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Post by andyhigham on Sept 17, 2020 12:08:54 GMT
I thought I'd create a build thread for the little Hunslet. Ok little is a bit ambiguous, the full size loco is only 12ft around 3.6M long the model is just under 1M long x 380mm wide. The loco has a well tank between the cylinders that could hold 3.6 Litres, I was worried about about the difference in weight between full and empty causing the loco to go from nose heavy to tail heavy 3.6L of water weighs 3.6Kg or around 8lbs I have decided to reduce the front tank to 3L and fit a smaller 2L tank under the footplate. 3L @ 200mm from the front axle should be balanced by 2L 300mm behind the rear axle. the tanks would have a connecting pipe so should stay balanced. The hand pump could be submerged in the rear tank and an axle pump submerged in the front tank. I have decided to attempt flanged smokebox ends, 2.0mm mild steel sheet scales at 7.2mm so should be do-able Hunslet works photo 1898 Jack02 by Sigma Projects, on Flickr
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mbrown
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Post by mbrown on Sept 17, 2020 13:22:02 GMT
Interesting, given your observations about the valve gear, that the photo shows the loco in reverse gear. I would have thought that was quite rare...
Malcolm
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Post by andyhigham on Sept 18, 2020 19:44:07 GMT
I have spoken to the peeps at Statfold Barn Railway, Jack is there at the moment and They will allow me to photograph and measure if I pay my £8 to go to the next event in October. It is also a dog friendly venue so Dio can come with me
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Post by andyhigham on Sept 19, 2020 19:28:36 GMT
Looking at the GA for the Waril class loco (slightly later but based on Jack) that Malcolm sent me, there is an axle pump driven from the rear axle
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Post by andyhigham on Sept 19, 2020 21:13:09 GMT
I know the position of the cylinders, I have the radius rod, union link, combining lever and lifting links. The steam ports in the cylinder are the same dimensions as the sweet pea so I presumed the valve slide will be the same. I used the Dockstader simulator to fill in the gaps and find the positions of the weigh shaft and link pivot. I have something that is almost symetrical in both forward and reverse, a bit more fine tuning and I can make the motion plate
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Post by andyhigham on Sept 22, 2020 20:31:23 GMT
More thoughts on the smoke box. There is no room to wield a hammer on the inside to close the rivets. A G clamp style rivet squeezer may struggle for access too as the rivets will be tight into the flanged ends. I'm thinking the best way to avoid tears would be to cheat, use button head Allen screws and fill in the hexagon hole before painting. Feel free to call me a philistine
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mbrown
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Post by mbrown on Sept 22, 2020 20:56:47 GMT
When Talyllyn No.6, which has a well tank, was given a major overhaul, one consideration was improving access to the tank, so the rivets holding the top plate were drilled out and replaced with button headed Allen screws.... I am not sure many people notice the difference, even without the heads being filled in. So there is a narrow gauge precedent - sort of.
Another option would be round head, but slot-less, screws with nuts on the inside if there is room for a spanner.
Malcolm
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Post by Deleted on Sept 22, 2020 21:34:28 GMT
More thoughts on the smoke box. There is no room to wield a hammer on the inside to close the rivets. A G clamp style rivet squeezer may struggle for access too as the rivets will be tight into the flanged ends. I'm thinking the best way to avoid tears would be to cheat, use button head Allen screws and fill in the hexagon hole before painting. Feel free to call me a philistine Hi Andy Have you considered using slotless screws, they look very much like rivets, I used them to fit my tender horns..It looks like your model will be fairly large in scale so you may find a suitably sized screw for the job in hand. You could either fit nuts on the inside or tap the smokebox shell. With nuts you can tighen the screws if long enough to grip with pliers. If screwing directly into the smokebox you can use pliers on the inside to tighten the screws and cut off the tails if required? Just an idea sir... Pete
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Post by suctionhose on Sept 23, 2020 1:32:09 GMT
A Philistine you may be but the Traction Engine boys often use "threaded rivets" for belly tanks etc. You can buy them I'm sure. (Live Steam Models)
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Post by Deleted on Sept 23, 2020 6:48:30 GMT
EKP do roundhead slotless screws in BA sizes...0 to 10BA.
Pete
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Post by andyhigham on Sept 27, 2020 20:01:13 GMT
The coupling and connecting rods are open at the back with a bolted in end to allow the bearing brasses to be inserted. The front end of the coupling rods have a rectangular hole, I assume the brasses only have a flange on the outside to enable them to be loaded into the rod Hunslet_0-4-0WT_684_Jack_cropped by Sigma Projects, on Flickr
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mbrown
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Post by mbrown on Sept 27, 2020 21:21:44 GMT
The brasses at the front will usually have a flange on the inside but at the front only. That way they can be put in the hole and slid forward so that the front flanges hold them in line with the rod. The glut and cotter at the other end of the slot will then hold the brass in the forward position and secure it laterally at the back.
Does that make sense?
Malcolm
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Post by andyhigham on Oct 1, 2020 19:40:21 GMT
I had a hunt on t'internet for Hunslet loco works numbers. Most are consecutive and very few gaps. I found a gap in the 1898 range and chose 689, just 5 away from Jack's 684. Whilst I was looking at photos of the cab side I was wondering about the side cut outs and how to commit them to CAD. I used the elipse function, tilted it and chopped it in half. It's probably not completely correct but a chap on a galloping horse wouldn't notice.
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Post by suctionhose on Oct 1, 2020 20:55:15 GMT
For those sort of problems I insert the picture into the CAD and trace over. I learnt that from this forum!
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Post by andyhigham on Oct 2, 2020 8:28:40 GMT
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