Howdy,
I'm currently working on a project to build an machine that uses
Impact Sensors (Tekscan, Interlink, any other inexpensive suggestions?)

to register the user's force of impact and convert the incoming analog
data into an electronic format for storage and data calculations. The
system will be able to run a number of pre-programmed routines that
control multiple analog outputs (LEDs, Sound Components, Etc) and
output statistical reports of a user's use during their session.

The force sensors would be mounted on a 8" diameter vertical tube
with a elastomer padding covering the sensor(s) for impact absorption
and protection. The system would need to register the force applied
directly by a user and activate an analog device to notify the user
they have reached or exceeded certain limits set by the system.

I'm looking for a small company or an individual in the Northern
LA area that is interested in helping build a prototype of this
machine.

The person needs to be willing to work one-on-one with me through
the prototyping stage. Please don't reply to this message with, "Well
I can build it for you for X thousands of dollars" because frankly, I
don't have that kind of money to spend on this. I can afford to spend
some money on the cost of development, but that would have to be worked

out on a personal basis with someone interested in the project, not
just the money.

If this sounds like a project you're interested in, please feel free to

reply to this post. I will be relocating from NY to LA the first half
of February and I would really like to get this project underway.

Thanks a ton,

- Jace

From your description you don't measure impact, which is a very

synapsedm@gmail.com wrote:
Howdy,
I'm currently working on a project to build an machine that uses
Impact Sensors (Tekscan, Interlink, any other inexpensive suggestions?)

to register the user's force of impact and convert the incoming analog
data into an electronic format for storage and data calculations. The
system will be able to run a number of pre-programmed routines that
control multiple analog outputs (LEDs, Sound Components, Etc) and
output statistical reports of a user's use during their session.

The force sensors would be mounted on a 8" diameter vertical tube
with a elastomer padding covering the sensor(s) for impact absorption
and protection. The system would need to register the force applied
directly by a user and activate an analog device to notify the user
they have reached or exceeded certain limits set by the system.

I'm looking for a small company or an individual in the Northern
LA area that is interested in helping build a prototype of this
machine.

The person needs to be willing to work one-on-one with me through
the prototyping stage. Please don't reply to this message with, "Well
I can build it for you for X thousands of dollars" because frankly, I
don't have that kind of money to spend on this. I can afford to spend
some money on the cost of development, but that would have to be worked

out on a personal basis with someone interested in the project, not
just the money.

If this sounds like a project you're interested in, please feel free to

reply to this post. I will be relocating from NY to LA the first half
of February and I would really like to get this project underway.

Thanks a ton,

- Jace

From your description you don't measure impact, which is a very
demanding measurement in terms of amplification equipment and the
accuracy required in calibration. You measure force applied, on static
known mass, completely different animal. For this an accellerometer with
peak recording instrumentation will do the job.
Just a notion (from lifetime in test department of aerospace industry).
And NO, am happily retired.

Have fun

Stanislaw

I'm throwing around the idea of creating two systems, one that only has
generic contact sensors and one that uses the variable resistance force
sensors.

- Jace

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one that only has
generic contact sensors and one that uses the variable resistance force
sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without degradation
and is longer than the strain gauge dimention, the attaching glue
transfers this in true form so NO shock absorbing action takes place.
Otherwise your readings recorded and reality have nothing in common.

If you insist on 'impact' as your measure stick better find someone
experienced in this kind of measurements. And such maybe rare like
chicken teeth.

Good luck

Stanislaw

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one that only has
generic contact sensors and one that uses the variable resistance force
sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without degradation
and is longer than the strain gauge dimention, the attaching glue
transfers this in true form so NO shock absorbing action takes place.
Otherwise your readings recorded and reality have nothing in common.

If you insist on 'impact' as your measure stick better find someone
experienced in this kind of measurements. And such maybe rare like
chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't know if it
would work for my application only because according to the description
on Wikipedia, "as the object is deformed, the foil is deformed, causing
it's electrical resistance to change", and the object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless we're
counting micro-deformations, the "object" shouldn't deform. But I
understand the principle, it's the same as the piezoresistive force
sensors just instead of using a chemical pressure sensitive ink, the
strain gauges cause variable resistance based on the shape.

I know this goes against most all electrical engineering ideals, but
this system doesn't have to be super accurate. Even rounding to the
nearest pound or point of a pound of force would be sufficient. Hence
why I said I'm considering not using force sensors at all for one
model. I've contacted Tekscan and described what I needed thoroughly
with them and they said that their product is 100% suited for my
application. The only problem is that I can't afford, personally or as
a per-unit cost, to have a custom run of 10,000 sensors made to my size
requirements and their standard "off the shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by 24" wide. They
have some leftover sensors from the company that makes those force
sensing brake pedals so that trailer brakes can be applied in addition
to the truck brakes, but they don't make a habit of selling other
people's leftover custom sensor designs, and those are only 3"x5"
anyway.

Basically it comes down to cost versus accuracy. I need to keep the
per-unit cost of my system down under the $1k range to make it
affordable for my prospective clients but I want to give them the best
experience for their buck. For what I'm doing, there are other
products on the market, but in my opinion, they don't fulfill the needs
of their (our) target market.

And just as additional info to take into consideration for the cost
projection, I need either 15 6"x24" sensors or 45 6"x8" sensors to
complete each unit. Using Tekscan's estimate of about $25 per sensor
(for the 3"x5" of which I would need about 90) I would be spending over
$2k just on sensors, not including the equipment to process, record and
control them or the cost to actually have them built.

So if you, or anyone else, has any recommendations for some way I can
inexpensively measure the force of a hit, either some kind of rig to
use 2 or 3 small piezoresistive sensors that can accept accurate
readings from a 6"x24" curved contact area, I would appreciate any
ideas.

synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one that
only has generic contact sensors and one that uses the variable
resistance force sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention, the
attaching glue transfers this in true form so NO shock absorbing
action takes place. Otherwise your readings recorded and reality
have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such maybe
rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't know
if it would work for my application only because according to the
description on Wikipedia, "as the object is deformed, the foil is
deformed, causing it's electrical resistance to change", and the
object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless we're
counting micro-deformations, the "object" shouldn't deform. But I
understand the principle, it's the same as the piezoresistive force
sensors just instead of using a chemical pressure sensitive ink,
the strain gauges cause variable resistance based on the shape.

I know this goes against most all electrical engineering ideals,
but
this system doesn't have to be super accurate. Even rounding to
the
nearest pound or point of a pound of force would be sufficient.
Hence why I said I'm considering not using force sensors at all for
one
model. I've contacted Tekscan and described what I needed
thoroughly with them and they said that their product is 100%
suited for my
application. The only problem is that I can't afford, personally
or as a per-unit cost, to have a custom run of 10,000 sensors made
to my size requirements and their standard "off the shelf" sensors
are the size of
a penny and I need a contact area of roughly 6" tall by 24" wide.
They have some leftover sensors from the company that makes those
force sensing brake pedals so that trailer brakes can be applied in
addition to the truck brakes, but they don't make a habit of
selling other people's leftover custom sensor designs, and those
are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to keep
the per-unit cost of my system down under the $1k range to make it
affordable for my prospective clients but I want to give them the
best
experience for their buck. For what I'm doing, there are other
products on the market, but in my opinion, they don't fulfill the
needs of their (our) target market.

And just as additional info to take into consideration for the cost
projection, I need either 15 6"x24" sensors or 45 6"x8" sensors to
complete each unit. Using Tekscan's estimate of about $25 per
sensor (for the 3"x5" of which I would need about 90) I would be
spending over $2k just on sensors, not including the equipment to
process, record and control them or the cost to actually have them
built.

So if you, or anyone else, has any recommendations for some way I
can inexpensively measure the force of a hit, either some kind of
rig to use 2 or 3 small piezoresistive sensors that can accept
accurate readings from a 6"x24" curved contact area, I would
appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber created
that could wrap around the steel tube and put an air pressure sensor
on
it. So when it's impacted, the force of the air could be measured
and it wouldn't require expensive piezoresistive sensors?

Just a thought.

- Jace

synapsedm@gmail.com wrote:


synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one that
only has generic contact sensors and one that uses the variable
resistance force sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention, the
attaching glue transfers this in true form so NO shock absorbing
action takes place. Otherwise your readings recorded and reality
have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such maybe
rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't know
if it would work for my application only because according to the
description on Wikipedia, "as the object is deformed, the foil is
deformed, causing it's electrical resistance to change", and the
object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless we're
counting micro-deformations, the "object" shouldn't deform. But I
understand the principle, it's the same as the piezoresistive force
sensors just instead of using a chemical pressure sensitive ink,
the strain gauges cause variable resistance based on the shape.

I know this goes against most all electrical engineering ideals,
but
this system doesn't have to be super accurate. Even rounding to
the
nearest pound or point of a pound of force would be sufficient.
Hence why I said I'm considering not using force sensors at all for
one
model. I've contacted Tekscan and described what I needed
thoroughly with them and they said that their product is 100%
suited for my
application. The only problem is that I can't afford, personally
or as a per-unit cost, to have a custom run of 10,000 sensors made
to my size requirements and their standard "off the shelf" sensors
are the size of
a penny and I need a contact area of roughly 6" tall by 24" wide.
They have some leftover sensors from the company that makes those
force sensing brake pedals so that trailer brakes can be applied in
addition to the truck brakes, but they don't make a habit of
selling other people's leftover custom sensor designs, and those
are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to keep
the per-unit cost of my system down under the $1k range to make it
affordable for my prospective clients but I want to give them the
best
experience for their buck. For what I'm doing, there are other
products on the market, but in my opinion, they don't fulfill the
needs of their (our) target market.

And just as additional info to take into consideration for the cost
projection, I need either 15 6"x24" sensors or 45 6"x8" sensors to
complete each unit. Using Tekscan's estimate of about $25 per
sensor (for the 3"x5" of which I would need about 90) I would be
spending over $2k just on sensors, not including the equipment to
process, record and control them or the cost to actually have them
built.

So if you, or anyone else, has any recommendations for some way I
can inexpensively measure the force of a hit, either some kind of
rig to use 2 or 3 small piezoresistive sensors that can accept
accurate readings from a 6"x24" curved contact area, I would
appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber created
that could wrap around the steel tube and put an air pressure sensor
on
it. So when it's impacted, the force of the air could be measured
and it wouldn't require expensive piezoresistive sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron wrote:

synapsedm@gmail.com wrote:


synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one
that only has generic contact sensors and one that uses the
variable resistance force sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention, the
attaching glue transfers this in true form so NO shock
absorbing action takes place. Otherwise your readings recorded
and reality have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such
maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't
know if it would work for my application only because according
to the description on Wikipedia, "as the object is deformed, the
foil is deformed, causing it's electrical resistance to change",
and the object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless we're
counting micro-deformations, the "object" shouldn't deform. But
I understand the principle, it's the same as the piezoresistive
force sensors just instead of using a chemical pressure
sensitive ink, the strain gauges cause variable resistance based
on the shape.

I know this goes against most all electrical engineering ideals,
but
this system doesn't have to be super accurate. Even rounding to
the
nearest pound or point of a pound of force would be sufficient.
Hence why I said I'm considering not using force sensors at all
for one
model. I've contacted Tekscan and described what I needed
thoroughly with them and they said that their product is 100%
suited for my
application. The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of 10,000
sensors made to my size requirements and their standard "off the
shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by 24"
wide. They have some leftover sensors from the company that
makes those force sensing brake pedals so that trailer brakes
can be applied in addition to the truck brakes, but they don't
make a habit of selling other people's leftover custom sensor
designs, and those are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to keep
the per-unit cost of my system down under the $1k range to make
it affordable for my prospective clients but I want to give them
the best
experience for their buck. For what I'm doing, there are other
products on the market, but in my opinion, they don't fulfill
the needs of their (our) target market.

And just as additional info to take into consideration for the
cost projection, I need either 15 6"x24" sensors or 45 6"x8"
sensors to
complete each unit. Using Tekscan's estimate of about $25 per
sensor (for the 3"x5" of which I would need about 90) I would be
spending over $2k just on sensors, not including the equipment
to process, record and control them or the cost to actually have
them built.

So if you, or anyone else, has any recommendations for some way
I can inexpensively measure the force of a hit, either some kind
of rig to use 2 or 3 small piezoresistive sensors that can
accept accurate readings from a 6"x24" curved contact area, I
would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber
created that could wrap around the steel tube and put an air
pressure sensor on
it. So when it's impacted, the force of the air could be
measured and it wouldn't require expensive piezoresistive
sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

synapsedm@gmail.com wrote:


Baron wrote:

synapsedm@gmail.com wrote:


synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:


I'm throwing around the idea of creating two systems, one
that only has generic contact sensors and one that uses the
variable resistance force sensors.

- Jace


"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention, the
attaching glue transfers this in true form so NO shock
absorbing action takes place. Otherwise your readings recorded
and reality have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such
maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't
know if it would work for my application only because according
to the description on Wikipedia, "as the object is deformed, the
foil is deformed, causing it's electrical resistance to change",
and the object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless we're
counting micro-deformations, the "object" shouldn't deform. But
I understand the principle, it's the same as the piezoresistive
force sensors just instead of using a chemical pressure
sensitive ink, the strain gauges cause variable resistance based
on the shape.

I know this goes against most all electrical engineering ideals,
but
this system doesn't have to be super accurate. Even rounding to
the
nearest pound or point of a pound of force would be sufficient.
Hence why I said I'm considering not using force sensors at all
for one
model. I've contacted Tekscan and described what I needed
thoroughly with them and they said that their product is 100%
suited for my
application. The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of 10,000
sensors made to my size requirements and their standard "off the
shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by 24"
wide. They have some leftover sensors from the company that
makes those force sensing brake pedals so that trailer brakes
can be applied in addition to the truck brakes, but they don't
make a habit of selling other people's leftover custom sensor
designs, and those are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to keep
the per-unit cost of my system down under the $1k range to make
it affordable for my prospective clients but I want to give them
the best
experience for their buck. For what I'm doing, there are other
products on the market, but in my opinion, they don't fulfill
the needs of their (our) target market.

And just as additional info to take into consideration for the
cost projection, I need either 15 6"x24" sensors or 45 6"x8"
sensors to
complete each unit. Using Tekscan's estimate of about $25 per
sensor (for the 3"x5" of which I would need about 90) I would be
spending over $2k just on sensors, not including the equipment
to process, record and control them or the cost to actually have
them built.

So if you, or anyone else, has any recommendations for some way
I can inexpensively measure the force of a hit, either some kind
of rig to use 2 or 3 small piezoresistive sensors that can
accept accurate readings from a 6"x24" curved contact area, I
would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber
created that could wrap around the steel tube and put an air
pressure sensor on
it. So when it's impacted, the force of the air could be
measured and it wouldn't require expensive piezoresistive
sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

No ! It wasn't. Impact implies vibration=noise. Something acoustic ?

--
Best Regards:
Baron.

Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:

I'm throwing around the idea of creating two systems, one
that only has generic contact sensors and one that uses
the variable resistance force sensors.

- Jace

"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention,
the attaching glue transfers this in true form so NO shock
absorbing action takes place. Otherwise your readings
recorded and reality have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such
maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't
know if it would work for my application only because
according to the description on Wikipedia, "as the object is
deformed, the foil is deformed, causing it's electrical
resistance to change", and the object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless
we're
counting micro-deformations, the "object" shouldn't deform.
But I understand the principle, it's the same as the
piezoresistive force sensors just instead of using a chemical
pressure sensitive ink, the strain gauges cause variable
resistance based on the shape.

I know this goes against most all electrical engineering
ideals, but this system doesn't have to be super accurate.
Even rounding to the nearest pound or point of a pound of
force would be sufficient. Hence why I said I'm considering
not using force sensors at all for one model. I've contacted
Tekscan and described what I needed thoroughly with them and
they said that their product is 100% suited for my
application.

The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of
10,000 sensors made to my size requirements and their
standard "off the shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by 24"
wide. They have some leftover sensors from the company that
makes those force sensing brake pedals so that trailer brakes
can be applied in addition to the truck brakes, but they
don't make a habit of selling other people's leftover custom
sensor designs, and those are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to
keep the per-unit cost of my system down under the $1k range
to make it affordable for my prospective clients but I want
to give them the best experience for their buck. For what
I'm doing, there are other products on the market, but in my
opinion, they don't fulfill the needs of their (our) target
market.

And just as additional info to take into consideration for
the cost projection, I need either 15 6"x24" sensors or 45
6"x8" sensors to complete each unit. Using Tekscan's
estimate of about $25 per sensor (for the 3"x5" of which I
would need about 90) I would be spending over $2k just on
sensors, not including the equipment to process, record and
control them or the cost to actually have them built.

So if you, or anyone else, has any recommendations for some
way I can inexpensively measure the force of a hit, either
some kind of rig to use 2 or 3 small piezoresistive sensors
that can accept accurate readings from a 6"x24" curved
contact area, I would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber
created that could wrap around the steel tube and put an air
pressure sensor on it. So when it's impacted, the force of
the air could be measured and it wouldn't require expensive
piezoresistive sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

No ! It wasn't. Impact implies vibration=noise. Something acoustic
?

--
Best Regards:
Baron.

Ok, that makes sense but do you think a system could be setup to use
the vibration to detect the force though?

The padding would absorb some of the impact and depending on what
direction the device is hit from, it might not register the same
force if it was from the front or the side?

I love the suggestion and would be interested if anyone could
elaborate how something like that would work. If that is a
plausible solution, it would remove all wearable parts from the
impact surface which would lower maintenance costs considerably
considering the machine is literally getting beaten to death.

- Jace

Not sure if that's a joke or not? If not, what do you mean?

- Jace

It has meaning for me;^)

synapsedm@gmail.com wrote:


Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:

I'm throwing around the idea of creating two systems, one
that only has generic contact sensors and one that uses
the variable resistance force sensors.

- Jace

"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample without
degradation and is longer than the strain gauge dimention,
the attaching glue transfers this in true form so NO shock
absorbing action takes place. Otherwise your readings
recorded and reality have nothing in common.

If you insist on 'impact' as your measure stick better find
someone experienced in this kind of measurements. And such
maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I don't
know if it would work for my application only because
according to the description on Wikipedia, "as the object is
deformed, the foil is deformed, causing it's electrical
resistance to change", and the object the user would be
hitting is a 8" diameter steel vertical cylinder. Unless
we're
counting micro-deformations, the "object" shouldn't deform.
But I understand the principle, it's the same as the
piezoresistive force sensors just instead of using a chemical
pressure sensitive ink, the strain gauges cause variable
resistance based on the shape.

I know this goes against most all electrical engineering
ideals, but this system doesn't have to be super accurate.
Even rounding to the nearest pound or point of a pound of
force would be sufficient. Hence why I said I'm considering
not using force sensors at all for one model. I've contacted
Tekscan and described what I needed thoroughly with them and
they said that their product is 100% suited for my
application.

Well since there selling you something, they would, wouldn't they ?

The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of
10,000 sensors made to my size requirements and their
standard "off the shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by 24"
wide. They have some leftover sensors from the company that
makes those force sensing brake pedals so that trailer brakes
can be applied in addition to the truck brakes, but they
don't make a habit of selling other people's leftover custom
sensor designs, and those are only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need to
keep the per-unit cost of my system down under the $1k range
to make it affordable for my prospective clients but I want
to give them the best experience for their buck. For what
I'm doing, there are other products on the market, but in my
opinion, they don't fulfill the needs of their (our) target
market.

Just what is the target market ?

And just as additional info to take into consideration for
the cost projection, I need either 15 6"x24" sensors or 45
6"x8" sensors to complete each unit. Using Tekscan's
estimate of about $25 per sensor (for the 3"x5" of which I
would need about 90) I would be spending over $2k just on
sensors, not including the equipment to process, record and
control them or the cost to actually have them built.

So if you, or anyone else, has any recommendations for some
way I can inexpensively measure the force of a hit, either
some kind of rig to use 2 or 3 small piezoresistive sensors
that can accept accurate readings from a 6"x24" curved
contact area, I would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air chamber
created that could wrap around the steel tube and put an air
pressure sensor on it. So when it's impacted, the force of
the air could be measured and it wouldn't require expensive
piezoresistive sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

No ! It wasn't. Impact implies vibration=noise. Something acoustic
?

--
Best Regards:
Baron.

Ok, that makes sense but do you think a system could be setup to use
the vibration to detect the force though?

The padding would absorb some of the impact and depending on what
direction the device is hit from, it might not register the same
force if it was from the front or the side?

I love the suggestion and would be interested if anyone could
elaborate how something like that would work. If that is a
plausible solution, it would remove all wearable parts from the
impact surface which would lower maintenance costs considerably
considering the machine is literally getting beaten to death.

- Jace

Flying by the seat of my pants here...... You describe a hollow
cylinder! Is it closed at both ends ? What does the cylinder
contain ? How is it mounted ?

You describe that it is hit (Impacted.) Your words. In what way ?
from what direction ? What with ?

--
Best Regards:
Baron.

Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:

I'm throwing around the idea of creating two systems,
one that only has generic contact sensors and one that
uses the variable resistance force sensors.

- Jace

"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample
without degradation and is longer than the strain gauge
dimention, the attaching glue transfers this in true
form so NO shock absorbing action takes place. Otherwise
your readings recorded and reality have nothing in
common.

If you insist on 'impact' as your measure stick better
find someone experienced in this kind of measurements.
And such maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I
don't know if it would work for my application only
because according to the description on Wikipedia, "as the
object is deformed, the foil is deformed, causing it's
electrical resistance to change", and the object the user
would be
hitting is a 8" diameter steel vertical cylinder. Unless
we're
counting micro-deformations, the "object" shouldn't
deform. But I understand the principle, it's the same as
the piezoresistive force sensors just instead of using a
chemical pressure sensitive ink, the strain gauges cause
variable resistance based on the shape.

I know this goes against most all electrical engineering
ideals, but this system doesn't have to be super accurate.
Even rounding to the nearest pound or point of a pound of
force would be sufficient. Hence why I said I'm
considering
not using force sensors at all for one model. I've
contacted Tekscan and described what I needed thoroughly
with them and they said that their product is 100% suited
for my application.

Well since there selling you something, they would, wouldn't they ?

The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of
10,000 sensors made to my size requirements and their
standard "off the shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by
24" wide. They have some leftover sensors from the company
that makes those force sensing brake pedals so that
trailer brakes can be applied in addition to the truck
brakes, but they don't make a habit of selling other
people's leftover custom sensor designs, and those are
only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need
to keep the per-unit cost of my system down under the $1k
range to make it affordable for my prospective clients but
I want
to give them the best experience for their buck. For what
I'm doing, there are other products on the market, but in
my opinion, they don't fulfill the needs of their (our)
target market.

Just what is the target market ?

And just as additional info to take into consideration for
the cost projection, I need either 15 6"x24" sensors or 45
6"x8" sensors to complete each unit. Using Tekscan's
estimate of about $25 per sensor (for the 3"x5" of which I
would need about 90) I would be spending over $2k just on
sensors, not including the equipment to process, record
and control them or the cost to actually have them built.

So if you, or anyone else, has any recommendations for
some way I can inexpensively measure the force of a hit,
either some kind of rig to use 2 or 3 small piezoresistive
sensors that can accept accurate readings from a 6"x24"
curved contact area, I would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air
chamber created that could wrap around the steel tube and
put an air
pressure sensor on it. So when it's impacted, the force of
the air could be measured and it wouldn't require expensive
piezoresistive sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

No ! It wasn't. Impact implies vibration=noise. Something
acoustic ?

--
Best Regards:
Baron.

Ok, that makes sense but do you think a system could be setup to
use the vibration to detect the force though?

The padding would absorb some of the impact and depending on what
direction the device is hit from, it might not register the same
force if it was from the front or the side?

I love the suggestion and would be interested if anyone could
elaborate how something like that would work. If that is a
plausible solution, it would remove all wearable parts from the
impact surface which would lower maintenance costs considerably
considering the machine is literally getting beaten to death.

- Jace

Flying by the seat of my pants here...... You describe a hollow
cylinder! Is it closed at both ends ? What does the cylinder
contain ? How is it mounted ?

You describe that it is hit (Impacted.) Your words. In what way ?
from what direction ? What with ?

--
Best Regards:
Baron.

Stanislaw,

I'm not sure I'm 100% on the same wavelength as you. I did mean
impact
in the literal sense. I am going to physically whack the machine
with
a blunt object, be it a fist, foot or weapon of some sort. The area
that would be struck can be anywhere on the circumference of the
steel pipe that is facing the user, hence why I can't use a single
small
sensor at a specific point. It would be as if you wrapped a parking
meter with sensors and then started wacking it with a stick. Inside
the parking meter would be the measurement equipment.


Baron,

The target market is for entertainment / sports / fitness
applications.

The cylinder is hollow, standing vertically with the circuitry
inside
and is capped at the top and the bottom is fastened to the floor.
It
is hit with a large blunt object. The user can choose to hit it
with their fist, foot or use a weapon, most likely a staff or some
sort of club. Think of a bop the weasel game but instead of the
weasel you're aiming for lights and hitting this cylinder instead of
weasel heads.

That's about as detailed as I can get without describing the rest of
my
machine and nullifying the whole point of selling it . But
basically it's a sports machine that can be used for entertainment
and physical
training. It has multiple components but this is the only one that
I'm stuck on; the rest have already been worked out.

- Jace

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

Baron wrote:

synapsedm@gmail.com wrote:

synaps...@gmail.com wrote:

Stanislaw Flatto wrote:

synapsedm@gmail.com wrote:

I'm throwing around the idea of creating two systems,
one that only has generic contact sensors and one that
uses the variable resistance force sensors.

- Jace

"Strain gauges?" would do if:
the 'impact' shock wave moves along the test sample
without degradation and is longer than the strain gauge
dimention, the attaching glue transfers this in true
form so NO shock absorbing action takes place. Otherwise
your readings recorded and reality have nothing in
common.

If you insist on 'impact' as your measure stick better
find someone experienced in this kind of measurements.
And such maybe rare like chicken teeth.

Good luck

Stanislaw

Stanislaw,

I've been doing some research into Strain Guages and I
don't know if it would work for my application only
because according to the description on Wikipedia, "as the
object is deformed, the foil is deformed, causing it's
electrical resistance to change", and the object the user
would be
hitting is a 8" diameter steel vertical cylinder. Unless
we're
counting micro-deformations, the "object" shouldn't
deform. But I understand the principle, it's the same as
the piezoresistive force sensors just instead of using a
chemical pressure sensitive ink, the strain gauges cause
variable resistance based on the shape.

I know this goes against most all electrical engineering
ideals, but this system doesn't have to be super accurate.
Even rounding to the nearest pound or point of a pound of
force would be sufficient. Hence why I said I'm
considering
not using force sensors at all for one model. I've
contacted Tekscan and described what I needed thoroughly
with them and they said that their product is 100% suited
for my application.

Well since there selling you something, they would, wouldn't they ?

The only problem is that I can't afford,
personally or as a per-unit cost, to have a custom run of
10,000 sensors made to my size requirements and their
standard "off the shelf" sensors are the size of
a penny and I need a contact area of roughly 6" tall by
24" wide. They have some leftover sensors from the company
that makes those force sensing brake pedals so that
trailer brakes can be applied in addition to the truck
brakes, but they don't make a habit of selling other
people's leftover custom sensor designs, and those are
only 3"x5" anyway.

Basically it comes down to cost versus accuracy. I need
to keep the per-unit cost of my system down under the $1k
range to make it affordable for my prospective clients but
I want
to give them the best experience for their buck. For what
I'm doing, there are other products on the market, but in
my opinion, they don't fulfill the needs of their (our)
target market.

Just what is the target market ?

And just as additional info to take into consideration for
the cost projection, I need either 15 6"x24" sensors or 45
6"x8" sensors to complete each unit. Using Tekscan's
estimate of about $25 per sensor (for the 3"x5" of which I
would need about 90) I would be spending over $2k just on
sensors, not including the equipment to process, record
and control them or the cost to actually have them built.

So if you, or anyone else, has any recommendations for
some way I can inexpensively measure the force of a hit,
either some kind of rig to use 2 or 3 small piezoresistive
sensors that can accept accurate readings from a 6"x24"
curved contact area, I would appreciate any ideas.

Oh, one more thing, I thought of this last night.

What if I had some kind of extremely thin rubber air
chamber created that could wrap around the steel tube and
put an air
pressure sensor on it. So when it's impacted, the force of
the air could be measured and it wouldn't require expensive
piezoresistive sensors?

Just a thought.

- Jace

Based on this and previous posts you could just as well use a
microphone !

--
Best Regards:
Baron.

Baron,

Not sure if that's a joke or not? If not, what do you mean?

- Jace

No ! It wasn't. Impact implies vibration=noise. Something
acoustic ?

--
Best Regards:
Baron.

Ok, that makes sense but do you think a system could be setup to
use the vibration to detect the force though?

The padding would absorb some of the impact and depending on what
direction the device is hit from, it might not register the same
force if it was from the front or the side?

I love the suggestion and would be interested if anyone could
elaborate how something like that would work. If that is a
plausible solution, it would remove all wearable parts from the
impact surface which would lower maintenance costs considerably
considering the machine is literally getting beaten to death.

- Jace

Flying by the seat of my pants here...... You describe a hollow
cylinder! Is it closed at both ends ? What does the cylinder
contain ? How is it mounted ?

You describe that it is hit (Impacted.) Your words. In what way ?
from what direction ? What with ?

--
Best Regards:
Baron.

Stanislaw,

I'm not sure I'm 100% on the same wavelength as you. I did mean
impact
in the literal sense. I am going to physically whack the machine
with
a blunt object, be it a fist, foot or weapon of some sort. The area
that would be struck can be anywhere on the circumference of the
steel pipe that is facing the user, hence why I can't use a single
small
sensor at a specific point. It would be as if you wrapped a parking
meter with sensors and then started wacking it with a stick. Inside
the parking meter would be the measurement equipment.


Baron,

The target market is for entertainment / sports / fitness
applications.

The cylinder is hollow, standing vertically with the circuitry
inside
and is capped at the top and the bottom is fastened to the floor.
It
is hit with a large blunt object. The user can choose to hit it
with their fist, foot or use a weapon, most likely a staff or some
sort of club. Think of a bop the weasel game but instead of the
weasel you're aiming for lights and hitting this cylinder instead of
weasel heads.

That's about as detailed as I can get without describing the rest of
my
machine and nullifying the whole point of selling it . But
basically it's a sports machine that can be used for entertainment
and physical
training. It has multiple components but this is the only one that
I'm stuck on; the rest have already been worked out.

- Jace

OK ! I get the picture. Use a simple microphone capsule, say
electret. Take the signal from it and manipulate it to get what you
want. Amplitude will tell you how hard the device was thumped and the
frequency will tell you where.

Obviously you are going to have to play around a little to get the
optimum mounting/location for the mic. I would suggest suspending it
on a stalk inside near the bottom but above any circuits.


--
Best Regards:
Baron.