It so happens that I have a Walchaerts design which I developed for my 7¼ inch gauge engine derived from Romulus and named Maggie, which appears in the Blackgates catalogue. This design worked well in six of the engines I have built over the years and the design will suit Sweet Pea and also Metre Maid, using existing holes on the frame (photo 1). All that is required is to remove the Hackworth gear.
It is important to know the names of the parts of the gear and fig 1 should help.
The parts fall into two groups: existing parts, to be modified, and new parts.
The existing parts to be modified are the crosshead, the slide bar and the reversing lever and we’ll deal with those first, followed by the new parts we need to make.
Crosshead
There is a change to the gudgeon pin holes in the crosshead (fig 2) and a new gudgeon pin is needed to hold the drop link in place, together with a screw in the 5mm hole tapped in the crosshead on the outside faces.
The slide bar (fig 2) is to be shortened or made new with a 5mm tapped hole tapped in its end. A four jaw chuck in the lathe will help to do this. A 2BA thread can be substituted but I prefer 5mm as I can get 5mm screws from F.W.B. (usual disclaimer), which are plated and made from high tensile material - and no stripping.
Esta historia es de la edición 4625 de Model Engineer.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor ? Conectar
Esta historia es de la edición 4625 de Model Engineer.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor? Conectar
WORKSHOP TIP - Boring Eccentrics
I am making a 1 inch Minnie traction engine and have arrived at the machining of the eccentric straps.
Wenford A 7¼ Inch Gauge 2-4-0 Beattie Well Tank
The stage has now been reached where the well tank body can be completed but beforehand there are some internal details to add.
Vertical Boiler Locomotives
Vertical Boiler Locomotives
Union Nuts, and How to Make Them
These are quite different from those commercially available and are made from copper
SHOWCASE Paul's Engine
One day my son Paul came to me and asked if we could make something in my workshop, so that he could learn engineering processes.
CLUB NEWS
My secret’s out!
Building Dancer - The Boiler
Dancer needed a boiler that would be somewhat larger than the size permitted under the Model Engineering exemptions in the New Zealand regulations.
An Inverted ‘Ross Yoke' Watercooled Stirling Engine
As with all my hot air engines they are cheap to build, mostly from scrap
A Draught Proposal
A Draught Proposal
A Boiler Feed Pump
A Boiler Feed Pump