Build a useful workshop tool.
Develop one well-defined chamber and process first, then extend the construction set from measured results.
Engineering design preview
Useful heat.
On your terms.
A repairable electric furnace, kiln and forge concept for the independent workshop. Match the chamber to the work, shape the heat, and keep the whole process in view.
- 01Replaceable hot zone
- 02Program & record
- 03Independent cutoff
The workshop problem
The process deserves
more than a setpoint.
A useful furnace is the chamber, its power system, its tooling and the record of what happened to the work—not just the number on a display.
| The job | A common starting point | The Fire direction |
|---|---|---|
| Working hardware | A furnace often treated as one fixed appliance. | A serviceable frame with a hot zone developed for the chosen process. |
| The heat cycle | A setpoint tells you little about the history of a part. | Ramp, hold, cooldown and a temperature record tied to a batch. |
| Repair & expansion | A failed assembly can stop the whole workshop. | Accessible components and separately developed heating modules. |
Shape the heat
Ramp. Hold. Cool.
Know what happened.
Start with a chamber and process you can characterize. Explore the heating architecture and an illustrative temperature program.
Two heating architectures
Serviceable modules · process-specific tooling
A chamber heated from the outside in.
Replaceable resistance elements heat an insulated working chamber. This is the first architecture to develop for general chamber heating; lining, fixtures and ratings depend on the selected process.
- Working chamber — matched lining, shelves or crucible.
- Program controller — ramp, hold, log and inspect.
- Independent protection — temperature cutoff and power isolation.
Explore a profile sketch
Non-ferrous melt
750 °Ctarget
30 minhold
6.7 hwith nominal cooldown
Illustrative schedules. The material, chamber and temperature measurements determine the real recipe; passive cooling does not follow a guaranteed ramp.
Planning tool
Plan the batch.
Count the energy.
Use the selected profile sketch to make a heater-energy allowance. Adjust the input power, assumed duty and local tariff; the schedule stays visible above.
heater allowance = rated input × ramp-and-hold hours × assumed duty
Schedule arithmetic, not a melting or thermal model. Nominal cooldown is excluded; auxiliaries, standby and active temperature control during cooling add energy. Actual duty and consumption need measurement.
5.28 kWhHeater allowance at the entered tariff.
The open workshop
Machines you can maintain.
Knowledge you can reuse.
Inspired by Open Source Ecology’s construction-set approach: useful machines built from serviceable modules, with the documentation to understand, repair and eventually reproduce them.
Repair the wearing parts.
Heaters, linings, crucibles and sensors are service items. Design access and replacement into the machine.
Keep the process reproducible.
Tie a run to its material, tooling, temperature history and inspection results. A setpoint alone is not a recipe.
Where it stands
A design to develop.
A clear first step.
Design researchEquipment not yet built or rated.
The past notes establish the common-furnace idea and the resistance/induction question. Chamber dimensions, material recipes, power rating and complete-system cost are open design work.
Diagrams are functional concepts. Calculators and profiles are planning tools, not live controls or measured performance.
- Source reviewWorkshop, furnace and measurement notes indexed.
- First hot zoneSelect a material, process envelope and chamber.
- Instrument & characterizeCalibrate sensors and measure a reference load.
- Repeat & documentRecord useful runs and publish repairable assemblies.
What goes into it
A module list.
An honest starting point.
Component groups define the scope before hardware is selected. Every group is currently unquoted; there is no complete-system price or retail offer.
Frame & insulated hot zonePROPOSED MODULEUnquoted
Serviceable enclosure, lining, hearth and process-specific contact parts.
The first material and temperature envelope are still to be selected.
Resistance heatingPROPOSED MODULEUnquoted
Replaceable elements and correctly sized power components.
Initial architecture to develop; no whole-system rating yet.
Temperature & batch recordPROPOSED MODULEUnquoted
Matched sensors, calibration, controller and energy measurement.
Workpiece temperature and sensor placement must be characterized.
Isolation & extractionPROPOSED MODULEUnquoted
Independent cutoff, power isolation and process-specific extraction.
Part of the machine scope, separate from the software controller.
Induction development branchPROPOSED MODULEUnquoted
Converter, resonant components, matched coil/crucible, cooling and protection.
A separate future module, not included as a resistance-chamber capability.
Notes & precedents
Built from the
work already started.
The common-furnace, workshop and oven sketches supply the starting point. Fire develops the hot zone, thermal program and measurement side of that work.
Independent Redgold concept. Public references reviewed 28 October 2026.
- Open Source Ecology · Global Village Construction Set ↗
The precedent for a construction set of repairable machines and documentation that supports local production.
- OSE · Induction Furnace Overview ↗
Power electronics, coil, cooling and melt-chamber architecture. Its power and throughput goals are historical design targets, not Fire ratings.
- OSE · Open Source Induction Furnace ↗
Related design pointers. The incomplete build and BOM are research leads rather than a qualified machine package.
- Fire · public design brief ↓
Scope, calculation assumptions, open questions and interfaces with the neighboring projects.