Tuesday, December 24, 2013

088 The Navajo Mining Railway - Building an Ore Car Fleet #3

Designing the car is the next phase.  Now that I know what I need to do to cast the car, I need dimensions and details so that I can build the masters.  We'll start by drawing the car in CAD.

A car model, wheels, drawings and several scales and measuring tools are needed

The Phase 2 car is 14' 9" long.  That is about 3 1/5" long.  These are tiny cars!  The trucks are the fixed measurement as I've already got them.  They are almost the same size as the prototype at 4 1/2'.  This is about half the size of an On30 box car.  I'm thinking the car should be a tad bit longer due to the On30 wheel spread instead of the 2 foot spread.  Yet, that is only half a foot.

Sorry I'm writing like this...but I want you to know what I'm thinking and how I plan stuff in my head.  You may not want to do it this way...but you sure won't find this stuff in a train magazine!

I'm going with a 16' car in length.  Keeping car and part lengths at easy dimensions helps prevent errors.  At least on freelanced cars like a Phase Five which has never existed.  But could exist.

After drawing the wheels from the Grandt models, I realized the wheel base is just too tight for the platform length.  I'm adding 1' to make it 17' and increasing each side by 6".

This section will only be modeled once, and will be duplicated.  The bolster (what the wheels mount on to) is the problem.  We won't be able to mold this unless we fill in the area above it between the beams.  This will not be see, so we'll do that.  I'll also put in a hole dimple for drilling out the hole for the screw to hold the trucks.  I may have to tinker with the coupler pocket and coupler to get them at the right level.

Rivets are being added, dimensions tweaked...

Here is about as far as I need to go.  It gives me critical measurements and the look I'm after.  I can build it from here.  Naturally I'll add more details from the photos...but there is no real need to draw it all out accurately.  There once was a time when I'd take several days and draw it out in fine detail.  Then I found out I was mostly modeling from the photos and just didn't need the detail...it was a waste of time.

This is a tiny car!  When you compare the full size drawing to the 25' boxcar, this is a really small ore car.  That will be perfect, but its like modeling in HO, not O scale.

First work on the model...the ore bin!!!

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