Member postings for Paul Kemp

Trevor,

Many thanks.

Paul.

David,

Glad to hear you are making progress. Remember Jason's previous comment that the valve needs to be free in the buckle to find its own position on the port face. Doesn't want to be a sharp feeling in a bucket type of fit but it must be free to move. It's not uncommon on full size engines with plenty of wear when they are idling and the differential pressure across the valve is low to hear the valve slapping as it moves on and off the port face, not desirable and some have light finger springs fitted to prevent it, holding the valve on the face. Too heavy a spring can lead to wear though and if the engine primes it's beneficial for the valve to lift rather than smash a cover if it primes suddenly and the drains are closed!

Paul.

Jason,

Thanks, didn't notice one at the show, trip to specsavers! However OP said he got pressure in the cylinder when he put air direct in through regulator port but when putting air on safety tapping it rushes out exhaust. That implies the valve is sort of doing its job at least? If the lower exhaust drilling blanking plug is missing then pressure in steam space around liner could go direct to exhaust without going anywhere near the valve chest. Either that or a drilling has broken through somewhere it shouldn't?

Paul.

David,

As I said I don't know the internal layout of the DNY but a lot of miniature TE cylinders require a drilling for the exhaust from under the saddle which has to be plugged at the end after. If you have air rushing from the exhaust it sounds like you may not have fitted the plug? This would allow all the air to go direct to exhaust and give the symptom you describe.

Paul.

David,

Mmmm, well......... Like I said I don't have any intimate knowledge of the DNY apart from having seen a few! Never looked at the drawings or made any bits for one! Just thinking it through from general principles though, a few questions;

You said in the first post you could hear air coming from the exhaust. Is this a full volume flow of what you are feeding in or just a wisp?

Did you confirm as Jason suggested that the slide valve (I assume it is a slide and not a piston valve) is free to float on the valve spindle and can find its own seat on the valve face?

Depending on answers depends on where to look next.

Some suggestions though;

Is there a tapping anywhere direct into the valve chest, lubricator input perhaps, where you could put live air direct into the valve chest.and bypass everything between boiler and valve chest?

Are you sure you have the timing right?

Are you sure you have done all the required drillings (silly question perhaps but sometimes it's easy to overlook something).

Paul.

I went yesterday too with three fellow club members. Seemed a similar amount of people around as last year, many carrying bags and boxes indicating money was being spent! Do agree though that with the exception of RDG, Tracey Tools, Warco, myford, Polly and Blackgates some of the traders had pulled their horns in further. What did strike me is the balance between 'engineering' and 'ship' models seems to be steadily shifting towards marine. Very few traction engine models at all. There were some cracking models in both classes and some of the steam powered boats combined both disciplines. Also good to see more of the less than gold medal standard, polished within an inch of destruction models around! Personally I think it's good to see things that are less than perfect on display, gives those aspiring or just starting out some confidence in what they can achieve too. It's good to see clubs supporting the event and putting on a good show and variety of members work, it's not easy to get members inspired to support a club prescence, well done.

All that said and despite being able to pick up most of what was on my shopping list I think all in our party (who have all been regular attendee's over the years and various venues) came away feeling a little flat. Not easy to really put a finger on why. Three of us up until a couple of years ago used to make the trek to the Midlands Show too, with increasing costs and a similar feeling for that show we haven't made the journey since 2016, I suspect that London for us will go the same way.

Paul.

David,

As Jason says! I am not very familiar with the DNY engine but there should be at least one bush low down on either the sides or front of the fire box just above the foundation ring for a blow down valve, possibly more than one in which case the others will be for wash out plugs, any of these that are accessible will do to connect your air line if you don't have the blow down valve fitted yet. In fact if you don't have any fittings mounted on the boiler yet then any of the tapped bushes will do for this test as long as you fit blanks to the others. Putting pressure on the boiler as Jason says has the advantage of being able to test the regulator and also the saddle flange to the boiler. You should only need to put 15 or 20 psi on it to get it to turn unless it's exceptionally tight, in which case you need to find out why it's tight and ease it first! Sticking high pressure air on the boiler / assembly may not be the best idea if you haven't checked the integrity of all the plugs and fastenings first with a hydraulic test as even 20 psi of air can project a loose plug out with enough force to do injury if it hits you in the eye! I add the latter because your post suggests you may not have great deal of experience of boilers and steam engines - if that is wrong, my apologies! It's not a massively high risk operation but do take due care and make sure you have a pressure gauge connected somewhere in the system so you know you are not over pressuring the boiler!

Paul.

I have had exactly the same over the last couple of months, been looking for a company that will sharpen some involute gear cutters for me, have used email addresses on half a dozen web sites and the contact us feature where no other email address is shown, all with zero result!

Makes you wonder why any organisation would maintain a web presence advertising their services if they are not going to bother to respond to enquiries? They may be making an assumption that it's a one off job and they are not interested but how long does it take to type, sorry we are too busy with large jobs? Certainly less time than it takes for someone to answer the phone if I call them! Is a lack of response a true indicator of their reliability and competence to do the job? Also how do they know their assumption that this is a pain in ass one off job will not lead to a regular contract for more work or is it such a niche business that they have as much as they can handle already and don't care?

That aside, does anyone know of a company that can sharpen 4DP cutters that I can try?

Paul.

David,

I am probably being extremely dumb here but what is the test designed to show / prove? If you have removed the valve and buckle then I am assuming you are not expecting it to run?

Paul..

Derek,

Sounds about right. Couple of off the cuff comments; previously when making pistons I have roughed out the blank including the centre hole / fixing arrangements and ring grooves and then mounted the piston on its rod and held the rod true in a collet or clocked in the four jaw and finish turn the details to make sure everything is concentric and square with the rod. Good test is mount the piston on its rod, put your hand over the end of the liner, pull the rod / piston and release, the piston should return to the initial position or thereabouts if there is no or minimal leakage.

Paul.

Keith,

If you are within travel distance of London nip up to Ally Pally tomorow or over the weekend and you will find some vendors with machines on display. If you are judging them against S&B, Hardinge or Bridgeport though in terms of rigidity prepare to be disappointed. That said most of them will do what they claim just not as quickly in terms of metal removal rates.

Paul.

You could also use a compressed air jet in place of the fan (or shop vac) in Jeff's second method. Use small drillings in the nozzle to reduce the volume of air used, if you three or four small jets appropriately angled (like a loco blower) you can get maximum effect for minimum compressed air volume.

Paul.

Alan,

Well done. Good to hear you are making progress, don't forget to take some pictures!

Paul.

I had a similar requirement with 1/2" pipe and a 1" radius bend a few years back for the blast pipe on my traction engine. Bend needed to be tight to get the blast nozzle in the centre of the chimney! The pipe was thin walled AC copper pipe also which made it worse. Did a bit of research and salt was recommended rather than sand as it is finer and packs tighter. In order to get the salt to pack down tight it was recommended to hold an engraver or similar against the pipe to induce vibration to pack it down (didn't try that as I didn't have one!). Was told there was no way I would get a bend that tight! Red rag........ I annealed the pipe and packed it with salt, crimping the ends. Got a lump of hardwood and filed a profile of half the diameter of the pipe into it and the radius required. Then clamped the pipe to it with a horseshoe type bracket and used the back former from a commercial bender (straight lump of ally with a u groove milled in it, half the diameter of the pipe) and worked it round by hand. On completion it was a pretty fair bend, the pipe had gone a little oval but removing the salt, another anneal and some careful dressing with a planishing hammer sorted it. Polished up quite nicely. Subsequently I was advised to put a cork in one end of the pipe, fill with water and put in the freezer (after annealing) instead of filling with salt or sand. Not had a need to try that yet but it sounds plausible and it's cheap and clean. Would allow a second anneal during the bend without having to un crimp the pipe to empty the filling medium and clean it out before annealing again. I have a similar job to do with 1" pipe this year for the latest engine so may give the ice method a shot.

Paul.

Hmmm, this rings a bell! When I got my mill I wanted to get it up and running, was on a tight budget, so looked to China for VFD's. I found one supplier on the rainforest marketing site that was offering what I needed for just over £20ea!! So I ordered two which including shipping came to around £48! I didn't expect the transaction to go through as the gear cutters but got order acknowledgement and then notification of shipping. Eight weeks later I noticed the tracking said they had been delivered! Checking they were apparently at the mail reception centre in Southampton! Vendor then advised they had been damaged in shipping and were being returned to them and offered a refund. I refused a refund and requested they send replacements, they said they couldn't send replacements until the originals were recieved back and after a bit of bouncing around they refunded the money anyway and refused to respond to any further contact. Luckily I have a friend who does a fair bit of business with China and he passed me a local contact to whom I explained the situation and copied the correspondence. He found the company and contacted them and apparently their MD was very rude to him, he got annoyed and referred them to the Chinese equivalent of trading standards, 3 weeks later I got my VFD's with a grovelling apology FOC! Real result. Not a normally achievable resolution but very pleasing, subsequently the supplier has contacted offering to supply a coat rack, shoes and other stuff FOC in return for a positive review! I have been waiting for the triads to knock on the door ever since!

Paul.

Derek,

I couldn't find easily a video of a traction engine cylinder steam flow or a decent drawing (and don't have Jason's excellent CAD skills to be able to draw one!). Niether do I have direct experience of the Allchin cylinder so have tried to put in words a general description of how steam flows from the boiler to the chimney, hope it makes sense!!

Traction engines, particularly English ones do not normally have a dome to collect 'dry' steam from the boiler like a railway loco. The dome on a loco provides a space where steam collects and is drawn off for use that will hopefully not contain entrained water. So on a traction engine the cylinder casting usually performs this function. The casting is generally hollow around the liner so steam gravitates from the boiler barrel into the the space in the cylinder casting around the cylinder bore, this achieves 2 things, it gives a space seperate from the boiler barrel for the steam to be drawn off for use and because the steam surrounds the cylinder bore (in your case liner) it keeps the bore warm reducing condensation of the steam inside the bore when the engine is running. As you are fitting a liner to create the steam space in the cylinder casting and this space will be directly connected to the boiler and at boiler pressure the seal between the liner and the casting needs to be leak free. Any leak can either get into the bore via the end covers bypassing the slide valve which will lead to reduced or non existent performance or will be blowing to atmosphere! Steam is then taken from the steam space via the regulator to the valve chest via drilled or cast passages. The regulator is arranged so that the high pressure (boiler) side acts on top of the sliding regulator valve, so keeping the regulator on its seating face. It is a good idea to make the regulator port under the valve a pear shape so as the regulator is opened the area of the port exposed to high pressure steam progressively increases, this makes the engine easier to control. The passages for the regulator must not break through into any other passages! Once the steam is in the valve chest it is directed to each end of the cylinder by the valve. The steam ports (outer two ports) and the drillings to the ends of the cylinder again must not break through to any other area or drilling. The exhaust port (wider, centre port) is connected to the steam outlet flange for the blast pipe on the exterior of the cylinder casting again by drillings or cast passages and again these must not break into any other passage or area. So you have four areas that must remain isolated from each other within the cylinder block, the high pressure steam space around the liner, the regulator passages and valve to the steam chest, the steam ports to each end of the cylinder and the exhaust arrangement. You will also likely have cylinder drains which are drilled directly from the external boss where the clave will be fitted to the bottom of the bore and usually a steam take off for the steam blower that will be drilled from a point on the front face of the cylinder 'block' directly into the high pressure steam face surrounding the liner (with your engine it will probably turn 90 degrees down and connect with the space in the saddle.

1000 words when a decent picture would do!

As to piston material, bronze as Jason said should be fine. Remember 'technically' the piston does not run on the liner as it is supported by the rings although in practice that is a moot point. Full size generally have cast iron cylinders and pistons, another example of a material running on itself if you like.

Paul.

Gary,

Whilst lagging is important and will have an undoubtable effect on overall rate of steam production it won't make your fire burn any better. Personally I think your experiments have followed the right route so far and if you can boil water and make some steam without lagging then when you fit lagging you can be confident it will boil harder and make more steam. Twisted shim in a tube or two is not a bad idea as it will slow the passage of hot gas through the tube allowing more heat transfer. It's worth bearing in mind that with a traditional loco type boiler the greater proportion of heat transfer to the water takes place as direct radiant / conducted heat from the fire through the firebox sides and crown than from flue gasses through the tubes. Some American design traction engines also had 'wet bottom' fire boxes to give another surface around the fire! Your activities with firing are very interesting to follow, giving some direct practical experience rather than theoretical speculation.

With the engine; why not start with the 12mm bore version and follow up with a 24? I am sure your boiler is well able to run the former and most likely the latter, it might even run both!

Paul.

Well I am with John on this. My electrical tuition was about 40 years ago, never really sunk in, never really had any interest in it! Consequently I have a base underpinning knowledge of electronics which gets me by but no real ambition to expand or develop it. All I wanted when I got my mill that has 3 phase motors is to get it running from a single phase 240v supply. I bought a couple of the Chinese Huangthingamyjig inverters from e Amazon for less than £90 ea. Connected them up, switched on and for a year they have been doing exactly what it says on the tin (having written this they will probably go bang!). Programming them was a bit of fun but plenty of resources on YouTube and regarding the pot range on the speed control some great feedback on here. They were the means to an end - getting the machine running and cutting metal, nothing more than that! I am very happy with them as they have done exactly what I want. Yes I could have gone more expensive (between 2x and 3x the price I paid) for European versions, yes they may be better built with better quality gizmo's and with greater programming flexibility and more functions and they probably would last longer and have more local support / warranty and possibly repair options. Mean time however I have an extra £200 - £400 in my pot for tooling, equipment and materials to push my project on. The VFD's were just another step towards a bigger project, not the project itself!

Paul.

David,

When I cut my traction engine gears which were quite big and a mistake would be costly in both time and material I gave myself a check to make sure there were no issues. Clamped a square to the table against the edge of the gear (gears were parallel to the table) and went round and scribed a line at every division. I then clamped a scribing block to the table lined up with the first line and checked each time I advanced the gear that the tip of the scriber lined up exactly with my previously scribed lines. Probably took an hour on the biggest gear to set up but it saved me 2 mistakes due to brain fade over the 6 gears. However focussed and organised you think you are it's very easy with the boredom of winding handles to get distracted

Paul.

Derek,

Well done. Excellent progress. In less than 2 weeks you have gone from looking for someone to machine the cylinder for you to being almost halfway there. That includes overcoming the issue with the dodgy casting for the liner and sourcing a replacement and a bit of out of the box thinking as to how you can overcome the limitations of your machine capacity. I bet that's a lot more satisfying than paying someone else to do it and the bank manager will be happy too!

The really great thing about this forum is seeing people achieve things with a little advice they didn't think they could do. Well done indeed.

Paul.