Work on Exo Arm Base Moves Forward

Work on Exo Arm Base Moves Forward

Date: 4.27.17
Location: Logan HS
Time: 3.5 hours
Goal: Fabricate a base that will support the linear rail assembly.


Work on the base has moved at a rapid pace. Based on the wooden prototype base we extracted measurements to help us determine the angles and lengths we needed to attain stability. The 3 x 3 aluminum tube stock provided a nice welding and bolting surface for Mr. Pitz and his students to build off of.

A aluminum plate platform has been bolted on to mount the linear actuator and electronics. We are concerned about the stability of the arm when moving right or left. We feel we may need to strengthen the back support or increase the base support under the platform to help stabilization. The front to back motion is well supported by a diagonal brace that was installed.

We may need to replace one of our linear bearings that mounts on the rail system. We noticed some wear and tear on it. The bearing is designed for a different type of load. We are using it in a vertical application which puts more stress on the bearing. This is not a manufacturer defect, but a result of the application we are using it in. Calls have been made to our supplier to see if a metal bearing is available instead of a plastic one.

Plate and arm being bolted to the base.

View from the back which shows the angle support and weight holder.

I know this does not look good, but the 2 x 4 just hold the arm in place until we install the linear actuator.
The arm is contracted back toward center mass and secured with velcro.

Another view of base assembly.

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Taren welding the base

Taren welding the base.

Picture of linear bearing that has experience some wear and tear toward the opening. Again, we do not feel this is a manufacture defect, but a result of the application we are using it in.