I apologise if my previous posts appear condescending...was certainly not intended ....simply frustrated with the erroneous myths that have circulated the industry for so many years....and couched as fact.
500... I agree now that you describe your process by weighing the tip/root ends and using that as your yardstick...it is a crude way of assessing the mass distribution....but there are other, much better ways is all I am saying...and it is the distribution rather than the straight overall mass which is the kicker. You can have blades 250gms different in mass fly quite successfully together on the same head....providing the tip weights have been adjusted to compensate and ensure the Span CofG is within the design specs.
Mass is not critical for the balance ....distribution of the mass is far more critical. This is adjusted via span/chord static weights. If the distribution of mass is migrates outside the original design engineering tolerances for what ever reason, (Trapped water, in-field painting, small blade repairs/bogg, blade erosion etc) this will create your dynamic balance problems and you will begin to notice you will have to fly "sets" of blades rather than having interchangeability across the fleet.
Track has its place most certainly. But simply because a blade appears to be flying out of track does not condemn the rotor system to be out of balance....as is often the belief. It is most common actually, to fly the tracks apart in order to achieve a smooth vertical ride....particularly with variations in verticals with IAS.
Nooby...
.don't look at the tooling ....look at the research behind the tooling. In particular......look at the RWAS site and review the back ground and explanations offered to improve your rotor blade management. Look at the difference in importance between the Static Balance and Dynamic balance.
Look at the means of measuring and adjustment between the two.
How you achieve the static balance in isolation from the Dynamic balance is up to you. Read the sections pertaining to the static balance and why static balance is so important for rotor craft versus the tyre industry. But if you try to compensate the static balance (ie Span moment arm adjustment) with the dynamic balance, all you do is chew up Dynamic Lateral adjustment capability while correcting a static problem...then when it comes to correcting the Dynamic problem (wear in bearing, engineering tolerances/play within the hub/Tx components, small variations between blades etc)....you find there is no more adjustment capabiltiy left....or very little
How many people have run out of room (capacity) to correct a lateral balance problem with their Dynamic Tool (whether RADS/Chadwick./Helitune/ACES or whatever - doesn't matter). This manifests itself as when the move line on correction chart starts to run tangentially past the origin but fails to track inwards towards the origin (we've all seen that right
)....and most people are forced to accept an uncomfortable ride because the Dynamic balance chart takes the vibration out the opposite side of the chart without getting down to an acceptable level. The move line passes tangentially past the origin at 0.2ips or greater. This is a classic indication that you have a span moment problem......its tip weight time most likely.
This is particularly true for the teetering systems eg B204/205/206/212. How many Huey drivers (ALL helicopter pilots for that matter) have spent HOURS flying round the flag pole trying to get a pair of blades to fly together. Remember the old Chadwick "Clock Angle" corrector in the older Dynamic Balancers. When the old "static" Balance technique for teetering heads was to suspend the entire rotor head including hub in a box on the hangar floor and add weight to correct the see-saw balance methodology. Where was this weight added? To the Hub bolts ie the DYNAMIC adjustment point.......not the Static adjustment point - (the tip weights where you gain maximum effect for the minimal mass change)..
I'm sure this will sound awfully familiar to a lot of the old & bolds out there.....the same is true for all blades.
I could go on but this is really not the right place..I do not wish to offend anybody on this site...I simply would like to shine some light on an areas which I'm sure you would mostly agree has been treated as a Black Art for far too long ...
Anyway.....once again, please go and read the research and the descriptions on these 2 web sites of why it is so important to treat static and dynamic adjustments as separate things. Because one will definitely affect the other as all of us who have been in this game for longer than we would all like admit.
By way of validation of the bona fides of the RWAS web site in case you were wondering, AgustaWestland (read Leonardo) in Chapter 18 of AW139 Airframe Type Training Course plagiarised the content of this site and published it in their earlier tech training manuals under Vibration Analysis Rotor Track & Balance as their own proprietary knowledge. For those with the earlier digital Agusta tech manuals feel free to look it up and compare.
I apologise to Steve B for diverting his original thread...but maybe content we have discussed will help him sometime in the future when it comes to RTB on any helicopter.
Make your own mind up whether what I have been trying to describe is fact or fiction......
cheers
RG