Serving Minnesota and Northern Iowa.
 Home > Midwest News 

Farmer designs rock picker

By Carol Stender

Date Modified: 05/13/2010 8:59 AM

E-mail article | Print version

SEBEKA, Minn. —Mel and Merf Aho and their 16 siblings were no strangers to rock picking on their Sebeka farm.

Many started the chore at age 5, picking rock and loading them onto a wagon. Rock picking ended when the crops grew tall.

"We'd talk about the day when a machine would be made that would eat up the rocks," Merf said.

As an adult, Mel has created a machine that he says does just that.

The RP1000 he designed with friend Perry Gilmour efficiently picks up rocks ranging from 2 to 15 inches. It has a 20-foot swath with two 10-foot rollers placed on a diagonal to funnel the rocks to the conveyor. Two tires at the conveyor's mouth help kick bigger rocks up the system.

The rocks then move into a drum that rotates and knocks off dirt and debris. From the drum, the rocks move by conveyor to a hopper wagon that, with its hydraulic system, can lift and dump the rocks into a truck. The process can take place anywhere in the field, Merf said.

Mel's design started out of necessity. He has, over the past two decades, purchased land in the township where he grew up. As he started to convert marginal land into viable farmland, Mel's biggest challenge was the soil condition and the numerous rocks it contained. He purchased several rock pickers, but struggled to find one that did the job more efficiently.

Perry understood his friend's dilemma. He grew up on a West Virginia farm and dealt with rocky soil. As they discussed the problem, they abandoned their search and build their own.

They wanted to build a self-propelled unit with a front-facing orientation. Mel and Perry searched for four-wheel drive combines.

As Perry drove around farms in Woodland, Wash., he spotted a New Idea power unit that had been used for picking sweet corn. It gave him an idea.

They purchased a New Idea 803C UNI power unit with a Cummins engine they located in Iowa. Perry got busy in his shop and fabricated the picker's frame. The internals of the machinery were built using common off-the-shelf parts. Once it was built, they took the machine to Minnesota. Merf liked what he saw.

After the brothers discussed the machine's potential, Mel told Merf to "have at it." Merf has since been using the RP1000 picking rocks on custom jobs.

The machine picks up roughly 60 percent to 70 percent of the rocks in the first pass, Merf said. Farmers can make as many passes as they want. While larger rocks need to be hauled using a skid loader, the RP1000 does a good job of picking up most of them.

Farmers like the hydraulic wagon feature that allows them to remain in the field for the duration of the rock picking.

Joining the group is Merf's brother-in-law Jerry Anderson. With his computer and marketing skills, he's developed a website for the machine and put a YouTube video of its operation on the Internet. Several manufacturers have contacted the group, Merf said.

The Ahos describe themselves as shy Finns. They don't have a flashy message advertising the RP1000. They merely describe the mechanics in a no-nonsense fashion. Anybody can see the machine, Merf said.

Merf doesn't recommend using the machine on corn stalks. While it can be done, the practice would take away residue from the field. It works best on field that have had small grains.

The RP1000 design is patented and, as they discuss mass manufacturing possibilities, Merf continues to custom rock pick.

For more information, check out their website at