Low Tech Inclinometer

A friend uses crutches and mows lawns to gain needed income. The manual for his Kubota zero radius turn mower advises to avoid tilting the mower to one side or the other more than 15 degrees. Beyond that, the wheels are prone to slip. I searched Instructables and there are several inclinometers, but all use microprocessors. My friend needs only something simple that always works and does not depend on batteries. I made an inclinometer for him from a curved piece of clear plastic tubing and a steel ball. See the photo. The two pointers mark 15 degrees to the left and to the right.

Materials

• 1/8" x 1/2" steel bar
• 1/8" steel rod
• Clear plastic tubing (I used 1/2" ID because it is larger than the steel ball I had and I had it leftover from some other project.)
• 1/4" steel bearing ball
• 1/2" wood dowel
• Hose clamp

Tools

• MIG welder (The welded parts could be made from wood if a welder is not an option.)
• Angle grinder and cutting wheel
• Large "C" clamp
• Round forms for bending different radii
• Vise-Grip pliers
• Vise
• Spring clamps
• Hacksaw
• Wood saw

I decided a 6" radius for the curve on the clear plastic tubing is as tight as I can go without creating a flat spot inside the tubing that hinders the movement of the steel ball. I clamped the bar to a lathe chuck 5" in diameter, knowing it would spring open to a slightly larger diameter. See the second photo. The curve sprang open to the diameter of this magnetic parts tray, which is 6".

I bent "U" shaped pieces from 1/8" rod. A piece of 1/2" concrete rebar was close enough to use as a bending form.

See the second photo. I welded the "U" shaped rod pieces to the curved 1/2" steel bar. The ends of the clear plastic tubing fit through the "U" shaped rod openings to hold the plastic tubing in place.

See the third photo. I tapered the ends of a 1/2" wood dowel to fit into the ends of the clear plastic tubing to retain the steel ball. Be sure to insert the steel ball. I gently tapped the dowels firmly in place with a hammer. Then I cut the dowels to remove what is not needed.

This inclinometer will hang from a handrail that assists the user in getting on and off of the mower. Remember that he uses crutches. (I did not check measurements carefully enough and the piece I made for hanging the inclinometer was too short. If you look closely at other photos you can see extensions I added by welding.)

I used a short piece of conduit as a dummy tube so I could align the curved steel that holds the clear plastic tube. Notice the distance between the ends of the conduit and the ends of the curved piece is equal on both ends. Then I tack welded the hanger in place and finished the welds.

Calibration is a little risky because I am doing it apart from the mower to which it will be mounted. I attached the inclinometer to a steel tube just a little bigger than the handrail to which it will be attached on the mower. The device I am using to calibrate the inclinometer is from another Instructable I did six years ago. I put some masking tape on the curved steel bar and used a pencil to mark where 0, 15 degrees left, and 15 degrees right are located. Then I used a cutting wheel on a Dremel tool to score the marks in the steel.

I welded short pieces of 1/8" rod as indicators for 15 degrees right and left. I did not weld an indicator at 0 degrees because it is unnecessary.

I used a hose clamp to mount the inclinometer to the handrail.