garygfletcher Posted March 31, 2015 Share Posted March 31, 2015 Hi All So this is my first go at scratch building a loco in 2mm Scale. As you can see I have got some rough plans and photographs for reference. I am trying to build the model up from 0.3mm brass sheet. All the parts can in theory be rolled into shape and the cylinder is only for reference, I will probably CNC the chimneys. I haven't got very far as I mentioned I have never attempted anything like this before and just decided to through open CAD and see how I would piece it together. I'm not sure what wheels or the chassis will come from I more so wanted to have a go at getting something together that I can etch (I have etched PCBs before) and then see if I can get the shapes soldered together in some fashion (I do work in micro electronics - so hopefully this will be the easy bit?). I'm interested in any comments and help is much appreciated, but as I say this is a prototype/experiment - an half hour of fun and feasibility so far. Thanks in advance. Link to post Share on other sites More sharing options...
RMweb Premium CF MRC Posted April 2, 2015 RMweb Premium Share Posted April 2, 2015 Gary Worth getting some decent drawings and photos of the engines you wish to model. I would strongly recommend nickel silver as being easier to work with and solder than brass. It is also much easier for painting if your bodywork dismantles into sub assemblies for painting. If you are making a single wheeler then it may be worth having the weight of the tender contribute to the engine by having a drawbar that allows weight transmission via a semi rigid joint, with movement only allowed horizontally. Just hanging the tender on to the back of the engine may simply lift up the engine front: it all depends upon wher you put the third point of the engine suspension - either between the two back wheels or the front bogie pivot. You could always cheat and simply drive the tender, but this does not always work well in 2mm FS. Sourcing the 7'6" or 7'9" wheels in 2mm is a bit if a challenge, but modern technologies can probably help. 38 years since I made my first single wheeler! Hope this helps. Tim Link to post Share on other sites More sharing options...
garygfletcher Posted April 2, 2015 Author Share Posted April 2, 2015 Thanks Tim that does indeed help a lot. I thought I would experiment a bit before heading down to the Railway Club in London next Thursday I hope. I am very keen to take advantage of the library as you suggested for more drawings. This included having a go at etching myself and creating some basic shapes for practicing soldering. I'm very keen to try some modern technologies for casting the single wheel. 38 years ago I wasn't even here, I'm just really starting here, I hope I manage the same career. Some questions if I may a ) I am very surprised you are able to even fit a motor in the actual loco rather than the tender, is this what you achieved? That seems like no mean feat! b )I am actually clueless as to the sourcing of wheels and chassis for driving - do you have any advice? Are these available to purchase or are these scratch built as well? c ) Who do you normally recommend as a source for nickel silver and who does your etching? d ) With the boiler do you tend to use tubular metal or flat rolled metal, I presume the latter allows more complex shapes. e) How much detail and accuracy do you aim for, I suppose this is a very difficult question to answer. Is the aim a similar visual representation or an engineered duplicate? I presume a meeting in the middle? Thanks again for the feedback. Gary Link to post Share on other sites More sharing options...
Caley Jim Posted April 2, 2015 Share Posted April 2, 2015 Some questions if I may a ) I am very surprised you are able to even fit a motor in the actual loco rather than the tender, is this what you achieved? That seems like no mean feat! b )I am actually clueless as to the sourcing of wheels and chassis for driving - do you have any advice? Are these available to purchase or are these scratch built as well? c ) Who do you normally recommend as a source for nickel silver and who does your etching? d ) With the boiler do you tend to use tubular metal or flat rolled metal, I presume the latter allows more complex shapes. e) How much detail and accuracy do you aim for, I suppose this is a very difficult question to answer. Is the aim a similar visual representation or an engineered duplicate? I presume a meeting in the middle? Garry, No doubt Tim will respond with his own answers, but from my perspective: a) In most cases, especially 19th century locos, the motor goes in the tender driving the loco through a shaft with some form of universal joint on either end. Ideally the joints should lie within the wheelbase of the Loco and tender respectively. Most people simply run the shaft through the front of the tender and into the boiler backplate of the loco. I prefer to drop the drive down below the footplate and keep the shaft out of sight, but that is just a personal idiosyncrasy. b.) Wheels, motors, gears, bearing, etc. are all available from the 2mm Scale Association http://www.2mm.org.uk/, wheels going from 7mm to 14mm in .5mm steps, up to 12mm and 1mm steps thereafter. If you are not a member and intend working in 2FS, then membership is pretty much a must as products are only available to members. c) Nickel silver can be obtained from several suppliers, such as Eileens Emporium, or from most good model shops. I use PEC for my etching, but there is also PPD whom I have yet to try, but probably will do with my next sheet of trial etches. d) Brass tube is by far the easiest way of producing plain boilers. Tapered boilers require rolling from sheet. e) That is entirely up to you! It's your model, you make it to please you and if others like it that is a bonus! (That's my bit of philosophy for today!) You can see how far i go in this post http://www.rmweb.co.uk/community/index.php?/topic/61066-scottish-locomotives/page-8, but that's probably further than most would be prepared to go. There's only one way to learn how to build locos in 2FS and that is get stuck in and try it! If it doesn't work out the first time, learn where you went wrong and have another go! (Ooops, that's 2 bits of philosophy!) Jim Link to post Share on other sites More sharing options...
RMweb Premium CF MRC Posted April 2, 2015 RMweb Premium Share Posted April 2, 2015 Gary You should look at the components available from the 2mm Scale Association. Certainly, most of your carrying wheels will be available. I hand build awkward size/spoke driving wheels. On small tender engines it is far better to have the motor in the tender driving through to the engine and all the weight you can muster in the engine. I often use etchings shot down from larger scales nowadays. As I have a lathe, all my boilers are turned as thin wall tubes, then filled with weights made of heavy metal (e.g. copper tungsten). On my Johnson Single, I used the outside axle boxes and made a crank axle so that the crossheads could be seen moving. On the 115 class the cylinder is above the valves and the slidebars very visible between the frames under the boiler. Nowadays, I make my engines much simpler, but the detail should still be there - if you can't do it to scale then don't do it. The engines on Copenhagen Fields run many miles. Tim Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted April 2, 2015 RMweb Gold Share Posted April 2, 2015 I seem to remember there was an article in an issue of MRJ by Tim on building a 2mm Single worth a read. Personally I am inclined to think a single might not be the easiest to start on. I think that looks like a Midland single. There were some very nice Midland 4-4-0s. It should be easier to source the wheels. Mind you as they say no guts no glory and fortune favours the brave so don't let me put you off if your heart is set. Don Link to post Share on other sites More sharing options...
garygfletcher Posted April 2, 2015 Author Share Posted April 2, 2015 I seem to remember there was an article in an issue of MRJ by Tim on building a 2mm Single worth a read. Many Thanks Don, I just found the article in issue 168 and look forward to receiving it next week It is indeed a Midland/Johnson Spinner and whilst it probably isn't the easiest its been in the works for too long and its time to delve in I think. I don't mind experimenting or a bit of a learning curve and there are some interesting techniques I want to try out here too. It will be quite a bit of trial and error I feel. Link to post Share on other sites More sharing options...
Graham Hughes Posted April 2, 2015 Share Posted April 2, 2015 I seem to remember there was an article in an issue of MRJ by Tim on building a 2mm Single worth a read. Personally I am inclined to think a single might not be the easiest to start on. It was what I started with. My Dad and I spent a Sunday morning climbing all over the real one with a tape measure. It never got finished though so you are probably right. I remember making the wheel rims from the ones off 15mm Romfords reduced in thickness by rubbing them in circles on a very large flat file, turning them 90 degrees every few "rubs". There's a single on the 2mm Scale Association website where the builder rolled the rims from flatbottom rail. I tried this after I saw it and they come out surprisingly true. I use brass tube for tapered boilers too. I use the size that is to scale for the smaller end, cut along the bottom almost to the front, open out the other end to the right size and solder a fillet in the gap. Link to post Share on other sites More sharing options...
justin1985 Posted April 2, 2015 Share Posted April 2, 2015 Hi Gary, Great to see you on here! Personally I'm still struggling to get kit built 2mm locos to run as smoothly as the regulars on Copenhagen Fields, but I have no doubt you'll be able to produce some stunning locos to go with St Pancras. As Tim and others have pointed out, the 2mm Scale Association is pretty much a one stop shop for most parts that you'll need, but the single needs larger wheels than are available off the shelf. Some modellers in the 2mm fraternity are playing with CNC techniques for this kind of thing: Julia, who posts (or posted?) on here as -missy- is the Association products officer, and has blogged about experiments with fabricated wheels either on her blog here, or her external blog: http://modelopolis.blogspot.co.uk/. Also Henk Oversloot, who is a regular poster to the 2mm Association members' Yahoo Group has some pages on various techniques for producing non-standard wheels on his website: http://www.fs160.eu/fiNeweb/Lconstruction/type29/type29.php#wheels (fiNe or fs160 is the continental equivalent to 2mmFS, but following the standard 1:160 scale of European and American N scale). Good luck! Justin Link to post Share on other sites More sharing options...
RMweb Premium CF MRC Posted April 2, 2015 RMweb Premium Share Posted April 2, 2015 At least singles don't need to be quartered! The inside cylindered engines appear to 'pour' themselves along the track, the GN 8 footer looks much more busy. On Cooenhagen Fiels that and the Ivatt rebuilt Stirling 2-2-2 can pull a very long train double headed. The latter is immensely powerful, as is the 8 footer on the straight, but this engine looses out a bit on the 600 mm radius curves as the clearances for wheels etc all start to diminish. The Johnson single was written up in Model Railways, probably in the early 80's: it was my first scratchbuilt engine. The one prior to that had been a conversion of a Minitrix 2-10-10 into the Lickey Banker. Tim Link to post Share on other sites More sharing options...
garygfletcher Posted April 3, 2015 Author Share Posted April 3, 2015 Some modellers in the 2mm fraternity are playing with CNC techniques for this kind of thing: Julia, who posts (or posted?) on here as -missy- is the Association products officer, and has blogged about experiments with fabricated wheels either on her blog here, or her external blog: http://modelopolis.blogspot.co.uk/. Also Henk Oversloot, who is a regular poster to the 2mm Association members' Yahoo Group has some pages on various techniques for producing non-standard wheels on his website: http://www.fs160.eu/fiNeweb/Lconstruction/type29/type29.php#wheels (fiNe or fs160 is the continental equivalent to 2mmFS, but following the standard 1:160 scale of European and American N scale). Many thanks Justin, I do have a CNC/Lathe and Furnace and was discussing techniques with a colleague of mine, neither of us have modelled on this scale before. I actually have some other methods in mind before I look at this route and hopefully have a go at producing something next week. I need to find some better plans of the Loco. I understand Martin Evens published some in issues 137 and 138 of the Model Engineer magazine in 1972 (albeit for 5"), I wonder if the Model Club in London keeps these in their library? Once I am happy with assembling/soldering and etching which I think I can do myself (have everything for PCBs here, the theory is similar) I hope to fabricate the chimney, wheels and whistle as well as the inside firebox detail using a prototype method. I really need to investigate the mechanics, certainly Tims crank axle is well beyond the scope of my abilities at the moment. I actually feel the mechanics is the most complex part, perhaps because I am not familiar with the insides of 2mm and what is available in the 2mm shop. I am really hoping I can leverage on a few people at the London Model Club to help me with this or indeed Tim if his time permits early May. Thank you for everyones input so far, tremendously useful thread! Link to post Share on other sites More sharing options...
Caley Jim Posted April 3, 2015 Share Posted April 3, 2015 I really need to investigate the mechanics, certainly Tims crank axle is well beyond the scope of my abilities at the moment. I actually feel the mechanics is the most complex part, perhaps because I am not familiar with the insides of 2mm and what is available in the 2mm shop. I am really hoping I can leverage on a few people at the London Model Club to help me with this or indeed Tim if his time permits early May. Gary, If it's any help, here are a couple of photos of the innards of two of my locos. The first is the chassis for my 0-4-2. The gears on the front of the motor take the drive down below the footplate level. You can just see the driveshaft below the tender drawbar. The spring carries current from the loco frames to the tender frames. The worm is in the bottom of the firebox with the worm wheel above it. The second photo is of the loco chassis for my 2-4-0, with one frame swung out of the way to show the gearing. The topmost gear is a laygear to link the one on the wormwheel shaft with that on the driven axle. Perhaps my methods are a little unconventional in keeping the driveshaft below the footplate, but I hope this is of some help to you. Jim Link to post Share on other sites More sharing options...
garygfletcher Posted April 3, 2015 Author Share Posted April 3, 2015 Jim that is immensely useful. I like the idea of the driveshaft below the footplate. I am incredibly impressed with how low profile it keeps the mechanics. I guess there is also some sort of fine art that goes into the gear ratios? I guess my question would be how much of that is sourced from the 2mm shop? I think I need to sit down with someone and create a shopping list and get my callipers out Link to post Share on other sites More sharing options...
Caley Jim Posted April 3, 2015 Share Posted April 3, 2015 Jim that is immensely useful. I like the idea of the driveshaft below the footplate. I am incredibly impressed with how low profile it keeps the mechanics. I guess there is also some sort of fine art that goes into the gear ratios? I guess my question would be how much of that is sourced from the 2mm shop? I think I need to sit down with someone and create a shopping list and get my callipers out Details of the gear meshing centres are in the Association Yearbook. It's as much a matter of what you can fit in as anything else. I draw all my chassis out in CAD nowadays , print the various parts out - frames, beams, etc., including shaft centres - and stick the outlines to the metal before cutting out. I don't have the luxury of milling machines, CNC or otherwise, and wouldn't have the knowledge to use them even if I did! In future i will probably get them etched. All the components, wheels, muffs, gears, bearings etc. are from the Association shop, with the exception of the coupled wheels on the 2-4-0 which were produced by the late Neil Ballantyne. Jim Link to post Share on other sites More sharing options...
RMweb Premium CF MRC Posted April 3, 2015 RMweb Premium Share Posted April 3, 2015 Gary Beware of Martin Evan's designs: they are for livesteam and have some major errors. I don't think the MRC library keeps the ME on the shelves anymore because of space constraints. The Essery & Jenkinson book 2 would suit your needs: see http://titfield.co.uk/WildSwan/WSP_LOCO.htm Tim Link to post Share on other sites More sharing options...
garygfletcher Posted April 3, 2015 Author Share Posted April 3, 2015 Beware of Martin Evan's designs: they are for livesteam and have some major errors. I'm glad you mentioned, I was sat here scratching my head at the differences in chimney height and spacing. For some reason in my naivety I thought the larger 5" steam would have been much more true. I have ordered the book suggested and will try and digest the 2mm handbook over the long weekend. Thanks Gary Link to post Share on other sites More sharing options...
RMweb Premium CF MRC Posted April 4, 2015 RMweb Premium Share Posted April 4, 2015 The Martin Evans design is for the "Pricess of Wales" class; the last, largest and last elegant design of Johnson Single. At least there is plenty of room to put a motor in the water cart.! Tim Link to post Share on other sites More sharing options...
garygfletcher Posted April 4, 2015 Author Share Posted April 4, 2015 I draw all my chassis out in CAD nowadays , print the various parts out - frames, beams, etc., including shaft centres - and stick the outlines to the metal before cutting out. You just had me wondering Jim, would you mind sharing the CAD drawings? What do you use? Link to post Share on other sites More sharing options...
Caley Jim Posted April 4, 2015 Share Posted April 4, 2015 You just had me wondering Jim, would you mind sharing the CAD drawings? What do you use? I would be happy to share them, but be warned, they are not annotated and in some cases the bodywork is not complete. They were only intended for my own use, after all. They are all now in AutoCAD, though some of the earlier ones were done in TurboCAD. I have just entered your details onto the Association membership database, so i will email them to you later. Jim Link to post Share on other sites More sharing options...
Caley Jim Posted April 4, 2015 Share Posted April 4, 2015 Forgot to add to the above. I would strongly recommend that you get the magazine archive, available on a memory stick. It doesn't seem to be listed on the shop lists in the handbook, but it is on the association website, shop 1, end of the list, p-109. That has many articles on loco construction, which I'm sure will give you plenty of ideas. Jim Link to post Share on other sites More sharing options...
garygfletcher Posted April 4, 2015 Author Share Posted April 4, 2015 I would be happy to share them, but be warned, they are not annotated and in some cases the bodywork is not complete. They were only intended for my own use, after all. They are all now in AutoCAD, though some of the earlier ones were done in TurboCAD. Really appreciate you sending those through the 98 Class seemed very well drawn, layed out and annotated to me - I found them very useful indeed! Especially in combination with the pictures above. Did leave me with a couple of questions though, how is the +ve/-ve picked up? I can make out the images above some sort of tape and some plastic so I hazarding a guess that this may have a split frame? But bearing in mind the power comes from the tender that may not be the case - left me a little puzzled. Secondly I wondered what the wheels were actually made of, are they nickel? The inside looks like a plastic material. I would guess brass wheels would be too soft? Finally the coupling/con rods (not really applicable for the spinner but from interest), are this also purchased from the 2mm store? are the end parts separate allowing differing rod lengths? It really is useful seeing the clearance and positioning of the under footplate drive shaft and mechanisms - it doesn't look all so scary now! Link to post Share on other sites More sharing options...
RMweb Gold 2mmMark Posted April 5, 2015 RMweb Gold Share Posted April 5, 2015 Gary In my blog, I'm documenting the build of a simple 0-4-0 chassis http://www.rmweb.co.uk/community/index.php?/blog/1345/entry-14132-peckett-y-class-framed-part-1/ http://www.rmweb.co.uk/community/index.php?/blog/1345/entry-14295-peckett-y-class-framed-part-2/ Hopefully, it'll show some of the 2mm components and how they get used. The current range of 2mm Scale Association loco wheels are brass castings with steel tyres. Amply strong enough. There's also the build of an 08 chassis and with your Midland interests, an outside framed loco might be useful http://www.rmweb.co.uk/community/index.php?/blog/1345/entry-14176-slight-digression-an-earlier-chassis/ I've got some updates to add when I get some photos done. Mark Link to post Share on other sites More sharing options...
Caley Jim Posted April 5, 2015 Share Posted April 5, 2015 Did leave me with a couple of questions though, how is the +ve/-ve picked up? I can make out the images above some sort of tape and some plastic so I hazarding a guess that this may have a split frame? But bearing in mind the power comes from the tender that may not be the case - left me a little puzzled. Secondly I wondered what the wheels were actually made of, are they nickel? The inside looks like a plastic material. I would guess brass wheels would be too soft? Finally the coupling/con rods (not really applicable for the spinner but from interest), are this also purchased from the 2mm store? are the end parts separate allowing differing rod lengths? It really is useful seeing the clearance and positioning of the under footplate drive shaft and mechanisms - it doesn't look all so scary now! Mark's links will answer some of your questions. Live frame pick-up is the standard arrangement in 2FS, allowing all wheels, including those on the tender, to pick up current. I use beam compensation to ensure that all wheels are carrying weight to help with pick-up. The wheels on 108 have plastic moulded centres, but the rims are shorted to the axles, so they still work for live frame. My coupling and connecting rods are all cut from steel strip, but etched n/s ones are available from the Association shop in a variety of sizes. The rods are the first thing I make, using them as a jig to pilot drill the holes in the beams. That way I know that the holes in the rods and beams will have exactly the same centres. I spent a lot of time on the ends of the coupling rods for No 391 to get the proper shape of the marine big ends, only to find that the front end spent most of its time hidden behind the crosshead and the rear one was hidden behind the connecting rod end! ;-( Jim Link to post Share on other sites More sharing options...
RMweb Gold Donw Posted April 5, 2015 RMweb Gold Share Posted April 5, 2015 . I spent a lot of time on the ends of the coupling rods for No 391 to get the proper shape of the marine big ends, only to find that the front end spent most of its time hidden behind the crosshead and the rear one was hidden behind the connecting rod end! ;-( Jim But at least YOU know they are right Jim. Don Link to post Share on other sites More sharing options...
garethashenden Posted April 10, 2015 Share Posted April 10, 2015 I took a couple pictures of Tim's engine last night and I thought I'd share. Link to post Share on other sites More sharing options...
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