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Member postings for Paul Kemp

Here is a list of all the postings Paul Kemp has made in our forums. Click on a thread name to jump to the thread.

Thread: Lead Bearing Solder is Banned
20/11/2018 10:27:11

SOD, well two examples in the last week. 1st, university student colleague of daughter signed up for a student union trampoline activity, fell awkwardly and broke ankle, now asserting that despite a safety lecture by instructor the student union as a body did nothing to physically prevent his injury and by organising the activity is responsible so is now instigating legal action against the student union. 2nd, last Friday the last of my father in laws vintage vehicles having been sold was being collected. It had not moved for 20 years so had to be extracted from garage at 90 degrees to road using winch on recovery truck. Truck parked in road, big yellow lights flashing on top, winch wire attached and as winching commenced woman approaches on foot. Despite footpath being clearly blocked by the wire stretching from ankle height up at an angle to the flat bed and the car slowly emerging with the associated noise of the winch she continued to walk towards it until I stopped her. Apparently there should have been footpath closed signs and barriers, a verbal warning was insufficient, her seeing the situation and making her own decision to cross the road, definitely off the agenda.

Plenty of other examples from safety management meetings I had to attend between 2002 and 2008 where all incident reports, injury and near miss were analysed for trends. Could not believe the increasing numbers of people (travelling public) shutting their fingers in the hinge side of toilet door cubicles and other doors on site. Insurers insisted on the fitting of hinge guards to all doors. None of the doors had been changed so what lead to the vast increase in incidents? Why would you have your fingers anywhere near the hinge side of the door?

Agreed my 'opinion' is based on subjective interpretation of 'evidence'.

But returning to the OP how does this discriminatory legislation significantly reduce the overall amount of lead used? There must be figures somewhere to show the amount of solder sold to the amateur market as opposed to the professional which apparently remains unaffected? The proportion of lead used by professionals must outweigh the amount used by ametuers by a massive amount? Is there eveidence to show a high proportion of ametuer users are suffering lead poisoning? Fair enough if a conscious decision has been taken to prevent the use of lead altogether but the implication of this ruling is a professional can be trusted to handle the stuff and continue to introduce it to the environment as they see fit but it's far too dangerous for the likes of you and me to have it in the house? Where is your evidence to support that theory? Surely if it really is a concern a health warning could be imposed on the packaging alowing the end user to decide if they expose themselves to the risk or control the risk using PPE? No, apparently it has been decided the non professional general populace cannot be trusted with lead solder..........


Thread: Brass or cycle thread ?
19/11/2018 13:22:38

Well if you make your male fittings (assuming all threads on the boiler are female) BSB (55 degree) they will fit either. They are not going to fall out or be significantly weaker for the sake of 2.5 deg on the flank angle!

The only way to be sure what is in the boiler is as you suggest, ask who made it.


Thread: Lead Bearing Solder is Banned
19/11/2018 13:16:15

Stupid is as stupid does!

I am just tired of the ever increasing legislation intruding on every day life! Yes without doubt there is some well intentioned and well meaning 'rules' imposed that make perfect sense. However, the one thing in recent years to creep into the safety arena is risk assesment, another sensible process but the application of its principles to the need to legislate seems quite often missed. The controls on acid being a good example, I wonder how long it will be before kitchen knives are banned altogether or have to be licensed??

The exponentially increasing focus on general safety seems to be generating a similar decrease in common sense and self preservation. The general population these days seem incapable of assessing risk for themselves and act with a general expectation that if something is not safe, someone else will tell them, there will be a sign, a fence or other measure to protect them! All new legislation has the men in wigs rubbing their hands at the opportunity of new revenue streams to explore and milk!

I am now off to machine some leaded bronze bearing slippers and will be looking over my shoulder wondering how I should dispose of the swarf, is there a standard size mouth gauge yet like the letter gauges at the post office that I can use to determine if the finished product is dangerous?


Thread: Electric Traction Engine
17/11/2018 23:41:46


It's a relatively small half size, a Savage, it's around 8' long and the completed weight will be in the order of 1000kg. I have been on it 2 years now and I am about 2/3 completed, hoping to light a fire in it later next year.

NDIY, well the next set of gears I will send your way then. The largest of the recent batch was 19" diameter, 4 DP. My set up for three of them was very similar to that Andrew shows, horizontal mill with no power feed to the knee. Nothing fiddly about setting it up, clamped down concentric on RT, put the right plate on, set the sector arms, centred it on the cutter, touched off, put on full depth of tooth space and away you go! About an hour to set up, 76 tooth spaces 0.540" deep and roughly as wide, gear is 1" thick - so a lot of metal to plough out in one go, avenged about 17mins per cut.


Thread: Warco Mini Lathe
17/11/2018 19:43:15

Cast iron machined hard with carbide tooling can produce brass coloured chips! If you really push it you can get blue ones too!


Thread: Electric Traction Engine
17/11/2018 19:35:02


I think a little while back you were considering getting a rotary table? That being the case you could get one with a dividing attachment and cut your own gears. However financially and in terms of time expended, buying your gears would be the cheaper and quicker option. Time you have bought said rotary table with dividing discs, found the std discs may not cover the divisions you need so made another custom disc, purchased the required gear cutters and then bought the material for the blanks, turned them up and cut the teeth........... You will be quite a bit older and poorer by more than £105! It all depends on your outlook really.

I have just cut the full set of gears for my half size traction engine, took me the best part of 3m of Saturday's and Thursday night's, despite borrowing the cutters I very much doubt I saved much money wise and it took a lot of time. I did it purely because I can and wanted to be able to say that apart from the professionally built boiler (too complicated in terms of certification for me to do) and actually pouring the castings I want to be able to say "I built that". There is not too much to cutting gears in terms of complication but it's a lot of handle winding and general effort! If I were to build another (which I doubt I will!) I doubt I would cut the gears again myself!


13/11/2018 23:11:27

Posted by Ron Laden on 13/11/2018 20:57:52:

Gradually putting together a material shopping list, I will be machining the cylinder block from solid and was thinking of what would be a good material for this. When using castings I dont know what they are made from, bronze, cast iron..? Of course I dont have to consider the cylinder in quite the same way as it wont be live steam and will be working in reverse... i.e. the piston will be driven by the connecting rod. In operation it will look the same but the drive will be from the drive motor further down the gear train.

I was thinking of using bronze, but any other thoughts would be helpful.


Edited By Ron Laden on 13/11/2018 21:15:30


Full size would be cast iron. In your case where you don't need to consider corrosion bronze would be an expensive way to do it! Unless you are planning to use the puff from a driven piston for a smoke effect or something why bother with a piston at all? You can just have the piston rod supported from the cross head and running in a brass gland (same with valve rod) and the 'cylinder' can be aluminium, steel or even wood! Whatever is easiest to machine and is cost effective.


13/11/2018 18:08:06


Not that I have made a habit of measuring them but most full size horn plates I would say dependent on the size and breed of engine range from 3/8" to a max of 3/4". Where they are normally an extension of the outer firebox sides the thickness will be governed by the thickness of the boiler plate. They are remember, stiffened up by fairly heavy castings bolted to them that carry the crank and second and sometimes third shaft bearings. They are also stiffened up by the front plate and spectacle plates fixed between them, forming a 'box' over the firebox / boiler. That said 3mm I would say is a good choice for yours. The phrase you can't scale nature holds true here, where an exact scale thickness in smaller sizes would make things a little 'floppy' and perhaps not too resiliant to out of scale forces!


12/11/2018 10:09:46


Looking good. Tube not being perfectly round is quite common for general purpose tube.

That price on the Minnie is pretty reasonable for a well made model I would say. The market value of most engines rarely reflects the time expended biulding them let alone the cost of materials. General estimate of time taken to build seems to be around 2000 hours, that's a bit over a full year of 38hr weeks with no holidays, cost that at a conservative £10 per hour - £20k!!!


Thread: Oil container
12/11/2018 09:51:23

+1 for hair colour bottles, get em for 'free' when your missus has emptied em!


Thread: Boiler certification in a launch
10/11/2018 00:30:28

Posted by Sam Longley 1

Please accept that I agree with you entirely & with some of the comments within this thread. I just am surprised that no one can come up with a statutory instrument to stop people having what would be quite a large boiler without having any sort of test during its lifetime

I suppose it is a bit like all the cheap air compressors that are sold to the public. I expect that once sold none are ever tested, but many sit in sheds collecting water in the tanks, never drained, & rusting gently away.

Still as one never hears of one exploding I suppose it is a non event, thus not requiring attention from the authorities


Accepted, lol. In terms of being quite a large boiler though, would it? 16' steam powered launch is likely to have something like a Stuart Compound as a prime mover and the boiler would be between 12 and 18 diameter probably and the water space maybe 24" high. Operating pressure as its a compound may be in the region of 150psi. So in terms of volume or bar/litre classification maybe towards the top end of the 'club' testing regime. In the grand scheme of things that isn't a large boiler. Yes if it went pop it has the potential to do a fair amount of damage and cause some pretty nasty even fatal injuries but if properly designed, manufactured and maintained the risks are pretty low.

My concern would be more the design, materials used, welder competence if steel etc than if it is subsequently regularly tested by an independent examiner. There was an incident with a steam boat a few years back in Beaulieu involving a fatality, the boiler had been inspected! I can't direct you to the info at the moment but I am sure a bit of Internet surfing will bring it up - if I remember correctly there is an HSE report on it.

Personally I think there are more than enough Statutory Instruments already, they tend to apply to those that abide by them, those that don't want too continue not too and bad things still happen! Codes of best practice can be just as effective and still carry weight in law, they are not statutory but you have to have a good argument why you didn't comply when things go wrong.


09/11/2018 20:09:02

Posted by Ron Laden on 09/11/2018 16:52:03:

I know very little about steam engines and boilers etc but how anyone can operate one at any scale with an untested boiler is beyond me. I would keep looking at the boiler thinking "is it safe" maybe its just me.

Edited By Ron Laden on 09/11/2018 17:07:15


Anyone operating a boiler ought to be capable of making an informed judgement if the boiler is in acceptable condition - if that is not the case then I respectfully suggest they stay well away from one! The real danger from boilers is a lack of understanding by the operator.

I regularly volunteer on a heritage railway and before anyone is allowed to light a loco up, let alone fire one they have to learn and demonstrate competence in the principles of operation and safety and carry out their own visual examination of the boiler for any signs of water leakage externally or within the firebox including stays and fusible plug(s) and the smokebox tube plate / tubes which is a daily check, to an assessor. Once in steam and before going off shed the safety valve should be observed to be operating correctly according to the pressure gauge and methods of water feed proved functional as well as a proper test of the gauge glass(s) or try cocks. Granted that is not a full trousers down inspection of the whole boiler but roughly once a month at wash out all fittings are inspected as well as an internal exam and integrity of stays checked, among other things. This is in addition to the annual formal boiler test by an independent inspector.

Things worth considering are; boilers rarely fail catastrophically without some prior indication like steam and water leaks - hence the importance of the operator having a full understanding of the implications of warning signs. A boiler inspection is a bit like an MOT, happens once a year and a lot of damage can be done to a boiler in a year by the operator running with low water, rushing into steam (unequal expansion damage), failure to wash out or in hard water areas descale so hot spots develop stressing the plates, etc etc etc!

The real risk of a miniature boiler exploding is small unless it has been made from a baked bean tin held together with chewing gum by someone with no knowledge or appreciation of the potential issues - in which case return to paragraph one! The relative level of risk is further evidenced by the low cost of insurance, if boilers were exploding left right and centre the premiums would be massive. Even the black museum of sectioned boilers parts showing quite serious weld defects and constructional issues which used to appear on various stands at exhibitions in a perverse way show the level of risk as they came from boilers that had been operated for years with those defects present before they were cut up and none of them failed catastrophically as far as I am aware?

As far as the OP question goes there is not enough information on the proposed boiler itself to make any reasonable assesment of risk - is/ was it being made to an established design? What are the materials? Builder competence? The question focused on a lack of intent to follow a formal independent inspection and certification regime because of a belief it wasn't required - that doesn't necessarily on its own make the boiler dangerous. It may be the owner is perfectly capable of making his own assesment and is confident in his abilities. It is interesting perhaps and seemingly little understood that it is the owner / operators responsibility under the regulations to appoint a competent person and be confident of his competence in so doing, to inspect a pressure system. It remains the owners liability for the safe operation unless it can be proved the person issuing the certification was negligent the owner / operator will carry the can. Having boiler certification means nothing 11 months after the test if the boiler has not been operated and monitored correctly by the operator.


Thread: Cylidner drain cocks
09/11/2018 11:00:41

I made mine for my 4" Ruston Proctor with parallel plugs and PTFE liner inserts. Never made a drawing, just had a back of an envelope scrawl for my design. They have worked fine since I first ran the engine, about 2010 I think off hand. There are some pictures on my thread on Traction Talk for the Ruston, difficult to post them here as I don't have easy access to where they are stored. Basically the body was profiled from brass hexagon bar. The hole for the plug and liner was drilled from one side, top end of hole tapped for the back / retaining gland nut the portion for the liner was left tapping size for the thread chosen. PTFE liner turned up a couple of thou over the drill size and pressed in with a purpose made dolly. Bar transferred to lathe and profile turned (form tool) and threaded each end and drilled through for the steam passage. Plugs turned from stainless, cross drilled in the right place to match the steam passage when fitted, OD turned to be a fairly tight fit in the liner (it nips down on the bore when pressed in so rather than faff about trying to work out how much I used the shanks of number drills to gauge the finished size of plug required). I put a thread on the ends of the plugs and left a small shoulder to file a square for the operating levers. The plugs have a shoulder so when the back nut is screwed in (looks like a short bolt with a hole in it for the plug spindle) the threaded end of the 'nut' bears on the end of the PTFE sleeve providing some compression adjustment and retains the plug in the body. Not hard to make, probably took me about 4 hours for the pair, more difficult to describe than to do it!

I made the three cock gauge frames in a similar manner, that was more difficult and time consuming but again they have been working without issue for the same period. I do find they leak a bit on the cold hydraulic test but they are 100% tight when in steam. They operate freely too unlike the taper cock designs which always seem to leak or sieze!


Thread: Boiler certification in a launch
09/11/2018 10:24:40

Very interesting question, the definitive answer to which is probably not available!

The link to the directive fizzy provided, according to the directive itself does not apply to equipment for 'ships' and for ship propulsion - Chapter 1, Article 1, 2.(n). However, there is probably a requirement under the seperate provisions of the Marine Equipment Directive - this is the one that underpins the 'wheel mark' in the marine sphere as opposed to the CE mark elsewhere. Whether a 16' launch can be classified as a ship is subjective. Sadly like most EU legislation the PSSR is poorly constructed for easy reference!

Without doubt as NDIY states it is highly improbable any insurer would take on the risk without any inspection and certification. However on the open sea, last time I checked there is no requirement for a vessel to carry insurance, situation on inland waterways is different though.

So, it is possible the claim no certification required, in the literal sense could be correct if the launch and its builder / operator are considered in isolation. But..... As soon as a third party is introduced such as a passenger (mate being taken for a spin, family member assisting as examples) or a bystander or another boat coming into close proximity the long standing legal principle "Duty of Care" comes into play. So any problem with the boiler leading to loss or injury where that duty has not been discharged by ensuring the boiler is safe (what better way of doing that than following established practice?) then the operator would be liable for any claim. Do you feel lucky? Like so many things the definitive answer would be influenced by legal precedent and the attitude of the judge / jury on the day!


Thread: Wyvern cylinder head sealing
07/11/2018 23:51:00

You could try the dodge the AA seem to recomend to verify timing belts intact and give it a whiff of easy start! If you don't get a pop or a bang with that then you really do have a fundamental problem!


Thread: Cylinder boring
05/11/2018 11:38:02


I would use an HSS tool, nice sharp point with perhaps a very small stoned radius and go slower. It's all very well sticking to theoretical cutting speeds but they assume ideal conditions in terms of tool geometry and machine rigidity. So sometimes you have to deviate from the recommended by quite a bit. With HSS I would try about 100 rpm, I would say your 500 even with a carbide insert is a bit fast. With an HSS tool you have the opportunity to also play with the geometry by grinding on more top rake, clearance or even adjust the angle of attack!

I have just finished doing the boiler saddle radius on a 6" scale traction engine cylinder (6 1/8" radius, cast iron cylinder, machined on a horizontal borer). Took me three attempts for the finishing cut to get the finish I wanted, final adjustment was increasing the top rake on the tool bit. Don't be afraid to experiment, cast iron can be a very variable material even within the same casting!


Thread: Electric Traction Engine
31/10/2018 08:55:06


I would say 4mph would be plenty fast enough for something your size, maybe 5 if you want it turbocharged! As to crank revs, it's a little subjective. It's been said a Showman's engine when generating does around 150rpm. A full size Avelling roller from a royalty sheet working back the crank revs from quoted road speed is around 300rpm flat out. So no more than 300rpm at top road speed for you I would say - you can't scale time! Less wouldn't hurt. Most general purpose engines were two speed, high and low gear. "Road" locomotives - those designed for haulage were three speed.


30/10/2018 13:00:26


That is basically the arrangement but! Where is the drive coming in? If you are going to drive onto the axle then I think at first glance that will work - as long as the wheel with its "sun" gear and "planet" housing is free to rotate on the axle.

However, your terminology is a bit mixed up there. What you have drawn with 4 bevel gears is not a sun and planet diff. A sun and planet set up would be a bit different to that using straight cut rather than bevel gears. So 'correct' terminology for the above would be crown wheels for those mounted on the axle / wheel and pinions for those mounted in the diff.

Also on a 'normal' (if there is such a thing) traction engine the pinion carrier / diff housing / or as you have termed it 'planet gear carrier' would be the driven component, the final drive gear being mounted on its outer diameter and it would be free to rotate independently of axle, wheel or anything else. The inner crown wheel would be pinned to the axle as you have it, the outer crown wheel fixed to the wheel, as you have it. Thus the diff housing would be driven from the second or third shaft and drive on the crown wheels via the pinions. The wheel being loose on the axle, the opposite wheel being fixed to the axle so the 'differential' movement imparted by going round the corner will be taken up between the two crown wheels.

Not sure I have explained that in a very clear fashion! Maybe Jason can do one of his CAD drawings which would show it better.


Thread: New Mill - Starter Tooling
29/10/2018 22:55:58


You have the lathe and you have a drilling facility with the mill so you could make a fly cutter reasonably easily to use 1/4" or 3/16" round HSS, readily and cheaply available from various sources. You can grind the tips on an ordinary wheel (which I believe you have?). That said fly cutters are reasonably cheap but making your own allows flexibility to tailor exactly to your needs and will give you some practice / experience in using your machines.

On your question on fuel the most common in the UK was coal but overseas wood and even straw was used. Generally though engines intended to burn other than coal had firebox dimensions adjusted to suit wood or straw. I can't think of any traction engines that were originally designed to burn oil.


Thread: Electric Traction Engine
28/10/2018 16:37:14
Posted by Jon Lawes on 28/10/2018 14:07:49:

A solid axle isn't going to create an understeering death chariot surely. It's just going to slip a wheel, especially if the front axle has some weight over it.


You would think so. However, have you tried driving a Maxitrak Avelling with both pins in, on grass or the road? Interesting is the only way I could describe it. Not a particularly large or heavy engine but it wouldn't go round any significant corner! Most conventional traction engines (exclude rollers, Showman's and Ploughing engines) do not have that much weight on the front end. Although Ron's is going to be a bit different the overall geometry / volume is the same so unless the batteries are right forward in the smokebox the effect won't be much different. I can't see any major disadvantage driving on one wheel. Especially if a pin arrangement is built in to allow the second to be driven if conditions dictate.


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