Low Tech Inclinometer

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About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first ...

Intro: 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

Step 1: Bend the Steel Bar

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".

Step 2: Bend Rod and Plug the Ends of the Tubing

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.

Step 3: Bend and Cut a Support for the Inclinometer

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.)

Step 4: Place and Weld the Hanger

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.

Step 5: Calibrate

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.

Step 6: Add Indicators

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.

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    25 Discussions

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    wilwrk4tls

    3 days ago on Introduction

    Very nice! I love the simplicity. Hope your friend got it mounted up.

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    Norm1958

    12 days ago

    Thank Goodness there are people out there building simple, useful, reliable things.

    Thank you for the idea and sharing..

    1 reply
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    Phil BNorm1958

    Reply 12 days ago

    Thank you for your comment. I understand very well what you are saying. In the past I have seen a number of center finders made with CAD programs and laser cutters. I posted some Instructables for slightly different (from each other) center finders based on using simple principles of high school geometry and basic tools, and they are quite accurate.

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    charlessenf-gm

    15 days ago

    Looking at the tool you made to Calibrate the device, I wondered if that would suffice in and of itself!

    Good idea and execution.

    I need one for my Kubota Tractor!

    5 replies
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    Phil Bcharlessenf-gm

    Reply 15 days ago

    Tapping on the orange words “another Instructsble” should take you there. If not, search Instructables for “precision angle finder.” I did not use a pendulum style device because the front of the mower pitches up and then down with the contours of the ground, and the pendulum would bind on the frame of the angle finder. The ball in a tube is not affected by the front of the mower pitching up and down.

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    charlessenf-gmPhil B

    Reply 15 days ago

    Good point. I do wonder about the advisability of determining the tipping point of the machine while sitting in/upon it. With my tractor, my ears tell me when Im approaching that point (or at least, I make that assumption and go to level ground promptly).

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    Phil Bcharlessenf-gm

    Reply 14 days ago

    I spent my early years on a farm in Iowa. We were very aware of all kinds of unsafe situations with tractors, and tried to be careful. Some caution and some wisdom are good preventative measures. A gauge should also be a good asset for those times when self-imposed pressure just to push forward and “do it” overtakes good sense. My friend wanted a handrail on the front of his mower so he can get on and off more easily and more safely. (He uses crutches.) He also feels the handrail I made for him would act as a forward roll bar to protect his legs if he did tip the mower over. Here is a photo of the railing I added to his specificstions, but the inclinometer is not yet made or installed. It hangs from the railing nearer to the left side as viewed in the photo.

    0DB80E60-6871-45DC-B4ED-F0538F7DFA43.jpeg
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    charlessenf-gmPhil B

    Reply 14 days ago

    Good points. I know I 'feel' the tilt and immediately back off without knowing at what point (degrees) I feel the tilt.' So an inclinometer might be something I could use to see if I've been 'over reacting' all these years! I wonder of you used a hard plastic tube (filled with sand to do the bend) . . . or knew a glass blower . . . Ignore the musings.

    It appears that the mower is equipped with Rollover Protection bars - as is my Kubota. The problem I worry about is it simply tipping over and catching me between the side and the cold hard ground.

    Regardless such musings good work on all counts, your friend has a friend indeed.

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    Phil Bcharlessenf-gm

    Reply 14 days ago

    Thank you. Personally, I was expecting that Kubota would say anything under about 30 degrees is safe, but was surprised when they recommend stayng under 15 degrees. They are also concerned about when wheels begin to slide, which could put you into a sharp list unexpectedly. I used rather soft plastic tubing. Something with firmer walls would have been good. I do not want to think about a spinning mower blade grinding away at me because a mower tipped over. One of the other commenters here mentioned learning to fly an airplane a bit more than 50 years ago. Pilots are drilled to rely on their instruments because intuition can be so very in error leading to vertigo.

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    GTO3x2

    15 days ago

    Just browsing - great little device. Simple, no batteries. lol. I can see how substitution could lead to using an air bubble.

    1 reply
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    Phil BGTO3x2

    Reply 14 days ago

    I thought about using a bubble of air (like a spirit level) in a clear tube, but with colored liquid. My first thought was oil with a color in it, like transmission fluid. Then I wondered what might happen if the chemical composition of the oil and that of the plastic tube were not compatible, or if the plugs I used at the end of the tube leaked. And, I wondered if the bubble wouod be as responsive to changes in the tilt of the machine as the single steel ball in a tube.

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    imW2

    15 days ago

    The item in step 5 is an inclinometer. There's a lot more markings on it, but it does the same thing.

    You could also hang a small chain. Old pinball machine I had as a kid used a bead chain and a ring for tilt. That's what I used for an LED in a GhostBusters backpack to make "sparks". Maybe I need to make a post about that, I can't find anything like it on the web

    1 reply
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    Phil BimW2

    Reply 14 days ago

    The angle indicator I made from a school protractor and needle indicator is an inclinometer. I decided against a pendulum style because the pendulum indicator would stick on the scale behind it whenever the mower nose is pointed downward in the least. A ball in a tube is not affected by rolling lawns that pitch the nose of the machine up and then down and up again.

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    caitlinsdad

    15 days ago

    That's great! Simple fix and works. Do you think it needs to be filled with oil or something to dampen the indicator like in a compass needle? Maybe a high contrast ball/liquid or background or mirror for parallax view correction...yup, now to overengineer it...

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    Phil Bcaitlinsdad

    Reply 15 days ago

    The owner had the opportunity to use this for the first time two days ago. I will ask him if the ball needs dampening when I next see him in a day or two. I have seen him on his mower and he moves forward at a modest speed that should not necessitate much dampening.

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    Phil Bbillbillt

    Reply 15 days ago

    Thank you for looking and commenting.

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    pjcrux

    15 days ago

    Well done. Are there any pictures from the friends mower and how it was mounted?