gowest Posted August 17, 2019 Author Share Posted August 17, 2019 Having decided to go for the change to the electric motor position I needed to work out the servo motor gear box positions for the gear train.The gear that the motor mates with needs to be higher than the position for the Hornby layout as I need to keep the motor well clear of the track.So making a start on the motor servo gear assembly some measurements for the 2 main gears were taken along with other dimensions that will go to reproduce this new gear assembly.These measurements were then marked out on a solid block of brass bar starting with the 2 gear centre points which you might be able to pick out in the picture below on the right.The brass angle I will use to make the motor bracket and silver solder this to the gear assembly main frame./media/tinymce_upload/93332eab88d255c55884ba4657139098.jpg/media/tinymce_upload/0e7c0dcfad29e01c186d75573ab2ff63.jpgNext will be to put all this to the test so will start to mill out this lump of brass and see what happens.The Hornby chassis will need milling out a little larger where the motor has to pass thought the frames but I will come to that part a little later after the gear assembly and motor bracket has been built. Link to comment Share on other sites More sharing options...
gowest Posted August 18, 2019 Author Share Posted August 18, 2019 Next will be to put all this to the test so will start to mill out this lump of brass bar and see what happens.The Hornby chassis will need milling out a little larger where the motor has to pass thought the frames but I will come to that part a little later after the gear assembly and motor bracket has been built./media/tinymce_upload/acfbd77f3a8bb6dac604f04160c4e7f7.jpgThe standard Hornby layout for the motor servo assembly with just the basic main 2 parts.The first part of the gear casing I will copy onto my brass gear assembly some can be milled out but some will have to be pre fabricated and silver soldered onto the brass gear frame.Starting with the brass bar is to add some marking out paint and I started by marking out the 2 holes/media/tinymce_upload/b1e35659b7637e070444639201e2a106.jpgfor the 2 gear positions as you can see here.The next step before any mill can take place is to drill these 2 hole in the brass bar right through to the other side.I did this type of assembly on the GER S69 so I could go through some of my paper work and see what I did then just to refresh my memory but i think this one might be a little different./media/tinymce_upload/9dcbed2a3c13dadabe10e0d666b9b3f0.jpgDrilling the 2 holes is straight forward but start by drilling them under size and open them out later to the correct size for the small Hornby bearing that are fitted to the gears./media/tinymce_upload/4cf9cae5162d1eb77d879685e14a56e0.jpgAs the milling of the brass bar goes on you might be able to see the new gear frame emerging./media/tinymce_upload/468d180a5618404db3f8f07ee4335894.jpg It’s a slow job but then if you make a mistake you have to start all over again and that will take even more time to make this new unit.Years ago an apprentice at Stratford works was scraping a regulator port face to remove any unevenness and scratches due to wear, and after spending hours and hours scraping and polishing he called the foreman over to check out his work when the foreman looked at it just to see how good a job he had done the foreman reached into his pocket pulled out a sharp scriber and dragging it from one end to the other of this shiny metal surface scratching it deeply and said very good now do it again. That was in the good old days, I can remember send an apprentice down the stores for a box of sparks for the welder or going to the stores for a long weight whereby the store man would tell the chap to sit there on a chair and leave him till ether the store man or the chap realised he had been had./media/tinymce_upload/6815eaa067d821d5dac0d72bd6828148.jpgThe work on the brass gear assembly is coming on nicely a little more metal needs to be removed from the inside section where the shoulders of the Hornby bearings fit as I want to make them a good tight fit as I have found that there is a little end play in this area on the Hornby models and this tends to lead to too much backlash in the gear assembly which makes for a slower respond to the controller commands. /media/tinymce_upload/f562941db77bd42eb1899e269eef21ed.jpgMaybe in this picture as the 2 different gear frame are side by side you might just see hoe the new frame is growing as I remove more and more of the brass from the bar of metal./media/tinymce_upload/2aef6cb73984a7b1c0a4f12de8e7a854.jpgI have made the motor mounting bracket and you can see it here fixed in position held by 2 screws these screws are only there to keep the 2 parts together for silver soldering once the bracket is a permanent fixture with solder then the screw heads can be filed off and the motor fitted. That would complete that part and as I will need to silver solder the round boss on the front end of the gear frame to hold the regulator lever and reverse paw in place, a reheat will not disturb the previous soldering operations as the 2 screws will keep everything in position./media/tinymce_upload/55ffdef93233c65eb9ced27c10d9a715.jpgHere you see the gear servo frame in its raw state which needs the regulator gear and paw boss to be fix as said and all the holes drilled and taped 1,2mm that will hold all the gears in place and the 4 fixing hole to fix the new gear frame to the Hornby chassis./media/tinymce_upload/ee2d795dc5297c45d185a7bbcb2c5173.jpg Fitting the first gear in place and its as I wanted a good tight fit at that now for the next gear assembly and that fitted nicely to all going well so far. /media/tinymce_upload/84a99d5f0185802bad8ae3b5d872f1cc.jpg/media/tinymce_upload/9161c1d0a95b341a7e5aac6274b52ed2.jpgWith all the major parts complete there is still the clamping plates that hold the gear bearings in place so I will have to make them next and drill the 4 main fixing holes to fix the new servo gear frame to the Hornby chassis. once these parts are completed I will need to mill out the Hornby chassis so that the completed servo and motor unit can be fitted to the Hornby frames.Having made a good part of this unit I feel that things are going well and we might just make a tank engine after all that works with out having to pull a goods wagon for the tender. 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96RAF Posted August 18, 2019 Share Posted August 18, 2019 I was down at Margate today Ken and in their visitor centre they have a display case for live steam and there is a noticeable difference you can see between the A4 and Scottie chassis and parts, the most noticable being the valve housing block at the front. I didn’t have a camera with me or I would have photgraphed them for comparison, but I expect you are well aware as you have mentioned various differences between the models before. Link to comment Share on other sites More sharing options...
Bulver Posted August 19, 2019 Share Posted August 19, 2019 Ken, yet another master-class in the art of loco construction. Thank you for sharing it with usRod Link to comment Share on other sites More sharing options...
gowest Posted August 19, 2019 Author Share Posted August 19, 2019 Hi Bulverglad you find it interesting I feel a lot better having made the new servo unit and in doing so freed up a lot more space for this tank enginethere is as said a great deal of difference between the A3 and A4 chassis my preference is for the A3 so much changed in the design and the last ones that were made are some of the best. It is for this reason that the A3 parts lend them selves to be incorporate into other engines it's a bit like lego with the ability to make what ever you want. I still wonder what Hornby might have done should they have continued with live steam being as all the parts are there just waiting for the model to build. Which over the years I have produce and get great pleasure from building and running them. Link to comment Share on other sites More sharing options...
gowest Posted August 19, 2019 Author Share Posted August 19, 2019 The servo unit was now almost complete just a couple of jobs to finish it off one the boss for the gear that holds the regulator lever and a hole to take the end of the valve drive shaft.Having completed so much I was eager to see if it would fit in the chassis as the space between the middle and last driving axles is very limited and if the available space was not going to be enough then the standard Hornby layout would have to be reconsidered.Taking the Hornby chassis into the work shop and setting it up on the mill I started to mill a hole in the bottom of the chassis big enough for the electric motor and its bracket to pass through the only problem I had was that the motor is fatter than the distance between the inside of the cast frame section so the inside section of the Hornby frames needed about half a millimetre machined off./media/tinymce_upload/cadd617818cf6c010b630b9248afe4cc.jpgI did look up the motor servo that I built for the GER S69 and its almost the same layout the only difference being that I was using the metal frames from the brass kit so there was a little more room and the fixing system was different so a new design was needed for this tank engine so that I could use the Hornby fixing points./media/tinymce_upload/869821f184dbca20ccdedf579fa07c6a.JPGAll the Hornby bearings were removed and the cast Hornby frames were clamped in the machine vice on the milling table and a large cutter was put through the bottom of the frames as in the pictureOnce the hole was milled to the correct size it needed to be finished off by filing this hole square and all the time checking that it fitted ok as I did not want to remove more metal than needed as it would make these cast frames a little weak in the area of this square hole.You can see from the picture here the difference between the 2 frames the one above has the square hole and the frame with the wheels has no hole and you can see just how thin the metal is on the frame sides./media/tinymce_upload/1273157337339bd98bb0fcd663a35eac.jpgWith the gears and motor all assembled to the brass servo unit it was time to try it in the frames and see the position of it and the other relative parts along with how much it will hang out the bottom of the chassis./media/tinymce_upload/ad284bc3738e3430d14f1807aba491c2.jpg/media/tinymce_upload/b7bff29b0a61fcfa1f5581d44ef4743c.jpg/media/tinymce_upload/23a74b706501ad45f59b50641959e1a3.jpg/media/tinymce_upload/1b456b554724ed3fd401c84f2ba1dfc4.jpgThe servo unit fitted ok and its fixing holes all lined up and here the next set of pictures show me inserting the servo unit into the Hornby frames and a nice snug fit it was to. And you can see from the last picture that the motor didn't hang out the bottom of the frames that far and you can see just how much space we now have to fit the water tank but not sure if it will be below the cab windows./media/tinymce_upload/88fdd5d41a89d6e86af8860314d822f7.jpgWith this part almost finished I tried the complete chassis and servo unit in the body just roughly so I might get an idea as to where we were going on this build and things were looking good so must finish the servo and start on the cylinders and there new fixing position on the chassis./media/tinymce_upload/46b3311249383bea7806e7fb370ec252.jpg/media/tinymce_upload/57b71d2caafa40e8cdee35b92a6eda9c.jpg Link to comment Share on other sites More sharing options...
96RAF Posted August 20, 2019 Share Posted August 20, 2019 Nice KenHow about a U shaped boiler to keep the window line clear. Link to comment Share on other sites More sharing options...
gowest Posted August 20, 2019 Author Share Posted August 20, 2019 Good idea U shape might work if my memory serves me I think the Hornby tank held 35 ml of water and given the length of the new boiler you might still get near that figure to give a run time of 30 minutes Link to comment Share on other sites More sharing options...
gowest Posted August 21, 2019 Author Share Posted August 21, 2019 Just a thought on the boiler as Rob said maybe with a flat top on two thirds of a round section leaving the last part round which will appear in the coal area for access to the water filler screw have a few drawings on his idea./media/tinymce_upload/2f6c1b44b1779a857d6367f6bcb2661b.jpgNot sure how these drawings will look in the forum but I thought I would put them up as they are very detailed and if it were just an electric motor driven model you could go into much more detail than I will with the cab layout as space will be filled with steam raising gear./media/tinymce_upload/30d5a578989c3daa82335c36ea0ec104.jpgWith the wider body it might be possible to fit the Hornby safety valve in the left hand water tank.I have made a few drawings to show what I have in mind but its most likely I will not have as much space as I think I have time will tell/media/tinymce_upload/5f37f2543a0a57d025817f3540c4daf7.jpgthinking on for the power pickups this might have to be spread between the main drivers and the last pony truck wheels which will need some sort of springing on them to keep good contact with the rails for the best conduction between the two./media/tinymce_upload/6296f1e178ad8962e808b1eab095c382.jpg Link to comment Share on other sites More sharing options...
gowest Posted August 22, 2019 Author Share Posted August 22, 2019 I've just noticed that goods wagons and coaches do not have vacuum pipes? I looked through the internet and did not see any this crossed my mind as a relative that worked with steam years ago told me the drives of pasanger trains thought them selves the best of the bunch like top link but many had more powerful locos and breaks on all coaches where as he told me you need to apply power slowly and brake in good time as it was possible to break coupling if you got it wrong and the chap in the break van had to know his stuff Link to comment Share on other sites More sharing options...
96RAF Posted August 22, 2019 Share Posted August 22, 2019 Ken - no point having the extra volume on the boiler at the back if the steam take off is at the lower level, unless you are running an internal pipe to the higher level. Thinking back to my U shaped proposal, that would need a link pipe between the high parts for much the same reason. Link to comment Share on other sites More sharing options...
gowest Posted August 22, 2019 Author Share Posted August 22, 2019 Well spotted yes all that would come out of the steam pipe would be water not thinking straight that the trouble when you get old a million brain cells die every day o getting a bit short on them thanks Rob Link to comment Share on other sites More sharing options...
96RAF Posted August 22, 2019 Share Posted August 22, 2019 ... the trouble when you get old a million brain cells die every day o getting a bit short on them...Join the club Ken - At times I reckon I’m down to single figures. Link to comment Share on other sites More sharing options...
mark roberts1707820076 Posted August 24, 2019 Share Posted August 24, 2019 what a great project Ken, I really like the idea that the tank loco will have its water/heater inside the loco, not as an additional wagon.Will be watching with interest, Joe Link to comment Share on other sites More sharing options...
gowest Posted August 24, 2019 Author Share Posted August 24, 2019 Hi joeyes it will be a nice little job if I can get it to work these are one of my favourite locos hearing them roll along with the regulator shut as they glide into the platform and all you can hear is that tick tick tick of the vacuum pump like most GWR loco'sI hard 2 brothers in our family that worked on these engines at Swindon and if they were still here would have been interested in this project to and no doubt had a story to tell.Must finish off the servo unit to day and look into the cylinder position but can't see a problem here as this type of assembly has been carried out before so will follow a previous build maybe.ken Link to comment Share on other sites More sharing options...
gowest Posted August 24, 2019 Author Share Posted August 24, 2019 /media/tinymce_upload/a7321c0d67360c23865fe21e91817969.jpgI can see more problems around the corner with this engine as the boiler area on the body is very much smaller than an A3 engine.But before I go into the next stage an update for the boiler for Rob and in the new drawing the steam pipe now starts at the highest part of the boiler and being inside rather than out side a good level of heat can help keep it away from any heat loss in the pipe work. Also for those with a back ground like RAF 96 a MOD label has been added and MOD one carried which was to add the copper pipe work.Back to the problems this is with the cylinders and will involve more machining if I want the engine to look right. i started with machining metal away the sides of the cylinder and valve assembly this was to allow the first set of drivers to be closer to the cylinder assembly. Not a problem I have carried out this operation on other engines. And as you can see in the picture one set of fixing screws have been lost with this machining operation but these can be repositioned from the under side of the cylinder block and re drilled and tapped 1.2mm for the new fixing screws./media/tinymce_upload/af8e2ee019099e31ecba8d7a6a536a56.jpg/media/tinymce_upload/55e622881aca38d6a7cc17d71e691c6a.jpgThis picture is the completed unit after the machining operation./media/tinymce_upload/26b44d1591af85580de4ec2f76d3ca5c.jpgNext was the new position for the cylinders on the chassis this had to be machined a little nearer the first set of drivers and not as the Hornby chassis. You can see the old front fixing point for the A3 this I cut off and with the wheels and bearing removed it was now time to machine in the new fixing point./media/tinymce_upload/80d1e54b9b120c9980bdbb3c4ac7ab63.jpgAs I’m not sure what I’m doing and its all trial and error I just took out about 5mm then I can see what fitting and what’s not and make further adjustments./media/tinymce_upload/cfdb21e0e1886987c87daaa1dd2e82b4.jpgWith the front wheels back on the chassis it was set up and fitted into the body that was when a second problem came about.If you look at the picture here the red ring highlights a gap between the running board and the top of the cylinder valve chest this is because the supper heater and oil tank will not go any further into the body as they are hitting on the top of the inside boiler barrel this can also affect the wheels and how they sit in the wheel splashers.I could make the valve chest a little higher but I thought I might try to machine 1.5 millimetres off the top of the valve assembly. But this might cause more problems and run into the servo unit?I will have to keep trying fitting the complete chassis system and see what’s the best way to go. Link to comment Share on other sites More sharing options...
96RAF Posted August 24, 2019 Share Posted August 24, 2019 Good to see you are keeping proper configuration control Ken. Clever design keeping the steam pipe inside the boiler to maintain heat. Does the safety valve have to be vertical to work or could it be horizontal. Link to comment Share on other sites More sharing options...
gowest Posted August 24, 2019 Author Share Posted August 24, 2019 Hi Robit can be horizontal it won't make any difference we use to strike the O in MOD for mod state zero not sure why now all that has gone from the old memory banksken Link to comment Share on other sites More sharing options...
96RAF Posted August 25, 2019 Share Posted August 25, 2019 Wandering off topic for a minute Ken hopefully to keep your audience amused whilst you get some more fettling done.Mod 0 - I think that was to denote the design had moved from prototype-development to baseline production. Prototype being the development unit which could end up a long way from the production design as changes were made along the way. Generally the prototype would never be reworked to exact production standard. For example the RAF Dominies reworked for the Avionic Update. The prototype had new extended nose skins to cover the new radar and these were wheeled to shape in the old fashioned way, with pressed dimples for the flush rivets, whereas the subsequent production aircraft had skins stretched over a former with cut countersinks for the rivets. The prototype looked like a bashed bean tin but the others were nicely done. Our drawing system from memory (also fuzzy) was the drg numbers had a format that indicated they were schemes for development e.g MXX:??:1234, (?? = 03 maybe) which by way of change notices (often just red pen amendments on working drawings) then had all necessary change incorporations done and went to production as MLX:nn:1234 where nn was in accordance with the allocated series for the system in production, e.g. 53=fuselage structure, 57=wing structure, 29=hydraulics, etc. The MXX denoted which platform the drawings applied to. E.g ML9 I think was Hercules, MK2 was Tristar, etc. These designations may be way off as it is donkey’s years ago now since I used them. Unfortunately when working on contract to other manufacturers we often had to comply with their drawing systems so you could end up with a beggars muddle of formats including part numbers (just like Hornby) that were the same item but with different PNs across the suites of drawings for various folk. So we could have Boeing, Lockheed, BAe, British Airways and others drawing systems running alongside our own. Configuration Control was tight. Link to comment Share on other sites More sharing options...
gowest Posted August 25, 2019 Author Share Posted August 25, 2019 i can't remember what the drawings were numbered like only the wiring sheet that all started with a N so it would beN 8879 shsets 1 to 56. Any changes raised had to go through the design engineer one thing comes to mind when a problem arised with a below deck tracker a bit bigger than a 9 foot shed on top of the cabinets was a fan unit to keep the electronics cool (stay with me)info came back saying people were sitting and standing on these fan units and bending the top cover thereby jamming the fan and stop it from working some of the top engineers turned up to take action on this problem and all sorts of ideas came out out to correct this problem mainly to beef up the cover when one of our bunch a great chap that always cracked a joke for those that had run into him before would have known. So with all these serous faces and deadly silence Pat said "why not put 2 strands of barbed wire on top of the fan unit that would stop any one sitting on the fans? The other engineers looked at him as if he were mad and me and few other just laught. Link to comment Share on other sites More sharing options...
96RAF Posted August 25, 2019 Share Posted August 25, 2019 Every company has its characters Ken.We had a Facilities Manager well past retiring age who was Sir Arthurs right hand man on his daily tours of inspection. The old man used to fire this guy at the drop of a hat, usually more than once a day and expect him to turn up for work again when the old man shouted for him. One day Sir A was inspecting a classroom we had been having done out for a course and he disagreed with something in the room, which set off the Facilites Manager, who was promptly sacked for arguing. His retort was ‘Thank you sir, but when you see fit to hire me again I will be in the canteen drinking tea on my reduncancy money’. Those of us in the room trying hard not to burst out laughing. Unfortunately the old boy is long gone and I found out his son Sir Michael died on holiday a few weeks ago. Link to comment Share on other sites More sharing options...
gowest Posted August 25, 2019 Author Share Posted August 25, 2019 Like you say these people are hard to find now but might still be about. Link to comment Share on other sites More sharing options...
gowest Posted August 25, 2019 Author Share Posted August 25, 2019 /media/tinymce_upload/81d8728f0c1fc7890d6985abd37b7a59.jpgI built this pressure switch idea on the Lord Nelson loco and it worked ok so will build one for this engine if there is room but before I do that there are still problems fitting these parts into the body but will explain later it might be an idea to skip this problem and just carry on the construction and do some steam tests. Link to comment Share on other sites More sharing options...
gowest Posted August 25, 2019 Author Share Posted August 25, 2019 /media/tinymce_upload/3e26ed4284547937750f550276791d74.jpgThe one good thing that has come about with out me doing anything is that the hole in the smoke box for the chimney lines up with the tapped hole in the top of the oil tank so that’s one thing less to worry about./media/tinymce_upload/b6d2e6716414bdf49fde52c2e4432e12.jpgI did mention previous that there is a problem in achieving the correct distance from the running board to the cylinder and the distance from the top of the wheel to the wheel splashier to get this to fit a little better the supper heater needs to be lowered by about 1.5 millimetres but to do this causes other problems with the supper heater jamming the last servo gear that connects to the regulator arm. You can see in this picture that the wheels need to go a little higher but to save a lot of work I might go with what we have./media/tinymce_upload/37a35e41f2c9f4e2d20940ffdcfd8343.jpgA way round this would to build a new shorter supper heater as above?So looking at the drawing what I propose is to cut down the Hornby supper heater and then wrap some small bore copper tube around a 6mm diameter steel bar and by drilling the hole in the regulator end the same size as the copper tube silver solder the tube in place then run the remaining tube to the safety. /media/tinymce_upload/248572e2895401f7cbdfc68043c3a895.jpgThe picture here shows the problem but it might be the servo gear assembly is too high I will have to check that out so will get back to you on that one?/media/tinymce_upload/7772c8fac22abd10cae06d0170afc4d1.jpgThe oil tank pressure switch all assembled on to the front of the oil tank you can also see that I have filed the top of the oil tank taking off the corners so that it’s a better fit in the smoke box this has improve the fit and look of the wheels under the running boards. Because the cylinders are now nearer the first set of drivers the Hornby valve rod is too long so will need cutting down to fit correctly./media/tinymce_upload/f4bd4cb1cd9e6f05a53a3f9cc09b1516.jpg/media/tinymce_upload/2200816916bd57cc8d2cd37fca1c87b2.jpgI have also machined the very front of the Hornby chassis and fitted a brass block for the new position of the cylinders this brass block was held in place by 4 x 1.2mm screws and then the new fixing holes drilled and tapped to fix the cylinders to as you may see in these pictures here. must clean these parts before i take pictures as you can see all the filings. Link to comment Share on other sites More sharing options...
96RAF Posted August 26, 2019 Share Posted August 26, 2019 Some very good ideas there Ken.It is interesting to compare this evolution with the standard chassis to see how the various components have been cleverly modified and rearranged. Link to comment Share on other sites More sharing options...
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