Horsetan Posted February 20, 2013 Share Posted February 20, 2013 .... privet collection.... In Bushey? Link to post Share on other sites More sharing options...
ozzyo Posted February 20, 2013 Author Share Posted February 20, 2013 That is one fine chimney. Thanks for that asa, I have been trying to see how Stan has made the chimney. I think that he has turned the base diameter, then the small mounting face and the screw thread. Then rough cut the chimney diameter, fly cut the mounting face on the base, back on to the lathe and parted the chimney off. Mounting it onto a mandrel and then turning the diameters to size along with the base root flare. But it's how has he machined the flare that comes down the side of the smoke box? As it looks to have been machined with a very small amount of cleaning up with files. I also saw some double chimneys that had been made the same way. I have made my own chimneys and machined the base flare using an adaptor to follow the curve of the base but my chimneys look course compared to this. I'll do a couple of photos later to show what I mean. If any one can give me any ideas how he has done this I'd like to know. OzzyO. Link to post Share on other sites More sharing options...
ozzyo Posted February 20, 2013 Author Share Posted February 20, 2013 In Bushey? I was just hedging my bets Link to post Share on other sites More sharing options...
Pete Harvey Posted February 20, 2013 Share Posted February 20, 2013 OzzyO Will you be painting the completed engine yourself? Pete Link to post Share on other sites More sharing options...
ozzyo Posted February 20, 2013 Author Share Posted February 20, 2013 Hello all, I did say that I'd put some photos of my chimneys and domes up, well here are one of each along with Stan's. I think that you will see why I say that mine are crude compared to Stan's, his work just looks so much crisper that mine. The base flare just looks so nice, the lip around the top of the chimney is so sharp (working in copper this is very hard to do as copper will rip when it's being turned). Looking from the base it looks like Stan and myself (mine was picked up from some articles in M.R.J. some years back) have used the same method of mounting them, Stan used 3mm I used 6BA screws. This is the jig / adaptor / tool, that I use when I'm cutting the base flare. For cutting the base flare I use burs, I did try using milling cutters but these proved to be a bit to course for this job. This is mounted onto the cross slide of the lathe, with the follower towards the headstock, the job is then rotated clockwise around to produce the base curve. The follower and the main spindle shaft are both on the lathe centre line. This was also in M.R.J. a number of years back. So it's not something that I thought of. For turning the top of domes these are what I use, all they are are lengths of silver steel with a hole drilled in the end and a chamfer turned on the end, and then hardened. Looks like I will have to do some work on them before I use them next. OzzyO. Link to post Share on other sites More sharing options...
ozzyo Posted February 20, 2013 Author Share Posted February 20, 2013 OzzyO Will you be painting the completed engine yourself? Pete Hello Pete, no I never do unless it's for myself, this one will more than likely go to Conrad and then onto Fred. OzzyO. Link to post Share on other sites More sharing options...
asa Posted February 20, 2013 Share Posted February 20, 2013 Your efforts look good enough to me Oz. Link to post Share on other sites More sharing options...
Grasshopper John Posted February 23, 2013 Share Posted February 23, 2013 Lovely stuff OzzyO, that post of yours was a least two cans of John Smiths Slightly Off topic OzzyO but 7mm related, you know how much i have been bitten by the bug of building these fine pieces of engineering, I would love a go at 7mm as you know, so i am setting up a savings plan to make my purchase. I have put some stuff in the classified on here to help me on my way, sadly not much interest though but its early days and if i may i would be honored if you and Martyn will help me make my purchase in TELFORD by which time i hope to have saved enough. ATB Grasshopper John. Link to post Share on other sites More sharing options...
ozzyo Posted February 23, 2013 Author Share Posted February 23, 2013 Hello Grasshopper, I'm sure that Martyn and myself will help you spend money at Telford. OzzyO. Link to post Share on other sites More sharing options...
Sandy Harper Posted February 23, 2013 Share Posted February 23, 2013 Noooooooooooo! he never gets out of the bar!!!!!!!!!!!!!!!!!! Link to post Share on other sites More sharing options...
ozzyo Posted February 23, 2013 Author Share Posted February 23, 2013 Noooooooooooo! he never gets out of the bar!!!!!!!!!!!!!!!!!! Who me, Martyn or John? Well it looked like I'd used epoxy for attaching the chimney to the smokebox, so it was out with the blow torch and warm it up. I was not looking forward to doing this as I could have damaged the boiler casting. This photo was posed without the flame as you can imagine. Anyhow it came off with no damage to the smokebox, the epoxy that was left on the smokebox came off very easily while it was still warm. While all the above was going on, I was also fitting some dummy bolts to the base of the chimney. These are now in place, but look a bit too tail. After the bolt heads had been reduced in hight by about half they looked a lot better. A visit into the grit-blaster followed. The base in place on the smokebox. I think that it looks nice. Miss Prism, one of the next locos that I've been asked to build is an ex G.W.R. 517 0-4-2T with CBS for the suspension. Would you be able to point me in the right direction on the CLAG site for information on where the pivot points should be. Thanks for any pointer OzzyO. I'm looking at using some handrail pillars for a W.D. from Markit's. Using the 7mm and 10mm ones for the fixing points. If these can't be used I'll just have to make some of my own. OzzyO. Link to post Share on other sites More sharing options...
Horsetan Posted February 23, 2013 Share Posted February 23, 2013 Wow, you can actually see that the heads are hexagonal! Link to post Share on other sites More sharing options...
Pete Harvey Posted February 23, 2013 Share Posted February 23, 2013 OzzyO How have or will you be fixing the new chimney to the resin smoke box? Pete Link to post Share on other sites More sharing options...
asa Posted February 23, 2013 Share Posted February 23, 2013 Fabulous work Ozzy. Link to post Share on other sites More sharing options...
Miss Prism Posted February 23, 2013 Share Posted February 23, 2013 Miss Prism, one of the next locos that I've been asked to build is an ex G.W.R. 517 0-4-2T with CBS for the suspension. Would you be able to point me in the right direction on the CLAG site for information on where the pivot points should be. There are a number of options for the 0-4-2T/2-4-0: springy equaliser over drivers, CSB over drivers, and CSB over all 3 axles. Solutions for the first two options are elementary, whilst the third is most problematic. Since the 0-4-2T issue is one I'm often asked about however, it's about time I consolidated existing thoughts and practices together in a dedicated section on the CLAG CSB page, which I will do and notify shortly. Link to post Share on other sites More sharing options...
ozzyo Posted February 25, 2013 Author Share Posted February 25, 2013 OzzyO How have or will you be fixing the new chimney to the resin smoke box? Pete Hello Pete, looks like my reply to you has gone missing. I fitted this chimney using thin super glue as the base of the chimney fitted the smokebox so well. All I did was get the chimney in the correct position and drip the super glue down the chimney, making sure that I did not move the chimney while I was doing this. OzzyO. Link to post Share on other sites More sharing options...
Miss Prism Posted February 26, 2013 Share Posted February 26, 2013 Ozzyo - I've added a section at the bottom of the CLAG CSB page showing most of the CSB options for springing 0-4-2s (and 2-4-0s). I would not recommend the option of a single CSB over all three axles of your forthcoming 517 for the reasons given on that page, but if you are keen on that route, I can do you a plot, but I'd need to know whether you are going for the 7'4" + 7'8" or the 7'4" + 8'2". I will also need to look up what the typical 517 axle weights are! (I guess they are close to being 13.5T each?) Here are the spring diameters for the two preferred options, and they apply to all the 517 wheelbase variations: Link to post Share on other sites More sharing options...
ozzyo Posted February 27, 2013 Author Share Posted February 27, 2013 Hello Miss Prism, thanks for all the above. Getting the true weights for the 517s is a bit of a guess, but it looks to be some thing like this. Leading coupled, 10tons 12 cwt. + driving coupled 11 tons 16 cwt. + trailing 8 tons 18 cwt. The wheelbase that I'll be using will be 7'4" + 7'8" total 15'. The one that I'm thinking of using is the equalised springy beam, along with the separate one with the screw adjuster on the rear spring. For the screw adjuster I'm thinking of using an 8BA Allan grub screw. With the end bent up and going into the socket. Could N/S wire be used instead of steel? Or will N/S tend to settle into shape. I've just weighed the etches and castings and the total weight is 535 g. I think that I'll be adding to this weight to get it to about 900g. Aiming to get the CoG just in front of the rear driver. Am I right in thinking that when I come to add the weight that I'd be best to do this without the wheels motor and gearbox in place? As most of the weight of the motor and gearbox will be carried by the axle. OzzyO. Link to post Share on other sites More sharing options...
3 link Posted February 27, 2013 Share Posted February 27, 2013 Hi Matey, Just an observation I personally would go for the top option, a bit more straight forward in my opinion. And as for the rear spring give it a try first and if the loco is not sitting level then put in place a screw adjuster for fine tuning. Miss Prism stated " final weight " so that must mean including wheels motor and gearbox. Talk soon, Martyn. Link to post Share on other sites More sharing options...
Miss Prism Posted February 27, 2013 Share Posted February 27, 2013 The one that I'm thinking of using is the equalised springy beam, along with the separate one with the screw adjuster on the rear spring. Excellent. For the screw adjuster I'm thinking of using an 8BA Allan grub screw. With the end bent up and going into the socket. Good. (It's called 'the Dave Bradwell'.) Suggest ensure the grub screw has a deep enough hole so that when you pick the loco up, the spring tail doesn't fall out! Here's an alternative suggestion to get round that problem and avoid having to bend the beam: Could N/S wire be used instead of steel? Or will N/S tend to settle into shape. You would need a 50% or so increase in beam diameter, but nickel-silver really doesn't make a good spring at all. Hard brass or hard phosphor would be better. Nothing beats tempered steel for a resilient spring. Blacken it if you're worried about rust. Am I right in thinking that when I come to add the weight that I'd be best to do this without the wheels motor and gearbox in place? As most of the weight of the motor and gearbox will be carried by the axle. Hmmm, yes and no. The prototype CofG for the 517 scales out at about 2mm forward of the rear driver, but I suspect when the prototype tanks were filled and the bunker full of coal, it was more likely to be directly over the rear driver. Model-wise, it doesn't matter too much, since the spring arrangement is impervious to CofG placement, but at least you know within a few mm where you are aiming for, so you can proceed with the build with most of the extra weight being incorporated as you proceed (leaving the smokebox door off until late on is sensible though, because that's one place you will need to maximise weight). Wheels, and a proportion of the motor weight impinging on the driven axle, will all be unsprung weight of course, and although part of the total, the final balancing should be done with everything in place. It is possible to factor in the imbalance of the extra unsprung weight arising from the motor portion on the rear driver in the balancing point of the springy equaliser, but cantilevers are rather lively, and it all depends on exactly what proportion of the motor weight is involved. Link to post Share on other sites More sharing options...
ozzyo Posted February 27, 2013 Author Share Posted February 27, 2013 Hello Miss Prism, thanks again for your help with this as it's going to be the first time that I've used CSBs. The idea looks and sounds fine to my engineering mind, none of the loco weight riding on any hard spots so a smother ride all around. I do like the idea of the modified Bradwell, I think that I'll use something like that on the build. I'm not sure if I've got this right in my head so I'm attaching a sketch of what I think is right. The 10mm sizes are just numbers as a reference size. The two in yellow will have to be the same (yes?), the size in red is that the same or should it be about 0.25mm (10 thou) below, so as to pre load the spring beam? Or will this just try and make the loco ride a bit higher on the drivers and put more weight on the trailing wheels. As you can imagine I want to have as much weight on the drivers as possible. I must make time and read all of the CLAG site on CSBs. In the parts that I have read in the CLAG web site it seem to be saying that you don't want any of the spring beams attach to the pivot points? Or is it OK to attach them to one of them so that the beams will not drop out. Or should you have two small collars one each side of one of the pivot points? The middle one for the drivers and the fixed one for the trailing wheels. Thanks again for any pointer on this, OzzyO. PS. it looks like Eileen's and Markits are going to be getting some money off me in the near future. Link to post Share on other sites More sharing options...
Miss Prism Posted February 28, 2013 Share Posted February 28, 2013 Ozzyo - my beam diagrams contain symbols, for ease (I hope) of comprehension. The things the symbols represent are many and varied, and I am reluctant to be prescriptive about the particular desired style of those bits. In addressing some of the points in your post, I hope the following principles are of some use: No hornblock beams are pre-loaded in CLAG's version of CSB land. They act solely by virtue of being trapped vertically between the force of gravity acting on the weight of the loco impinging down on the frame fulcrum points and the reaction forces at the railhead to the wheels. No hornblock beams are rigidly attached at or to their fulcrum points. The beams are allowed to 'do their thing', and take up their natural curvatures. The use of 'handrail knobs or tags' is merely a means of loosely holding (note, not rigidly attaching nor rigidly securing) bits of the system together, and is a matter of individual taste and inclination. Any constraints considered to be desirable or necessary on the longitudinal and lateral drift of the beams within the chassis can be treated seperately. Btw, for a springy equaliser, it is particularly important that the bit of steel you use is straight. (Finger bend if necessary, or roll the springs between two hard flat plates. Iron out any kinks.) This degree of straightness is not so critical in multi frame fulcrum situations, e.g, the second of the options in my post #1317 above, where the outer ends of the beam are constrained vertically by frame fulcrum points. Link to post Share on other sites More sharing options...
Miss Prism Posted February 28, 2013 Share Posted February 28, 2013 Getting one's head around the height setting of beams is always a bit fraught initially, and there's no getting around doing some simple sums: Here's a worked example of the above I did for JeffP a while ago: Link to post Share on other sites More sharing options...
Miss Prism Posted February 28, 2013 Share Posted February 28, 2013 Link to post Share on other sites More sharing options...
Sandy Harper Posted February 28, 2013 Share Posted February 28, 2013 No good for modelling purposes then?!! Link to post Share on other sites More sharing options...
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