Other Applications

Let our staff of more than 50 engineers design a custom solution for your specific requirements.

Most of what BTI builds is not a catalog machine. If your part is not on one of the application pages, that is normal — a large share of the equipment leaving Whitmore Lake was engineered for a component that had never been through a balancing machine before.

What follows is the set of questions that actually determine what equipment a part needs. They are the same questions our engineers ask on a first call, and working through them before you call will make that conversation considerably shorter.

1. What Does It Weigh, and How Fast Does It Turn?

These two numbers set the permissible unbalance before anything else is discussed. Permissible unbalance scales with rotor mass and inversely with service speed, so a light rotor turning fast can carry a tighter requirement than something ten times heavier turning slowly.

Use the speed the part actually runs at in service, not the speed of the machine it is fitted to. A camshaft at half engine speed and a damper at full engine speed do not share a tolerance. You can work the arithmetic yourself with our free ISO 21940-11 balance tolerance calculator.

2. Is It Rigid or Flexible at Service Speed?

A rigid rotor keeps the same mass distribution at every speed, so two correction planes describe it fully and a low-speed balance is valid at operating speed. A rotor that bends does not, and the bow itself creates unbalance that only appears as speed rises.

Long, slender, fast components — driveshafts, turbine rotors, slender tooling — frequently fall on the flexible side. That answer changes the method completely, from conventional two-plane work to multi-plane or at-speed balancing, so it is worth settling early rather than discovering it late.

3. One Correction Plane or Two?

Disc-shaped parts — large in diameter, short along the axis — can usually be corrected in one plane. Anything with appreciable axial length can develop a couple that single-plane correction cannot remove, and the couple’s effect grows with speed. Where a part sits near the boundary, two planes is the safe answer.

4. Where Can Material Go, or Come Off?

This is the constraint that most often decides the machine, and it is the one people bring to the conversation last. Working surfaces, sealing surfaces, locating features and aerodynamic profiles are normally untouchable. Thin walls, castings, pressure vessels and magnet pockets each rule out particular methods.

If material cannot be removed, correction has to add mass — welded weights, clips, adhesive, or weights into designed pockets — and that brings its own questions about resolution, placement accuracy and retention in service. Parts designed with correction features from the outset are far cheaper to balance than parts that were not.

5. What Else Has to Be Measured?

Very few production lines measure unbalance alone. Runout, dimensional features, crack detection, leak testing, surface finish, resonant frequency and functional performance frequently sit on the same station or the same cell, and combining them usually costs less than separate operations.

It is also common to find that unbalance is not the characteristic actually causing the complaint. Brake judder is usually thickness variation. Driveline noise is usually gear mesh. Knowing which variable you are chasing before buying equipment to chase it is worth the time.

6. How Many, and How Fast?

Production rate decides configuration far more than part type does. The same component might justify a single manual station in a repair shop, a semi-automatic station with assisted correction at moderate volume, and a fully automatic cell with load, correction and data collection at high volume. Layouts vary to accommodate any production rate.

If You Have Answers to Those Six

You have most of what a quotation needs. What helps beyond that is a drawing, the tolerance you have been given or think you need, and a description of the failure you are trying to prevent — the last one most of all, because it occasionally turns out that balancing is not the right answer.

BTI has designed and built balancing, gauging, crack detection and test equipment since 1968, for components across automotive, aerospace, defense, energy, medical, appliance and general manufacturing. For platform selection across the full range, see BTI balancing machines, or talk to an engineer.