Showing posts with label CAD Systems. Show all posts
Showing posts with label CAD Systems. Show all posts

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!!!

Tuesday, December 27, 2011

Willamette River Railway - Grades and Running Trains

It was sad to see the relative fly out this morning.  My little ones cried.  But its quiet now...so back to the basement.  Today we want to put in the grades on the mainline and get her running.
 To get the grades set, let's start up top.  The area in light blue is what we'll work with first since it is a flat siding at 4.5" high.  4.5" in this cases means 4.5" from the lower rail head to the upper level rail head.  This allows for the ballast profile below, and allows for plenty of clearance.  The mainline crossings are far enough apart to give us great clearance and still stay at a grade maximum of no more that 2%.
 Here you can see where I've raised all the trackage on the siding to 4.5".  It looks a little funky in 3-D, but you get used to it after while.  On a complex layout I would hide the trackage that I wasn't working on to keep it out of view.

 Next, we'll work on the upper main and siding tracks.  We want to make sure the upper tracks clear the lower tracks before descending.  The right radius track will need to be cut in half as we want it to start descending after it crosses over.

 Putting all the track on one level of 4.5" is easy.  Starting the downhill grades is more difficult.  You can draw the grades as you draw the track, but I find this very time consuming as I make so many changes.  To change the grade you select a track segment and input its starting and finishing point.  This takes time, and there is probably a faster way that I don't know about.
 Once I set the grades on a stretch of track, I'll switch to 3D mode and take a look at it to see if it is a nice, smooth grade.  Here is the upper level, which should be uniformly level and 4.5" up.  Nice!
 As we go from the upper track over the lower track, we need to start descending.  I put in the transition grades on several pieces of track.  As you can see here, I goofed up something.  Usually it is because the start and end points of the track are backwards and I put the dimensions in wrong.  This is a quick fix.  As I put in the grade points I make sure that no section of track is over 2% grade.
 There!  The grade down to the switching district looks much better!

 Sometimes errant bits of track show up in the 3D view that aren't visible in the 2D view.  We have to clean them up.  I do this by selecting bits of track and moving them to see what is beneath.  When I find a problem piece I delete it and clean up anything that needs work.

 There it is.  A very small piece of track, probably from where I started a cursor point and didn't draw anything.  We'll erase it and reconnect the track.

 On this section I actually overdrew a tangent track.  We'll shorten it and reconnect all the track to make sure it is all correct.
 We adjust all the grades to make them smooth and run the locomotive over them to make sure everything is connected.

 Now we'll move to the other side of the track where we have a down grade, now highlighted in light blue.  This grade will go from 4.5" to 0" in about 24 feet giving us a grade of less than 2%.  We'll be sure to keep the lift out trackage flat to help prevent problems.
 Once the grades on the mainline are all set, we put a train on the track and run the train in 3D to see how it looks and reacts.  If a cross over is too low, it will knock the train off the track.  If track grades are too steep, it will slow the train.  It really acts like a layout!  I watch it go around several times from different angles.  Looks good!
 Here are some screen shots from the 3D view.  This will allow me to also check the scenery and how it will look with the grades and track.

 I try some switching maneuvers and test all the sidings.  Everything is working except the passing siding at the switching district, which I'll work with later.

http://youtu.be/QHdBVSw1-3w

I've made a movie of the first train around the layout, showing it from several different views...enjoy!


That's all for now...maybe more later today.

Oh, I've updated the Layout Standards:


Willamette River Railway

Layout Notes and Information
Updated 12-23-11

Owner: Thayne Tenney, Sandy, Utah
Designer: Scott Perry, Sandy, Utah
Scale: HO
Gauge: Standard
Standards: NMRA
Track Centers: 2 2/3” mainline, 2” yard and other
Size: 8 x 20 feet
Railroad: Union Pacific, Portland Terminal Railroad Co.
Height: 42”
Track: Walther’s Code 83
Turnouts: Mainline #8, Sidings #6, Switching District #5
Radius: Mainline minimum 32”, Switching district 18”
Grade Maximum: 2%
Sub-Roadbed: spline or cookie cutter plywood
Roadbed : Homabed
Layout Style: twice around, over under with lift outs, hidden staging.
Track Clearance: 4.5”
Train Length: 8 cars, 50 foot length + loco is average
Purpose: Hauling freight through Portland on UP’s Brooklyn Subdivision, moving freight to the Portland Terminal customers, and supporting customers on the mainline including a large power station.
Traffic: grain; IBC’s, coal, mixed freight, etc.


Sunday, February 14, 2010

Switching to XTrackCAD

For years I've been using 3rd Plan It.  While it is handy, I've spend over $600 now trying to keep up with the latest version.  My friends and I are having a helluva time sending drawings to each other because we are all on different versions.  That and the software is always a bit buggy.

I'm working on a Cotton Gin in HO for my Dixie Central Railroad and I need to draw the structure.  3PI doesn't do plain old drawings very well, so I'm going to switch over the XTrackCAD to give it a try.  Lots of people use it.

Download XTrackCAD Software

XTrackCAD Wiki

I'm also going to try Google Sketchup since it is free as well and does 3D drawings.