Smart Avionics new PB4 Dynamic Rotor/Prop Balancer

Mike G

Junior Member
The Smart Avionics website has announced the arrival of the PB4, the successor to the PB3 Dynamic Prop and Rotor Balancer that I’ve often written about.

Brent Drake makes a point when he says here:http://www.rotaryforum.com/forum/showthread.php?p=634993#post634993

“As of now, I can't possibly see how a PB4 could be any better than the PB3.”.

A little history

Back around 2011, the PB3 was a propeller balancer that Mark Burton of Smart Avionics wanted to develop as a gyro rotor balancer but he didn’t have a gyro. I had a gyro that I was trying to balance with a dynamic balancer for large high-speed industrial machines that didn’t do the job. The solution was that Mark would (very bravely) send me a PB3 and I would feedback any problems and suggestions. After a very frustrating few months for both of us Mark developed a new accelerometer to handle the higher vibration levels found at the lower speeds of the typical gyro rotor and a new tacho to handle better the problem of the optical tacho getting confused by the sun flashing through the rotor. I then started to get some usable results but started asking for lots of new inputs and outputs to the PB3 to satisfy my quest to further understand why a gyro vibrates the way it does and especially to look more at the 2/rev vibration.

As a result of my requests Mark constantly updated the software but, as any one of you who has written any form of software knows, there’s nothing worse than working with a guy like me who decides what he wants as he goes along. As a result the menus in the PB3 became more and more overloaded with options and choices that 99% of the users would never use and many of which we finally decided weren’t very interesting anyway.


So Mark’s prime aim in developing the PB4 was to do away with a lot of junk that I’d asked him to put in as we went along, thus making the PB4 much easier for the non-initiated to use.


His second aim was to get away from the PB3’s reliance on Android and make it compatible for Apple iphone/ipad users.

So the PB4 uses wi fi rather than Bluetooth, and the program runs as a web page which is more in line with our everyday use of the internet and should be able to run on any browser system.

The hardware has been made to incorporate a second two dimensional accelerometer input and a second tacho input. The thinking here is that it should allow an operator to be able to capture and plot polar charts for the main rotor and the tail rotor of a helicopter during the same flight thus saving expensive helicopter hours. This feature has yet to be tested but the hardware is there.

This feature will allow a gyro operator to capture rotor vibration in two directions at 90° (horizontal and vertical or horizontal fore/aft and side to side) at the same time as two directions at the stick or at some point in the cabin giving the possibility to look at 4 accelerometers at the same time. The point being that there are possibilities built into the hardware that will allow future development.


So on the positive side we have :
1) A simpler, more user friendly menu system.
2) Compatibility with any device and browser system
3) More hardware inputs and future possibilities.
4) It has a remote button to allow you to capture data without taking your hand off the controls.
5) you can easily look at the polar chart and files on a pc reducing the need to work on the files with a tablet/phone touch screen (I love this feature because I hate the touchscreen).

On the down side:
1) It’s about twice the size and weight of the PB3
2) It uses rechargeable batteries that have to be taken out to be charged (I carry a spare set af 4 AA batteries in my pocket when I fly just in case). The PB3 could be run off a 12v cigar lighter socket in the gyro.
3) It’s going to be more expensive.

I’ve been testing the prototype and at first I didn’t like it but then I hate any changes to anything to do with computers because I’m very slow to learn new systems, but I’m really warming to the PB4 now.


To give you an idea of how seriously Smart Avionics is taking gyro balancing, I’ve run tests with two dual Smart Avionics accelerometers (each accelerometer is in fact 2 accelerometers at 90° to each other) at the rotor so plotting vibrations side to side (roll), back to front (gyro pitch) and vertical at the same time using the PB4.

Here's the installation of the 2 dual accelerometers and the tacho.



Here's me with the PB4 in my hand. The cables fixed to the right hand control tube are for the PB4 and the cable on the left hand is a second tacho for the PB3 measuring side to side and vertical vibrations at the cabin floor.





I did this to plot the rotor vibration response to:

Span imbalance (one blade heavier than the other)

Chord imbalance (rotor shifted axially along the teeter bolt)

Pitch variation (tracking)

All three imbalances have a different response in each of the three dimensions at the rotor and two dimensions at the cabin floor. The result is 15 move lines on 5 polar charts. Mark and I are looking at how we can get the PB4 to look at this data and make an assessment of what changes to make to arrive at the best compromise solution.

We currently have an algorithm that looks at the vibration response for Span, chord and pitch (tracking) in 2 dimensions and compensates for the third dimension giving corrections for Span, chord and pitch to reduce the horizontal and vertical vibration at the rotor to an acceptable level. Our current results suggest that with this solution we don’t need to have an accelerometer in the cabin and we only need one dual accelerometer at the rotor to carry out a full dynamic Track and Balance of a typical 2 bladed gyro rotor.

If anybody is interested I'll start a new thread about this test with a bit more detail.

Of course the average user will never get this carried away but in my opinion any serious gyro manufacturer should.

Most of you won’t understand a word of what I’ve written but the bottom line is;

If you (or one of your group) are reasonably capable and have a basic knowledge of what balancing is about and you have a use for a balancer that’s more than once a year, and you’re prepared to read the manual, buy a PB3 now before they go of out of production and while the UK pound is low, especially if you already have an Android tablet.

The PB3 will still be supported and some of the new software developments (not the menu simplification) will be made available to existing PB3 owners.

If you want/need a balancer but aren’t really into the technicalities and especially if you’re an Apple ipad guy (or gal) wait for the PB4.

One very well known European gyro manufacturer has already purchased the first batch of PB4s for their maintenance centres and another purchased 20 PB3s last year for their maintenance centres.

If you ever had any doubts about the capabilities of the PB3 for balancing a gyro you can forget them now especially with the arrival of the PB4.

Mike G

PS I do not work for, or get paid anything by, Smart Avionics, I do this because it interests me, it keeps me busy in retirement and allows me to balance my own gyro.
 

GyrOZprey

Aussie in Kansas.
Very interested ...

Very interested ...

We REALLY need to get a balancer & get trained how to fine-tune Neil's rotors !

(He does a great job of making sure they are optimized to his exacting standards before he ships his machines ...BUT over time & in the process of dismantling & transporting from Rotorcraft events back & forth ... there is an obvious need to tune-up rotors from time-to time!)

I like the sounds of the evolution of the PB4!


The Smart Avionics website has announced the arrival of the PB4, the successor to the PB3 Dynamic Prop and Rotor Balancer that I’ve often written about.

Brent Drake makes a point when he says here:http://www.rotaryforum.com/forum/showthread.php?p=634993#post634993

“As of now, I can't possibly see how a PB4 could be any better than the PB3.”.

A little history ......


.........

If anybody is interested I'll start a new thread about this test with a bit more detail.

Of course the average user will never get this carried away but in my opinion any serious gyro manufacturer should.

Most of you won’t understand a word of what I’ve written but the bottom line is;

If you (or one of your group) are reasonably capable and have a basic knowledge of what balancing is about and you have a use for a balancer that’s more than once a year, and you’re prepared to read the manual, buy a PB3 now before they go of out of production and while the UK pound is low, especially if you already have an Android tablet.

The PB3 will still be supported and some of the new software developments (not the menu simplification) will be made available to existing PB3 owners.

If you want/need a balancer but aren’t really into the technicalities and especially if you’re an Apple ipad guy (or gal) wait for the PB4.

One very well known European gyro manufacturer has already purchased the first batch of PB4s for their maintenance centres and another purchased 20 PB3s last year for their maintenance centres.

If you ever had any doubts about the capabilities of the PB3 for balancing a gyro you can forget them now especially with the arrival of the PB4.

Mike G

PS I do not work for, or get paid anything by, Smart Avionics, I do this because it interests me, it keeps me busy in retirement and allows me to balance my own gyro.
 

swilliams

Newbie
Would be interested in the third if you would start it Mike. Iam knew to Gyros but would like to learn about balancing the rotor and I am interested in the PB3 or possibly 4.

Sincerely SWilliams
 
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