mickoo
Western Thunderer
That option did cross my mind but it would have taken longer to draw up than to cut from brass to be honest, besides it’s good to get the crayons and scissors out, though I find it easier if you don’t use the squiggly ones
7mm Mickoo's Commercial Workbench
- Thread starter mickoo
- Start date
mickoo
Western Thunderer
That's the JLTRT King done ready for paint, there's still bit to add after paint like whistles (the shield pops off to aid painting) rear sand pipes, top feed pipework across the footplate, sanding lever rods/cranks, washout plug cores etc. I need to fit some longer crankpins as the current ones are a bit tight on the intermediate driver, I could skim the connecting rod boss but don't really want to as that big fat boss is quite a distinct feature on the Kings.
Two things I've missed and need going on before paint (final photos always sort the trees from the wood), ejector elbow drain pipework down the smoke box and bracket to support the pipework behind the reach rod.
The full metal jacket kettle added about four days but then It'd probably take a day and a half to do the resin lump with all the fittings etc so was it worth it; I'm probably biased but yeah, that boiler is a one hell of a dopamine rush.
Two things I've missed and need going on before paint (final photos always sort the trees from the wood), ejector elbow drain pipework down the smoke box and bracket to support the pipework behind the reach rod.
The full metal jacket kettle added about four days but then It'd probably take a day and a half to do the resin lump with all the fittings etc so was it worth it; I'm probably biased but yeah, that boiler is a one hell of a dopamine rush.
michael080
Western Thunderer
the pin diameter could be much larger than the visible nut thread.
simond
Western Thunderer
Indeed, as long as it’s smaller than the flange on the nut!
And the very limited clearance between the rods and rod to pin will both help too, but even so…
quick and dirty estimate #1 Weight on driving wheels around 67 tons. It can spin its wheels, assume mu about 0.1 so say 7 tons thrust at the wheel-rail interface, ratio of driver to stroke 55:30, more or less 2:1, that suggests about 14 tons limited by mu.
quick and dirty estimate #2 boiler pressure 225psi, piston 18”, force = 9^2 * pi * 225 =57,255 lbf. 57255 / 2240 = 25.6 tons. But a bit less due to gas flow and thermal effects.
quick and dirty estimate #3 Published Tractive effort = 35380 lbf, scale for ratio of driver and stroke 35380 * 55 / 30 = 64863 =~ 29 tons. I’m surprised this is the highest.
lots, anyway…
And the very limited clearance between the rods and rod to pin will both help too, but even so…
quick and dirty estimate #1 Weight on driving wheels around 67 tons. It can spin its wheels, assume mu about 0.1 so say 7 tons thrust at the wheel-rail interface, ratio of driver to stroke 55:30, more or less 2:1, that suggests about 14 tons limited by mu.
quick and dirty estimate #2 boiler pressure 225psi, piston 18”, force = 9^2 * pi * 225 =57,255 lbf. 57255 / 2240 = 25.6 tons. But a bit less due to gas flow and thermal effects.
quick and dirty estimate #3 Published Tractive effort = 35380 lbf, scale for ratio of driver and stroke 35380 * 55 / 30 = 64863 =~ 29 tons. I’m surprised this is the highest.
lots, anyway…
Last edited:
Not forgetting that it has two cylinders of course ... unlike QDE #3 which assumes only one
25t seems about right. The big American 2 cylinder locos tried to limit the crankpin force to about 62t and this was the motivation behind the Union Pacific "Tandem" coupling rods which diverted some of the piston thrust to the adjacent pins.
I don't think you need worry too much about this design - it has been around since 1903, hundreds have been in use and failures seem not to have made the news!
simond
Western Thunderer
At mid stroke the 28 (to which I was referring) has only one cylinder pushing on one crank pin as the other is at T/BDC and the tractive effort is the tractive effort, it all goes through the big end to which that cylinder is attached! (And mu doesn’t care how big/many contact patches)
Kings are more complicated, as I’m sure I heard Camilla complaining.
mickoo
Western Thunderer
Yes but your figures put all the power into one crank pin it should be two, it's a four cylinder engine and if one is mid stroke then another (inside 180° out of phase) will be mid stroke as well....I believe. Also, as soon as the cranks are out of perfect 0, 90, 180, 360° orientation then the trust is spread over all four.At mid stroke the 28 (to which I was referring) has only one cylinder pushing on one crank pin as the other is at T/BDC and the tractive effort is the tractive effort, it all goes through the big end to which that cylinder is attached! (And mu doesn’t care how big/many contact patches)
Kings are more complicated, as I’m sure I heard Camilla complaining.
LarryG
Western Thunderer
The full metal boiler will most likely have added quite a bit of value to the model. Nothing can go wrong over the next 100 years.
The resin boilers on 0 gauge locos I painted wouldnt stay still, so I was constantly confronted with bare metal where the boiler handrails had slid out of the knobs during expansion/contraction.
The resin boilers on 0 gauge locos I painted wouldnt stay still, so I was constantly confronted with bare metal where the boiler handrails had slid out of the knobs during expansion/contraction.
76043
Western Thunderer
I think Simon was referring to the 28xx photo previously posted?
Tony
mickoo
Western Thunderer
Ah well, if you're going to move the goal posts (I posted pictures of a King which frankly thought that's where the/my conversation was rightly headed) then that's fair play 
simond
Western Thunderer
Blame Simon, t'other one...
simond
Western Thunderer
Numbers would have been the same, more or less…
mickoo
Western Thunderer
Okay, after clearing the decks with the King and setting up for the next one (Javelin Black 5) alongside the County and 3232 builds I found a few moments to finish off all the little details on the Gladiator S15 (Maunsell).
DCC fitted and run in on the rolling road, it's now time to give it some load testing on a layout before hand over.
DCC fitted and run in on the rolling road, it's now time to give it some load testing on a layout before hand over.