Problem with Tilt Meter

[Slamfire]

You would probably find the bubble broken up into one fairly large with some little ones on the ends. Thats caused by vibration, it happens to carpenters quite often, and they just smack it with their hand to break the surface tension that makes the little bubbles. If I'd been inventing this meter I'd most likely went with a damped weighted rod, like the one used for the fore and aft indicator on the two axis model. Maybe it wouldn't work, but that's what I'd have tried first.

 

[Henro]

<font color="blue"> I have done EXTENSIVE research, and found
that static IS the problem when one sticks.
</font>

Rick,

This problem is very interesting. Could I ask that you share with us how you determined that static was indeed the problem?

I mean, as compared to a possible magnetic problem if the tiltmeter in question used a steel ball.

After a couple decades in maintenance in the steel industry, I know how difficult some problems are to solve and also know that what appears to be the problem is, in the end, not the root cause all the time.

But now I am retired...and those days are just memories... /forums/images/graemlins/grin.gif

All the best in your quest for a solution!

 

[RBManufacturing]

Hi Guys,
Using an air bubble instead of ball has a few inherent
problems. First, the bubble has to be fairly large, (thus not
very accurate) because the liquid expands. A small bubble
lets to much pressure build up, and the tube pops. My very
first meters were pendulum type. Either the pendulum
swings too freely, or not free enough. Temp., dust, moisture,
all effected its movement. I looked at the problem being
magnetic field, but do not think it is culprit. First, the ball is
stainless steel. Non magnetic. Second, when one sticks, it
stays stuck when tractor is turned off. Holding static charge???
Could hold a magnetic charge also I suppose. And, the ball
works again when hit with water, and discharges. We also
used a glass ball and it still stuck. Don't believe glass would
hold a magnetic charge. I'm not a rocket scientist, but this
small RARE problem has been a real challenge. What works
to fix one has not always fixed another. As I said, it is rare,
but we are going to keep trying until it never happens at all.
Thanks, Rick

 

[buck1]

I believe it's a combination of static electricity and resonant frequencies. I've been looking at times when my tiltmeter has stuck and it always seems to be when my tractor is operating at 2600 RPM. If I see it stick, I just lower the RPM's and in a few seconds it frees back up. If I have the bushhog on (hence PTO engaged) and operate at 2600 RPM, it sticks fairly often. If I'm running up and down the road at 2600 and no PTO, it never sticks. Every tractor will vibrate through a huge frequency range that changes depending on implements and engine "rev's". When that frequency matches the resonant frequency of the tiltmeter, it will seize up. I wonder what would happen if you mounted one of these things on a fairly tight spring system rather than the plate it's currently made on????

 

[Mike_Dumond]

OK, here's one from deep left field. What if the back side of the tube was coated with a metalic, reflective material and then grounded to the vehicle? It might fix the static problem and allow for a mirrored effect possibly improving visability of the ball.

Incidently, the dual axis indicator is fantastic. A little free swining on the fore/aft, but otherwise, truly outstanding. I wonder if fluid damping would be an option here?

 

[diggerdave]

glad to hear that about the DA model(dual axis). I ordered one from Rick last friday and reading a few more posts.
I like the idea of knowing the incline before getting sideways on the slope.

interesting and useful thread.
thanks,
dave

 

[CTyler]

I'm curious if you have tried a dampning material to isolate the vibration causing the static build up. Something like Sorbothane as an example. This works very well in audio applications, keeps my CD player from skipping when the sub-puppy is thumpin anyway.

 

[RBManufacturing]

HI CTYLER,
I TRIED A 1/4 IN. THICK FOAM RUBBER ONE TIME. SINCE
THE BOLTS STILL MADE A SOLID CONNECTION, IT DID NOT
HELP. IF I USE THE FOAM WITHOUT THE BOLTS, AND GLUE
THE INDICATOR TO THE FOAM, AND THE FOAM TO THE
BRACKET, IT MIGHT WORK. I AM SURE WE WILL GET THIS
THING DONE SOONER OR LATER. I AM WORKING ON A NEW
FIX IDEA NOW. I SENT OUT TWO MORE INDICATORS TO
CPRUNTY YESTERDAY. BOTH HAVE NEW OILS. I HAVE AN
ELECTRONICS ENGINEER WORKING ON IT ALSO. HE HAS
ONLY BEEN ABLE TO GET ONE TO STICK. IT TOOK HOURS
OF EXPERIMENTING TO GET JUST THE RIGHT VIBRATION.
I CALLED 23 OF MY TRACTOR CUSTOMERS FROM LAST
YEAR THE LAST TWO DAYS. NONE HAVE HAD A PROBLEM
WITH STICKING. I'LL GET IT SOON. THANKS, RICK

 

[CTyler]

Whats nice about the Sorbothane is that it has actuall dampning properties. It has both solid and viscous dampning properties. I'm sure there are others out there, this is just the one I'm familiar with. If it was located between the mount and the meter it would not matter if the bolts were connected to the tractor.

Good luck and update us on your fix.

 

[BigEddy]

Rick - you might want to change the resonation properties of the subject tilt-meters. A couple of ways to do that. Simplest - Add some weight to the meter - just stick it on for now to test it out - I'd add a couple of wheel weights for starters - this will change the frequency of the resonation.

Resonation is an interesting problem - but not difficult to overcome. By changing the weight of the device, you change the frequency at which it resonates. If that doesn't fix it, try adding a brace to the top of the unit such that you have a 3 point mount rather than a cantilever mount. Now it won't vibrate anywhere near the same amount for the same base vibration.

If resonation / vibration is the root of the problem, try these approaches to eliminate the vibration then see if it was in fact the cause.