Project Log

Selected Projects (When the client gives us permission to put their project on our web page. Projects are completed for several years before posting.)

Model Train Start Valve 03/06/2014

posted Dec 10, 2020, 8:53 PM by Jay Gross

I modeled this functional part and produced the mold used to make the wax patterns for investment casting. The mold halves for the main body were 3-D printed in stainless steel and mounted by the client in aluminum blocks for better cooling. The stainless steel printed parts took a lot of polishing for use in a mold. Epoxy based filler can also be used. The padding on the mating surfaces was machined off to provide a better seal. The other smaller parts were produced using lower temperature metal in rubber molds. The smaller patterns for the rubber molds were 3-D printed in bronze which is easier to polish but much more expensive per volume when printed at Shapeways. Another more expensive (but simpler!) production method for molds is to CNC machine them out of aluminum blocks. My client is an experienced traditional machinist.
Assembly drawing for the whole start valve the back side of the 3-D printed mold parts
inside of the mold halves. note triangular tell-tales on corners



Model Train Clam shell lights and small junction boxes 06/15/2014

posted Dec 10, 2020, 8:29 PM by Jay Gross

The projects are working model train cab lighting and electrical junction boxes to match those offered by Pyle National. Again, the metal castings and associated hardware were offered as a kit by the client. Once the base design was in SolidWorks it was easy to produce variations. The junctions boxes are only about 3/8 inch in diameter.
a typical junction box from an old train catalog 
 
Assembly drawing another version of the light
final kits for lights


Model Train Main Junction Box kit 06/22/2014

posted Dec 10, 2020, 7:38 PM by Jay Gross

For this project we needed to get the castings as small as possible and still fit the pre-made terminal block. I used my 3-D printer to cheaply and quickly make parts for the client’s verification. As you can see, the quality here is too poor to use in production parts or for patterns to make molds. (I later got a better 3-D printer that can make sand cast patterns that work after some hand finishing.)  More expensive Shapeways printed brass was used to make the production patterns. This is about the largest part that can be produced using rubber molds and spin-casting with low melting point metals. 
Original junction box from old train catalog My3-D printed case
Another view of the 3-D printed case Much smoother final kit



Model Train Headlight Kit 05/23/2014

posted Dec 10, 2020, 6:50 PM by Jay Gross   [ updated Dec 16, 2020, 12:49 PM ]

The client re-released his original kit. I scanned and reproduced all the parts from the original kit in SolidWorks. We then revised many of the parts to improve the authenticity, fit and strength of the final product. Many light configurations were tried to get the right look. This time, I directly machined the circuit board traces and cut out the boards using my small CNC milling machine with added high-speed spindle. While it is better to use an CNC lathe to turn the reflector blanks, I used my small mill because that is what I had. The client machined the back side on his lathe. The client did the miniature name plate based on my scan and drawing of the original using photo etching.
full-sized headlight on display (similar version) Parts from old kit
Assembly model in SolidWorks CNCed Circuit boards have LEDs for side number plated too
CNC milling reflector blank on follow up orderPhoto etched name plate Some finished kits

Tender Light, Backup Light 04/01/2014

posted Dec 10, 2020, 6:31 PM by Jay Gross   [ updated Dec 10, 2020, 7:41 PM ]

This project also includes an electric circuit board and associated electronics which I designed and produced for the client. The finished castings were made by the client from 3-D printed metal patterns. 
A different version of the tender light mounted on a display board Simple electrical design using photo etching process
cutting out circuit board in water bath Testing out batch of circuit boards
Final kit

Pennsylvania Railroad Style Brake Wheel (Completed 11/15/2013)

posted Dec 10, 2020, 6:05 PM by Jay Gross

The Pennsylvania Rail road specific brake wheel was scanned in a local train museum. I have a better structured light scanner as of 2016, but the example I was scanning had layers of shiny gloss paint making the scan difficult. The original was also bent so I only used a section and repeated it. I later found a drawing of the part… The parts for the wheel were cast in a low temperature rubber mold. The molds were made using 3-D printed metal patterns. The final kit developed for sale by the client is also pictured.
Full-sized wheel in normal position  scanned part 
side by side comparison given to client view of assembly model of all of kit parts 
Final kit supplied by client

Mercer Tender Step for 1/8 scale model train (completed 12/21/2013)

posted Dec 10, 2020, 5:48 PM by Jay Gross

For this early project I went to a local train museum and scanned the step using a structured light scanner as well as took pictures and basic measurements. I did prototype models out of sheet metal and also a cast version that had draft like the original. After reviewing and revising my cast version with the client, we decided to have the part 3D printed from Shapeways (www.shapeways.com) in black Nylon. We only needed one pair of steps so it didn’t make sense to have the part investment cast. The part is too big cast from a low temperature metal in a rubber mold. The final part was painted black and is show mounted on the client’s 1/8 scale model train.

Original full-sized step as scanned (reverse side)

SolidWorks Model  Nylon 3-D printed part from Shapeways 
part installed on client's 1/8 scale model train

Wooden Trim for Antique Automobiles

posted Jul 6, 2013, 9:04 AM by Jay Gross   [ updated Jul 6, 2013, 9:10 AM ]

Here is a completely different kind of project than the trains and metal industrial parts; it is wooden trim for 1930’s and 1940’s automobiles known as “woodies.” As you can imagine, it is difficult to find wooden car parts from 1940’s that are in serviceable condition. JG Conversions’ role in this restoration process is scanning the old parts and getting STL data files of the shape to the client.  The client produces a new wooden part using a CNC controlled router. Here is a link to the client’s blog.  http://recycled40fordwoodie.blogspot.com/
 
 
trim prior to preparation for 3-D scanning Front           trim prior to preparation for 3-D scanning - back
 

Here are the front and back side of both halves of the original pattern part. This part is about 4 feet long.

 
 
wooden trim after to preparation for 3-D scanning          wooden trim after to preparation for 3-D scanning - back
 

A patched-up original is used as the object that is scanned. The patch up job does not need to look good and can even consist of clear tape with a white powder spray. I can do some touch-up and repairs digitally, but it is faster and cheaper to fix the physical object before scanning. The trim is finished in a clear finish, so no putty or patches can be used for the final part. 10 thousandths extra for the tape thickness for a wood part does not matter. The client did the more important front side with putty to save money and to preserve the correct details. Lighter color paint would scan a little better; the surface can be coated with the white talc powder too. I quickly did the back with tape. The damaged tendon sticking out from the end was re-constructed using tape since there was nothing smooth to extend with the correct cross-section. The part then (after the above pictures) got another light coat of white power spray to make the surface more uniform and cover up the tape. The scanner scans thru the clear tape to the surface of the wood at the bottom of the holes I am trying to cover up! The ping-pong balls and dots are for alignment of the individual scans.

 

trim in good shape            measurements after SLS scan - back side

 

This part, a rear quarter trim was in good shape and was actually used as a pattern to (slowly and meticulously) make other identical copies using a mechanical pantograph arm and a router before being bought by our client. Defects in the wood for this piece prevent its use as an actual trim piece on a car. I digitally extended the outer surfaces on both ends around 3 inches lengthwise and covered over the complete tendons. Since the original was smooth, I was able to duplicate the individual scans of the ends, slide them down and trim them before fusing (attaching and averaging) all the scans together. It is easy to copy something, but difficult (and expensive) to create all new surfaces. The 70 inch long part is at the limits of the 3-D CNC router and the scanner. The part was scanned using a Structured Light Scanner.

 

 

 

3-D CNC wood milling machine/router
 

The client, Jeff Yeagle, has a 3-D CNC wood milling machine/router. The CNC router, pictured above can make the wooden part using a digital STL file much the same as a 3-D printer produces a plastic or metal part, but on a much larger scale. The bed of the CNC router is 45x45x6 inches. The part above of course is foam and has a much rougher finish than the final wooden part due to less cutter path overlap. The foam part are used just to inexpensively test the fit on the car. Wood parts produced this way are useful as patterns for metal sand cast parts. The cost is lower than manually created patterns (from a traditional pattern maker) or ABS plastic 3-D printed patterns especially for larger parts. Jeff does this as a service.

 

Thermo Cap

posted Mar 27, 2013, 7:13 PM by Jay Gross   [ updated Jan 1, 2016, 9:04 PM by Benjamin Gross ]

 
This small die cast part shows the accuracy we can do the scanning and modeling. It turns out the horizontal tube was pulled when it was cast (or bent afterwards) and goes down a few degrees. There was also some local distortion around the gating. These areas were trued up (straightened) in our SolidWorks model. Not counting these areas, we were able to get all surfaces of the model to within +/- .005 inches.   
 
 
                   
 
The original part, about 2.25 inches long.
 
 
 
           
 

This is the scanned part. The brown areas indicate we were not able to scan to the bottom of the hole or inside the horizontal tube. Complete coverage is not critical when building out a complete model.

 
  
                      
       
    The filtered and simplified Low Resolution points (left) and profiles are used as a guide for manual creation of SolidWorks model.
 
 
     
 
             
 

Here are a few views of the SolidWorks model. This can optionally be created by client who has CAD expertise.

 

Nathan M5 horn for Train

posted Mar 27, 2013, 7:13 PM by Jay Gross

Here is part for a newer diesel train. Our client had purchased a 1/8 scale part in plastic from another vendor, but it was too fragile and broke. We scanned the broken parts and fixed everything digitally in software. The sections were made thicker and deviated from scale is some areas for additional strength. Finally, the finished product was compared against photos of an actual horn and adjusted accordingly.  The finished model is around 1.5 inches long. The best source of information on this horn is found here: http://atsf.railfan.net/airhorns/m5.html
 

Here is the finished model.

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