Prop balancing!

[srbell]

Anyone else have trouble balancing propellers? It seems my old trusted Dubro units have way too much friction to balance the newer light weight props and the magnetic balancers seem to have a lot of trouble with strait shafts. It was obvious with the Dubro's wheel setup it wasn't going to work but I was surprised how poorly the TF magnetic units worked. Seems with the soft steel shafts you're guaranteed it won't be true. I've ordered a half dozen more with the same results. You think it's balanced and then turn the prop 180 on the shaft and it's way out of balance. There's got to be something more accurate out there. Anyone? It would be nice of it could accommodate up to 26" propeller as well. I cut my TF sides in half and added some carbon square tubes to extend to 22"

 

[Bartman]

try stripping the steel shaft of the hubs and check it with a straight edge. if it isn't perfectly straight you can try to bend it straight. i've been able to manage with mine but when I think I have a prop all balanced out I turn the shaft and hubs to a different position and check it again.

 

[srbell]

It's amazing how easy it is to knock the TF balancing shafts out and getting a strait one is hard enough in the first place. I'm getting an oscillation on my 950mm quad running 18 fox tech carbon props and can't get rid of it. Even with the DJI IMUv2, it drops serious altitude if forward flight. Wish someone made a commercial grade mag balancer. It would be worth the extra money. These balancers from the airplane hobby are for the birds lol (aka fixed wing).

 

[srbell]

Problem solved. For a $150 I can get a Vortex Dynamic Balancer. Well that is if any were in stock lol! If it works half as well as advertised I'm set. It's sold by http://www.dynexhobby.com. Very cool. Anyone run across this unit?

 

[snurre]

While careful balancing certainly does good, consider that the props unevitably produce vibrations exponentially to the copter air speed due to assymetric airflow over the blades, causing more lift on the blade moving forward and less on the one moving backwards.


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[PeterLester]

I have been hoping to buy one as well...... but also have heard that it is best used for more precise balancing after conventional prop balancing has already been done. At least it does it by proven scientific methods versus the crude use of IPhone iseisomometer method that can get a bit confusing at times.

Problem solved. For a $150 I can get a Vortex Dynamic Balancer. Well that is if any were in stock lol! If it works half as well as advertised I'm set. It's sold by http://www.dynexhobby.com. Very cool. Anyone run across this unit?

 

[vtaildriver]

Don't forget about the hub. A prop may balance horizontally, but when held vertically falls off to one side. Let the prop find the low (heavy) side and mark it. If it's not hanging straight down, the heavy spot is not the tip of the blade but more in the hub area. I ran into this with a batch of APC's. Took an hour to balance all six. Got them all to where they will stay in any position on the balancer.

 

[gtranquilla]

I discarded my Dubro magnetic prop balancer. I discovered that the steel shaft had become magnetized such that it always stopped rotating at the same position which threw off prop balancing. I tried to demagnetize the shaft by a few quick hits on one end with a hammer but that in turn created a slight bend that could never be completely straightened. I trust the ball bearing type more and get better results.

Anyone else have trouble balancing propellers? It seems my old trusted Dubro units have way too much friction to balance the newer light weight props and the magnetic balancers seem to have a lot of trouble with strait shafts. It was obvious with the Dubro's wheel setup it wasn't going to work but I was surprised how poorly the TF magnetic units worked. Seems with the soft steel shafts you're guaranteed it won't be true. I've ordered a half dozen more with the same results. You think it's balanced and then turn the prop 180 on the shaft and it's way out of balance. There's got to be something more accurate out there. Anyone? It would be nice of it could accommodate up to 26" propeller as well. I cut my TF sides in half and added some carbon square tubes to extend to 22"

 

[DucktileMedia]

I think the best invention for balancers would be a magnetic setup that allowed you to install your assembled prop AND bell housing off the motor and spin that whole assembly. The steel shaft could go to the magnet side and the nose would need a cone to center it on a bearing for since that is generally non magnetic materials. You would probably need to do an initial rough balance of the prop by itself but this would ensure a really accurate total balance. Surprised no one has made it yet.