LifeTrac Prototype II Completed

On September 14, we finished the loader arms for LifeTrac II – completing the second prototype of the open source tractor:

LifeTrac Prototype II Completed from Marcin Jakubowski on Vimeo.

We have not been able to post sooner because we have been away at the Steam Automobile Club of America Meeting. We will cover the exciting developments that emerged over the next 2 or 3 blog posts – since there is lots worth sharing.

In the meantime, we’re back to further preparations for building this season. We will fabricate a second Power Cube – an improved second prototype – so that LifeTrac II will have 35 horsepower of drive in total. At the same time, we are beginning on the second prototype of the soil pulverizer for CEB construction.

It is worth noting that the quick attach mechanism on the LifeTrac quick attach plate – which was shown briefly in the video above – has been completed successfully. It has been proposed first about 2 years ago, and we have finally built it. You can download the design for the quick attach plate here, as well as the LifeTrac and Power Cube drawings in Blender.

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14 Comments »

  1. Edward Miller said,

    September 20, 2010 @ 2:41 pm

    Awesome work guys! Looks great, very professional. Glad someone is helping save the world!

  2. neodynos said,

    September 20, 2010 @ 4:41 pm

    This machine has a style of its very own :) Hope you like to work with it as much as I like watching at it.

    BTW, steam engine stuff: using a Stirling engine instead would mean to not need to carry water with you, for creating the steam. Or am I missing out an important disadvantage of Stirling engines?

  3. Marcin said,

    September 20, 2010 @ 9:54 pm

    Is not the lower efficiency of working with fluids other than water, and therefore higher engineering requirements, the reason why Stirlings are less popular?

  4. MGPalmer said,

    September 21, 2010 @ 12:56 am

    Hey wow, this is great ! It has a real Mad Maxish feel to it, too :)

    And to think that I’ve contributed a small part to it makes me all warm and fuzzy.

    A question, though: I know that you didn’t manufacture the parts, especially the hydraulic cylinders, and tubes etc. from raw materials yourselves.
    Are there plans for being able to do that with the GVCC ? Is it even feasible ?

  5. neodynos said,

    September 21, 2010 @ 6:20 am

    Is not the lower efficiency of working with fluids other than water, and therefore higher engineering requirements, the reason why Stirlings are less popular?

    Ah, ok. And I just saw that there are “closed” steam engines that do not consume water, but condense and re-use it [source]. Was not aware of that … that would be a better solution, probably.

  6. Sekenre said,

    September 21, 2010 @ 10:42 am

    Hi Marcin,

    Sterling engines generally approach the theoretical maximum efficiency for any heat engine.

    Their disadvantage is in their low torque per volume.

    I wrote a long post about it on the Factorefarm forums, including some suggestions for making a steam engine more suitable for lifetrac, but it probably got lost in the spam:

    Problems with Steam Power

  7. Nick said,

    September 21, 2010 @ 11:22 am

    Great stuff, keep it up!

    Concerning stirling vs steam: The biggest disadvantage is that to obtain similar energy densities with a stirling pressurization and the use of helium or light working fluid is required. This drives cost and manufacturing complexities
    significantly.
    OSE may not however need the energy densities that the previous industrial age required and perhaps low energy density stirling are again feasible.

  8. Marcin said,

    September 21, 2010 @ 12:16 pm

    Parts fabrication is our next step, and yes, it’s absolutely feasible. We will be taking the long way – starting from metal scrap to induction furnace to metal components to surface grinding to machining. Add CNC, and you can be talking of an advanced industrial economy in a box, deployed inexpensively anywhere in the world. The real feasibility limit here is human imagination, so our role is to show that this could be done on a micro scale.

  9. Marcin said,

    September 21, 2010 @ 12:37 pm

    Our opinion is that the number one fault with steam power is widespread human ignorance about its true nature.

    I repost your Problems with Steam Power note below for reference. I would also like to comment that your 10 disadvantage of steam comments may have been true some time ago, but Cyclone Technologies has proven ALL of them wrong with their breakthrough, lightweight, water-lubricated, modern steam engine. See http://www.cyclonepower.com/works.html for more info. The next blog post discusses Cyclone Technologies in passing, and I will also post a dedicated post on this important topic, including our interview with Harry Schoell, the lead developer.

    Here’s some disadvantages of steam power that could harm replicability and safety:

    1. Requirement for fresh water.
    2. Slow startup/preheat time and most of the wasted energy is lost here.
    3. Valves & pistons are prone to wear and cracks
    4. Explosion risk with poor materials (quite likely if it’s made of scrap)
    5. Corrosion
    6. Poor power/weight ratio for mobile applications
    7. Sheer physical size of firebox/boiler/chimney would make it impractical on L
    ifeTrac
    8. No option for waste-heat or water recovery on a mobile application, a conden
    ser would be far too heavy.
    9. Hard to replicate!
    10. Need for an auto feed system greatly complicates mobile applications. (and adds more weight!)

    Steam Power would work ok at Factor e Farm for stationary applications however, as long as the water and heat could be recovered.

    I would like to suggest an alternative, although it’s not as ‘sexy’ as steam.

    Stirling Engines

    Advantages:

    1. Also an external combustion engine
    2. Much simpler construction
    3. Lighter weight
    4. Constant power output (may be an advantage for hydraulic applications)
    5. Working fluid is non-corrosive (air/helium)
    6. Working fluid is not used up
    7. Closest to Carnot theoretical maximum efficiency of any heat engine.
    8. Lower working pressure (also lower power)
    9. Less need for close-fitting parts
    10. Quieter / lower vibration
    11. Faster cold-start time

    Disadvantages:

    1. Less well understood by the majority (but is that going to stop you? I think not!)
    2. Lower power for a given cylinder size

    If Stirling Engines are not a good choice for you, I have a few suggestions foryour Steam powered LifeTrac design.

    * Build an insulated high-pressure storage tank onto LifeTrac and before use, fill it up with superheated steam from your stationary steam power-plant.
    * Use a babington burner and liquid fuel for the heater. It’ll be much easier than a mobile auto-loading pellet feeder. Also the unit heat per volume of fuel will be much greater.
    * A simple expansion chamber and radiator for cooling the exhausted steam will let you recover some of the water and potentially pre-heat the incoming steam.

    References:

    http://en.wikipedia.org/wiki/Fireless_locomotive
    http://en.wikipedia.org/wiki/Stirling_engine

  10. Sekenre said,

    September 21, 2010 @ 3:10 pm

    Hi Marcin,

    Cyclone power does look very cool and if you can make it light enough, superfluid steam will make an excellent working fluid.

    I look forward to your future posts on this subject, as I get the feeling my objections will be answered.

    Cheers,
    Sek

  11. Steam Engine Electric Generator | Open Source Ecology said,

    September 21, 2010 @ 4:47 pm

    [...] development of mobile power units, such as replacing the gasoline engine in the Power Cube of LifeTrac with a steam-power version. By the way, that was Harry Shoell in the audience (commenting that we [...]

  12. Miquel said,

    September 22, 2010 @ 3:07 am

    This steam engine discussion is fascinating. It certainly is a technology I hadn’t even considered.

    I occurs to me though, what happens when you find a design that would be perfect for OSE, but has the Patent Menace hanging over it?.

    For example, lets assume for the sake of the argument, that the cyclone steam engine design is perfect, and its characteristics are compatible with OSE criteria. You can’t just go all out and copy the design. They have it patented (parts of it).

    How can the problem be approached?

  13. Marcin said,

    September 22, 2010 @ 5:34 pm

    The truth is that there are just so many different ways to do it that we don’t see a problem accomplishing something that works. OSE operates on the principle of sufficiency – a sufficient design may be adequate from the holistic perspective, without necessarily achieving peak point performance. For example, our CEB press is sufficient in design. People can add all kinds of bells and whistles, but that does not prevent The Liberator from still being adequate, excellent, or outstanding.

  14. Open Source Ecology - Overview said,

    January 5, 2011 @ 11:40 am

    [...] LifeTrac is a versatile, 4-wheel drive, full-sized, hydraulically-driven, skid-steering tractor of 18-200 hp with optional steel tracks. LifeTrac is intended to be a minimalist but high-performance, lifetime design, design-for-disassembly workhorse and power unit of any land stewardship operation. It features easy serviceability by the user. Its modular nature allows for quick attachment of implements; interchangeability/stackability of multiple power units (Power Cubes) for adapting power level to the task at hand; quick attachment of all hydraulic components via quick-coupling hoses; including quick interchangeability of hydraulic motors for use in other applications. [...]

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