An instrument you can build for under $5
I JUST STARTED TO GET SERIOUS about my Sonex’s instrument
panel. My goal is to keep it simple (aka cheap). Since I haven’t
been in the market for instruments in a while, I was absolutely
taken aback by how expensive slip-skid indicators are. I found
prices anywhere from $40 to $90! There had to be a better—
cheaper—way, so off I went to the EAA Sport Aviation online
archives. Bingo! Val Bernhardt, EAA 59376, had shared plans
for a homebuilt inclinometer back in January 1982. Here is a
full-size template to make an inclinometer for well under $5.
Plus you’ll have the satisfaction of building it yourself.
The hardest part of building this instrument was finding
the raw materials. I found my supplies at a True Value
hardware store after striking out at the local big-box store.
Try your local bike shop for the ball bearing. You can scale the
template down a bit if you don’t want to burn that much space
on your panel. I copied the template on a photocopier at 80
percent. I modified mine by using a tubular rivet (3/16 inch by
1/4 inch) as a plug and used a smaller vinyl tube with a 1/4-inch
outside diameter and 0.170-inch inside diameter. I liked the
tubular rivet because it hides some of the trapped air within the
mineral spirits we used as the liquid medium.
Charlie Becker, EAA 515808, is EAA’s Director of Member Services Programs.
1/8” O.D. ball bearing
rubber “O” rings
Bend up 90º at
1/8” mounting hole
.032 inch aluminum
Full Size Template
rivet .250 diameter
1 1/8” O.D.
1 3/16” I.D.
heavy wall plastic tube
1 .032 inch
2 .250 diameter rivet
2 black rubber