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Dorn's picture


Member for
2 years 2 months


# of Wiki Edits: 312

# of Forum topics submitted: 77

# of Comments: 119

Stream of Wiki Edits

Title Edited on Edit message
Covercrop remote sensing imaging Monday, April 14, 2014 - 10:15 View changes View current version
Skywalker 2013 iFARM mapping setup Monday, April 14, 2014 - 09:57 View changes View current version
Encyclopedia of Practical Farm Knowledge Sunday, March 16, 2014 - 21:36 View changes View current version
Encyclopedia of Practical Farm Knowledge Sunday, March 16, 2014 - 21:35 View changes View current version
Yeoman's plow field trials Sunday, March 16, 2014 - 17:18 View changes View current version
small axial flow combine harvester Sunday, March 16, 2014 - 14:26 View changes View current version
Oat Dehuller - Model SR-50 Sunday, March 16, 2014 - 10:56 View changes View current version
Oat Dehuller - Model SR-50 Sunday, March 16, 2014 - 10:43 View changes View current version
Covercrop remote sensing imaging Friday, March 14, 2014 - 22:45 View changes View current version
Covercrop remote sensing imaging Friday, March 14, 2014 - 22:43 View changes View current version


Stream of Forum Topics

In 50 characters or less... Posted by Post date Last commentsort ascending Number of Comments # of Comments new to you
Open Source GPS Tractor Guidance-cross posting Dorn Sunday, March 16, 2014 - 10:28 Sunday, March 16, 2014 - 21:56 2
Tool Template Wiki _ farm bike Dorn Saturday, March 1, 2014 - 18:39 Sunday, March 2, 2014 - 12:50 3
Great use of Google Doc spreadsheet Dorn Monday, January 6, 2014 - 11:16 Sunday, March 2, 2014 - 12:08 2
Outcomes from Triange Build Day Dorn Friday, December 27, 2013 - 00:43 Friday, February 28, 2014 - 10:42 3
Interest in having the guide de l'auto-construction book translated into english ? Dorn Saturday, December 22, 2012 - 12:44 Friday, February 28, 2014 - 10:23 2
Some Design Principles for Open Farm Tools and Questions to Consider Dorn Thursday, December 20, 2012 - 23:00 Wednesday, February 26, 2014 - 22:47 3
Grazers "kit" for fido/apitronics Dorn Tuesday, February 25, 2014 - 17:13 Tuesday, February 25, 2014 - 21:22 1
Agricultural Lending Library @ NOFAVT Hackathon Dorn Saturday, February 15, 2014 - 16:31 Friday, February 21, 2014 - 13:14 2
Code for BVT Documents and notes Dorn Monday, February 17, 2014 - 16:08 Wednesday, February 19, 2014 - 22:39 1
Agricultural Lending Library @ NOFAVT Hackathon Dorn Saturday, February 15, 2014 - 16:30 Saturday, February 15, 2014 - 16:30


Stream of Forum Comments

Dorn's picture

Could you share your case study and the problem you are trying to solve? I am sure is a matter of using the appropriate image analysis software tools and developing the ground truthed image/spectral libraries to calibrate the image anaysis. You may also be interested in Public Lab's open source water monitoring project

Ecosynth is also a related open source community that could be helpful

Dorn's picture

I would love to try the newest version.
What about embedding the google doc in the tool - even if it is read only. You could then add a download link with a permissions layer like tool post

I think that might encourage use and feedback but also enable monitoring etc...

Dorn's picture

My understanding is that the screen size is very important so that after the dehulling process both the hull and the grain are able to fall or push through the screen and then are carried by the air flow up and out of the housing to the cyclone separator. There are details about the vacuum setup in the engineering drawings and notes posted. I think it was 2000cf/min and a 2hp suction fan.

My understanding is that even with the large commercial systems the process is fairly manual for re-running unhulled grains - and requires some fine tuning and attention to varying crop conditions. larger capacity seed cleaners and number of screens both prior to and after hulling will help reduce the labor of the process to get a quality finished product and reduce loss. Like with most of this kind of processing sizing and sorting for consistency helps prior to processing. That is why I think the fanning mill is so important.

Dorn's picture

I will try and add more to the the wiki later - but your description is pretty accurate. The vanes in the rotor spin the seeds out where they hit the stator (stationary ring. The hull is knocked off by the impact. In some impact dehullers I have seen, the stator is a stone like material, but the one documented here used a steel ring.

The seed/grotes and hulls are blown/expelled by the air movement caused by the rotation of the fins on the side of the rotor. The cyclone separator is designed to have a vacuum on the top to separate/winnow out the hulls and have the heavier seed drop down for collection. Alternatively the mixture can be collected and run through a fanning mill (which I will be documenting later this spring). A fanning mill screens for over and under size and separates by weight.

To hull barley or spelt more velocity is needed and a higher rotational speed. Hammers/impellers are also added to the rotor and a correctly sized screen is substituted for the stationary ring such that the hulled grain can be expelled, but the unhulled grain is beat up further until it is able to exit through the screens. I do not yet have any drawings of this feature.

It will be great to have this design into autodesk inventor. I hope that the sketchup drawings are helpful as a start. It needs some cleanup but I can save it in another format like 3ds for importing if it would be useful. My hope is that we can post machine files here too if you use a torch table or water jet etc. for cutting any of the pieces.

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Looks like RTK is also mentioned to add precision (
but I think there are many potential applications with lesser precision requirements - like basic record keeping, and assuring a good spread pattern or when no-tilling or tedding, or tine weeding when it is hard to see where you have been previously(some times) and a little overlap is OK, and manual correction is still possible. The precision for total automation seeding is also different then holding a heading when a manual backup and correction is possible. A fairly rough system would still enable more attention to be dedicated to cultivator or transplant adjustment etc. Fun discussion to add to the electric allis G, farmbot, and the weeder platforms etc...

Dorn's picture

Definitely a feature that will be added, plus more - if you are interested in leaning more about the web development plans you can follow it and participate here - and you can join the google group here!forum/farm-hack-web-team

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I think there is some confusion with how to use the template - I edited the tool profile again with language that I hope helps. With luck the poster will try again by posting a new tool rather than editing the profile again. Any idea who is posting the Farm Bike?

Dorn's picture

Great! I will add this to the tool template wiki right now. One thing to add is that in the embed code if the
width="100%" rather than a fixed pixel width- then the spreadsheet fills the available horizontal space- which can make it easier to read too.

Dorn's picture

Here are some images of approaches we use on our farm - everything from the screw in "pencil" dryer fans to drying outside or hoop structure on tarp up to 10 tons. If you have the weather and the quantity isn't that large - it is a very fast and economic way to get grain dry, and is not much labor. We have also used a small bin with a screen bottom and fan (Image is of Cayuga pure organic's dryer). I agree that it would be good to post sources for the bottom screen and fans. I have also heard of using drainage tile inside grain wagons or bins (prior to dumping grain in) used with the pencil type dryers or other fans. I have not had to try that yet, but expect I will at some point.

Dorn's picture

Here are some more photos which may help explain how it works - I like the idea of an eccentric axel - but would be great to have it function without hydraulics. That is one of the nice things about this design is that it will function even if you don't have a tractor handy.

here is a video of a similar design in action

Dorn's picture

Yup - part of GreenStart's mission is to make its work open source - and we have a focus on documentation this year. I think a Farm Hack event would be a good idea - probably mid-summer. There are a number of tools coming along that would be fun to work on- including a new roller crimper inspired by the ADA bio folks that I am particularly excited about.

Dorn's picture

Funny you should ask about more documentation. There is a LOT more documentation coming for this tool really soon. I have detailed process flow diagrams, parts lists with major suppliers and will be doing a video with operational instructions which I hope to complete this summer. I also have performace data and will be able to post the arduino based temperature data logs up and running again in its new fancy enclosure. I will also be building a new modular processor which I will swap out for the existing static mixer/tank. This change should drastically reduce the price of the whole unit by eliminating the need for the co-generation unit for heating the oil and running the air compressor. The new unit will be a smaller diesel direct drive air compressor and hydraulic power unit to run the air operated pumps and two metered hydraulic drive pumps for a cavitator type processor which should work at ambient temperatures. Thanks for your interest and will post more as soon as I can!

It would be great to see this system built at different scales and variations.

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By contributing to the community you become an affiliate. Feel free to open an "open shop" for your organization to organize the tools and activities of your group on Farm Hack. Welcome to Farm Hack!

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Which tool are you asking about? I think your post got decoupled from the tool wiki

Dorn's picture

I will have to give FreeCAD a try. It may be a good option. I primarily use sketchup because it was accessible and free. I have become comfortable with it, models are easy to share, and I can export to CAD if I need to. Some of my buddies work in solidworks a lot too, but I have not tried that yet either.

I think that maybe a stand alone wiki tied to the getting started page & tool template might be a good way to start to document CAD training resources, techniques and tips etc? Other ideas?

Dorn's picture

Thank you for participating in the Food Systems Hackathon at the NOFA-VT Winter Conference! This email contains some important information about how you can stay involved after this past weekend's hackathon. A special thanks to all of our sponsors, producers and partners:

Photos from the opening workshop:

Photos of the various concepts generated during the workshop:

A document summarizing each concept:

The latest issue of Seven Days includes an article about the hackathon:
Hack-to-the-Landers? Farmers and Coders Cultivate Connections

Code for BTV

Code for BTV is an official Code for America Brigade that facilitates sustainable collaborations on civic software and open data projects between coders, designers and organizations (both governmental and non-governmental) in the greater Burlington, Vermont area. Code for BTV hosts events for civic hackers to come together and work on building and reusing civic apps and support open data initiatives.

Stay in touch:

Farm to Plate Tech Task Force

The Farm to Plate Tech Task Force strives to deliver increased business viability to the Vermont food system by connecting technology needs with solutions through education, events, programs, networking and referrals.

Join the Farm to Plate Tech Task Force:

  1. Create a profile on the Vermont Food Atlas:
  2. Once your membership is approved, join the Tech Task Force:

You can also contact Stan Ward <> if you would like to join the Farm to Plate Tech Task Force call scheduled for this Thursday, February 20 from 10am to 12pm.

Farm Hack

Farm Hack is an open source community for resilient agriculture. Farm Hack has set up a forum to continue the conversations from this past weekend's hackathon:

Farm Hack has also captured some notes and documents from this past weekend:

Some specific tools documented by Farm Hack from this past weekend:

Vermont Digital Economy Project

The Vermont Council on Rural Development's Digital Economy Project is looking for volunteers to assist in the building of WordPress websites for nonprofits and other organizations that provide essential services to their communities. Email Rob Fish <> to get involved. This past weekend, this team made progress on a new website for Seedfolks Farm in East Calais.

Dorn's picture

There are still free versions of sketchup - but they are harder to find on the site because they don't promote it.

Options are Sketchup Make or 8. Here is the link

Dorn's picture

Great idea - for reference I attached a screen shot of what I think we are both talking about.

Anyone out there want to tackle this, or come up with a way to accomplish this in another way?

Dorn's picture

For communicating and sharing design elements I have found sketchup really helpful.
We have had sketchup introductions as part of some of the events and I agree it would be good to emphasize how helpful it is to get drawings done of the project. It is nice that these can also be so easily embeded.

I started a 3d-warehouse library here with farm hack models and related components - but this could be greatly expanded and more clearly incorporated into the site too.

Dorn's picture

Funny you should mention this - I have been in touch with Alec Ellsworth who is organizing a student club already, and I think they will even have a budget. chriscallahanuvm ( is working with Alec to get this kicked off. I will suggest that they put some info onto the UVM open shop. It sounds like it is prime time for an event on UVM campus!

Dorn's picture

You bring up a great point that has been part of our design discussion from early on. I think that handling it well will be a crucial feature - as you mention there are ways to accomplish the relationships by manually linking to other tools and wikis, but it is tedious to set up. I imagine that in the shorter term we might be able to enable a menu to check and list related tool wiki's. One of the things I will be working on myself is developing groups of tools for "kits" both for various scales of grain production but also observatory "kits" for different types of environmental monitoring.

I think you might find the following document helpful - it came out of a hackathon last fall to develop a build out plan for the "open shop" concept. Part of that plan involves introducing the concept of a "problem statements" which would have relationships to tools and or wikis. That way we can relate groups of tools in a meaningful way to a single problem statement, or a single tool to relate to multiple problem statements. There is still a lot to work out as far as how to construct meaningful relationships between problem statements, but I think this is at the heart of figuring out collaborative open source development.

Dorn's picture

Thanks for the suggestion!- I will add it to the tool wiki template instructions.

Dorn's picture

Here is a sample wiki that shows how to embed an imgur images and albums inline with text

Here are instructions for embedding albums

Just follow these steps:

1. Go to

2. Upload photos from your computer.

3. Be sure to select "Group images into an album".

4. Start the upload.

5. When all the images have been uploaded, you will be redirected to the album page.

6. Click on "Embed Album" - you'll be given a code to cut and paste. It looks something like this:

The xxxx is your album ID.

That's it. Your uploaded images should now appear within the post as a gallery.

Dorn's picture

Thanks for posting. These are super helpful. Once they are posted we can also embed the models in our posts and use them for future tool postings.

The farmhack collection of other sketchup models is here

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Could you post your sketchup files to the 3d warehouse? I would be happy to add them to the Farm Hack collection already started.

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That would be great! Open office or Excel both work fine for me.

Dorn's picture

I agree that a common "trunk" for farm practice record keeping is needed - that can have "branches" for all the various type of analysis that a farm might want to do along the way. As you mention it doesn't make sense to enter the same data in several systems throughout the year.

Other spreadsheet products might be considered too - Open office and google docs spreadsheets for example. Google docs/drive has a mobile interface that would make editing in the field fairly easy. There are now lots of mobile spreadsheets and mobile excel, - the question I suppose is integration.

I think that integration of enterprise analysis tools with the field planning and records keeping will become inevitable at some level - and in the future may be facilitated by farm hack tools like to auto populate fields or or provide an up to date visual reference to spreadsheet data without even getting into georeferenced images and GIS etc.

Here is a list of the related tools listed so far on Farm Hack out of UVM is also coming along for nutrient management analysis. It has a mobile interface and may become open source as it evolves.

Dorn's picture

It might be interesting to start working on integration with some of the other enterprise tools listed on Farm Hack - a few I identified

GreenStart ( just had a recent meeting that recommended the expansion of the oilseed/biodiesel calculator to extend it to integrated small grain enterprises. I believe that this is something that we will be working on this year and would love to see integrated into
a feed ration calculator for milling/sprouting and mixing home grown grains for poultry, hog and bovine feed.

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Some more Photos from World Maker Faire 2013 - some taken with telescoping fibreglass pole from above since it was too gusty for kites and too windy for a balloon shot.

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Hi Joel

You can see the most recent web activity including forums, open shop and tool activity on the home page - just scroll down a bit to see the what is going on. The subscription function on tools and forum should alert you to new content by e-mail. Most of the recent activity has been in the tools section for example...