I decided that it was time to make a whistle and this was made to the 'words and music' in 'Shop Shed and Road'. LBSC suggests using brass 'treblet' tube for the body which I believe was a very thin brass tube available at the time. I managed to find a length of suitable tube in the scrap bin so this was used. The plug with the slot and the two end plugs were turned from brass bar and soft soldered in place along with a connection for the steam pipe and a brass fixing bracket. In his book LBSC tells how to adjust the whistle to give a nice clear note by adjusting the position of the slotted plug but as it happens mine worked perfectly first time (beginners luck!) and gives a really loud piercing note on 50psi of air. We'll see how it sounds on steam.
The whistle is mounted between the frames over the top of the rear bogie stretcher as there is plenty of room here. The whistle fits with the opening facing downwards so that any condensate can drain easily.
Whistle mounted over rear bogie
The whistle valve follows the standard design with a pin operated by the lever which pushes a stainless ball off it's seat to open the valve. The only difference is that I again used an O ring to form the ball seat as I thought that this may be more reliable. The actual body part of the valve was made some time ago at the same time as the steam valves and turret. The connection to the whistle is by 1/8" copper pipe bent to fit.
Whistle valve and operating lever
I'm hoping to have most of the remaining work done for the 23rd as I'm taking Helen to the opening day of the the new 2½" gauge track at Warrington SME. The track is 1700' long so should be a good run! The only concern is that the track is alloy so I hope I don't have a repeat of the Little Hay experience!
Incidently I've obtained a couple of Rocol products to try out which may be useful to steam enthusiasts. These are 'Oilseal' and 'Pipeseal' which come in 300ml tins. Pipeseal is a liquid PTFE jointing compound which is applied with a brush (much easier than trying to squeeze stuff out of a tube!) and can be used instead of the PTFE tape. It's not cheap but the tin will probably see me out! Oilseal is a similar product (in fact they look identical) designed for flanged joints but is considerably cheaper than the Pipeseal so presumably does not contain the PTFE. Both can be used for screwed joints. The only thing is that they both contain Methanol as a solvent so care must be taken when using the products.
After fitting the boiler the side tanks were refitted which involved trimming the front and rear ends of the tanks to fit snugly against the boiler cleading. Before finally fitting the right hand tank I made up a simple water gauge to show the water level in the tanks. This is just a length of gauge glass open at the top which fits into a fitting screwed into the top of the tank where it projects into the cab.The tank tops were then also trimmed to fit against the cleading and fitted with 10BA screws tapped into the angle around the top of the tanks. Two fillers were fitted onto the tops consisting of short lengths of brass tube soldered to the tops with two brass lids turned from brass bar. These fillers are really just dummies as the tanks are filled via the rear bunker but by removing the right hand lid you can see the end of the bypass pipe from the water pumps to check they are working ok.
Tank tops and fillers fitted
Next job was the spectacle plate and this was cut from 18swg brass sheet using a CAD template stuck to it. The windows were cut out by drilling holes in the corners and then sawing and filing to shape. The spectacle plate is fastened to the cab sides with short lengths of 3/16" angle folded up from some scrap bits of 18swg brass and a few 10BA brass screws. Two longer lengths of 1/4" angle were folded up to run along the top of the cab sides to support the cab roof and to join the top of the rear bunker to the cab sides. These pieces of angle are actually about 120° to take into account the curvature of the cab roof. Two short lengths of brass strip were then cut to fill in the gaps in trhe cab sides over the top of the doors.
The cab roof is being made in two sections, the front part being fixed permanently and a rear section which can be removed when the loco is being run and is really just for show. The front section has a large cutout in the middle to allow easy access to all the controls. The cab roof was rolled to shape in one piece using the bending rolls and then cut into the two seperate pieces afterwards to ensure both bits would fit together properly and have the same curvature. The cutout in the front section was sawn out after rolling as it would have been very difficult to roll the roof if this had been done first. The front section of the roof is fastened to the angle with 10BA screws again and to pieces of angle soldered to the top of the spectacle plate.
Spectacle plate with front section of cab roof attached
Cab roof from the rear
(note tank water gauge on right hand tank and dome over filler on rear bunker)
To cover the filler in the rear bunker tank I turned up a simple dome from brass bar. In a full size loco this would probably be for the water scoop if fitted. This again is just for show as it has to be removed to use the hand pump and just fits loosely over the filler tube.
I thought it was about time Helen had a chimney so I utilised the old chimney casting from the Flying Scotsman. Dad had turned this for the A3 version but as I am building an A1 it is too short. However it was just about the right height for Helen's chimney. The diameter was plenty big enough to bore out to fit the chimney liner and the base was flycut in the lathe by soft soldering the top of the chimney to a brass plate which could be bolted to the vertical slide (very similar to flycutting the smokebox saddle). The base of the chimney was then thinned out and shaped by hand filing. This is quite fiddly but really the only way it can be done. The chimney is a nice push fit over the chimney liner so does not really need to be fastened down. The liner itself has a step cut into it, really only because I think it looks better!
Chimney machined and fitted
Took Helen to Warrington & District MES today for the Grand Opening of their new 2½" gauge track. Apart from turning up the M56 the wrong way and finishing up at Manchester airport trying to turn around it was a really good day. The track is 1700' long and in very pleasant surroundings. It's a very nice even track but has a steep climb back up to the steaming bays that takes some getting up! Helen put up a very good performance and I did about 10 laps virtually none stop with no trouble at all apart from the occasional bout of wheel slip on the alloy rail after a few locos had been around. Probably a bit of oil on the track.
After a tea break I had another go but lost the fire on the second lap. I think I had started off with only half a fire and I couldn't revive it so called it a day. It was about time to go home anyway. Hopefully brother Mick got some photos of the day so I'll put a few up later. I think the society will put some up on their website anyway.
When I got home I looked at the speedometer readings and they seemed a bit low. The speedo said I had only done 1.47 miles which equated to only 4.6 laps. I then discovered that I had initially set the speedo up with the wrong wheel circumference and had used the circumference in inches when it should have been in centimetres! This means that all the readings were about 2.5 times too small and the 1.47 miles was actually 3.74 miles. This equates to 11.6 laps which seems about right. When I was going around after getting used to the track I noticed a top speed of 6 mph which when corrected for the error in wheel diameter would have actually been 15 mph. Phew!
Whilst chatting to Peter de Salis-Johnston today it was suggested that Helen should become a new design for the 2½" Gauge Association so I'll have to get cracking over the winter and get the drawings finished! I'll probably put together a set of build notes as well. Peter also suggested that we should get castings made for the loco but I think this would probably only entail making patterns for the cylinders as the Association already has the driving wheel castings (Black Five) and the bogie wheel castings (Ayesha). Other castings such as chimney and dome could probably use the Flying Scotsman ones.
It would appear that Helen would be eligible to enter the 'Curly Bowl' as she is based on the original LBSC design and modifications are allowed so that's something to think about for next year. Peter won the event back in 2001 with his immaculate Fayette and he thinks Helen would be in with a good chance.
Over two weeks since the last update! I've been busy working so have not had much time for ME.
Warrington & District MES have put some photos of the track opening on their website which can be seen here There's a couple of good ones of Helen running on the track.
I've spent a bit of time building the test boiler for the injectors but I'll write that up under the relevant section.
Whilst running at Warrington I had noticed a lot of steam coming from under the front end so I decided to strip the steam pipes again to look at the new PTFE seals. They had expanded with the heat as expected but had been permanently deformed and had not returned to the original diameter when cold. Consequently they were now a very loose fit in the manifold and were probably leaking badly when cold. I decided to replace the seals with ones turned from some of the PEEK material which has a lower expansion and give these a try.
The loco was rebuilt just in time to go to the last 2½" rally at Chesterfield and I was looking forward to having a run around the track there as it is probably the most demanding track in the country having a lot of very steep inclines including one about one in 50!
I managed one circuit in fine style with Helen blasting up the 1 in 50 to the tunnel with no trouble at all but disaster struck on the second circuit when one or more of the valves seized and we ground to an abrubt halt! With the loco having to work much harder than ever before the cylinders had obviously got hotter than usual and the valves had expanded more. After a brief cooling off period we were away again but the same thing happened again further around the track. This time Helen refused to run again and a quick look showed that the bolts holding the 2 to 1 lever pivot had sheared again. (This had happened before when testing on the rolling road). Fortunately no other damage was done but it put paid to any more running that day.
The rest of the day was not wasted as I helped perform major surgery on the Kingette originally built by the late Dick Colbran but now owned by Ian Gordon. The loco had a bad water leak on the top fittings of the axle pumps and the nuts are virtually impossible to get at without removing the boiler. Pretty much like Helen's actually! However by turning the loco upside down and removing one of the pump rams we managed to get a spanner in and eventually managed to tighten up all the nuts. Whilst Ian went for a cup of tea I fired up the loco again and when he returned she was ready to run. Ian had not yet run the loco so was somewhat nervous I think but he managed a complete lap of the track which surprised us all! With a bit of work the Kingette will be a very nice little loco and is obviously not short of power if it can get around Chesterfield!
Back to Helen and in view of the valve problems at Chesterfield I have decided to bite the bullet, scrap the PEEK valves, and fit plain stainless ones instead. I could take a bit more off the original PEEK ones but this will make the fit even looser until the valves heat up. I have noticed quite a bit of leaking past the valves when starting off and reducing the valve diameter again will just make this worse. The PEEK valves were an interesting experiment but the expansion rate of the PEEK is a major stumbling block to their success. Perhaps further experiments in the future may give better results.
The new valves will be turned from ½" bar and 'fitted' by the Don Young method. Don's method is to turn the valves so that they will only just enter the end of the bores. The bobbins are then coated with molybdenum disulphide grease and literally driven through the bore with a hammer! This is repeated with more grease until the valves are free enough to be pushed through with finger pressure. This method may seem somewhat drastic but it leaves both the bore and the valve with a mirror finish and any further wear will be negligible. Don reckoned that the valves should never leak throughout the life of the engine. The problem with trying to get the right fit by merely turning is that no matter how good the turned finish the surface is still like a ploughed field and once the ridges have worn off (quite rapidly) the valves will be too small and will leak.
I've started work by stripping the boiler etc. off the chassis ( I'm getting quite quick at this now!) and removed the middle cylinder assembly. Removing the valve showed that there was plenty of oil around so lack of oil was not the cause of the seizure and expansion must have been the problem. I also removed the rear cover and the piston to have a look at the O ring. I had been concerned that the piston O rings might have suffered the same fate as those on the steam manifold i.e. gone soft with the heat but the one on the piston was fine and still fitted the bore ok.
I've also dismantled the steam manifold again and the new PEEK seals are not as good a fit as when originally fitted so I think there is still a problem. Further thought is needed to maintain steam tightness here.
I've turned up the three new valves and 'fitted' them as per Don Young's method. It's actually quite difficult to get the initial fit just tight enough and the valves probably only need to be a few tenths of a thou oversize. The first one I made a bit too tight and it was a devil of a job to drive it through the bore so I removed a tiny bit on the diameter with carborundum paper and then tried again. Eventually all three valves were completed, the fit being such that they could be moved in the bores by finger pressure but were still a little tight. I think the job was made more difficult due to the valves bores already having a high polish due to the initial honing and also the turned finish on the valves was like a mirror anyway so the valves were already quite a good fit.
Finish turning the new stainless valves
After fitting the first valve I heated the cylinder with the valve in situ in the domestic oven to 200° C and was pleased to find that the fit of the valve seemed to be just the same as at room temperature so hopefully the expansion rate of the valve and the cylinder material are pretty much the same.
The valves were reassembled in the cylinders and the cylinders re-fitted to the frames and along the motion work. The pivot for the 2 to 1 lever was fitted with new bolts and all the nuts on the valve gear pins were fitted using threadlock as they did tend to work loose occasionally. Actually when I had dismantled the valve gear after the seizure I noticed one nut had come off completely and a couple were very loose but I put this down to the high loads on the gear at Chesterfield. Incidentally, before I removed the old valves from the spindles I had measured the distance from the end of the valve to the end of the valve spindle so that the new valves could be set at the correct position without having to reset the valve timing.
The steam manifold still posed a problem but as a temporary measure I turned a groove in the PEEK seals and fitted a couple of O rings again so that there are now two types of seal. The O rings will probably deteriorate again but hopefully the PEEK seals will still work at steam temperature. We'll see!
When all the motion was re-assembled I was suprised to find that it was all still fairly free as I had expected it to be stiff due to the new valves. Running the chassis on air proved all to be in order and I must admit the exhaust sounded much crisper than ever before. One thing I did notice however was that the drive to the lubricator seemed a bit intermittent and had probably not been working properly again, although as mentioned before, there seemed plenty of oil in the cylinders when they were dismantled earlier. I wondered if the drive shaft for the lubricator had worn slightly and the roller clutch was slipping. I have seen it recommended that the shaft on which the clutch runs should really be hardened so to be on the safe side I made a new one and hardened the end on which the clutch runs. This also meant making new pump cams as the original ones were silver soldered onto the shaft and could not be removed. This time I fastened the cams on the shaft with Loctite rather than solder them.
The next job is to refit the boiler and try the chassis on steam and hopefully I should get that done today.
Another run on air showed that the lubricator drive was still slipping despite the new shaft and the problem seemed to be the roller clutch. I had a spare one so fitted this which cured the problem completely. It seems strange that the original clutch had failed as it hasn't had that much use really. There does seem quite a load on the lubricator even with no oil in it but the rams etc all move freely and the return springs are not that strong. We'll see how the new one holds up.
I've now steamed the loco again and the valves are obviously still a little tight but are freeing up slowly. I think they will be ok after a good run. The problem is that the valves tend to get hotter than the valve chest as they are exposed to the incoming steam and so expand slightly more than the valve chest. The exhaust is very sharp compared to before and sounds like a machine gun when running in full gear! The initial run was curtailed when the lubricator decided to blow all the oil out through the filler cap - one of the ball valves must have stopped seating allowing steam to blow back through the pump Aaaahh - another strip down! I can see why a lot of builders are now using hydrostatic lubricators rather than mechanical ones!
The pump was stripped down and fitted with new balls which were reseated with another tap from the hammer. I did notice some bits of grit in the bottom of the tank which probably got in when I was running the loco without a top on the tank. It is possible a bit of this had got into the works and stopped one of the balls seating. I decided that it would be a good idea to fit another check valve between the lubricator and the steam manifold to prevent further problems. I should probably have done this in the first place as this seems to be standard practice with lubricators and water pumps etc.
This was a simple turning job and used a 1/8" ball spring loaded against an O ring seat and was fitted vertically in the delivery pipe. Rather than fit proper pipe unions which would make the fitting quite long I just silver soldered the pipe into the top and bottom fittings of the valve before assembly.
Another run showed everything seemed ok with the pump delivering plenty of oil - perhaps too much but I'll leave things as they are until the new valves are run in properly. I'm hoping to get to Whitwick on Thursday and/or Sunday for a test run so we'll see how Helen performs with her new valves. Hopefully I can now get back to finishing her off and getting the injectors sorted out.
I've had another rush of blood to the head and bought a nearly complete chassis for LBSC's 4 cylinder Princess Royal! I've been hankering after one of these after seeing the one belonging to John Moxham at the rallies and I bought the construction book from TEE Publishing some time ago. John's is the only one I've seen so far although part built ones crop up now and again. Like most of LBSC's designs the loco is a compromise between a working model and the real thing. For example the full size loco has four sets of Walscheart's valve gear whereas the LBSC version has only two with the inside valves driven from the outside ones by rocking levers as in the GWR Kings which makes construction somewhat easier (the Princess Royals were basically a modified King anyway! Stanier brought the design with him when he moved to the LMS) The chassis should arrive tomorrow (Royal Mail allowing this of course!) so we'll see what I've got. Hopefully it won't need much work to get it running.
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