Size Matters: The Importance of Balance Wheels

SKU: X-HT-300331



The Sailrite® Ultrafeed® Sewing Machines have a long history of helping both sailmakers and DIYers sew their dream projects. While there are many features of this machine series that make it exceptional, the Ultrafeed would not be the powerhouse it is today without the help of our revolutionary balance wheels.

The WorkerB® Balance Wheel on the Ultrafeed LS (left) and the Monster® II Balance Wheel on the Ultrafeed LSZ (right).

What Does a Balance Wheel Do?

A sewing machine’s balance wheel rotates the upper drive shaft for machine operation, which causes the needle and hook to move in a manner that produces stitches. The transfer of power through a sewing machine is a key part of its operation. Essentially, the motor powers a belt which then turns the balance wheel, transferring power through the internal components to push the needle through fabric. Sailrite has developed proprietary mechanical technology to enhance the success of this power transfer in all Ultrafeed Sewing Machines.

Cogged Construction

In addition to their larger size, the cogged construction of our balance wheels provides a slip-free transfer of power from the motor to the balance wheel when paired with a mating cogged belt. Many sewing machines use a friction belt-to-groove setup, which is simply a belt in a channel under tension to drive the balance wheel, meaning that there is a high probability of slipping and loss of power. You’ll never have to worry about this issue with Sailrite’s proprietary balance wheels.

Balance Wheel Improvements Over the Years

Balance wheels should be judged according to their diameter and mass. Overall diameter is important, but it’s not as crucial as the diameter of the balance wheel’s belt track region. This factor impacts power and rotation speed. A balance wheel’s mass can be important since it builds momentum, meaning that the wheel wants to stay in motion even if it’s not turning very fast.

With Sailrite’s previously standard AC motor (prior to the February 2023 integration of the WorkerB® Power Pack Motor System on all Ultrafeed machines), it was advantageous to have both momentum and an oversized wheel at the belt track region because AC motors run at high RPMs and don’t have much torque at slow-speed operation. Therefore, the use of the Power Plus® or Monster II Balance Wheels was common and desirable. Both of these wheels are the same diameter — the only difference was the heavier weight of the Monster II. Under motor power, the two wheels are equal in power and speed.

The included hand crank and heavy weight of the Monster II wheel allows DIYers to sew at the marina, on the road and at conventions without power — a huge benefit for on-the-go sewers and repair shops.

The advantage of the Monster II wheel is its weight. Made from 7 pounds of nickel-plated steel, its mass creates enough momentum that you can use the hand crank to sew heavy fabrics effortlessly without electricity. The Monster II can be used on Ultrafeed machines equipped with the WorkerB Power Pack as well as those with the previously standard AC Ultrafeed motor.

The WorkerB Balance Wheel: A Game Changer in Balance Wheel Design & Operation

With the February 2023 debut of our newest Ultrafeed model (what we internally refer to as the Version 4 Ultrafeed), a third variable in balance wheel requirements needs to be considered: the motor. Technically, we look to both power and the motor RPM (how fast the shaft turns).

Sailrite's new WorkerB motor system turns at a much slower RPM and with more power. And the power band is maintained much better at slower operational speeds. As a result, reducing the belt track diameter of the WorkerB Balance Wheel retains a similar top end sewing speed to the prior Power Plus and Monster II wheel-equipped machines. But the system also benefits from the greater power at slower operating speeds. Top speed is maintained with more power throughout the range. With the WorkerB wheel, you can sew 1 stitch per second in a heavy 10-layer canvas assembly.

The Monster II Balance Wheel (left) has a much larger belt track diameter compared to the WorkerB (right). The larger overall diameter of the WorkerB wheel helps with manual operation.

And if you’re looking for even slower operation, nothing beats the Monster II paired with the WorkerB motor. With this setup, you can sew an incredible 1/2 stitch per second through 10 layers of heavy canvas. Now that’s slow-speed control! The Speed Reduction Upgrade package (#123372) will equip your Ultrafeed with WorkerB motor with everything you need to slow down your machine and sew with the utmost care and precision. With two balance wheels to choose from, you now get a much wider overall range of sewing speed — from super slow to production-level output.

You might be wondering, “What about the Power Plus Balance Wheel? Does it still have a place in the Version 4 Ultrafeed updates?” Yes, it absolutely does. We consider it a more economical alternative to the Monster II Balance Wheel upgrade to the V.4 Ultrafeed. When operating the machine under motor power, you have the same stitches per minute rates as with the Monster. The Power Plus makes a bit more noise under operation, and you also sacrifice the convenience and versatility of the Monster wheel's hand crank feature.

The WorkerB Balance Wheel on the Ultrafeed LS.

In conclusion, today’s Ultrafeed Sewing Machines are better than they ever have been. WorkerB power beats the prior AC motor machines, even when using the Monster II Balance Wheel. Adding a Monster wheel to a current WorkerB-powered machine — that is an all-new world of speed control and power!

Our proprietary balance wheels are just one of the many pieces of industry-leading technology found on our Ultrafeed Sewing Machines. At Sailrite, we're constantly innovating and improving our machines to give our customers the most enjoyable and productive sewing experience possible. If you'd like to learn more about the world-renowned Ultrafeed Sewing Machine, visit our Ultrafeed landing page.

Footnote: This blog was updated in January 2023 to include mention of the WorkerB Balance Wheel and new Ultrafeed version updates.