Dynamic Prop Balancer

Can anyone tell me how a dynamic prop balancer works? I have heard that it
involves an accelerometer to detect vibration, but it what do they use to detect
the prop position to correlate with that accelerometer? Could it be an optical
pickup from a mark placed on the prop? Or perhaps a pickup from the magneto?
Although a mag pickup would be ambiguous by 180 degrees, I think. I was just
brainstorming on how I might design one from scratch.

Robert Scott
Ypsilanti, Michigan

On Mar 4, 7:28 am, ---@--- (Robert Scott) wrote:
Can anyone tell me how a dynamic prop balancer works? I have heard that it
involves an accelerometer to detect vibration, but it what do they use to detect
the prop position to correlate with that accelerometer? Could it be an optical
pickup from a mark placed on the prop? Or perhaps a pickup from the magneto?
Although a mag pickup would be ambiguous by 180 degrees, I think. I was just
brainstorming on how I might design one from scratch.

Robert Scott
Ypsilanti, Michigan

I believe an optical pickup is placed on the cowl with a reflector on
one of the prop blades.

On Mar 4, 5:28 am, ---@--- (Robert Scott) wrote:
Can anyone tell me how a dynamic prop balancer works? I have heard that it
involves an accelerometer to detect vibration, but it what do they use to detect
the prop position to correlate with that accelerometer? Could it be an optical
pickup from a mark placed on the prop? Or perhaps a pickup from the magneto?
Although a mag pickup would be ambiguous by 180 degrees, I think. I was just
brainstorming on how I might design one from scratch.

Robert Scott
Ypsilanti, Michigan

On the Acers unit I use to balance my prop the accelerometer is bolted
to the centerline of the engine in the proper direction. That sensor
is position sensitive. The light sender is taped on the top of the
cowling facing forward shining on the prop. it is about 13" away from
the reflective tape thats applied to the prop. The handheld unit is
routed into the cockpit using long cables from both sensors. The thing
works amazingly good. My last balance procedure got the prop/ spinner
to within .001 IPS. The smoothness is well worth the hour or so of
setup and running...

Ben
www.haaspowerair.com

I've got one in the back of my head that I want to use for a future
Kitplanes article. I'm going to use an old phonograph cartridge with a
short "ball on the end of a needle" as my accelerometer and I was seriously
thinking of an inductive pickup on the #1 plug wire. The optical gig was
also a consideration, but I got to thinking how that would work out in the
sunlight.

Jim


"Robert Scott" ---@--- wrote in message
...
Can anyone tell me how a dynamic prop balancer works? I have heard that
it
involves an accelerometer to detect vibration, but it what do they use to
detect
the prop position to correlate with that accelerometer? Could it be an
optical
pickup from a mark placed on the prop? Or perhaps a pickup from the
magneto?
Although a mag pickup would be ambiguous by 180 degrees, I think. I was
just
brainstorming on how I might design one from scratch.

Robert Scott
Ypsilanti, Michigan

Robert Scott wrote:
Can anyone tell me how a dynamic prop balancer works? I have heard that it
involves an accelerometer to detect vibration, but it what do they use to detect
the prop position to correlate with that accelerometer? Could it be an optical
pickup from a mark placed on the prop? Or perhaps a pickup from the magneto?
Although a mag pickup would be ambiguous by 180 degrees, I think. I was just
brainstorming on how I might design one from scratch.

Robert Scott
Ypsilanti, Michigan


No idea, but can anyone recommend a shop that will balance my single
engine grumman - one close to KISP - Long Island NY? I have no problems
travelling to CT or RI or MA or VT for this - might make a day trip out
of it.

thanks

On Sun, 04 Mar 2007 13:55:54 -0500, Tim
wrote:

No idea, but can anyone recommend a shop that will balance my single
engine grumman - one close to KISP - Long Island NY? I have no problems
travelling to CT or RI or MA or VT for this - might make a day trip out
of it.

Keyson at Nashua, NH.

Peter Clark wrote:
On Sun, 04 Mar 2007 13:55:54 -0500, Tim
wrote:


No idea, but can anyone recommend a shop that will balance my single
engine grumman - one close to KISP - Long Island NY? I have no problems
travelling to CT or RI or MA or VT for this - might make a day trip out
of it.


Keyson at Nashua, NH.

ok, thanks. that's a hike, but it would be a fun trip. I might wait
until it warms up a bit.

On Sun, 04 Mar 2007 19:38:28 -0500, Tim
wrote:

Peter Clark wrote:
On Sun, 04 Mar 2007 13:55:54 -0500, Tim
wrote:


No idea, but can anyone recommend a shop that will balance my single
engine grumman - one close to KISP - Long Island NY? I have no problems
travelling to CT or RI or MA or VT for this - might make a day trip out
of it.


Keyson at Nashua, NH.

ok, thanks. that's a hike, but it would be a fun trip. I might wait
until it warms up a bit.

Yea, and they like to see winds of ~10 or less for best results. The
restaurant is closed on (Wednesday?). Call ahead and ask for Byron to
confirm they'll do the model (I doubt you'll have a problem with
practically any single/multi engine piston though). I've done the
stay-and-wait thing, it generally runs them around +- 3 hours from
sign in to release.

On Mar 4, 6:06 pm, Peter Clark
wrote:
On Sun, 04 Mar 2007 19:38:28 -0500, Tim
wrote:

Peter Clark wrote:
On Sun, 04 Mar 2007 13:55:54 -0500, Tim
wrote:

No idea, but can anyone recommend a shop that will balance my single
engine grumman - one close to KISP - Long Island NY? I have no problems
travelling to CT or RI or MA or VT for this - might make a day trip out
of it.

Keyson at Nashua, NH.

ok, thanks. that's a hike, but it would be a fun trip. I might wait
until it warms up a bit.

Yea, and they like to see winds of ~10 or less for best results. The
restaurant is closed on (Wednesday?). Call ahead and ask for Byron to
confirm they'll do the model (I doubt you'll have a problem with
practically any single/multi engine piston though). I've done the
stay-and-wait thing, it generally runs them around +- 3 hours from
sign in to release.

The only way to get perfect results is for the wind to be calm. A 10
MPH breeze give you false readings, At least it does on the Acers
unit.. YMMV...

Ben
www.haaspowerair.com

On 5 Mar 2007 06:41:42 -0800, " wrote:
The only way to get perfect results is for the wind to be calm. A 10
MPH breeze give you false readings, At least it does on the Acers
unit.. YMMV...

Are you saying that a 10 MPH breeze causes a perfectly balanced prop to vibrate
noticeably?


Robert Scott
Ypsilanti, Michigan