2016 – Various – GE Ergo-Mill – Team 12


Project Overview

Early during the Fall 2015 semester, General Electric of Bangor, Maine came to us with an issue that was offered to the University of Maine Mechanical Engineering Technology Dept. to solve. GE has requested a devise that would hold a hand held grinding tool to reduce the strain on its welders. The part that is being machined is referred to as a steam diaphragm, which houses static air foils that direct steam as it enters the turbine. These foils in the diaphragm become worn and pitted over time. When this happens, they are sent back to GE to be repaired, and here is where our product comes into the picture. To remove the damaged blades, a hand mill is used to grind away the damaged material. Being hand operated, a heavy amount of strain is put on the welders. The Ergo-Mill will dampen the shock from the tool and keep the welder at an upright, ergo friendly position, while being simple and easy to operate.

Criteria/ Constraints

The parts that are being repaired are quite unique with respect to one another. This apparatus must be able to adapt to different dimensions and features on each diaphragm. Angles on the inner and outer diameter of each foil must be adapted to. Inner and outer diameters of the diaphragm arch are specific to each as well. The final product will be modular with no section weighing in excess of 25 pounds. Other constraints such as reach and safety precautions must be accounted for in the design of this product as well.


After two meetings with GE on refining our concept designs, we have gone from five designs to one and are now refining the single, most favored design. This latest concept will be supporting two separate attachments that will hold the hand mill. These two attachments together will cater to any single diaphragm that GE needs to repair.

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Figure 1. Ergo-Mill concept to what will be the final design of the Ergo-Mill MkI.

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Figure 2. Outer diameter mount where controls for radial and linear travel.

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Figures 3 and 4 are the two main tool holders that will attach to the carriage.

Figure 5 Depicts the latest Ergo-Mill MkI.

Figures 6, 7, and 8 show the center, carriage and the outer diameter mount.

Weekly Update

In this past week, the group has completed several part in the University’s Machine Tool Lab. All members have been devoted hours to manufactures parts such as the base plate, different covers, and housings.

The AMC will now be manufacturing only the most difficult of parts, being the tool carriage and the tool lock, which is integrated with the carriage.

General Electric is printing off the final batch of parts on their commercial printers.

Portions of the Ergo Mill have been assembled and more can be accomplished this week as we have received more bearings and minor components required for assembly.

Figure 11 and 12, are the inner shaft housing and outer diameter mount. These parts hols the shafts in place and maintain alignment as well as the structures integrity. They are made of Altim, a high strength printable material that enables us to save weight but retain strength and durability.


Figure 13 is the Bull gear. This stationary part is fastened to the underside of the base plate. A worm gear meshes with this and as it is spun, this gear will rotate the mill at a much lower speed and with ease.

Future Work

This week, we plan on completing the remaining machined parts and assembling next week.

Testing will consist of an extensive reach study, in addition to a load analysis. The work that will be done by this machine will create great chatter, vibration, and loading. It is very important that tests assure the reliability of the final product.

Meet the Team


Jacob Hallgren

jake bio pic

Jacob is a Senior in Mechanical Engineering Technology at the University of Maine. He is the webmaster for this team. He enjoys studying thermodynamics, power transmission, and renewable energy. He is also a member in the Maine Army National Guard. He will be commissioning as a 2nd Lieutenant in May of 2016 into B Co- 3/172 IN (MTN) where he currently serves as a simultaneous membership program cadet whilst in Army ROTC at the University.

Caleb Farley
south twin bassCaleb is a senior in the University of Maine’s Mechanical Engineering Technology program. He has worked for Somic America as a Suspension Line machine operator, and manufactured parts for the Toyota Camry, Rav4, and Venza. He hopes to work for Somic America as a Suspension line engineer after graduation from the University of Maine. In his free time he enjoys hunting, fishing and following his favorite Boston sports teams.

Sean Teixeira

Sean is a fourth year student at the University of Maine Orono pursuing his B.S. degree in Mechanical Engineering Technology. For the past year and a half he has worked for Global CNG at a natural gas compression station operating the site and preforming billing and dispatching duties. He graduated from Morse high school in 2012 in Bath, ME. He immediately begin attending the University of Maine after high school and is graduating in December of 2016.

Richard Lafreniere

Richard is a 4th year Mechanical Engineering Technology­ student at the University of Maine in Orono. For two years he has worked in the Machine Tool Lab as a Tool Crib Attendant and has experience as a Teaching Assistant in the shop. He was raised in Oakland, Maine and graduated from Messalonskee High School in 2009. In 2012 Richard enrolled in the MET program at the University and is expecting to graduate December 2016. His hobbies include working on vehicles, snowboarding, snowmobiling and projects around the house.

Connor Jensen



Connor is a senior in the University of Maine’s Mechanical Engineering Technology program. He has worked for JR Higgins Associates as a CNC operator and School Bus sign assembler. He achieved the rank of Eagle Scout and graduated from Westford Academy in the spring of 2011. In the winter he enjoys working at Nashoba Valley Ski Area as a ski patroller.