3D pantograph mold making

Andy Carlson

I wish to be clear--I do not think that old-school 3D mold making is better than CNC. I am simply saying that 3D mold making has made some great model parts and has no need to be viewed as not worthy of fine toolmaking.

In then decades since Athearn switched from Blue Box zinc outside axle bearing blomberg diesel trucks there has been dozens of HO blomberg trucks arrive on the market, and I would not be surprised to learn that ALL of them were made from CNC tech. Yet the folks who have earned high praise for their diesel locomotive builds are nearly unaminous in their preferring the Athearn styrene inside axle bearing blomberg diesel truck. And as I mentioned yesterday, that truck's tooling was made with 3D pantographed toolmaking and remains to the present the best such truck side frame in the hobby.

To me the better CNC tools are using high quality digital scanning which allows the makers to avoid repeating those horrible Dreadnaught ends from the past which resulted from simplified data points placed into the CNC programs. We all remember seeing Dreadnaught ends with breaking steps in the swells' slopes. Those problems go beyond fixing with tool stoneing.

-Andy Carlson
Ojai CA

Bill Welch

Just wondering what we are supposed to do with this information?

Bill Welch

Robert kirkham

I guess I learned two things:

  • make our masters a lot bigger, or
  • make them as large digital files and visualize them carefully . . .


Was really impressed with the rivet detail on the large scale master, BTW.


Rob Kirkham


From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Bill Welch
Sent: Thursday, December 12, 2019 2:47 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] 3D pantograph mold making


Just wondering what we are supposed to do with this information?

Bill Welch

Donald B. Valentine <riverman_vt@...>

I was always told that 10 times the desired finish size was a good figure for a 3D pantograph master. Perhaps the
larger question is where do you find anyone with a 3D pantograph? I know at least one shop that sold one for scrap,
a good Decelle, after listing it for sale and receiving no inquiries for six months of better.

Cordially, Don Valentine


Bill - You can put all this good pantograph information to use making freight cars!  Just purchase my Deckel GK-21 pantograph engraver!  I have the actual machine that was alleged to have created the Bowser plastic injection molding dies for the PRR H21a hopper cars!  It is here in south Texas waiting for a purchaser  PM if interested!   A.T. Kott

Doug MacLeod

Don, I had my 3D Frederick Deckel pantograph since 2004 and hardly used it as the 2D Gordons pantographs do about everything I want.  Gordon 2D pantographs have a taper attachment which is a nice feature when needed.

A CNC mill is almost a requirement on time consuming projects.  The plastic injection molds I make are in brass or aluminum.  Steel molds take ten times or more to make than brass or aluminum.  CNC machining would be the only way to go.  CNC machining is a whole different concept.  A CAD drawing is required  and drawing with CAD is time consuming.  I still like the basic machining methods best. 



Sent from Mail for Windows 10