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Linear actuator

  • Thread starter Dirk Bruere at Neopax
  • Start date
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Looking for a LA with a stroke of around 30cm, force around 1000N and capable of
full stroke in less than 200mS.

Anyone any idea where I can find that, or how much I can expect to pay?

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Does it have to operate more than once? How about a pyro device?
Probably several million times.
Accuracy is not too critical, and repeatability within a mm is acceptable.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
D

Don Lancaster

Jan 1, 1970
0
Dirk said:
Looking for a LA with a stroke of around 30cm, force around 1000N and
capable of full stroke in less than 200mS.

Anyone any idea where I can find that, or how much I can expect to pay?

http://www.tinaja.com/adeptinv.asp
Almost sold out, though.

But check your math.

What maximum mass could you accellerate to around 6 meters per second
mid velocity and zero meters per second final velocity with how many
Newtons?

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
D

Don Lancaster

Jan 1, 1970
0
James said:
Don said:
Dirk Bruere at Neopax wrote:

...
[about linear actuator]

...

Glancing at that, I see your 2 Parker Hauser
robotic sliders listed at $990 each or $1990
for the lot -- why that extra $10 ?
-jiw

Um, 990 times three is $2970.
There were THREE sliders, not just two.
One slider lacked the stepper motor.

These flew on outta here.
We do still have bunches of the SUV cargo nets they were used to
produce. At $19 per case of FIFTY.

We only have eight of the Adept sliders left, five medium duty 950 mm
and three heavy duty 1000 mm. Repositionable to ONE TENTH OF A MIL!!!!!!

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
D

Don Lancaster

Jan 1, 1970
0
Don said:
http://www.tinaja.com/adeptinv.asp
Almost sold out, though.

But check your math.

What maximum mass could you accellerate to around 6 meters per second
mid velocity and zero meters per second final velocity with how many
Newtons?

Also, unless partial position repeatability is important, hydraulic or
pneumatic solutions would be ridiculously cheaper and simpler.

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Don said:
Also, unless partial position repeatability is important, hydraulic or
pneumatic solutions would be ridiculously cheaper and simpler.

I'm trying to avoid all of that stuff.
I might eventually go for a DIY version using a high speed motor and optical
encoder with some custom electronics. As I said, repeatability is not especially
relevant, but brute force is.
The kind of price I'm looking for is around the $150 mark for production runs of
1000+

The arithmetic I can take care of when I get down to the detailed design. Right
now I'm just doing a quick survey of what's possible.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
R

Roger Hamlett

Jan 1, 1970
0
Dirk Bruere at Neopax said:
I'm trying to avoid all of that stuff.
I might eventually go for a DIY version using a high speed motor and
optical encoder with some custom electronics. As I said, repeatability
is not especially relevant, but brute force is.
The kind of price I'm looking for is around the $150 mark for production
runs of 1000+

The arithmetic I can take care of when I get down to the detailed
design. Right now I'm just doing a quick survey of what's possible.
Except that the point being made is that what is 'possible', depends on
the mass of the attached object. If this is more than about 33Kg, the
force available, will not be enough to meet your 0.2sec specification. You
need to be including these limits in your thinking _now_, or you will have
major problems latter...

Best Wishes
 
D

Don Lancaster

Jan 1, 1970
0
Dirk said:
I'm trying to avoid all of that stuff.
I might eventually go for a DIY version using a high speed motor and
optical encoder with some custom electronics. As I said, repeatability
is not especially relevant, but brute force is.
The kind of price I'm looking for is around the $150 mark for production
runs of 1000+

The arithmetic I can take care of when I get down to the detailed
design. Right now I'm just doing a quick survey of what's possible.

Why would you "avoid all that stuff", when pneumatics or hydraulics is
by far the simplest and most cost effective solution where it is applicable?

If repeatability is not particularly relevant, pneumatics should do it
for under ten dollars.


--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
D

Don Lancaster

Jan 1, 1970
0
Roger said:
Except that the point being made is that what is 'possible', depends on
the mass of the attached object. If this is more than about 33Kg, the
force available, will not be enough to meet your 0.2sec specification. You
need to be including these limits in your thinking _now_, or you will have
major problems latter...

Best Wishes


Probably more like 8 kg or less if a reasonable velocity profile is
used. Ideally your initial and final velocity should be zero.

Otherwise the neighbors a block or two down the road may complain.


--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
R

Rene Tschaggelar

Jan 1, 1970
0
Dirk said:
I'm trying to avoid all of that stuff.
I might eventually go for a DIY version using a high speed motor and
optical encoder with some custom electronics. As I said, repeatability
is not especially relevant, but brute force is.
The kind of price I'm looking for is around the $150 mark for production
runs of 1000+

The arithmetic I can take care of when I get down to the detailed
design. Right now I'm just doing a quick survey of what's possible.

The physics tells you that :

force(N=kgm/s^2) = mass(kg) * acceleration(m/s^2)

using the max force to acclelerate and the max negative force
for braking gives 15cm in 100ms = 1/2* a*t^2

Solve for "a" gives 30m/s^2 . Since the force is 1000N,
the mass is 33kg or lower.

Rene
 
R

Rene Tschaggelar

Jan 1, 1970
0
Don said:
Probably more like 8 kg or less if a reasonable velocity profile is
used. Ideally your initial and final velocity should be zero.

Otherwise the neighbors a block or two down the road may complain.


As sidenote : the work is force times pathlength, and
power is work per time.

so : 1000N times 0.3m in 200ms is 300Nm/0.2s =1500Watt

Rene
 
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Don said:
Why would you "avoid all that stuff", when pneumatics or hydraulics is
by far the simplest and most cost effective solution where it is
applicable?

If repeatability is not particularly relevant, pneumatics should do it
for under ten dollars.

Well, I don't know much about plumbing.
Plus electric seems more reliable, given that it will all start to leak after a
while.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Rene said:
The physics tells you that :

force(N=kgm/s^2) = mass(kg) * acceleration(m/s^2)

using the max force to acclelerate and the max negative force
for braking gives 15cm in 100ms = 1/2* a*t^2

Solve for "a" gives 30m/s^2 . Since the force is 1000N,
the mass is 33kg or lower.

I did a slightly different bit of maths.
1000N through 0.3m (vertical worst case) = 300J
In 0.2 sec = 1500W

Still, correct to within a factor of two or three for my pursposes.
I'm still looking for the most cost effective solution given the constraints,
one of which is that the machine should be able to handle a million cycles.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
D

Dirk Bruere at Neopax

Jan 1, 1970
0
Roger said:
Except that the point being made is that what is 'possible', depends on
the mass of the attached object. If this is more than about 33Kg, the
force available, will not be enough to meet your 0.2sec specification. You
need to be including these limits in your thinking _now_, or you will have
major problems latter...

A factor of 2 or 3 probably won't translate into a cost differential of 2 or 3.
Right now I'm just in the hand waving phase of a possible project.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
 
D

Don Lancaster

Jan 1, 1970
0
Dirk said:
I did a slightly different bit of maths.
1000N through 0.3m (vertical worst case) = 300J
In 0.2 sec = 1500W

Still, correct to within a factor of two or three for my pursposes.
I'm still looking for the most cost effective solution given the
constraints, one of which is that the machine should be able to handle a
million cycles.

Again, your 1500 watts will be more like 5000 watts with an acceptable
velocity profile.


--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
R

Rene Tschaggelar

Jan 1, 1970
0
Dirk said:
Rene Tschaggelar wrote:


I did a slightly different bit of maths.
1000N through 0.3m (vertical worst case) = 300J
In 0.2 sec = 1500W

Still, correct to within a factor of two or three for my pursposes.
I'm still looking for the most cost effective solution given the
constraints, one of which is that the machine should be able to handle a
million cycles.

Electric means a motor with a gearbox to handle 1500W aka
2 horsepower. A synchroneous motor with sliders or a brushless
will do. The gearbox needs proper dimensioning.

For those not knowing, the first gear in a car is dimensioned
to last 30 miles or so. Then the teeth are falling off...

Together with a 2HP frequency inverter to generate the appropriate
signals you'll be throwing out a stack of dollars.
Compare that with a pneumatic system where together with the actuator,
a compressor is required, or with a hydrolic system where together
with the actuator, an oilpump is required.

Rene
 
R

Robert Latest

Jan 1, 1970
0
If repeatability is not particularly relevant, pneumatics should do it
for under ten dollars.

Does that include the compressor?

robert
 
R

Roger Hamlett

Jan 1, 1970
0
Rene Tschaggelar said:
The physics tells you that :

force(N=kgm/s^2) = mass(kg) * acceleration(m/s^2)

using the max force to acclelerate and the max negative force
for braking gives 15cm in 100ms = 1/2* a*t^2

Solve for "a" gives 30m/s^2 . Since the force is 1000N,
the mass is 33kg or lower.
Exactly what I calculated too.
As others have pointed out, the 'real' mass for which this will be
acheivable assuming some ramping of the acceleration, will be less...
Given that a motor system will itself have inertia, and inductance, and
switches or valves will take time, and the short times involved, the
extras will be quite large.

Best Wishes
 
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