DynaVibe F.A.Q.

Q: Can the DynaVibe be used on geared prop installations?

Yes. It actually works very well on geared assemblies since the geared drive puts the engine vibration frequency at a different frequency than the prop vibration frequency. This makes it easier to isolate just the prop vibration.

Q: Will the DynaVibe work on a 3 blade prop?

Yes. The number of blades on the prop is irrelevant in the balancing process.

Q: Can the DynaVibe be used on rotorcraft?

A: Sure! The rotorcraft version of the DynaVibe Balancer includes an additional accelerometer and remote averaging button. Note that we're not rotorcraft experts so we can not offer technical support for tracking and balancing a rotorcraft other than how to operate the DynaVibe itself.

Q: Can the DynaVibe be used with turboprop and radial engines?

A: Yes. Everything focuses on the prop assembly. It doesn't matter how the prop is driven. We have many customers using the DynaVibe on turboprop aircraft. Regarding radial engines, the orientation of the cylinders is cause for concern since vibrations from combustion are in the same direction as the prop vibration. However, we've had several customers use the DynaVibe on aircraft with radial engines and it worked well.

Q: How do I mount the accelerometer and optical pickup?

A: Due to the variety of engines, we're not able to supply mounts to fit every configuration. You will need to build a fixture to bolt the accelerometer and optical pickup to the engine. Typically, the mount is bolted using one of the case bolts. The accelerometer is mounted on the bracket in the vertical direction, and the optical pickup is pointed toward the prop, near the hub.

Q: Can the DynaVibe be configured to read where to add weight instead of where to remove weight?

A: Yes. Simply mount the accelerometer upside down (with the cable pointing toward the hub).


Q: Should the reflective tape be removed from the prop after it is balanced?

A: It takes a very small change in weight to cause an out-of-balance. Since the prop is balanced with the tape on, the tape is usually left in place to maintain balance. Note that some people do prefer to remove the tape from metal propellers to avoid corrosion.

Q: How can I practice using the DynaVibe

A: It is very helpful to practice by balancing a box fan. You can drill small holes and attach small (i.e. #6-#10) bolts to the fan blades to see how the DynaVibe responds.

Q: What can be causing the DynaVibe reading to fluctuate or give inconsistent results?

A:

  • Hold RPM as stable as possible when balancing. It will take several seconds at a stable RPM for the reading to stabilize.
  • The engine should be running smoothly from idle to max RPM. Don't try to balance a prop with a rough engine!
  • Route all of the DynaVibe wires well away (4" or more if possible) from spark plug wires or other sources of electrical noise.
  • Make sure there are no loose components on the engine that can be moving, such as the spinner, magnetos, exhaust pipes, alternator, etc.
  • Keep the accelerometer mounting bracket as short and stiff as possible. If the bracket starts to resonate, the magnitude and phase angle will be affected resulting in an incorrect measurement.
Q: What RPM should I use to balance?

A: The best readings can be taken at cruise RPM, or the maximum stable RPM safely sustainable for one minute.

Q: Does the DynaVibe tell you how much weight to add/remove?

A: The DynaVibe tells you what correction is needed by indicating the vibration magnitude and angle (where weight is needed). You will get an indication of how weight affects the IPS reading after your first measurement, correction, and subsequent reading. For example, if your initial reading is 1.00 IPS and one washer reduces the out of balance to 0.75 IPS then you know that one washer corrects 0.25 IPS. Therefore, it will take an additional 3 washers of that size to balance the prop assembly.

 

Q: Are the DynaVibe accelerometers fragile?

A: No. We make our own accelerometers using state-of-the-art sensor technology, not piezo crystals. DynaVibe accelerometers are quite tough and will not be damaged by normal handling or drops. While it is possible to crack or chip the sensor's epoxy housing, we have never had sensor failure due to accelerometer mechanical damage.

Q: What does the angle measurement mean on the DynaVibe reading?

A: The angle is the location where the prop assembly is too heavy. Either remove weight at this angle (measured from the master blade in the direction of prop rotation), or add weight at the reading angle +/-180 degrees.