The below chart is generally considered the "standard" values for balancing.
My goal is 0.050 IPS or better when balancing, .010 is very seldom obtainable on professional balancing equipment.
I've done balance checks after Dynavib balances and other "hobby" balancers and my numbers are always higher (I can't even get .01x on my own aircraft after multiple attempts). I have had a few over the years that got into the .01x range but after hundreds of balance jobs I can assure you that .01x is generally impossible to achieve (notice my equip goes out 3 places while most only go 2 places)
What some of the manufactures say:
Unless otherwise specified by the engine or airframe manufacturer, Hartzell
recommends that the propeller be dynamically balanced to a reading of 0.2 IPS,
Most dynamic balance equipment manufacturers specify 0.15 - 0.2 ips as being an
acceptable level. McCauley Propeller Systems agrees that 0.15 - 0.2 is an acceptable
level, but our experience has shown that 0.07 ips or lower is noticeably smoother.
DANGER — 1.25 Inches Per Second (IPS) Peak Amplitude. The propeller should be removed and a static balance performed.
VERY ROUGH — 1.00 Inches Per Second (IPS) Peak Amplitude. Propeller can be dynamically balanced; however a large amount of weight will be required. A propeller static balance is recommended. Operation at this vibration level could cause damage.
ROUGH --- 0.50 Inches Per Second (IPS) Peak Amplitude. Propeller definitely requires dynamic balance. Long term operation at this vibration level could cause excessive wear.
SLIGHTLY ROUGH -- 0.25 Inches Per Second (IPS) Peak Amplitude. Dynamic balance will improve passenger comfort.
FAIR---- 0.15 Inches Per Second (IPS) Peak Amplitude. This is the maximum acceptable vibration level after dynamic balancing.
GOOD ---- 0.07 Inches Per Second (IPS) Peak Amplitude. Vibration levels below 0.07 will not be detectable by pilots or passengers.
Walt Aronow, DFW, TX (52F)
EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
, Email: email@example.com
, Cell: 972-746-5154
Last edited by Walt : 04-13-2019 at 01:31 PM.