Among avid hobbyists the issue of propeller balancing is a must, a ritual carried out with almost religious attitude. This is, however, not the case with DJI products, targeting customers not always familiar with such chores. Modern mold injecting technology is fully capable to deliver perfectly balanced propellers for our quadcopters.

Yet - occasionally - some pilots are reporting excessive frame vibrations. Some are blaming infamous propellers rattle/looseness, plaguing early batches of Inspire 2. Others are convinced about propellers itself as being off balance.

To get to the bottom of this issue I decided to perform balancing of all Inspire propellers I've got in my barn. To do so, custom balancing shaft had to be manufactured to snugly fit 5 mm hole at the bottom of propeller mount assembly. The mount must be used since there's no other way to install the propellers on balancing shaft. The shaft was manufactured to the highest accuracy standards modern machining can deliver. Pretty much staple and reliable Dubro rig was used to perform balancing procedure ...

The verdict? After several hours of tidious work and double checks I can conclude beyond any doubts that all 16 Inspire 1 and 2 propellers at my disposal are perfectly in balance.

That said, inevitable qestion remains ... Assuming perfectly intact propellers, what other issues may cause sporadic airframe vibrations? Well, the only other suspects are the un-balanced motor(s). This is relatively easy to confirm or deny. Remove all propellers, start the machine and spin the motors pushing the throttle stick up slowly. With one hand on aircraft arms you'll be able to detect excessive vibrations build-up. If that's the case, motor replacement is the best way to eradicate the annoyance.

Great job Matthew!

Hello and good day Matthew Dobrski. Thank you for sharing this information with us to day and thank you for sharing your experience with us in creating and using a custom balancing shaft on your DJI Inspire 1  Pro. Great work and thank you for supporting DJI.

Thanks for sharing!

Nice Job Matthew

I agree with your assessment and wanted to show you my set up. I have a very old Highpoint all metal rolling wheel balancer.  Because I do not have your machining skills, I have the Infinity balancing shaft. This was offered back in the original Inspire 1 screw on prop days and has a 5mm shoulder. It will work with both the I1 or I2. I found another bal. shaft offering linked below. Even after reading your information..... some Inspire pilots would like to verify their props are not out of balance. I have a link to purchasing the balancing shaft
Rich
Balance shaft on Ebay

RichJ53 Posted at 2-20 11:16
Nice Job Matthew

I agree with your assessment and wanted to show you my set up. I have a very old Highpoint all metal rolling wheel balancer.  Because I do not have your machining skills, I have the Infinity balancing shaft. This was offered back in the original Inspire 1 screw on prop days and has a 5mm shoulder. It will work with both the I1 or I2. I found another bal. shaft offering linked below. Even after reading your information..... some Inspire pilots would like to verify their props are not out of balance. I have a link to purchasing the balancing shaft

That's a nice rig, Rich. Either way, we're on the same page ...

Matthew Dobrski Posted at 2-20 11:33
That's a nice rig, Rich. Either way, we're on the same page ...

Yes sir  

thanx for testing and sharing the results !

Flo the Pirate Posted at 2-22 08:10
thanx for testing and sharing the results !

You're welcome, pleasure is mine ...

Can you point me to where I can buy the adapter to fit the Inspire 2 props? Maybe an STL file? Thanks very much! Danny

fans2dba4e36 Posted at 4-20 11:43
Can you point me to where I can buy the adapter to fit the Inspire 2 props? Maybe an STL file? Thanks very much! Danny

A. Inspire 2 props are too big to fit on Inspire 1, if this is what you're after.
B. Never, never consider printing prop mounts.
C. You can install High Altitude props for Inspire 1 with corresponding mounts. These will tax the flight time for 1 or 2 minutes, but are better than nothing.