Practical Innovation – “Vess Balance Ring”
by Robert Vess
Vess Propellers

Almost everyone in this hobby has been faced with the issues and challenges of prop balancing. The process of sanding the heavy blade or adding some sort of lacquer to the light blade of your beautiful new wood prop in an effort to get it to reach some state of balance is not a trivial pursuit. And what do you do with carbon or multi-blade props? What effect does the spinner have? Add to this the common practice of sticking an ugly pad of Velcro to the side of the hub and loading CA onto it in an attempt to correct any lateral imbalance and one can certainly understand why many just skip these steps, bolt the prop onto their engine, and hope for the best.

As an avid RC enthusiast, engineer, and propeller designer, I have been quite keen to address this problem and provide a easy means of achieving smooth operation of model aircraft powerplants. I have studied the facts, read articles, consulted experts, and tinkered. It became apparent that the vibration due to the total rotating mass that is attached to the engine drive shaft (prop, washer, bolts, and spinner) is simply an issue of the net center-of-gravity of these components not coinciding with the axis of rotation of the engine. If the prop blades are tracking properly such that it is rotating in a single plane, the solution lies in accurate static balancing to correct any CG offset.

Here's the list of design goals that I felt were important. I wanted to be able to use good quality balancers on the market like the Dubro "Tru-Spin" (Cat. #499) to simultaneously balance all of the rotating components assembled just as they would turn on the engine. I knew my design would have to be light, non-intrusive, and readily adaptable to any powerplant/prop/spinner. And, most importantly, it had to provide an intuitive means to correct the CG offset such that anyone could do it simply and accurately. It's often said that "the best ideas are usually the simplest". That adage certainly applies to my final design! Let me introduce you to the "Vess Balance Ring".



It simply an NC-machined, aluminum part that’s much like the prop washer and, in fact, is used in place of your standard prop washer. There are several sizes to match the various prop bolt patterns of different engines. The series of tapped holes in the boss around the perimeter of the ring accept set screws that are inserted as required during the balancing process. The best way to understand how it’s used is to refer to the instruction card that accompanies each ring:






As you can see this is a very straightforward process that works with any prop/spinner combination, regardless of the number of blades or construction material. And our extensive testing has shown that the balance achieved by proper use of the “Vess Balance Ring” produces remarkably smooth powerplant operation, even at idle. Reduced vibration means lower airframe fatigue, improved equipment longevity, and lower noise. The first customers and test pilots have been astonished!
Right now, we have sizes to fit many popular engines that have the industry-standard DA/3W prop bolt patterns. And other engines will be accommodated soon. The first place you’ll be able to get yours will be at the Desert Aircraft tent on the main flight line at Joe Nall, where I’ll be from around noon on Wednesday, May 12 until the evening of Friday, May 14. I look forward to speaking with you there!

I've got one of these sitting on the bench at home. I'll be getting my airplane ready for Nall this week and can't wait to try out the Balance Ring on it!

I have seen this...Very, Very cool!

I like this idea!

How does this address the need for varying the weight required to balance?

I'd recommend that anyone who tries the "Vess Balance Ring" observe the vibration of your current aircraft setup at idle first before you change. Look at things like the tips of the ailerons, which always seem to shake (killing aileron servos). Then compare the vibration after properly balancing the rotating mass with the VBR. I think you'll note the difference right away as we have in many different applications!

Cool idea. How much do they cost and where can I order one?

Originally Posted by gareth.ky

I like this idea!

How does this address the need for varying the weight required to balance?

The balancing process takes a few "passes". You add another set screw (weight) each time as required until proper balance is achieved as noted in the instruction card graphic.

Personally, I've had some systems balance with one setscrew and the most I've seen is five. Others seem to have similar results.

Originally Posted by vwchad

Cool idea. How much do they cost and where can I order one?

After Joe Nall, which is the official launch of the product from Vess Propellers, they will be up in our online store at www.vessaero.com.

Very interesting concept.....

How much does it weigh?

What engines does it fit?

Great new product! Best results come from balancing the entire prop assembly instead of just the props themselves.

Very smart Robert!

Congratulations on the new line of product!

Pretty cool. Will have to try some of these out!

Awesome new product! Just picked one up from Mat B at the contest last weekend. Well done Robert!
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Its very neat guys! I have one. Great concept. A must have in my book!

Well done Robert as usual!

I need some of these. Awesome idea!