Author Topic: GWR Armstrong Goods Engine  (Read 962 times)

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Offline 753

GWR Armstrong Goods Engine
« on: Jan 31 2021 13:04 »
Continuing my admiration of early GWR engines I am going to build an Armstrong Goods engine, should keep the Covid blues at bay for a few months.
These were the predecessor of the popular Dean Goods. Designed by Joseph Armstrong at Wolverhampton. Quite a simple engine with outside frames and a small 2500gal tender they were the work horse of the system.
I found this excellent video of a 5 in version
 https://www.youtube.com/watch?v=WU-hE480h3s

Mike






Offline AshleyW

Re: GWR Armstrong Goods Engine
« Reply #1 on: Jan 31 2021 21:36 »
mr david gregson of chorley driving, superb model.

Offline 753

Re: GWR Armstrong Goods Engine
« Reply #2 on: Feb 28 2021 11:45 »
The basic chassis of the Armstrong Goods, the frames are made from 1.5 mm steel sheet with 96 rivets per side using a copper snap to put in the rivets and stop the heads from distorting. The axles have squared ends that fit into squared holes in the cranks to assist quartering, and run in sprung brass axle boxes.
The wheels are cut from 6mm ali plate, the steel tyres are heat shrunk onto the wheels, just as full size practice..
The power unit is made up from items found on e-bay, the motor/gearbox that has been mentioned in other projects is rated at 400 rpm and drive through two helical and 2 to 1 spur gears to give an axle speed of 200 rpm at full speed.
The space between the inside frames will be visible so an ideal candidate for working inside motion.

Mike



Offline 753

Re: GWR Armstrong Goods Engine
« Reply #3 on: Mar 11 2021 14:20 »
One thing I have wanted to include in a model engine is a fully working inside Stephenson motion. Most of the G3 engines I have built the idea would not be worth the effort as the motion would hardly be seen, but the Armstrong is the exception so I decided this was the moment to for fill my ambition.

The motion plate and cylinder back are made as a subframe so the whole assembly can be removed as one piece for painting and service.

Mike






Offline Nick

Re: GWR Armstrong Goods Engine
« Reply #4 on: Mar 12 2021 08:34 »
Very nice, Mike. I always think it's a shame when builders leave a big hole between the frames where the valve gear should be. But maybe I'm biassed. I find making valve gear is far more fun than, say, bodywork.

Nick

Offline 753

Re: GWR Armstrong Goods Engine
« Reply #5 on: Mar 12 2021 09:58 »
Nick
As you know making inside motion is a lot of work, if it can’t be seen I don’t see the point apart from one own satisfaction.
We spent a lot of time trying to replicate full size engines so including motion is part of the process, and yes enjoyment.
I added inside motion to a 7mm Dean Goods kit engine many years ago, which was like watch making. I sold the engine on e-bay last year, eight bidders fought for it and sold for silly money. You could deduce that enthusiasts consider motion to be desirable!!

Mike

Offline 753

Re: GWR Armstrong Goods Engine
« Reply #6 on: Mar 23 2021 15:50 »
Progress on the Armstrong Goods, I could not find a suitable spring casting so had to make them, each spring has eleven parts so it takes a while to put them together.

The dome was turned from 2in dia brass bar and the flange was formed over a steel bar the same dia as the boiler barrel. The chimney, and safety valve bonnet are also turned from solid bar.

Mike




Offline 753

Re: GWR Armstrong Goods Engine
« Reply #7 on: Apr 03 2021 15:34 »
Further progress with the Armstrong with the details added, it’s surprising how many hours go into this detail. Now for the tender!

Mike



Offline Nick

Re: GWR Armstrong Goods Engine
« Reply #8 on: Apr 04 2021 09:19 »
It is looking very nice, Mike. Are the boiler fittings from castings, or turnings flared to the boiler using your shaping method?

No, I'm not surprised at the number of hours! I find that keeping up the motivation during a long project can be difficult. In my head I divide it into a series of mini projects so as to feel a sense of accomplishment when each is complete.

Nick

Offline 753

Re: GWR Armstrong Goods Engine
« Reply #9 on: Apr 04 2021 11:01 »
Nick

The boiler fittings are turned from brass and formed over steel  bar, I had a piece of 2in dia brass, it was just large enough for the flair on the top but as it gest dressed down it gets smaller dia, so I silver soldered extra pieces to the rim to get the correct shape.

Project motivation happens to us all, I used to leave one project and start another to refresh the mind, then swop back, but now I like to press on. I give myself goals for the day which works well and not be to ambitious.

Mike