JRH SCALE CARS
JRH SCALE CARS
TRACTION AVANT
1935 Austin Seven Ruby Mk1 - 3D Printed Parts
3D Printing
Other than nuts, bolts and other hardware, there are no commercially available parts for building a model of a 1935 Austin Seven. Pretty much everything has to be scratch built. Nevertheless, the emergence of 3D printing technology provides the opportunity to get some of the more complex parts made by a machine rather than by hand.
Rather than buy a machine right away, I chose to use a 3D printing service (www.shapeways.com). This would let me explore the range of 3D printing capabilities and the different materials available before deciding if buying a machine made sense. I also had to learn CAD (Rhino 5) in order to provide the printers with appropriate input files and there was no point in buying a machine until I was comfortable drawing the parts.
There is a wide range of materials available; from nylon and acrylic to ceramics and metals. However the biggest issue turned out to be wall thickness. When I started the project, in 2014, most of the less expensive choices of material need a minimum 1mm thickness for an unsupported wall. Even at 1:8 scale that can present appearance challenges on some parts. For those situations I chose a more expensive material that could accept a 0.6mm supported wall thickness. It is now possible to purchase parts with supported wall thicknesses of 0.3mm, but the cost of the parts is about five times that of the least expensive material. In all likelihood this will change as the technology grows and the industry matures.
Rather than buy a machine right away, I chose to use a 3D printing service (www.shapeways.com). This would let me explore the range of 3D printing capabilities and the different materials available before deciding if buying a machine made sense. I also had to learn CAD (Rhino 5) in order to provide the printers with appropriate input files and there was no point in buying a machine until I was comfortable drawing the parts.
There is a wide range of materials available; from nylon and acrylic to ceramics and metals. However the biggest issue turned out to be wall thickness. When I started the project, in 2014, most of the less expensive choices of material need a minimum 1mm thickness for an unsupported wall. Even at 1:8 scale that can present appearance challenges on some parts. For those situations I chose a more expensive material that could accept a 0.6mm supported wall thickness. It is now possible to purchase parts with supported wall thicknesses of 0.3mm, but the cost of the parts is about five times that of the least expensive material. In all likelihood this will change as the technology grows and the industry matures.
Some of the Parts
Unfortunately, these photos aren't of the greatest quality as I don't have my usual camera equipment available. Nevertheless they'll give you some idea of the quality and level of detail possible in small 3D printed parts.
It wasn't possible to get molded rubber parts, so this tire will be used to make a silicone mold from which rubber tires can be cast.
Cylinder block
Tiny carburetor
The light colored center button is a separate piece. It will accomodate the trafficator control.
Takeaways
This chassis end plate ties the two rails of the 'A' frame together. Tough to fabricate from scratch.
Another tiny piece ... the hinge plate for the torque tube support
- For 1:8 scale, 3D printing is for real
- Great for complex parts
- Part quality is generally excellent
- Costs are relatively high, but not prohibitive
- Drafting will now be a bigger part of crafting