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Post by terrier060 on Jun 15, 2019 23:52:39 GMT
With so much effort being put into getting the static appearance of the loco right, to rob it of the characteristic nod and weave when running seems perverse. Wilf I agree with you so much Wilf - it gives the loco personality as if it is happy to be bouncing along the track! Rather like the tick of a bracket clock with a verge escapement - happy, happy! But we all know a clock is a sad sight when it is stopped!
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Post by terrier060 on Jun 15, 2019 23:57:10 GMT
Hello all--------didn't the 57xx have leaf on the first 2 wheelsets and coil on the third inside the cab I believe the Kings had square section coil on the front axle ( after the Midgham incident ) ?? I have progressive coil on my Enfield Bullet forks...........If you opt for "Coil within a coil" then the one coil must be wound in the opposite direction to the other or they will become "Coil bound" and lock up.. You are quite correct about some GWR locos having coil springs. I am not sure off the top of my head which loco it is, but one of ours on the South Devon Railway has two coil springs per wheel in the cab, rather like an upside-down version of the ones on our models. The cab interior of GW pannier tank steam locomotive no. 5786 at Buckfastleigh on the South Devon Railway. by Willi_G
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Post by Roger on Jun 16, 2019 5:52:52 GMT
With so much effort being put into getting the static appearance of the loco right, to rob it of the characteristic nod and weave when running seems perverse. Wilf I agree with you so much Wilf - it gives the loco personality as if it is happy to be bouncing along the track! Rather like the tick of a bracket clock with a verge escapement - happy, happy! But we all know a clock is a sad sight when it is stopped! You'll never stop that from happening, but it can be excessive on soft sprung Miniature Steam Locomotives because our track is much less level than in full size. Damping ought to give a more scale dynamic appearance if anything in my opinion.
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Post by terrier060 on Jun 16, 2019 18:03:56 GMT
You really must go for active suspension Roger. Bendy bits of steel rod are so old hat!!!
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Post by Roger on Jun 16, 2019 18:11:01 GMT
You really must go for active suspension Roger. Bendy bits of steel rod are so old hat!!! Hi Ed, The trouble is that when you say things like that, I automatically daydream about what that would entail...
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Post by terrier060 on Jun 16, 2019 20:14:56 GMT
Yes it would probably mean replacing springs, or part replacing them with some sort of hydraulic oil system?!
Have to have a look and see what the Formula One guys do.
Ed
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Post by lankyyorky on Jun 16, 2019 20:37:28 GMT
Hi Roger, Fancy miniaturising Citroen suspension when you have a spare moment? youtu.be/zcUSMJ_bEjwShould iron out the humps and hollows :-) Dave
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jma1009
Elder Statesman
Posts: 5,896
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Post by jma1009 on Jun 16, 2019 21:11:46 GMT
Just a few (hopefully non contentious) points...
The GWR 0-6-0 Pannier Tanks often had the rear axle sprung via coil springs above. I did this on my own 57XX in 5"g, and in fullsize and miniature they are huge! You would not be able to fit these below the axleboxes as they would hit the ballast/sleepers.
The extension of the above is that to fit coiled sprung axleboxes, and for them to work properly on a miniature locomotive, you need a lot of room, which if underneath an axlebox creates considerable restraints, and lack of proper springing, especially on locos with small or medium sized wheels.
The usual result is that when the axlebox is at it's top position the below axlebox springs do not engage at all, and when at the bottom position the springs have already bottomed out.
We usually make the studs for the below axlebox springs just long enough to clear the railheads (vital, obviously, for ground level running over points etc.) and so the springs can be added without compressing them, so that they can be compressed by the bolts on the ends of the studs to get the bolts on easily onto the studs.
In 3.5"g this is a particularly difficult problem.
I am sure I am not the only person to encounter all this, and I have ample stocks of pretty much all wire gauges of spring steel (and phos bronze) and can wind my own springs, plus have a large tin full of all sorts of springs. I also measure all the weights on all axles to get this all right.
Cheers,
Julian
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Post by simplyloco on Jun 16, 2019 21:30:06 GMT
Hi Roger, Fancy miniaturising Citroen suspension when you have a spare moment? youtu.be/zcUSMJ_bEjwShould iron out the humps and hollows :-) Dave Many years ago I owned a Citroen CX2400 Pallas. It ironed out the bumps alright but fell to pieces around me! John
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Post by Roger on Jun 16, 2019 22:18:55 GMT
This is the first proper attempt at fitting the two tanks and balance pipe to the locomotive. 20190616_215441 by Anne Froud, on Flickr It's touching the band on the front of the throat plate where the rivets join at the change of section. Those need filing away and a chamfer added to the inside of the wrapper as well as lowering the heads of the rivets there too. 20190616_215519 by Anne Froud, on Flickr Putting a Vee block and Steel rule against that, I can see that the RH tank is sitting parallel to the frames. Not so on this side which needs the same treatment as the RH one to get the top of the tank closer to the boiler cladding. It's only a problem near the back, and it isn't that much so it shouldn't present a problem. 20190616_230344 by Anne Froud, on Flickr Even so, the 3D printed bridge pieces are still going to be slightly too short by the look of it. The top edge of the tanks will be covered by a thin piece of shim which is bolted onto the edge of the tanks all the way along. I've probably made it all a bit tight, but if the tanks don't fit closely, you run into trouble because of where the fillers are so close to the edge. Anyway, it looks like it's going to just fit with a little bit more work with a file. The balance pipe fits spot on and I can get all of the fixing holes in the brackets, so that's good news. Mind you, it's not possible to get the balance pipe off without removing both tanks, it's too close to the frame to be able to do it without. It's not a problem really, there's no reason to take it off once it's on. 20190616_230435 by Anne Froud, on Flickr
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Post by Roger on Jun 16, 2019 22:27:55 GMT
Just a few (hopefully non contentious) points... The GWR 0-6-0 Pannier Tanks often had the rear axle sprung via coil springs above. I did this on my own 57XX in 5"g, and in fullsize and miniature they are huge! You would not be able to fit these below the axleboxes as they would hit the ballast/sleepers. The extension of the above is that to fit coiled sprung axleboxes, and for them to work properly on a miniature locomotive, you need a lot of room, which if underneath an axlebox creates considerable restraints, and lack of proper springing, especially on locos with small or medium sized wheels. The usual result is that when the axlebox is at it's top position the below axlebox springs do not engage at all, and when at the bottom position the springs have already bottomed out. We usually make the studs for the below axlebox springs just long enough to clear the railheads (vital, obviously, for ground level running over points etc.) and so the springs can be added without compressing them, so that they can be compressed by the bolts on the ends of the studs to get the bolts on easily onto the studs. In 3.5"g this is a particularly difficult problem. I am sure I am not the only person to encounter all this, and I have ample stocks of pretty much all wire gauges of spring steel (and phos bronze) and can wind my own springs, plus have a large tin full of all sorts of springs. I also measure all the weights on all axles to get this all right. Cheers, Julian Hi Julian, I can see how the studs are close to the track, I had to shorten mine when I took the chassis to Vince's track many years ago. It certainly does constrain what you can achieve. Still, with a bit of forethought it looks like it shouldn't be too hard to wind some springs of a suitable weight. I've got quite a lot of wire to experiment with. I'll weigh the axle loads first and use a spring manufacturer's data to make a first stab at what to wind. To be honest, I'm looking forward to that stage because it will mean I'm almost at the finishing post!
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Post by simplyloco on Jun 16, 2019 22:31:35 GMT
That looks lovely. David likes to comment on my Brit versus his locos. "John's loco is a precision instrument that doesn't run because it's too tight: my locos are all over the place but they run!" We will wait and see... John
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jma1009
Elder Statesman
Posts: 5,896
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Post by jma1009 on Jun 16, 2019 22:38:43 GMT
Hi Roger,
The tanks on the loco look very good! They are probably better made and fit better than fullsize. I don't think the GWR were too particular about these things.
Just a small query - why are the cylinders and wheels etc off the chassis? I presume waiting for good weather for painting the frames etc again?
Anyway, you ought to be very pleased with the pannier tanks.
Cheers,
Julian
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Post by terrier060 on Jun 16, 2019 23:07:15 GMT
Excellent work as usual Roger. The detail is superb. I assume as on the Terriers there are thin sheets covering the joints so any gaps between the tanks and the boiler will not show, and also allow for expansion and contraction?
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Post by Roger on Jun 17, 2019 7:15:42 GMT
Hi Roger, The tanks on the loco look very good! They are probably better made and fit better than fullsize. I don't think the GWR were too particular about these things. Just a small query - why are the cylinders and wheels etc off the chassis? I presume waiting for good weather for painting the frames etc again? Anyway, you ought to be very pleased with the pannier tanks. Cheers, Julian Thanks Julian, the outside flat faces of the tank aren't dead flat, but as you point out, the tanks are not precisely made anyway so I'm not overly troubled by that. The wheels are off the chassis because I needed to strip the paint off because it wasn't really suitable. I also had a lot of additional holes that needed to be added and various parts had to be riveted on. There are still a few holes that need to be drilled and that's just easier to do with it all in pieces. Much as it's nice to see a locomotive gradually come together with everything in place. it doesn't really help with the process of getting it finished.
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Post by Roger on Jun 17, 2019 7:17:31 GMT
Excellent work as usual Roger. The detail is superb. I assume as on the Terriers there are thin sheets covering the joints so any gaps between the tanks and the boiler will not show, and also allow for expansion and contraction? Hi Ed, Yes, the covering sheets are the same as you describe on 1501. I'll probably make those later since there are still some bigger parts that need to be made.
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dscott
Elder Statesman
Posts: 2,437
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Post by dscott on Jun 18, 2019 0:22:37 GMT
Wonderful work as always Roger. Talking of Wheels Off? Yes it had to happen but at the very Best Time. My in steam for this Summer project took another Step back yesterday. (And do... Yes laugh we all need to sometimes) I carefully cleaned up the fully assembled wheelset, all round the axle boxes. Then the wheel moved! No not drinking? Not lack of sleep? But superbly made but not quite a press fit from the first builder!
'Bounce' and on the last two trains of the day behind 1501!!! Yes all over the place and what power! Thoughts of bringing paint to be stirred the next time and reserve the front of the leading coach! Not on the Severn Valley but when she shows off at other tracks. When the crew like to see what they have got. Didcot was great as you can stand next to the fast line. Put me down as 5 journeys behind HER if we are counting!
I am currently trying Halfords Extreme temperature Paint for the wheels as it just goes on and if chipped just shows the cast iron underneath. Paint brush on and it smooths out superbly. Also in Red for the interior of the frames. And in Matt or Gloss!
Best Regards David, and Lily amused over the wheel... The other came off fairly easily with an extra pair of hands.
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Post by Roger on Jun 18, 2019 7:05:02 GMT
Wonderful work as always Roger. Talking of Wheels Off? Yes it had to happen but at the very Best Time. My in steam for this Summer project took another Step back yesterday. (And do... Yes laugh we all need to sometimes) I carefully cleaned up the fully assembled wheelset, all round the axle boxes. Then the wheel moved! No not drinking? Not lack of sleep? But superbly made but not quite a press fit from the first builder! 'Bounce' and on the last two trains of the day behind 1501!!! Yes all over the place and what power! Thoughts of bringing paint to be stirred the next time and reserve the front of the leading coach! Not on the Severn Valley but when she shows off at other tracks. When the crew like to see what they have got. Didcot was great as you can stand next to the fast line. Put me down as 5 journeys behind HER if we are counting! I am currently trying Halfords Extreme temperature Paint for the wheels as it just goes on and if chipped just shows the cast iron underneath. Paint brush on and it smooths out superbly. Also in Red for the interior of the frames. And in Matt or Gloss! Best Regards David, and Lily amused over the wheel... The other came off fairly easily with an extra pair of hands. Thanks David. What a wind up about the wheels, will you re-make the axles or add a keyway and use Loctite?
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Post by Jock McFarlane on Jun 18, 2019 10:15:44 GMT
To my mind, the obvious solution to a 'bouncy' Speedy is to fit proper leaf springs rather than coiled springs. Leaf springs are far superior in their characteristics, and also prototypical. Coiled springs are very difficult to get right and adjust, and easily 'bottom' out, and have a tendency to oscillate on short wheel bases. I have never quite understood why Bill Perrett's 'Speedy' bounced about as it is a heavy loco, and if it had light springs these would have bottomed out. If it had stiff coil springs it would not have bounced about, but would have presumably slipped quite a bit. Cheers, Julian Julian, What is the best way in your experience to fix the end of the leafs to the hanger pins ? I am looking at a slotted hole in the leaf but full size practice in my book "Lococomotives by A.M. Bell" shows much more sophisticated methods.
I am working in 7 & 1/4" gauge.
Regards
JM
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Post by Roger on Jun 19, 2019 21:01:19 GMT
The fillers have a tiny split pin that goes through the 0.6mm hole in the pivot pin. I've made some using Florist's wire, but those will go rusty if I use them where there's going to be water. I found this wire on eBay which was actually described as being Silver plated Brass wire. As it happens it's Copper, but it's good enough. 20190618_172328 by Anne Froud, on Flickr 20190618_173107 by Anne Froud, on Flickr The same 'mangle' works just as well with this wire to form the required 'D' shape from the initial round section. The flat side is wrapped around the former and cut to length. 20190619_213728 by Anne Froud, on Flickr It's pretty small. The idea of using Silver plated wire is so that they look like they're Steel but they won't rust. 20190619_213909 by Anne Froud, on Flickr
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