Hammermill Page

The Desert Harvesters hammermill is available for your community’s milling event: click here for more info.

What is a hammermill?
A hammermill is an industrial mill for making flour. Our community hammermill was purchased exclusively for making mesquite flour. The hammermill easily breaks up the mesquite pods and some of the hard seeds to produce quality flour. While not designed specifically for mesquite pods, it is the best tool we’ve found that will make mesquite flour in large quantities, while also saving a lot of time compared to labor-intensive hand grinding or blender methods.

Desert Harvesters hammermill at Tucson Meet Yourself 2008

How Our Hammermill Is Set Up and Operated
We use a Meadows Mills No. 5 hammermill mounted on a trailer for mobility. (NOTE: If you purchase a Meadows Mills hammermill, let them know we referred you to them, and they’ll make a donation to Desert Harvesters.) We chose a trailer with standard-sized automotive tires, since we found many tire repair facilities do not work on smaller trailer tires. In addition, the larger tires position the mill at a perfect operating height if the operator stands on the ground behind the trailer (the operator can stand up straight when feeding mesquite pods into the mill).

We now power our mill with a 13-horse power Honda GX390 gas-powered motor so we can set up anywhere. We originally mistakenly purchased a three-phase electric motor, but it was too hard to find power at most sites. A diesel motor was considered to utilize biodiesel or waste vegetable oil (recycled cooking grease), but a farmer advised us that the diesel exhaust fumes could’ve potentially contaminated the mesquite flour.

Our mill’s motor is a pull start (recoil starter) motor. This works well, but can be tiring for hammermill operators that continually start and restart the motor. Thus we think a better set up would be to install a motor with pull start and electric start. This is what the Tohono O’odham Community College uses with their #5 Meadows Mill Hammermill. Here are the specifications on their 13 horsepower Honda motor:

The ideal set up — a motor with pull start and electric start, as on the Tohono O'odham Community College hammermill.

Model GX390U1QNE2
- Overhead valve, commercial grade horizontal engine
- Electronic ignition with 10-amp charge coil
- Recoil starter
- Low oil alert
- Cast iron cylinder liner
- Ball bearing supported crank shaft
- Approximate engine weight, 90 pounds
- Shaft, 1″ x 3 31/64″

Note: once a year the rope snaps on our recoil starter. Here is a video that shows you how to replace and tension the rope.

The gas motor is mounted on an adjustable steel base bolted to the trailer. If we need to tighten the belts (from motor to mill) we can tighten an adjusting bolt on the motor’s base that pulls the motor further from the mill.

We use a heavy duty 1/64 inch screen within the mill which results in a finely ground flour.

Meadows mills provided us with ductwork, a funnel bag, and a filter bag. The ductwork directs the screened mesquite flour from the mill’s fan to the funnel bag, and then a large garbage can in which the flour collects. We clamp the funnel bag to the ductwork with a bungee cord so it can be quickly removed or replaced as needed. Flour dust (pastry flour) is collected in the filter bag.

When someone brings mesquite pods to be ground, we inspect the pods to make sure they are dry (snap in two when bent) so they won’t bind the mill from excessive moisture, clean (no rocks, dirt, or debris that could damage the screen or mill), and free of black mold. We schedule our millings in dry months after the high dew point of the summer monsoon rainy season has dropped, since dry mesquite pods will uptake some of the atmospheric moisture.

After inspecting the pods we run them through the mill. Once they’ve run through, we turn off the mill, empty the flour from the filter bag into a bucket, and we remove the chaff from atop the screen in the milling compartment. Chaff removal is the slowest part of the process because you must make sure the chaff does not slip by the screen into the lower compartment from which screened flour will be blown into the filter bag. Chaff must also be removed from around the mill’s blades. All this can be done by hand, but the fastest method is to use a wet/dry shop vacuum dedicated solely for chaff removal. The chaff collected by the vacuum can then be reused to make mesquite drinks, mesquite beer, or fed to livestock. If chaff is not regularly removed, the mill will over work the motor and the pods will not be properly ground. For every 5 gallons of whole pods run through the mill, the mill is shut off and the chaff removed.

Eye and ear protection is required gear for all those operating the equipment.

Community Millings in Tucson
Desert Harvesters hosts an annual milling day and mesquite pancake breakfast at the Dunbar/Spring Organic Community Garden in central Tucson, Arizona. Our community hammermill does the grinding. The gathering is held on a Saturday or Sunday in November. All milling events we participate in are scheduled from late September through November, so we’re out of the humid monsoon weather and the beans have a chance to dry well. Click here for our Calendar of Events. The only stipulation is that the milling be for home consumption (non-commercial) use only. Bring as many beans as you like.

An annual milling day is also held by David Omick and Pearl Mast in Cascabel, Arizona (just north of Benson) usually the second or third Saturday of November. Contact David and Pearl via email at david@omick.com, or U.S. mail at David Omick and Pearl Mast, 5780 North Cascabel Road, Benson AZ 85602. Phone (520) 212-4628.

THE DESERT HARVESTERS HAMMERMILL IS AVAILABLE FOR YOUR COMMUNITY’S MILLING EVENT

Our mesquite mill has been mounted on a trailer to make it mobile, so we can take it around to various neighborhoods or communities wanting to organize their own milling events.

To request a reservation of the hammermill for your milling event, contact our milling coordinator at chaff@DesertHarvesters.org with your first (and second choice) of dates.

What we provide:
The hammermill and two trained operators.

However, we also require the organization hosting the milling event to provide three trained volunteers to act as the third, fourth, and fifth staff persons. Such volunteers can be trained for free by attending our pre-season training and/or another preceding event where they gain experience operating the mill. That way more people learn to operate the mill for future events. Volunteers should show up at least 30 minutes before milling is scheduled to begin. Note: Desert Harvesters does not provide insurance coverage for any volunteer help. If such insurance is to be provided, it is the responsibility of the event-hosting organization.

We recommend you first attend one of our events to see how we organize millings and to give you ideas for your own. It’s up to you if you provide food or not, though we find food, such as mesquite pancakes, is one of the best ways to bring people together and to introduce them to the delicious potential of mesquite flour.

THE TERMS:
• Rental of the hammermill is $125 per day for non-profit groups or $175 for commercial purposes. Advance payment of the hammermill rental fee is required to reserve a date.
• $15 per hour must be paid to Desert Harvesters for each of our staff persons transporting; setting up, breaking down, and cleaning the mill on site; operating the mill; plus one hour each of set up and break down at the location of the mill’s storage.
• $0.485 per mile to cover transport from mill storage near downtown Tucson to and from the milling site.
• Hosting organization must also provide three trained and competent volunteers (see above) to assist Desert Harvesters staff, electricity to the mill site via extension cord to power a shop vac, a spot with sufficient natural shade or a moveable shade structure that can go over the mill trailer and keep the millers out of the desert sun, and a minimum of two 6-foot tables (clean surfaces or covered with clean tablecloths) to be used as pod-sorting stations. If the required number of trained volunteers is not confirmed in advance, Desert Harvesters will require hosts to pay for up to three additional staff at $15 per hour per person. If sufficient shade is not provided, Desert Harvesters reserves the right to bill an additional $100 per day to compensate our staff for the work conditions. 

To request a reservation of the hammermill for your milling event, contact our milling coordinator at chaff@DesertHarvesters.org with your first (and second) choice of dates.

OTHER HAMMERMILLS/MESQUITE MILLING ORGANIZATIONS IN ARIZONA

Mesquite millings and those with hammermills grinding mesquite pods is growing! See below:

• Cascabel Hermitage Association Education Program, Cascabel, Arizona.
Organizers of the first community mesquite milling, and the annual mesquite milling and mesquite pancake and waffle breakfast in Cascabel, Arizona. Hammermill obtained in 1998.
Contact: David Omick and Pearl Mast, david@omick.net. Website: www.omick.net.

• Baja Arizona Sustainable Agriculture (BASA), Bisbee, Arizona.
Hammermill obtained in 2010.
www.bajaaz.org

• Tohono O’odham Community College, Sells, Arizona.
Hammermill obtained in 2008.
Contact: Clifford Pablo, cfpablo@tocc.cc.az.us

• Prescott College, Prescott/Chino Valley, Arizona.
Hammermill obtained in 2008.
Contact: Tim Crews, tcrews@prescott.edu, or 928-350-2215.

• Kyle Young and Peter Ragan, Arivaca, Arizona.
Organizes an annual mesquite milling and mesquite pancake breakfast in Arivaca, Arizona.
Contact: Kyle Young, Web: http://web.mac.com/camelboo/iWeb/Natural_Building/Welcome.html

DESERT HARVESTERS HAMMERMILL OPERATION MANUAL
Click here for Hammermill Operation Manual