ROEHRIG ENGINEERING INC.

Models: All crank type units are designated by the horsepower of the motor.  As an example, the 3VS has a 3 hp motor and the "VS" means variable speed.

Software: Same on all model.  Latest version always available for download and use.

Frame/size: The 2–3–5VS all share the same frame and components.  The 10-20VS use the same frame.  The 30VS is a unit all of its own.

Strokes: Up to 2.0” on the 2-3-5VS.  Up to 6.0” on the 10-20-30VS.  Customizable to user.

Velocity: This is based on horsepower, stroke and internal gear ratio and to a degree the sensor range.  We can alter the ratio to get different velocities.  Keep in mind, if the crank is turning at the same frequency, by running at different strokes, the user gets different velocities.  When trying to run higher velocities, the machine may become horsepower limited.

Force: We can make some generalizations on force capability, but it also depends on the type of curve.  A linear damper curve draws the power differently than a digressive curve.                                                                                   HP = F (lbs) x V (in/sec) / 6600    or    KW = F (kN) x V (m/sec)    and     1 HP = 0.746 kW

Roehrig Engineering will always offer to test your damper for you to best determine the proper unit.  We can provide you the data to examine and using our free demo software, available on our website, you can decide for yourself if the results were achieved.

Crank type comparison table

MODEL

MOTOR

VELOCITY (PEAK)

STROKES (CUSTOM AVAILABLE)

WAVE FORMS

POWER REQUIREMENTS (VAC)

SPECIMEN

IR TEMP

NICKLE

DESIGN

(on max stroke)

Max Stroke

SINE

CUSTOM

TRACK

220 I

220 III

380-400

440

AREA

COLUMNS

Standard

Optional

PLAY

Step Up/Down Transformers Avail

std column

(hp)

(in/sec)

(inches)

(inches)

(inches)

STANDARD UNITS

2VS

2

20

NA

1.0, 2.0

2.0

Y

NA

NA

Y

N

N

N

29

OPTION

OPTION

TABLETOP

3VS

3

38

38

0.5, 1.0, 1.5, 2.0

2.0

Y

NA

NA

Y

Y

Y

Y

28

Y

Y

TABLETOP

5VS

5

38

38

0.5, 1.0, 1.5, 2.0

2.0

Y

NA

NA

Y

Y

Y

Y

28

Y

Y

TABLETOP

10VS

10

64

90 (138)

0.75, 1.0, 1.5, 2.0, 3.0, 3.9

3.9 (6.0 Option)

Y

NA

NA

Y

Y

Y

Y

33

Y

Y

FLOOR MNT

20VS

20

64

138

0.75, 1.0, 1.5, 2.0, 3.0, 3.9, 6.0

6.0

Y

NA

NA

N

N

Y

Y

33

Y

Y

FLOOR MNT

(kW)

(Met/sec)

(mm)

(mm)

METRIC

2VS

1.5

0.51

NA

25, 50

50.0

Y

NA

NA

Y

N

N

N

735

OPTION

OPTION

TABLETOP

3VS

2.2

0.97

0.97

15, 25, 40, 50

50.0

Y

NA

NA

Y

Y

Y

Y

710

Y

Y

TABLETOP

5VS

3.7

0.97

0.97

15, 25, 40, 50

50.0

Y

NA

NA

Y

Y

Y

Y

710

Y

Y

TABLETOP

10VS

7.5

1.63

2.3  (3.5)

15, 25, 40, 50, 75, 100

100 (150 Option)

Y

NA

NA

Y

Y

Y

Y

840

Y

Y

FLOOR MNT

20VS

15.0

1.63

3.5

15, 25, 40, 50, 75, 100, 150

150.0

Y

NA

NA

N

N

Y

Y

840

Y

Y

FLOOR MNT

What kind of dyno do you need?  Roehrig makes a large variety of testing equipment to fit a large variety of needs as well as budgets.  If budget was not a problem, the choice would be easy, but we always have to think of cost vs. function.  We have sold many 2VS’s to people that needed more dyno but did not have the capital to afford a more powerful unit.  The reason being that having some data is better than none at all. 

If you have to be able to run displacement data from the race track or if you must run custom wave forms such as square waves, sine on sine or frequency sweeps, etc..then Roehrig Engineering’s solution is the EMA series, Electro Magnetic Actuators.  This series of actuators provides superior performance to a hydraulic solution at a fraction of the cost.  Please go to the EMA section.

If you have to perform a sine wave test then there is nothing better than our line of crank type dynamometers.  Roehrig crank type dynamometers are designed to develop a sine wave as the input wave form.  They do this using a bolt in an offset hole on a crank shaft.  This then drives the yoke to produce a sine wave.  Our models provide a large variety of different parameters designed to fit your damper testing needs.

Our models are based on horsepower, velocity capability and strokes available.  They run through a belt drive reduction to turn the crank head at varying frequencies.  We have set up the units to achieve a wide variety of performance envelopes.  Chances are if one of these is not right in standard configuration, then we can custom fit changes to configure it right.

The 2VS, 3VS and 5VS are all built on the same table top platform.  They differ in the horsepower of their motor.  The hp of the unit allows for more velocity and greater force capability.  These are meant for table top use.

The 2VS is the entry level unit designed to get the user started down the path of damper learning, rebuilding and tuning.  It has some limiting features that keep its price at an inexpensive level yet deliver the information the user needs.  Due to hp, gear ratio and motor drive restrictions, it is ideal only up to about 1,200 lbs and 10 in/sec.  In standard form, the crank is limited to two strokes, 1" and 2".  It is a user option to upgrade to the 5VS crank.

The 3VS has more power, more strokes and a upgraded crossbar and load cell package to meet the requirements of this power.

The 5VS has the most power we can fit in a small compact size. 

From tabletop to floor models, we have the 10, 20 and 30VS.  Again, how fast do you need to test, how much force do you see and what stroke do you need to run?

The 10VS and 20VS are interchangeable, except for power.  The bigger motor in the 20VS allows it to go faster and keep pulling beyond the limits of the 10VS.  The 20VS also comes standard with the largest stroke, 6 inches and an encoder for increased low speed testing.  These remain option on the 10VS model.