Multimachine & Flex Fab

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Multimachine & Flex Fab- shows it - a general purpose metal fabrication tool including lathe, mill, and drill press. This could be the central tool piece of a flexible workshop - and this item is already open source! I have not assessed this more fully, but it appears to be a promising candidate to address tooling needs for a community- at absolutely rock bottom cost - eliminating thousands of dollars of expenditure requirement for similar abilities. The capacities and practicality of this lower tech 'personal fabber' need to be assessed fully. The multimachine could be the centerpieces enabling the fabrication of electric motor, CEB, sawmill, OSCar, microcombine and all other items that require processes from milling to drilling to lathing. Crucial.


Review of Project Status

We are currently assembling and evaluating the components that would make a robust flexible fabrication facility. To date, our list of proposed tooling is:


Multimachine Development (Zerohour template)

  1. The Theory: The underlying theory in a nutshell. The Theory must be presented as a working hypothesis that is being explored and tested. There must be an experimental procedure to test the theory- the theory must be testable. The Theory question must be well-posed: an answer must exist. If any of these criteria are missing then the project will not move forward effectively.
  2. Existing problems in the real world that relate to this theory, a brief description.
  3. Proposed way to apply the theory to those existing problems, the context or pre-requisites for this solution (solution in this case is application of the theory)
  4. Related existing work that verifies feasability with context summary of links to those references
  5. Related existing data or facts that support theory
  6. Existing constraints and barriers to deploying
  7. Related existing work that argues against theory (or summary and link to a place where this already exists)
  8. facts and data that support arguments against theory
  9. A brief summary about how this is related to Open Source Ecology (Relevance to OSE) core values
  10. Links to partner site references

Multimachine Parts list, Materials list, dimensions specs, assembly file

This will be a first draft of a spec file for multimachine

  1. Multimachine - , and documentation:
    1. Add CNC numerical control to its xyz motion to automate milling and lathing operations
    2. Include long lathe bed for CNC milling of roundwood for LPSA structures (would a larger than spec multimachine be needed to accomplish this large lathing? it seems to be the case)
  1. Torch table - similar to the Torchmate
    1. Commercial kits start at $4k from Torchmate
    2. Open source CNC version could cost $1k
    3. Torch attachment is the basic tool


  1. Plastic extruder - see Extruder_doc.pdf at this library. More up to date files may be found here:
    1. Ok, but who can translate that publication to English? Hi, I'm Erik de Bruijn is Dutch and I could help.... I'm also interested in this document for the RepRap.
  2. Metal casting - what is the best low-cost, robust solution available here?


  1. Circuit fabrication - solution etching or a PCB mill?
    1. PCB mill kit available for about $2500
  2. PC oscilloscope

The above minimal toolset includes major machining, metal cutting, metal casting, plastic extrusion, and electronics capabilities. We are talking of cars, solar turbines, motor controls, CEB machines, agricultural combines, and so forth from this set. Plastic and metal forming, and subractive machining of all types, is covered. Thus, we are talking of producing advanced technology at the cost of materials, and in particular, at the cost of waste stream materials, if, for example, scrap aluminum is melted and cast into motor housings and other useful parts.

Multi machine Bill of materials 2 Block version

(taken from

Engine blocks suggested specs calls for a 3 7/8" Bore inline 6 cylinder engine (not a sleeve bore engine block).

Engine blocks meeting criteria

  • Cummins 6BT 5.9 L B5.9 4.01"in bore (this engine is an option for Dodge Ram, and was agricultural engine in 1980's) Can be machined to close to 5 inch bore. ***Needs to be machined with Boring bar, or accurate boring machinery.*** Probably best candidate for largest Spindle Bore

Three bearing spindle and chuck assembly

Other Parts (this list will be cleaned up)

  • You will need a smaller cast iron block for the vertical slide. Well, not exactly at this stage but you will need it when assembly first begins and it is easier to search for it while you are searching for the “big” block. What ever you choose, it needs to be as short and heavy as possible. An iron V6 will probably work fine or look for a very common small Dodge D50 truck four cylinder block. I've used everything from a Model A Ford to a Volvo turbo block. (2) 4' of 4" OD "round" (if possible, most is not truly round) pipe for the over arm. Remember that the overarm may not be needed for some machines but is critical for others. At the very least, make the #1 cylinder bore able to be retro-fitted to an available size of pipe without having to take the entire machine apart to have it re-bored later.

(3) A 20?" long piece of extra-extra heavy wall 2 1/2" xxhw pipe or a similar sized hollow bar to use for the spindle. The length of course depends on the size of the engine block that you use. Try to leave at least three extra inches of spindle outboard of the pulley. Different kinds of tooling like a traveling head boring bar may need this space. Try not to settle for less than a 1 3/4" spindle bore on a short bed lathe that is to be used for a wide range of projects. (4) 2 roller bearings and a flange or home cast thrust bearing The roller bearings could be anywhere from about 2 1/8" to 2 3⁄4" ID (assuming 2 1/2" xxhw pipe) and between 3 7/8" and 4 1/8" OD. The flange bearing (third spindle bearing) bore could be a little smaller than the roller bearing IDs and the pulley bored slightly smaller still. Think seriously about using those Metric 100 mm spindle bearings. (5) A threaded chuck or back plate to test the spindle thread if you are going to use a threaded spindle. (6) A 1 1/2”" slice of 3-1/2" steel shaft or a similar sized ZA-12 casting that can be bored to fit the spindle. It will be needed for the bearing adjuster. Get at least 6 extra two inch "slices" for horizontal mill arbors, boring heads, fly cutters, thrust bearings etc. (7) A 2" washer for the floating part of the adjuster. (8) A 1 or 2 groove 12" OD pulley that can be adapted to fit the end of the spindle. (9) An approx. 6" long piece of 3 1/2" pipe to make into a separator for the roller bearings. Important, length is bore length less the width of the bearings. This spacer "floats in the cylinder so it should be just a few thousandth of an inch smaller than the bore, use shim stock and Locktite to make a snug fit because a loose fit can be the source of strange noises. Ends must be accurately machined or the bearings will slightly "cock" and cause great trouble! The spindle can be slightly undercut in the area underneath this spacer to make it easier to press on the front bearing. . (10) Used head gaskets for both blocks. (an easy way to mark holes but not absolutely necessary)

Parts Sourcing

See Multimachine Parts

Flex Fab - Current Work

The main point for the Multimachine is to start documenting the toolpath generator (Smari McCarthy) -> controller -> motor -> hardware (Multimachine) system knowhow integration. Massive cost reduction, F10 or better - is possible. If we're lucky, we could get the Multimachine to the accuracy of electronic circuit fab.

    • (Sam's temporary note: probably a simpler smaller design will be more appropriate for electronic circuit fab. something closer to "RepRap" construction would work just fine. Parts could be made for it on multi machine, in part...)**

Toolpath generation:

Controller integration:


Component References

See Also