prop balancing aggravation

I want to know if i am going about this the right way.

I have a topflite magnetic balancer and graupner 9x5 eprops. I am TRYING to balance them.
When on the balancer i work on getting the props level using tape. Then once they are holding level i move to balancing the hub. By this point i can already tell which side of the hub is heavier. I use CA to add weight to the lighter side. But now it starts to show that my previously balanced blades are out of.balance again! !!!

Arrrggghhhhh

Do i at this point fiddle with the blades or the hub?
 

Tomstoy2

Member
Ok, balancing props is a time consuming progress, but you are going about it incorrectly.

Ensure the balancer is level, first step.

Balance the blades by sanding down the inside surface of the heavy prop when the prop is level with the surface, don't use tape. When checking the balance afterwards, rotate the prop 180 degree's and continue sanding until it is holding level.

Next the hub, prop vertical. Sand the heavy side of the hub. If sanding does not remove enough weight then add weight to the light side. If the hub is so far out that glue is not enough you can try adding tape, but that is not a good idea as tape can be thrown. It's better to consider that prop unusable.
Once done, the prop should stay on the balancer in any attitude.
 

kloner

Aerial DP
I've sanded and i've added,,, i prefer the adding CA and sand that to taste. Theres some great videos online about doing it
 

I want to know if i am going about this the right way.

I have a topflite magnetic balancer and graupner 9x5 eprops. I am TRYING to balance them.
When on the balancer i work on getting the props level using tape. Then once they are holding level i move to balancing the hub. By this point i can already tell which side of the hub is heavier. I use CA to add weight to the lighter side. But now it starts to show that my previously balanced blades are out of.balance again! !!!

Arrrggghhhhh

Do i at this point fiddle with the blades or the hub?

I have the same issues using the topflight MB.... same procedure but after hrs of messing about sanding, adding CA to the hub ect to get a perfect balance ,I found out that once balanced if the prop is turned on the shaft it will show out of balance !...thinking somethings up I then marked the shaft and spun it without the prop and it would act like a polarized magnet always indexing to a set point , and in my mind this would influence any balance. I posted on another site asking if I was nuts and no one had a definitive answer. I finally gave up and bought a Dubro with the mechanical wheels. I don't think they are as sensitive....I noticed that the topfliht is highly sensitive ...2 or 3 strokes with 600 grit sandpaper is noticeable which might be to much for the light weight props we use.
 

I have the same issues using the topflight MB.... same procedure but after hrs of messing about sanding, adding CA to the hub ect to get a perfect balance ,I found out that once balanced if the prop is turned on the shaft it will show out of balance !...thinking somethings up I then marked the shaft and spun it without the prop and it would act like a polarized magnet always indexing to a set point , and in my mind this would influence any balance. I posted on another site asking if I was nuts and no one had a definitive answer. I finally gave up and bought a Dubro with the mechanical wheels. I don't think they are as sensitive....I noticed that the topfliht is highly sensitive ...2 or 3 strokes with 600 grit sandpaper is noticeable which might be to much for the light weight props we use.

I noticed this too so i rolled the stock shaft on a sheet of glass AND what do you know? Thete was a slight bend in it. So i use another trick. One that is suggested by topflite. Use the gp fingertip balancer. The shaft is only 2-3one inches , hardened and the cones thread on.
 

kloner

Aerial DP
I spin the prop on the shaft and watch for it to fall after i'm that close. most people call it a day when it is remotely close. getting graupners better than the package is pretty hard. starting with apc or anything wood and you see an immediate improvement

the replacement shafts are pretty cheap and you gotta treat em like a lady or they bend. i've had 2 times in a row bent in the mail
 

I rwally am suprised by graupner..for being german and costing more they are off by a bit. I have a set of folders for my zephyr. I have access to scales at work that can measure a diff of 0.0001 gms. One of the folding props was off by .1 gms which is a lot considering the rpms.
 

kloner

Aerial DP
alot of what shows up on that isn't fixeable. straight out of the package is the best. if it goes away, get a new set. there so thin they chip and cavitate wear pretty bad. i'm the worst, fly in a desert and take off in sand/gravel, etc
 

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