nfored

I am seconds away from tossing this top flight balancer in the trash. I watched more videos then I can count read the instructions 3 times. I can get a prop to balance take it off put it back on t G e exact same way and the dang thing is unbalanced again. Not to mention turning the balancing rid around with a balanced prop still attached shows the prop that was balanced facing one side is unbalanced facing the other side. Same thing if I balance both the prop and hub.

The prop balancing rod seems true but I have noticed the rod with no props on it when spun and stopped by my finger will always twitch to the same side.

Weasel Keeper

My Feedback: (16)

I didn't like my TF balancer either. Bought a Dubro Tru-Spin and it works much better. The Dubro seems to be much more precise. Anybody want to buy a TF prop balancer?

nfored

I wish this thing just kinda worked I mean if I could get it mostly balanced great. However it's unusable as is for all I know I could be making it worse. Thank goodness I decided to add weight and not remove it so no real damage done to the prop a member on rc groups suggest air flow in the room so I will try again in the morning in a room with no air movement.

grosbeak

Another vote for the Du-Bro...

AMA 74894

My Feedback: (1)

yup, although I love MOST top flite products... their magnetic prop balancer isn't one of them ;-/
another vote for the DuBro Tru Spin (I even do 50MM EDF fans with mine.)

CafeenMan

Unless you're turning super high RPM if you get it really close then it's close enough. Really. You're talking about the magnetic balancer, right?

grosbeak

Yeah, but how is the OP to know whether he's close or not when he can't get a consistent reading?

nfored

Yes I could be making it worse thinking it's getting close

iflircaircraft

Make sure the hole in the prop is centered. If it isn't it will drive you crazy trying to balance the prop.


Tom

Bozarth

My Feedback: (15)

And how do we do that? And how do we fix it if it's not?

Kurt

jester_s1

If the shaft isn't balanced with no prop then the balancer is defective. I like the Du-Bro balancer better too since it allows you to do really big props and spinners too, but the Top Flight design is sound.

rt3232

My Feedback: (6)

my first step for wood,props, is to maks a plug fot whole that just pushes in with finger pressure to find the center then measure to the tips to make sure the pre drilled hole is in the center ( hav found them to be off as much as 1/8 inch) span wise ie: tip to tip and the hub off 1/16, not offten but over my 40 years of flying rc .15 to G-62's and when I find one I have allways sent it back to the mfg at my expence with a polite note, and hace allways had good results generaly I have gotten 2 for 1 and a thank you note

once that is done I have used both balancers but I like thr du-bro best, and over the years I have a set of steps that works for me.
and once you have the center hols right balancing is a lot easer.

Hope this helps

Bozarth

My Feedback: (15)

Couldn't that tell you that the blades aren't the same length?

Kurt

rt3232

My Feedback: (6)

Kurt

Yes But if you take some good measurements tip to hub mill start points, or hole center to start of mill points it can also tell you the orignal hole is not centered. been there done that but that is just me some props will balance with a drop of ca at the tip or on one side of the hub, and you can scrape the back side of the heavy plade, add acoat of rattle can clear coat on the light blade just depends on how close you want to get.

Cheers

PS I check and balance every prop I buy

Bozarth

My Feedback: (15)

I agree with everything you are saying but I think we could measure everything until we are blue in the face. I have been buying props since 1975 and have never measured the location of the hole in the hub. I balance my pylon racing props (gave up balancing sport props decades ago), but APC props are almost perfect out of the bag, from my experience. And when I have had to pull one directly out of the package and install it quickly between heats, I could not tell a bit a difference. The only time I could ever attribute a poor run due to an imbalanced prop is after a prop strike. It reminds me of an old college engineering course addressing tolerance standards and how we can introduce more errors in our data simply by our poor measuring abilities.

Kurt

jester_s1

APC props might be "good enough," but by the accuracy of the Du-Bro balancer every one that I have ever taken out of the package has been out of balance. Same goes for Master Airscrew. I haven't used any other brands. I take the extra few minutes to get them perfect including the hubs. It might not matter much in the grand scheme of things, but I also don't have screws rattling loose and glue joints breaking from vibration fatigue either.

Bozarth

My Feedback: (15)

Exactly. But my point was that the balancer has to have a tighter tolerance/accuracy than the balancee. Not sure I would assume this with a Du-bro. Cheers.

Kurt

HighPlains

My Feedback: (1)

For small props (glow engines .60 and below) I don't bother to balance props. I just put the heavy blade on the same side as the crankshaft counter weight). Most engines can use more weight on the counter balance side.

rt3232

My Feedback: (6)

Ok guys maybe I should have said I am only talking about wood props, and the cutting tools have come a long ways from when I started balincing them about 40 years back. frist balancer was a bubble unit

I am not a fan of APC's except on the smaller engines, and never realy balenced them I did check a few. have given up on most other plastic props and have disposed of all of my small engines. so I am thinking 18 inch wheels and larger

But it is like I said it is just how close you feel you need to be and I like to soft mount my bigger engines just to get some of the natural vibration out of the air frames.

You do have to keep the du-bro unit clean, and if used correctly it will do a good job.
we all have to do what works for our selves

Cheers

hairy46

My Feedback: (1)

Had the top flight now I too am a Dubro fan, the top flight made me look harder for a better mousetrap"

CafeenMan

A magnetic balancer has close to zero drag so if the prop moves very, very slowly it is as close to being balanced as it can be. If the Dubro shows that same prop as being balanced it's probably just because the Dubro has a lot more drag with the wheels. I have a magnetic balancer that has the same trait as the Top Flite and I trust it a lot. I've never used the Top Flite though but it sounds like the same behavior as mine. If it is then it's nothing to be alarmed by.

jester_s1

The Du-Bro doesn't have much drag at all. I can put a 10x6 on it and get it balanced right and it will turn really slowly for several turns, probably one turn every 5 seconds for 2-3 turns. I even balance my little 6x4 electric props on it and can get a consistent reading even down to getting the hub balanced.

CafeenMan

Yeah, I understand how it works. It's basically a rip-off of the Robart balancer. But it's still a lot more drag than a pin-point touching a magnet. Think about it this way using pretend numbers.

If a balancer held between your fingers has drag of 10 and a magnetic balancer has drag of .001 then the finger balancer has 10,000 times more drag than the magnetic balancer. If the Dubro balancer has only .1 drag then it's still almost zero drag but 100 times more than the magnetic balancer.

On a magnetic balancer, if the propeller is exactly balanced and you lay half an eyelash on a blade near the hub that blade will drop pretty fast. On a 30K rpm motor a propeller that amount out of balance wouldn't be any problem at all.

jester_s1

There may or may not a difference at the minutely tiny number's you're talking about. I certainly don't have the equipment to measure the friction and compare the two. I do know that the Du Bro can sense a hub that is one little dot of CA from being in balance. Given the leverage that a hub has versus a blade, I'm confident that the Du Bro balancer is capable of getting the blades perfect and the hub very nearly perfect.

HighPlains

My Feedback: (1)

So Du-bro copied Robart? But Robart operates just like the original High Point Products multi-use precision balancer.

But it would appear that Robart bought the rights to the design some years back.