# My Big Boy Project in F-Scale



## Racer (Jan 26, 2013)

Hello everyone,My name is Tom Mihelich.My goal with this project is to show the progress of creating from scratch a3D Solidworks model of the Union Pacific's great 4-8-8-4 Big Boy Steam Locomotive and Tender.For reference, I am utilizing over 16,000 Union Pacific original engineering drawings whichshould produce the most accurate Big Boy Solidworks model ever created.I will be creating the models by the Union Pacific's CA Group Number Index sequence.In doing it like this, it is fairly quick to complete each part on its own which gives a feelingof small accomplishments instead of looking at the entire project overall at the sametime which would seem (make that IS) overwhelming.From these individual Solidworks parts, I plan on attempting to recreate the Big Boy as arunning display model in the relativity new F-scale. 1:20.32Usually, a model of this size would want to be made out of metal to take advantage of theweight for maximum pulling power.I am going to try a different technique for this which will be cold metal casting of all the components. As I progress down this road, I hope to show both the successes and ofcourse the failures which I am sure will come with the territory.I have turned the comments on in the blog and will try to answer questions the best I can.
Here is the link to my progress Blog which I will be updating pretty much daily. 

http://upbigboy.blogspot.com/

Enjoy...


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## Burl (Jan 2, 2008)

Looking forward to seeing your progress. Newbie question, but what would it cost an individual to buy SolidWorks?


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## Gary Armitstead (Jan 2, 2008)

Posted By Burl on 27 Jan 2013 01:02 PM 
Looking forward to seeing your progress. Newbie question, but what would it cost an individual to buy SolidWorks? I have used Solidworks for years before I retired in 2004. At that time, their package was about $3500. Here's a link to Solidworks "trial software"-fully functioning.

http://www.solidworks.com/sw/produc...nloads.htm

You will love working with it if you have some prior experience with higher-end CAD systems (NOT including AutoCad in this group).


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## Racer (Jan 26, 2013)

Gary is correct. 
It was a bit pricey but I figured I'd bite the bullet as this software will last me till I'm dead. lol 
Having worked as a CAD designer for Chrysler for the past 17 years, I picked it up very quickly 
and love working with it.


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## NTCGRR (Jan 2, 2008)

I'm lost.


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## lownote (Jan 3, 2008)

Cool project!

You might consider making some of the components available in CAD library for 3d printing.

And F Scale big boy will be what--6 feet long?


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## Greg Elmassian (Jan 3, 2008)

Can we help you Marty? 

I'm not lost. 

Greg


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## Scottychaos (Jan 2, 2008)

I am moderately lost.. 
I understand the model is being "drawn" in a version of CAD.. 
so its being created in the computer.. 
Then it sounds like its going to be physically built using "cold metal casting".. 

The thing I don't understand is..how does it get from the computer to the physical metal parts? 
What are the steps in-between? 

Scot


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## chuck n (Jan 2, 2008)

I am with Marty. I thought a cad was a less than a gentleman. Is the CAD program tied directly into milling machine, lathe? Will the first part be the part, or a mold for a later casting of the part, or both. I know things can be made from CAD drawings, but for those of us who are not engineers or machinists, some translation would be helpful. It does sound like a neat project and I will be following it. A little help on the process might help more than Marty and me. Chuck


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## Greg Elmassian (Jan 3, 2008)

Computer Aided Design CAD... pretty common term... the output of a CAD program can be used to run various machines, lathes, milling machines, etc, and yes, I would guess he would either make a mold directly, a master in a soft material and then a mold from it. 

Pretty much how everything is built nowadays... our trains have been made that way for years, Aristo has several videos showing this. 

Greg


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## NTCGRR (Jan 2, 2008)

I'll wait till the production and assembly photos start. The rest I'll trust Greg to keep an eye on him. I have enough on my mind with spring projects, more hands on. 

Will you have it finished by Sept Tom??


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## Greg Elmassian (Jan 3, 2008)

My guess is cold metal casting might be the relatively common urethane resin with powdered metal. 

The appearance is that of cast metal, and it's got some "good" weight thanks to the metal powder. 

Maybe the OP will confirm the technique, but it's got to involve a mold somewhere. 

Maybe there is also a 3d printing machine that will "print" this metal/resin combination. 

Regards, Greg


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## NTCGRR (Jan 2, 2008)

My thoughts exactly,,,,,,LOL.


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## chuck n (Jan 2, 2008)

Greg, I knew the meaning of the name. It is the process that I do not have clue about. What are the basic steps from the drawing to the end product?


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## Greg Elmassian (Jan 3, 2008)

Lots of ways to do this, depending on the end result desired. 

Example, Aristo wants to make a box car. They make the 3D CAD model... then use a program and numerically controlled milling machine to make a mold directly. Of course hand finishing and tweaks have to happen. 

Or, a modeller wants one or a few items, so makes a master from a milling machine driven by a program and the cad data, often out of hard wax. Then you put the wax master into plaster, let it set, then heat it up and the wax melts out (thus the term "lost wax casting")... pour molten metal in and let set, open the mold and you have your part. 

Or you make a master in a similar way and make a rubber mold and use it to cast urethane resin. 

Or you take the cad output to drive one of the new 3d printers to make the part directly. 

Lots of options, pro's and con's in each. 

Greg


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## SteveC (Jan 2, 2008)

Maybe this will be of some help.









Metal Cold Casting[/b]


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## Racer (Jan 26, 2013)

Hey guys, 

Steve has found the cold metal casting video where the process is shown. 
I own a CNC machine in my shop, a smaller size one capable of 12" x 5" work. 
I will take the CAD models and cut molds out of machinable blue wax. 
It is with these you can make the cold metal casting from. 
I have done this with many parts in the past and it has worked great for me.
Clearly this is a large long term project.
The plan is to first complete all of the Tender CAD work and start to 
make the molds for those parts.
Everything has to fit and work together first before molds are created.


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## Greg Elmassian (Jan 3, 2008)

Can you test-fit the blue wax? I guess that actually does not make sense, you are going right to the molds, very cool... eliminates a step.

Please post lots of pictures as you go, very interesting and ambitious project. 

Thank you for sharing it with us. 

Greg


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## chuck n (Jan 2, 2008)

Thanks Greg, maybe I will have a better understanding as we go through the creation of the BB.


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## Gary Armitstead (Jan 2, 2008)

Posted By Racer on 27 Jan 2013 04:20 PM 
Hey guys, 

Steve has found the cold metal casting video where the process is shown. 
I own a CNC machine in my shop, a smaller size one capable of 12" x 5" work. 
I will take the CAD models and cut molds out of machinable blue wax. 
It is with these you can make the cold metal casting from. 
I have done this with many parts in the past and it has worked great for me.
Clearly this is a large long term project.
The plan is to first complete all of the Tender CAD work and start to 
make the molds for those parts.
Everything has to fit and work together first before molds are created. 








Tom,

You have really opened some eyes on this forum, to the way our trains are manufactured these days! Thank you for doing that.









I have a few questions. Is your CNC machine a mill or lathe? I assume mill, but you do have to turn those axles. Just curious. Does the version of Solidworks have the ability to generate toolpaths for your machine? When I was using Solidworks 98 (I know pretty long ago!), we didn't have that capability. We had to use MasterCam to do toolpaths and post-process an NC file. I believe Solidworks now has the ability to work flawlessly WITHIN MasterCam. Correct? Are you going to actually make every single part on the 1:1 BB, in 1/20.3? You are DEFINITELY going to have to use the Bill of Materials module in Solidworks to keep track of these! You could make some of these parts as "one offs" and only cast those that would be too complicated to machine (especially if it would involve a four or five axix mill). OR do you have access to one of these beauties?!

We used to use blue wax to proof some of our toolpaths for cavities for press and drop forging dies. I will definitely be following this project.


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## SteveC (Jan 2, 2008)

Chuck

I think the following would describe the basics of the process.

On the software side it would be a multiple step process, and based on what Tom (i.e. Racer) has stated so far.
[*] He'll manually recreate the various parts in 3D drawings using the Solidworks 3D CAD (Computer Aided Design) software program using the information from the Union Pacific mechanical drawings.
[*] After creating the 3D drawings he'll have to use a CAM (Computer Aided Manufacturing) software program that can import the 3D drawing files exported from Solidworks 3D software to create the G-Code files needed by the CNC controller software.
[*] After the CAM software has created the G-Code files, these are used by the CNC controller software to control the CNC tool path.

Not sure about the following, but I think that the CNC machine would need to be of a 3-axis type (i.e. X, Y, & Z).

Second, the G-Code created I would think would need to be of a negative nature since he is cutting the mold out of the blue wax. Instead of cutting the part itself out of blue wax (i.e. a positive type file).

[*] Once the basic molds are made then any touch up required will have to be done
[/list]


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## chuck n (Jan 2, 2008)

Steve, thanks it is still Greek but it is slowly morphing into something I might be able to comprehend. Chuck


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## Mike Reilley (Jan 2, 2008)

Posted By Greg Elmassian on 27 Jan 2013 03:42 PM 


Maybe there is also a 3d printing machine that will "print" this metal/resin combination. 

Regards, Greg 
Yep...there is. My son just bought a 3D laser sintering machine. It prints metal parts by shining a laser on powdered metal. It builds 3D objects by repeatedly laying a layer of powered metal and then melting it with the laser. I haven't seen it work yet...but I'm sure interested.


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## Racer (Jan 26, 2013)

I have updated my blog with a nice picture which shows the overall size 
of the tender wheel assembly. It came out pretty cool looking. 
I pretty much now have all the pieces completed for the axle assembly except the one remaining 
part, the Axle Box Housing casting. It will be a tricky piece for sure.

http://upbigboy.blogspot.com/


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## Racer (Jan 26, 2013)

Pretty much have the tender box wrapped up except for a few plugs and such.
http://upbigboy.blogspot.com/


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