Forum Options

« Back to Engines and Rolling Stock Topics

Sign In above to begin adding replies.
 

7 1/4" gauge Greenly A3 Loco

Ayton

Joined: 1-01-98

Topics: 1

Replies: 1

Posted: Tue 25th Jan 2011, 7:30pm
7 1/4" gauge Greenly A3 Loco

Has anyone built this model and can offer practical advice on the following?
a) The weighshaft on the original Greenly blue print GP7 is located 5 1/4" from the centre line of the driving axle, whilst on GP7/2, drawn by E A Steel in 1955 it shows it to be 5 3/8".Why the difference? Was it to suit a specific model or for general use? Importantly, which dimension should I use?
b) Before finally securing the driving wheels on thgeir axles, what are acceptable wheel-to-axlebox, and axlebox-to-hornblock clearances to give free running and preventbinding?
c) Does anyone have a practical solution for a push/pull regulator using a ball valve on a modern copper boiler? Where is the valve sited, and what is the operating mechanism?
d) What "jointing" should be used for metal-to-metalfaces such as cylinder covers etc?
 

Replies To This Post

Xz

Joined: 1-01-92

Topics: 17

Replies: 244

Posted: Thu 27th Jan 2011, 12:46pm

I haven't built your model but as regards the reg/ball-valve it's really a question of fitting it where you can, within the dome, and making your linkage to suit your own situation. If you go one stage at a time it should become obvious what is required as it goes along.

For gasket material I use Permantite around 0.025" thick, you may consider a thinner version more suitable to your particular need. It comes in many thicknesses. Try a motor trade factors for supplies. Permantite is fibre based and has graphited surfaces.

Sorry I can't be more help.
 

paulreed

Joined: 1-11-08

Topics: 0

Replies: 3

Posted: Mon 28th Mar 2011, 10:21pm

Hi Ayton
I've sketched up a possible solution for the ball valve push/pull
regulator, you need to multiply the movements to get the full movement of the ball valve.
I'am fitting a ball valve to my 3.25 scale Joffre class loco.
I've posted pictures of the drawings in the gallery.
A full size mockup will be needed to prove the linkage.
Email me if you need more help.

Regards
Paul
 

Rob Walker

Joined: 25-10-10

Topics: 6

Replies: 12

Posted: Fri 3rd Jun 2011, 2:06pm

who does the drawings and castings for the A3

Rob
 

Ayton

Joined: 1-01-98

Topics: 1

Replies: 1

Posted: Mon 6th Jun 2011, 12:53pm

Rob, Maxitrack via Maidstone Eng'g have a Greenly archive and they also have drgs. As for castings, I was lucky in that the few extra that I needed to build my engine I was able to get from Greenly and Steel when they were in business! My last info (a few years ogo) was that Fincken were sorting out a batch of drgs and patternsbut I don't know what happened! Hope this hepls, but please contact me direct if you require any further info. Ayton
 

Rob Walker

Joined: 25-10-10

Topics: 6

Replies: 12

Posted: Wed 8th Apr 2015, 10:44pm

Ayton,

How did you get on with the greenly drawings?

Rob
 
 
« Back to Engines and Rolling Stock Topics

Web design by Slingshot