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prop ballancing tool

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Old 09-08-2011, 03:24 PM
  #1
DougB1
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Default prop ballancing tool

What does one use to ballance props ranging from an 18x6 to a 26x10 wooden
Thanks
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Old 09-08-2011, 04:49 PM
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flyallday
 
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Default RE: prop ballancing tool

I have this one http://shop.dubro.com/products/produ...1.1.0.0.0.0.0? I have used it up to 18" but you can do any size.

Harry

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Old 09-08-2011, 08:38 PM
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Default RE: prop ballancing tool

A t-pin.

Hold the prop horizontal in one hand and in the other take a "T"pin and hold it up at a 45º angle and set the prop on the pin so the tip of the pin is halfway through the thickness of the prop in the shaft hole. Let go of the prop and the heavy side will drop. Scrape the backside of the prop with a knifeblade on the heavy side. Repeat until it stays level. I have done 20" props with this method and it works as well as with 6" ones.
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Old 09-09-2011, 08:52 AM
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Default RE: prop ballancing tool

I use one of these:

http://www3.towerhobbies.com/cgi-bin...&P=SM&I=LXHY61

I don't usually shave weight off... I mix 5min epoxy and just dab it on heavy side until its balanced. After its dry I just hit that spot with touch of sandpaper to smooth it. In my opinion that's easier/better then taking weight off the prop... and its not changing the shape of the prop..other then the small splotch of smooth epoxy at the back of the tip. There's other ways too I'm sure.
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Old 09-09-2011, 08:56 AM
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Default RE: prop ballancing tool


Quote:
ORIGINAL: flyallday

I have this one http://shop.dubro.com/products/produ...1.1.0.0.0.0.0? I have used it up to 18'' but you can do any size.

Harry

The Dubro balancer is the way to go for all props. I tried the Topflite unit and it's worthless for big props. Wood props can be sprayed with poly U on the light side to balance.
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Old 09-12-2011, 03:37 PM
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Default RE: prop ballancing tool

I made my own for balancing 24" 4 blade props.

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Old 09-13-2011, 03:02 AM
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Default RE: prop ballancing tool


Quote:
ORIGINAL: DGrant

I use one of these:

http://www3.towerhobbies.com/cgi-bin...&P=SM&I=LXHY61

I don't usually shave weight off... I mix 5min epoxy and just dab it on heavy side until its balanced. After its dry I just hit that spot with touch of sandpaper to smooth it. In my opinion that's easier/better then taking weight off the prop... and its not changing the shape of the prop..other then the small splotch of smooth epoxy at the back of the tip. There's other ways too I'm sure.
I'm sure you meant to say apply the epoxy to the lighter side. I use the same technique but mask the prop and spray the tip with spray paint. I continue with consecutive light coats until it is balanced. No sanding required.
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Old 09-13-2011, 03:21 AM
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Default RE: prop ballancing tool

The Dubro unit is perfect.. I use it up 32" props.....
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Old 11-08-2011, 08:13 AM
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Default RE: prop ballancing tool

I use the Dubro balancer and will start with sanding t achieve balance. If it is really far off I put a drop of CA on a piece of plastic bag and wipe it across the backside light blade close to the tip. Then sand the CA smooth and check balance again.
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Old 11-08-2011, 07:07 PM
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Default RE: prop ballancing tool

Balancing the hub is the hard part. Haven't tried it yet, but guys at my field just showed me a genius method: Cut a tiny corner of sticky velcro tape (the soft hairy layer) and stick it to the light side of the hub. (Roughen up the hub surface for better adhesion). Drop CA on it until balanced. It dries to a bulletproof mass on the hub. Ugly but effective.

In regards to balancing the blades: I've heard you should sand or scrape or paint or tape the TOP (convex) face of the prop blade, not the under cambered back face. The back (concave) face is the critical "business end". Modifying this back face changes the PITCH=bad. Modifying the convex face just changes the airfoil slightly, which should have far less effect on efficiency or pitch.

It also seems to me preferable to take a bit off the heavy END of the blade or add paint or tape to the light end. Removing a bit off the end may make one blade slightly shorter or change the tip shape slightly, but that should be negligible to performance as long as it's balanced. The closer to the end you work, the less material you need to add or subtract. That seems preferable to changing the actual airfoil or pitch of the prop by messing with the faces.
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Old 11-09-2011, 04:56 PM
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Default RE: prop ballancing tool

Here is the balancer I use for large propellers:

http://www.teamaeroscale.com/fema3dbalancer.html



Another really nice one is the PSP Mfg:

http://www.pspmfg.com/RCPropBalancers.html


Iuse both of these....

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