GA,

Magnetic balancers work best with these small props, due to their very low friction. Alternatively, you can simply dynamically balance them on the plane. These little props are notorious for being out of balance. In 4 years of flying UMs, I have only had one GWS prop (a 5030) that didn't need balancing. I felt so lucky that I bought a lottery ticket.

Joel

Joel,

Thanks. Is dynamic balancing just sticking bits of tape on till vibration felt through your hand disappears?

Originally Posted by GoAround

Joel,

Thanks. Is dynamic balancing just sticking bits of tape on till vibration felt through your hand disappears?

Yup. Spool-up & check the vibration level. Put a small piece of tape on one blade & recheck. If the vibration is worse, move the tape to the other blade. If it gets better, add more tape. Rinse & repeat as needed. It usually only takes a few iterations once you get the hang of it. A magnetic balancer is a better option, but but dynamic balancing will suffice at this scale.

Joel

Originally Posted by turboparker

GA,

Magnetic balancers work best with these small props, due to their very low friction. Alternatively, you can simply dynamically balance them on the plane. These little props are notorious for being out of balance. In 4 years of flying UMs, I have only had one GWS prop (a 5030) that didn't need balancing. I felt so lucky that I bought a lottery ticket.

Joel

The APC 7040's I've been getting for my 540QQ have been perfectly balanced right out of the box! That's a first. What a relief to have at least one plane that runs silky smooth with no effort

Originally Posted by erkq

The APC 7040's I've been getting for my 540QQ have been perfectly balanced right out of the box! That's a first. What a relief to have at least one plane that runs silky smooth with no effort

Sounds like the Vox wood props I use on my 48" PA Extra. They're factory balanced. I still check them out of habit, but they've all been perfect so far. In contrast - the vast majority of wood props from Top Flite, Master Airscrew, Rev-Up, and Zinger that I've used over the years have required balancing. Also - I've never had a MA nylon or glass-filled prop that didn't require balancing.

Joel

Originally Posted by GoAround

The 5043 on a 2300kV is vibrating very badly and the AS3X goes bonkers, as I found out yesterday. I put the old prop back on which was better but no great shakes (geddit? )

I want to be able to balance these as well as a 4040 which I intend to pick up for the Stryker 180.

I believe the T28D is also out of balance so it is time to get something that will do a range of sizes.

I have been browsing prop balancers. As far as I can see, most will do the job on bigger props (e.g.T28D) just fine but I am not sure about micro ones.

My initial idea was a Great Planes fingertip balancer on razor blades or on the edge of 2 glasses. The shaft is 5/32" which is 3.97mm so I assume the micro props will fit straight on - no idea if it would be sensitive enough though.

Beyond that, we are moving up to spending 4 or 6 times as much.

I'd appreciate any info you have. The net is full of it until you come to micro props ...

I have been able use the Du Bro prop balancer on my props. It gets them pretty close. It has a pretty low rolling resistance.

Originally Posted by turboparker

GA,

Magnetic balancers work best with these small props, due to their very low friction. Alternatively, you can simply dynamically balance them on the plane. These little props are notorious for being out of balance. In 4 years of flying UMs, I have only had one GWS prop (a 5030) that didn't need balancing. I felt so lucky that I bought a lottery ticket.

Joel

How much did you win on that ticket?

I've been considering upgrading my balancer seeing as I have so many micros, and probably one more now that the GeeBee is only $65!! Which magnetic balancer would you recommend?

-Brian

Brian why did you have to go and say that! I am supposed to be selling stuff not buying it.

Luckily, the GeeBee does not attract me so, at least, I am saved that! Thanks for the balancer advice Brian. I am thinking of the Du Bro. If not, I will go cheap and just make a quick mount for a fingertip balancer to do big props and dynamically balance the little ones.

It did a couple of nasty flutters the other day at high speed so I slowed off damn quick (remembering Joel's 3S video ...) and vowed to strengthen it. I put a 1mm CF rod on the underside of the tailplane yesterday, held in place by an untidy application of CA and then a small strip of Scotch tape, which also hides the CA! Beads of CA at the joins on upper and lower side.. I am astounded how stiff it is now. More good advice off this forum.

I have also put bits of glass-fibre tape each side of the rudder and elevator U bends as a quick way to take the slop out of them. I remain too scared to make CA bearings so the back end is till a little loose.

Brian and Erkq you will be happy to know that I got a Top Flite prop balancer, it is REALLY nice the balancing shaft is held between two magnets and it works really well! Well it works a little better then the T pin taped to the top of aerosol can!

Originally Posted by IndyMatt

Brian and Erkq you will be happy to know that I got a Top Flite prop balancer, it is REALLY nice the balancing shaft is held between two magnets and it works really well! Well it works a little better then the T pin taped to the top of aerosol can!

Hahaha... you funny guy... welcome to the proper prop balancer club!

Originally Posted by erkq

Hahaha... you funny guy... welcome to the proper prop balancer club!

It was born out of necessity, I got a sweet deal on a 70" slick and wanted to balance a nice 20" wood prop. It was too heavy and long for the aerosol can balancer!

Originally Posted by IndyMatt

Well it works a little better then the T pin taped to the top of aerosol can!

I have just tried the top of an aerosol for my Sbach's 5043. Worked really well! I got it perfect on the can, moved it to the plane and found vibrations much reduced although the controls still shook a little. From there, I dynamically balanced it and now I can't see them move at all. It has a piece of tape 4 or 5mm square right out at the tip to balance - no wonder it wouldn't fly right!

Off topic but what would the max current draw of the 2500kv motor be? I am looking for an ESC to add with it to do a 2S conversion to the T28.

Originally Posted by IndyMatt

It was born out of necessity, I got a sweet deal on a 70" slick and wanted to balance a nice 20" wood prop. It was too heavy and long for the aerosol can balancer!

So I shouldn't tell you about the Torx #8 duct taped to the edge of the workbench balancer....

-Brian

Originally Posted by GoAround

Off topic but what would the max current draw of the 2500kv motor be? I am looking for an ESC to add with it to do a 2S conversion to the T28.

The brick's ESC is rated at 4.9A continuous & 5.8A peak, so I'd go with a 6A ESC. However, you could simply install an AR6400LBL brick & save some weight. It's a drop-in fit.

Joel