapping head in the drill press or mill is a pretty good way of dealing with multiple holes or bigger threads. Pay your money and take your choice.

Paul.

Steve,

Theoretically the initial 2xWP shell test remains valid for the life of the boiler but with the proviso it has not undergone any major structural alteration or repair - in which case it needs to be repeated.

The 1.5 WP test for a new boiler is carried out when it is installed usually and combined with all its fittings, cylinder block etc. For the first test on a new steel boiler this remains valid for 4 years and thereafter repeated every 2 years irrespective of use.

The final part of the puzzle is the annual cold exam and steam test. This must be done in combination with a valid 1.5 WP test to achieve insurance. Certificate for this can be issued for up to a maximum of 14 months but most inspectors will limit it to 12 to keep everything in "sync" as a steam test cannot be issued for longer than the validity of the 1.5 WP pressure test. Thus if you had a pressure test and steam test on the same day and the pressure is for 2 years, your second steam test can only be issued for 10 months to coincide with expiry of pressure test. Again the steam test is irrespective of use.

The annual cold exam and steam accumulation test is often abbreviated to steam test but in reality it should be a thorough visual examination of all parts of the boiler and its fittings and then the boiler being put into steam and an inspection of fittings and verification of pressure gauge and water gauge and then with the blower wide open and a good fire to ensure that the safety valves do not allow a rise in pressure of more than 10% of the safety lifting pressure. You will have no issues on this with your Ruston as there are 2 large valves so plenty of capacity to vent and with mine with both valves blowing the rise in pressure is hardly detectable.

The above is for the "club" scheme, the only major difference with the commercial approach is your 1.5 WP hydraulic is valid for 10 years, annual exams / steam test remain the same at a max 14 months.  Club test is usually free as part of your membership subscription, commercial tests vary but budget around the £200 per year mark!  As has previously been noted though clubs do not look favourably on members joining just to get a "free" test and rightly they expect some participation in club activities!

Hope that helps,

Paul.

Edited By Paul Kemp on 17/07/2020 20:10:43

Bazyle,

Dont overlook the fact that the majority of miniature TE designs use bolt on horn plates so the firebox outer and side stays are completely obscured when assembled. Hence better to convince who-ever you choose to use that everything is sound before assembly especially if they are going to insist on a new "initial shell test".

involve whoever is going to do your tests at the bare boiler stage and there will be no disappointments or dispute.

Paul.

You can get Mick on 07947 764156.

Paul.

I have been there three times now to the annual Great Miniature Weekend for traction engines. You won't be disappointed it's a fantastic set up, give yourself a good couple of hours in the roundhouse and take your camera if interested in narrow gauge! If you get an opportunity and you are interested in the behind the scenes stuff try to get on the workshop tour, they have some pretty impressive machining facilities there.

Paul.

Steve,

As long as you have the paperwork supplied with the boiler (material and welder certs) and a copy of the shell test certificate you should have no problems irrespective of its age. As you have provenance confirming it was commercially built before 2002 the CE marking regs do not apply so no issues there either.

I also have a Winson R&P that came to me in a similar way to yours! Mine had been previously built by at least two other previous owners niether of which achieved getting a fire in the boiler and a third owner who didn't do much to it. I knew the reputation of the marque when I took it on and consequently stripped it down completely and started from scratch throwing quite a few original bits in the scrap and making new. Mine goes quite well and I have done quite a few miles with it on the road and at rallies.

I think from memory the number of mine is 38.

As said above if your local club are happy to test steel boilers (and not all are) then you shouldn't have any problem getting it tested. With mine as it was stripped I had a new 2 X WP shell test done by my club as a bare boiler, followed by a 1.5 WP once built up with fittings etc and then the steam test. If I remember the original shell test it came with bore no real relation to 2 X WP (120psi), it was closer to 2.5 so getting a new one at a lower pressure was no issue. The only comment a club (or indeed commercial) inspector may make is the fact Winson decided to weld the tubes rather than roll them but that doesn't contravene any regs so shouldn't be an obstacle.

Somewhere I have a complete set of the Winson documentation including some invoices, a publicity leaflet the various kit contents lists and the build instructions but to be honest it's all to a pretty basic and in some cases lacking any real detail so not having it shouldn't be a real block to building up a decent engine. Couple of tips, they supplied 2 different slide valves (one was the wrong length) so make sure you have the right one! The safety valves are pretty rubbish as supplied and exit horizontally - your boiler inspector probably won't be impressed by those so best to make new ones. The hand pump is better located inside the tender tank rather than on the side as supplied and it's too small to provide anything other than a real last ditch method of putting water in. The kit supplied water gauge frames are useles and the single cock design, make yourself a set of 3 cock gauges. The plumbing for the crank pump is wrong on the Winson Drg and won't work, redesign yourself. The crank pump needs a gland on the ram, it's tight for space but there is room for a screwed castellated ring, you will be disappointed if you don't. Boiler clack valves that came with mine went in the bin and I made some better ones. Saddle radius of the cylinder block as supplied didn't match the boiler, needs addressing. Front steering pivot going into the smokebox sieze up with ash, needs a redesign (a friend also had one and suffered this so I didn't bother fitting mine as supplied but modified it before steaming). Probably a whole host of other small details that need addressing to get a good running engine that I have forgotton! If you search Traction Talk you will find a build thread I posted of most of the issues I came across.

Dont be discouraged! It's a lively little engine when put together right and in high gear you can keep up with bigger engines without thrashing it. Have fun.

Paul.

Andrew,

I don't have a 4 but do have a 3. Looking at all the info available the two are significantly different in operation. However there was one comment I heard or read last night after seeing your post and nosing around the web which referred to a built in design flaw that causes the internal gears to break! There was no real exact detail apart from saying one type of gear (unreliable one) is two part the better gears are single piece. Not sure if this is applicable to yours as the inference was more towards the 3. I could imagine though that if a gear has sheared the drive may be intermittent as the fracture slips and grips? There is a quite a good you tube video on operating the 4 by a French chap - unfortunately my French isn't up to the job of understanding but you may pick up a few points by watching.

Paul.

Also be interesting to have a poll as to what people actually have now. I have the impression (which may be completely wrong) that the majority on here have newer 'import' style machinery rather than the ex industrial stuff mentioned?

Paul.

Bob,

If you have a bucket load of silfos I think you should use it to make more buckets or use it on other less critical projects than a boiler. Following is taken from Silfos 5 product data sheet but the other grades have similar comments.

"Normally the corrosion resistance of Sil-Fos 5 is of the same order as copper, but under certain conditions it may corrode more rapidly. Sil-Fos 5 should not be used where the joints are exposed to sulfur compounds, especially in gasses or oils at temperatures above normal room temperature. As the corrosion by sulfur is cumulative, even very small percentages will eventually cause failure of the joint by disintegration. Exposure to pressured steam can also result in accelerated corrosion. "

Even if you use a sulfur free heat source to fire the thing it will still be exposed to pressurised steam. A decent solder will be fine with a conventionally designed joint, there have been thousands made that have performed perfectly well, this that I have seen that have leaked or had failed joints were down to the gaps being too small for the solder to properly penetrate forming a nice looking fillet on the outside but with nothing actually in the joint.

Paul.

Edited By Paul Kemp on 09/07/2020 21:29:30

I would echo John's suggestion re the knee and torque required as the standard set up takes a bit of turning (I have a larger diameter hand wheel on mine) although with a ball screw I guess it may be less?

From memory top speed as standard on the vertical head is around the 2000 mark, well short of CNC speeds but I don't suppose the bearings would mind too much they are a decent size, check the specs maybe? They could perhaps be swapped reasonably easy to something better suited to the speeds.

Nice machine even in manual form though, I was taking 50 thou cuts with a 2" facemill in steel on mine last weekend for fun. I love it.

Paul.

On the acetylene question I have often heard tell of insurance exclusions but does anyone have any specific info to back this up? Not that I have acetylene at home or any real intent of doing so in future but out of interest I dug out my home policy and there is no specific or related exclusion that I can see? Interested to hear if anyone has a concrete example of this being the case?

Paul.

Bob,

oxy acetylene; no real problem with this if you know how to apply the flame to the job, yes you could overheat either the parent metal or the filler but if used correctly you won't.

Diferential expansion is less about the speed of conduction and more about the absorption. A thicker section takes more heat (energy) to raise the temperature a given value in a given time than a thinner section. You don't need to be able to calculate it you can do an experiment with your soldering iron, a thermocouple and a stop watch.

Older copper boilers do develop leaks around the fire door ring / section and around the foundation ring. Agreed model boilers less likely to develop cracks in the backhead / inner firebox due to the malleability of the copper (although copper does work harden even in a boiler). Usual source of leaks in firebox tube plate, smokebox tube plate, firehole and foundation ring is joint failure.

Yes the shell will expand, but not as quickly as the firebox, only source of heat to the shell is by conduction through the water. The whole boiler will expand and yes both as a function of heat and pressure, my 4" scale TE boiler expands about 3/32" between 0 psi and 120 psi but that is steel and only an infestiminal amount is due to pressure, the rest is heat.

If the tube plate does get overheated in my experience as per cracking and quilting of the firebox sides and crown it is due to a boiler not having been maintained correctly and a layer of scale deposited which is a good insulator and stops the heat conducting to the water or the water level has been allowed to get too low!

I will claim to be able to file a piece of metal to within 5 thou, one of my first jobs as an apprentice was to make an engineer's square calibrated to a master, manufactured using only hand tools in fact the calibration was less than 2 thou and as to irregular shapes we had to produce other pieces that fitted inside each other supporting their own weight and with no light visible through the joins.

Dont get me wrong, there is absolutely nothing wrong with questioning a process that has always been done in a particular way as to whether that is the correct way. However there is usually an underlying reason why it has been done the same way for many years! Feel free to construct / redesign your own boiler in any way you wish, there is nothing stopping you. However to get it certified under either the MES boiler scheme or a commercial examination as it will not be to a published or established design you will be expected to present calculations to justify your method. I would suggest you run your ideas past whichever boiler inspector you intend to use for certification before and during construction to avoid any disappointment on completion.

All the best,

Paul.

I have two mills, one with a tilting column and one with a tilting head. The former I can only remember tilting the column once. The latter I tilt the head all the time, granted its bit bigger than your average hobby machine but in terms of say drilling steam passages in the cylinder of my 6" scale TE or drilling the stud holes in the saddle (radial) I would have needed a pretty massive tilting table and setting up for each hole would have been pretty time consuming! I don't find any particular problem tramming it back to vertical. If constrained by space (as I am at home) and if starting over I would definitely go for a tilting head over a tilting column.

Paul.