One thing leads to another. Starting with Arduino , going on to accelerometers , and finally to balancing. Or at least thinking of using a cheap accelerometer and maybe a Arduino to do dynamic balancing. Probably will never actually do anything, but thinking about things is better than daytime TV..

Searching on the internet I ran across reference to a Yakimoff balancer which was said to be able to build one at home. But no actual information about it.

So does anyone know what a Yakimoff balancer is? Know of a reference to it..

Not a panic. Just an inquiring mind wants to know.

Dan

wrote in message
...
One thing leads to another. Starting with Arduino , going on to
accelerometers , and finally to balancing. Or at least thinking of
using a cheap accelerometer and maybe a Arduino to do dynamic
balancing. Probably will never actually do anything, but thinking
about things is better than daytime TV.

Searching on the internet I ran across reference to a Yakimoff
balancer which was said to be able to build one at home. But no
actual information about it.

So does anyone know what a Yakimoff balancer is? Know of a reference
to it.

Not a panic. Just an inquiring mind wants to know.

Dan

===

Some years ago one shock mount on my truck broke from rust, in a place
I couldn't easily see. I thought the wheel vibration was from a lost
weight and had it rebalanced, without success. Then I made a fixture
to do it myself more accurately.

The fixture is a disk that centers in the hub, tapped through the
center for a threaded rod with a conical recess in the end, which
rides on the upright balancing point.

As I was adjusting the balance point to the wheel's three dimensional
center of gravity to increase sensitivity I noticed that it could also
dynamically balance the wheel by rotating it. If I statically balanced
it with a weight on top on one side and an equal one on the bottom on
the other it would wobble when spun, as centrifugal force pulled both
weights toward the central plane of the center of gravity.

When the balance point and recess were set just barely above the
wheel's center of gravity it was sensitive to around 1/4 ounce, but
unfortunately not rugged enough and I had to remachine the point and
recess after each balancing session.

I can visualise or draw this more easily than put it into words. But
see how clearly Wiki explains dynamic unbalance:
https://en.wikipedia.org/wiki/Tire_balance

And now, back to the problem of delicately positioning a 1400 Lb log
on my sawmill to square it.

-jsw

On Saturday, August 29, 2015 at 7:01:13 PM UTC-4, Jim Wilkins wrote:

So does anyone know what a Yakimoff balancer is? Know of a reference
to it.

Not a panic. Just an inquiring mind wants to know.

Dan

===


The fixture is a disk that centers in the hub, tapped through the
center for a threaded rod with a conical recess in the end, which
rides on the upright balancing point.

As I was adjusting the balance point to the wheel's three dimensional
center of gravity to increase sensitivity I noticed that it could also
dynamically balance the wheel by rotating it. If I statically balanced
it with a weight on top on one side and an equal one on the bottom on
the other it would wobble when spun, as centrifugal force pulled both
weights toward the central plane of the center of gravity.

When the balance point and recess were set just barely above the
wheel's center of gravity it was sensitive to around 1/4 ounce, but
unfortunately not rugged enough and I had to remachine the point and
recess after each balancing session.


And now, back to the problem of delicately positioning a 1400 Lb log
on my sawmill to square it.

-jsw

Sounds like an approach that works.

I am in the first stage of collecting ideas. Always better to think a lot before actually making something. RIght now I am thinking of something more like the dynamic balancers used in tire shops. Maybe using an accelerometer and a microcontroler to process the vibration and maybe fire a led strobe to show where the weights should go and maybe calculate how much weight needs to be added.

The references to the Yakimoff balancer made it sound as if everyone knows what it is. Yet I can find nothing on the internet.

Dan

On Saturday, August 29, 2015 at 4:01:13 PM UTC-7, Jim Wilkins wrote:
wrote in message
...
One thing leads to another. Starting with Arduino , going on to
accelerometers , and finally to balancing. Or at least thinking of
using a cheap accelerometer and maybe a Arduino to do dynamic
balancing.

Some years ago ... I made a fixture
to do it myself more accurately.

The fixture is a disk that centers in the hub, tapped through the
center for a threaded rod with a conical recess in the end, which
rides on the upright balancing point.

When the balance point and recess were set just barely above the
wheel's center of gravity it was sensitive to around 1/4 ounce, but
unfortunately not rugged enough and I had to remachine the point and
recess after each balancing session.

If you'd used a live center for the cone, and a wider-than-60-degree
socket, it might last longer.

"whit3rd" wrote in message
...
On Saturday, August 29, 2015 at 4:01:13 PM UTC-7, Jim Wilkins wrote:
wrote in message
...
One thing leads to another. Starting with Arduino , going on to
accelerometers , and finally to balancing. Or at least thinking of
using a cheap accelerometer and maybe a Arduino to do dynamic
balancing.

Some years ago ... I made a fixture
to do it myself more accurately.

The fixture is a disk that centers in the hub, tapped through the
center for a threaded rod with a conical recess in the end, which
rides on the upright balancing point.

When the balance point and recess were set just barely above the
wheel's center of gravity it was sensitive to around 1/4 ounce, but
unfortunately not rugged enough and I had to remachine the point
and
recess after each balancing session.

If you'd used a live center for the cone, and a
wider-than-60-degree
socket, it might last longer.

I did, the point is pressed into a ball bearing and has a sharper
angle than the recess, to let the wheel tilt. The problem is that
steel I can machine with custom HSS bits barely supports the weight of
the truck wheel. It didn't actually break, just became less responsive
to small weights as the point and recess apex rounded off.

The balanced front wheel ran smoothly up to 70MPH without a working
shock absorber (and loose ball joints, now replaced), so I think the
principle is correct, however I don't have a way to implement it
without a lathe handy to make the hardware and keep it working.

http://www.bksv.com/doc/bo0276.pdf
The instrumentation they use is quite similar to a Vector Network
Analyzer, which should be easier to research on line than a tire
balancer. Phase info tells you where the heavy spot is, Delay
compensates for latency in reading your sensors. Modelling at least
the front end of one with an Arduino may be simpler than building a
tunable Tracking Filter, unless you are good with op-amp active
filters.

https://en.wikipedia.org/wiki/Networ...er_(electrical)
I built a custom 16 bit, 8 channel A/D converter for a Macintosh for
the data acquisition component of a 6-port microwave network analyzer
implemented in LabVIEW. I wrote only the Virtual Instrument that
controls the A/D and don't know how the rest of it was done, but those
plus the experimental front end MMIC sensor were enough for the job.

-jsw

On Sunday, August 30, 2015 at 5:45:14 AM UTC-7, Jim Wilkins wrote:
"whit3rd" wrote in message
...
On Saturday, August 29, 2015 at 4:01:13 PM UTC-7, Jim Wilkins wrote:
wrote in message
...
One thing leads to another. Starting with Arduino , going on to
accelerometers , and finally to balancing.
...Some years ago ... I made a fixture

If you'd used a live center for the cone, and a
wider-than-60-degree
socket, it might last longer.

I did, the point is pressed into a ball bearing and has a sharper
angle than the recess, to let the wheel tilt. The problem is that
steel I can machine with custom HSS bits barely supports the weight

So, what about a spherical bearing instead of a point pivot? With a little
care, and lubrication, it should last indefinitely.