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Post by David on May 17, 2019 10:44:03 GMT
Other than the Tormach RapidTurn problems (if you're interested in that fiasco look at my CNC thread) I got help from a club member to roll the boiler barrel cladding. It has the usual flats at the ends but because I had cut it to size the flats are on the actual wrapper. But they're under the boiler so I don't care.
It doesn't quite meet up underneath, either due to the flats or just because it's sheet metalwork so you should never cut to size. I will live with the flats and the gap.
I did leave it a bit long though so I can't put the smokebox on properly yet to see how it all really looks. There should only have been about 0.5mm in it, but I think there is a band front and back that will hopefully hide any rough edges I leave bringing it back.
I neglected to drill the holes for the dummy cladding bolts along the top so will have to mark and drill them in the round.
Anyway, it's about done and it should be good enough. I won't bother with a photo until it fits nicely.
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Post by David on May 25, 2019 11:31:34 GMT
Spent the entire day making holes in the barrel wrapping. The line of holes for bolts went ok. My dinky height gauge was great for marking these out. The holes for the clacks were not so simple. I moved the one of the holes quite a way while using the step drill. These plugs allowed me to scribe the circle I needed to cut. I think this was a good idea and it's a shame I didn't have it before I got carried away with the step drill above. I could have used the plugs when the hole was just big enough to get the thread through and I might have been able to improve the alignment of things (see a couple of photos down). The hole ended up being just the right side of recoverable. Something's awry with the alignment or spacing. Given there's a boiler and sheet metal involved I was resigned to this being the case. When I took this photo I was sitting on a chair so the loco was at eye level. I don't know if you can see it but the boiler has an significant slope up from firebox to smokebox and it is blindingly obvious in person when looking at it side-on. It just looks completely wrong when you can reference it to the frames. I'll do what I can within the constraints of the cladding but will otherwise try to live with it. In the back of my mind is the idea of soldering strips onto the bottom of the firebox cladding so I can lift the firebox but I expect that would look terrible. I did spend a lot of time trying to detect this problem before I'd even started the cladding and obv missed it, but I've never been able to sight the boiler or it's features in relation to the rest of the loco properly. It's progress and one step closer to the day I don't have to think about sheet metal!
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Post by Roger on May 25, 2019 11:40:32 GMT
I think you're being way too hard on yourself. You're aiming very high and that's the right approach in my opinion. Sometimes it's not as good as we intended, but I really don't think there's anything noticeably wrong with any of it. I'd be very surprised if the full sized locomotive was millimetre perfect anyway. Gentle slopes of a boiler in the frame aren't going to show, and most people wouldn't know whether that's right or not unless they have an intimate knowledge of the locomotive. This is great progress, the locomotive looks good.
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Post by Jim on May 25, 2019 12:17:12 GMT
I'd agree with Roger. As modellers we all aim for the very best we can do in recreating a miniature of our favorite loco but things don't always go exactly as planned. What you have done so far has all the signs of becoming a top model of the NSWGR's B Class moguls that will be admired by many when you finally have it on the track.
Jim
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Post by suctionhose on May 25, 2019 13:05:00 GMT
I might mention that my 'first' loco, substantially a remake of a running engine, no longer ran after I'd finished! Later it did run again but the pistons came off.... I'm saying give yourself some credit. In fact, give us that have struggled for a lot longer than you have some credit too! It's not easy. It's not supposed to be easy. Easy is boring!
If you really want perfection you'll have throw a lot more of your work in the scrap and feel the pain of a thousand cuts each time you think it's not good enough. We have! Or you can be realistic and accept that a first build is bound to have a few mishaps. It can't be any other way...
BTW Today: a drill ran off. I tapped a hole off perpendicular, hot flanged a steel plate (with smoke alarms screaming in the house above) - came out a bit narrow - and discovered a prominent feature now made doesn't look much like the real thing. All in a days work and it will be ok in the end. That's the journey mate!
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Post by Deleted on May 25, 2019 15:34:14 GMT
looks excellent David, as Roger said, full size is never 'spot on'.. these are living breathing machines, when there's heat involved, nothing stays as intended...
Keep up the great work sir...
Pete
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Post by racinjason on May 25, 2019 22:42:32 GMT
David Remember the other details will get your attention also very few people will see it like you do when building.
cheers Jason
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pclass
Active Member
Posts: 29
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Post by pclass on May 25, 2019 23:03:26 GMT
It certainly looks good to me, I had my NSWGR 32class engine clad in stainless steel I didn't like it so I stripped it all off and now wondering whether to re-do it in brass or sheet steel, ? can I ask what thickness steel you ended up using, cheers Dennis
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Post by mugbuilder on May 26, 2019 5:17:10 GMT
Your problem is easy enough to rectify Dave. Simply thin out the top of the front spacer between the boiler and the cladding and thicken up the top of the rear spacer. It is a common enough problem and I usually adjust the spacers to suite.
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Post by David on May 27, 2019 5:09:49 GMT
Yesterday morning before seeing any replies I jacked the firebox up by 3mm using some scrap and it looked pretty good. However it caused the safeties and dome to tilt forward, and the top of the firebox was right up under the cladding, maybe touching in places. The first problem I think I could solve by levering the bushes around to make things straight. But the lack of room under the cladding is no good because there are bolts, nuts, and strengthening plates that need that space, there needs to be at least 1mm gap for a step on the body of the safeties that helps position the cladding, and the cladding was barely able to sit on the frames, wanting to lift and twist. Your problem is easy enough to rectify Dave. Simply thin out the top of the front spacer between the boiler and the cladding and thicken up the top of the rear spacer. It is a common enough problem and I usually adjust the spacers to suite. Thanks Barry. If I can make that work it sounds like a much simpler solution. I'll make a couple of eccentric supports and see what happens.
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Post by David on May 27, 2019 5:29:49 GMT
It certainly looks good to me, I had my NSWGR 32class engine clad in stainless steel I didn't like it so I stripped it all off and now wondering whether to re-do it in brass or sheet steel, ? can I ask what thickness steel you ended up using, cheers Dennis Ouch! I'm doing everything possible, including willful blindness, to avoid that. What was wrong with the stainless, and what thickness was it? Mine is 0.7mm steel with a gal coating. I sanded the gal off the outside. It is very easy to bend and work with but still surprisingly strong. The firebox was done by hand around a 25mm rod and then just faffing about to try and make it conform to the throatplate sides - that latter part wasn't overly successful and the creases are too sharp to my eye where it waists in and there's no reverse curve to be seen. That may be fixable if I dare try it. I had to do the top corners twice, straightening the piece between attempts, and got away with it which is why I think the sides could be finessed a bit yet. The barrel was rolled by a club member with a set of rollers thankfully. At this point I'm going to leave the firebox sides as they are because the handrails, dummy injector steam valves, etc are all around that level so I'm hoping they'll obscure it.
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Post by David on May 27, 2019 5:39:12 GMT
Sounds like a good day Ross. And what did you do to your first loco that it stopped running? Valve gear improvements?
My red loco has given me quite a few teaching moments and it also no doubt ran much better when it left Barry's workshop than after my early attempts at bringing it back to life! There was the eccentric strap with casting marks still in the bore when I'd 'finished' it, the eccentric rods that broke because I used the wrong grade of silver solder... That first problem was an interesting exercise to fix because I had to move the bore of the strap both forwards and backwards to get rid of the cast surface. Luckily I had more practice in machining by that time so managed to fix it.
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Post by David on May 27, 2019 8:50:19 GMT
Barry's solution is a good one - thanks!
I made another* MDF ring tonight, offset by 3mm. This was a bit much so I filed it down to a bit over 8mm and I think it's good now. I did not change the one at the front because the wrapper is in the right place at that end.
* Two rings - I wasn't thinking about the setup on the mill for the first one and a combination of mistakes saw it part company with the stock with the usual results except no broken cutter** because it was only MDF.
** The cutter was already broken from a previous job and had lost two of its four tips. Didn't matter in MDF.
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Post by mugbuilder on May 28, 2019 7:16:27 GMT
Had lunch with David, farther in law Roger and their wives today. was glad to hear from David that my suggestion worked OK. Am so full now that I won't need to eat for a week or so. Interesting model engineering conversation had by all.
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Post by David on May 29, 2019 23:48:12 GMT
Yes, it was a good lunch. Part of the ME conversation revolved around how to get steam into and out of the steam chest and cylinders on the father-in-law's current project. Barry has that job and has to adapt cylinder castings from a 7.25" model to work on this 1.125" :1' model. On the Baldwin prototype the inlet and exhaust passages were cast into the smokebox saddle but that isn't feasible with these castings on this model.
You don't see many commercial designs at our club. My father-in-law has 4 locos at present and not one of them is to commercial plans. I think Barry, Ross and a few others are largely responsible for the attitude down here of build what you want, not what you can get plans and castings for. Both of my locos are to Barry's design, so I haven't joined that DIY design club yet.
On topic, I've drilled the front washout plug holes in the barrel wrapper and hope to do the rear ones today. I turned up some more plugs so I could drill a 1/8" hole in the pop mark, then mark the outside of the final sized hole so I can catch any drift of the step drill before it's too late.
I'm tempted to epoxy the castings in place rather than solder them to avoid the risk of distorting the cladding. I did a solder test in the disc of material that came out of the dome hole but I wasn't convinced of its quality and don't really want to use too much heat.
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Post by David on May 30, 2019 5:23:06 GMT
I think my idea about using epoxy for the washout plug castings may have been the way to go. I have just soldered 4 of them into the barrel cladding. The steel - on the outside - has been pitted! Perhaps from hot flux? I tried using phosphoric acid for flux, which works excellently on brass, but it was useless on the gal steel. I bought some Bakers Fluid and that worked but who knows what damage it did? I washed the whole thing off in water afterwards. I also now have the problem of how to clean up the brass castings, they're looking a bit nasty. Being steel I can't just drop the wrapper in acid overnight like I would brass. Perhaps a good scrub with a brush with something on it, but what I don't know. No point worrying about it too much in this new world of 'get the damned thing finished'! Tomorrow I'll cut the tails off the castings and start figuring out where I need to give some relief on the rear crinoline ring to get it to fit again. I am quite pleased to have made a start on detailing the cladding, however small. I have some 1mm brass sheet I can fall back on if necessary and take this as a cautionary tale to stop being penny-wise and pound-foolish. The barrel wrapper is a much simpler job than the firebox side of things.
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timb
Statesman
Posts: 512
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Post by timb on May 31, 2019 7:48:37 GMT
I think my idea about using epoxy for the washout plug castings may have been the way to go. I have just soldered 4 of them into the barrel cladding. The steel - on the outside - has been pitted! Perhaps from hot flux? I tried using phosphoric acid for flux, which works excellently on brass, but it was useless on the gal steel. I bought some Bakers Fluid and that worked but who knows what damage it did? I washed the whole thing off in water afterwards. I also now have the problem of how to clean up the brass castings, they're looking a bit nasty. Being steel I can't just drop the wrapper in acid overnight like I would brass. Perhaps a good scrub with a brush with something on it, but what I don't know. No point worrying about it too much in this new world of 'get the damned thing finished'! Tomorrow I'll cut the tails off the castings and start figuring out where I need to give some relief on the rear crinoline ring to get it to fit again. I am quite pleased to have made a start on detailing the cladding, however small. I have some 1mm brass sheet I can fall back on if necessary and take this as a cautionary tale to stop being penny-wise and pound-foolish. The barrel wrapper is a much simpler job than the firebox side of things.
A tip I had not long ago was to use a thick paste of bicarbonate of soda. Spreading this over where the bakers fluid has been will neutralise any remaining acid. The lot can then be washed with water.
Might be worth a go.
Tim
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Post by David on Jun 2, 2019 3:28:05 GMT
Drilled the holes for the firebox washout plugs this morning. I checked all the positions against the stays and the only ones that clashed were the ones I couldn't move because they'd then be in the way or other features or just completely wrong in relation to existing scribed lines representing joins! Drilling started well enough - until the second hole. I put it in the wrong place, even though I'd double checked and marked its position, updated the drawing etc. It's a 1/8 hole I have to fill, perhaps with a rivet, or JB-Weld over a backing plate? The plug castings are held on with masking tape at the moment to check they don't foul the stays. It all fits so that's good. The plan is to stick them in with JB-Weld. The packet says it's good to 550 deg f (287 deg c) so it should be ok. I need to move one bolt hole on the RHS. I didn't plot out the washout plug position when I marked the bolt holes and got a clash. So that two holes that need to be filled. Glad to have these castings in place, I was pretty worried they wouldn't fit where they needed to.
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Post by Roger on Jun 2, 2019 7:30:59 GMT
Hi David, That's coming along nicely. We all put holes in the wrong place, I've got some on the Pannier Tanks that had to be filled in. I very lightly countersunk the holes on both sides and used a short length of rivet which was very gently squeezed in the vice, keeping it so the same amount was either side. You only need it tight enough in the hole to stop it turning and to spread into the countersink, so don't be heavy handed. You can keep taking it out of the vice to see if it's deformed enough. Then use a needle file to carefully remove what you don't want. The rivet only needs to be standing 0.5mm clear of the surface, more just takes more effort to file away.
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Post by David on Jun 14, 2019 11:25:19 GMT
The last week as seen progress on the cladding. Just in time as I've been dropped to the second page! I filled the bonus hole in the firebox cladding with a copper rivet and have done my best to sand it flush. Sadly the hole is on a curve so it isn't as easy as it could be. I'll have to see how it looks under primer so have stopped thinking about it for now. I covered the throatplate in soft solder and also tinned the inside of the wrapper where they overlap so in future I can apply some heat and solder them together. I used a solid copper bit I have from my old man's shed to do this. Heated with the little MAP torch it holds a lot of heat and combined with bakers fluid on the steel and phosphoric acid on the brass it was pretty easy. I rinsed the steel thoroughly afterwards. Then made the band that goes around the front of the firebox. The band itself isn't great because its width is a bit variable and the alignment between throatplate, wrapper, and band are all not good enough so that needs revisiting. I'll replace the band now I have pre-cut-to-width material. That all happened last week. Earlier this week was fixing the red loco. Yesterday and today I made the barrel bands. This was mercifully simple and seems to have worked. I had some 1/4" x 1/16" brass angle with a wiggly row of holes drilled in it from way back at the start of the project that wasn't good enough to use on the tender. The holes were just right for tapping 10BA and spaced such I could cut down between them and get slices the right size for soldering and riveting to the ends of the bands. I just had to drill a second hole in each of them for the rivet. I made the first one last night, and it took ages as I was figuring out how I wanted to do it. I went to do the second one, picked up a length of material and it felt completely different. All the other lengths of material were only half as thick (their width was fine)! It just so happened I picked the single odd one out to begin with. So I went back to see F-I-L and found some more thicker pieces. I was only going to do one tonight but having figured out how to do them last night it went pretty quickly so I did three! I'm happy to use the thicker stuff anyway (0.4mm) as it should be stronger against the spring of the barrel. I will use a piece of the thinner stuff on the firebox due to its much sharper corners.
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