pennsy a3 switcher

[mark_in_denver]

was wondering if anyone could tell me if the pennsy a3 could be built in 1.5" scale with a 9" swing lathe. any input would be appreciated

[timz1999]

<font face="Verdana, Arial" size="2">Originally posted by mark_in_denver:
was wondering if anyone could tell me if the pennsy a3 could be built in 1.5" scale with a 9" swing lathe. any input would be appreciated</font>

I checked Kozo Hiraoka's book Pennsy a3 switcher and on page 242 he suggest that you should have twice the swing as diameter so 6 inch driver's are going to need 12 inch swing
I hope this helps Pat

[andypullen]

Jamie Harris in the Philadelphia area is building one in 1 1/2" scale. He's connected to the www.discoverlivesteam.com (http://www.discoverlivesteam.com) website. I think in the bulletin board over there.

Andy Pullen

[GWRdriver]

&gt;&gt;Kozo Hiraoka's book Pennsy a3 switcher . . . suggest that you should have twice the swing as diameter so 6 inch driver's are going to need 12 inch swing&lt;&lt;

Excess machine capacity is always nice to have, there's no doubt about that, but IMHO an across the board guideline of 2X driver diameter is too exponential and asks the builder of the a3 (often a beginner, and not all that well equipped) to provide machine capacity substantially beyond what is needed for the rest of the project. By "exponential" I mean take an 8" driver . . . by this guideline you would now need a 16" lathe to do the job. Not so! Not everyone is going to be able to provide (buy) that much additional capacity and once the drivers are done leave it sitting on the table unused.

The typical US 6" lathe, such as the Atlas 6, will in all probability not be able to turn those wheels, but the Logan 8 would, and the South Bend 9 and 10 would, and the British Myford 7 would because it has a gap bed. The tradition in live steam and model engineering has always been, depending upon the design and capacity of many smaller lathe, for the builder to develop the ability to adapt his (or her) lathe to an occasional job which is beyond its normal capacity.

I think a 1.5X diameter might be a more reasonable and attainable guideline.


[This message has been edited by GWRdriver (edited 10-22-2004).]

[andypullen]

I would have to agree with you GWR....

When I bought the castings for my 1 1/2" scale 0-4-0, Mercer was running the ad saying it could be built with a 9" lathe. A 6.25" diameter wheel is do able on a 9" lathe. You won't clear the cross slide; but the drivers can be done on it. A bigger machine is obviously better for that kind of work. Look at all the engines built by the Brits on a Myford lathe.

Jamie Harris has patterns for the drivers for Kozo's A-3 in 1 1/2" scale. I don't have an email for him, but have talked with him online and he will get them poured for you. His website is: http://www.easternmachineworks.com/loco/a3progress.htm

Andy Pullen