There is a strange gap in modern engineering software. We have extraordinarily powerful CAD systems, sophisticated simulation packages, and increasingly capable manufacturing tools. Yet if you are a DIY builder trying to design a tubular chassis in your garage, the workflow can still feel surprisingly primitive.
The project started with a real build
FrameDesigner did not begin as an abstract idea for another CAD product. It grew out of the needs of a real vehicle project: designing and fabricating a custom tubular frame around existing components and reference geometry.
That sounds straightforward until you try to do it. You need to position the engine, wheels, driver, bodywork, suspension, steering, cooling components, and other systems. Then you need to design a structure around those constraints. After that, every line in the digital model eventually becomes a real tube that must be measured, cut, bent, notched, oriented, welded, and assembled.
Traditional CAD can absolutely model all of this. The problem is not that general-purpose CAD lacks capability. The problem is that the builder spends a large amount of time translating between the way CAD thinks and the way a fabricator thinks.
DIY builders have a different workflow
A professional automotive organization may have separate people responsible for CAD, structural analysis, manufacturing drawings, fixtures, CAM, and fabrication. A DIY builder is often all of those people at once.
On Saturday morning the same person may be measuring an engine, checking wheelbase dimensions, designing a cross-member, printing a tube-notch template, ordering material, and welding the first part of the frame. That workflow changes what software should optimize for.
The important question is not simply, “Can the software create a tube?” It is: “Can the software help me go from the thing I want to build to a tube I can actually cut and install?”
Why tubular structures are deceptively difficult
At first glance a spaceframe looks simple. It is made of tubes connected at joints. In practice, nearly every part of that sentence introduces another engineering or fabrication problem.
Tubes have real outside diameters and wall thicknesses. Joints are not just intersecting centerlines. A tube approaching another member at an angle needs a specific physical cut. Bend radius changes the location of the tube and its developed length. Clocking matters when multiple bends occur on the same member. A reference model can be visually convincing but dimensionally wrong. A structural simulation can look impressive while using unrealistic supports or loads.
For the builder, those details are not optional. They determine whether the part fits when it reaches the workbench.
The first goal: design directly around the real object
One of the earliest priorities was reference geometry. A builder should be able to import a vehicle, engine, drivetrain, body, seat, or another component and use it as the physical context for the frame.
The model can be measured, scaled, positioned, rotated, and used as a packaging reference. Instead of designing a chassis in isolation, the user can build around the volumes that must actually fit.
This is particularly valuable for replica vehicles, custom cars, race cars, buggies, roll structures, motorcycles, and one-off projects where there may be no complete engineering drawing set to start from.
The second goal: make the tube itself intelligent
A tube in FrameDesigner is not intended to be merely a cylinder drawn between two points. It has material, dimensions, wall thickness, joints, bends, and a relationship to the members around it.
As the software has evolved, that has led naturally to tools for physical notches, bend definition, developed lengths, printable fabrication information, structural simulation, and export into other CAD systems.
More recently, the same philosophy has been extended to exhaust systems, where the routing problem includes engine ports, collectors, bend geometry, tube lengths, and thermal behavior.
Why the DIY community matters
The most interesting engineering projects are not always happening inside large companies. They happen in garages, small fabrication shops, university teams, makerspaces, club-racing workshops, and home machine shops.
Those builders are often extremely capable, but they have to be selective about software. A tool that costs thousands of dollars, requires a complex workstation environment, or assumes a dedicated CAD department may be technically excellent and still be the wrong tool for the job.
FrameDesigner is being developed around a different assumption: specialized engineering capability should be accessible to someone who is actually standing next to the tube bender and welding table.
Free should still be genuinely useful
An important part of the project is maintaining a useful entry point for people who are learning, experimenting, or working on smaller projects. The free version is intended to let builders understand the workflow, create real geometry, and decide whether the tool fits the way they work.
ESA Motion's public tutorials and articles are another part of that approach. They are not meant to exist only as marketing pages. The goal is to build a library that explains the reasoning behind measurements, tube layout, bends, notches, simulation, and fabrication so that the community benefits even before opening the software.
What we are learning from early users
FrameDesigner is still evolving quickly. Early builders have already influenced the direction of the product by showing where real workflows differ from what looks obvious on a software-development checklist.
A feature can be mathematically correct and still be awkward on the shop floor. A rendering can contain all the geometry and still be difficult to read. A simulation can run successfully and still need better visual explanation. A reference model can load correctly but be frustrating if material selection or hidden-part interaction does not behave naturally.
That feedback is valuable because this project is not trying to reproduce a generic CAD package in a browser. It is trying to solve a narrower problem better.
Where FrameDesigner is going
The long-term direction is to connect more of the design-to-fabrication workflow: better reference-model handling, more intelligent joints and bends, structural and thermal simulation, fabrication documentation, solid CAD interoperability, and tools specifically useful to vehicle and tubular structure builders.
But the most important part is keeping the workflow understandable. A DIY builder should be able to look at the model and understand what the software is telling them, why a member is shaped a certain way, and how that geometry will become a real part.
This blog is part of the project
We are opening this blog to document that process. Some articles will explain engineering concepts. Others will follow actual builds, discuss features being developed, show mistakes and lessons learned, or examine how a design changes between the screen and the workshop.
If you are building a custom car, race car, replica, roll cage, buggy, exhaust, motorcycle, prototype, or another tubular project, this is the audience FrameDesigner is being built for.
Help shape what comes next
The best way to improve a specialized engineering tool is to put it in front of people building real things. If you try FrameDesigner, we want to know what slows you down, what feels natural, what is missing, and which output would save the most time in your own workshop.
That feedback can be submitted through the ESA Motion Support page. You can also explore the FrameDesigner tutorials to see the current workflow in practice.