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How important/ critical is Prop Balancing?

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Old 04-08-2012, 06:45 PM
  #26
baddley
 
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Default RE: How important/ critical is Prop Balancing?

Hi

Has anybody used the Vess balance ring ? Can you balance your prop on the dubro without the Vess Blance Ring ? I believe the shaft is long enough too. I have not found a accurate way to ensure the shaft is level and true within the towers to ensure I get a accurate balance ?

Also is it better to balance the spinner and prop at the same time or do them seperately ?

This is my first time messing with gas props I used to just used the cheap fingertip balancer.


Thanks Scott
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Old 04-08-2012, 07:35 PM
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Default RE: How important/ critical is Prop Balancing?

I balance my props on the Dubro balancer

I do not own a balance ring
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Old 04-09-2012, 07:15 AM
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Default RE: How important/ critical is Prop Balancing?

You can balance props and spinners separately. Would be hard to rig all together anyway.

I always balance props, then track the tips and finall hub balance.
I use the same Velcro trick for inside the spinners to get them true.

If you still damage props regularly then it's probably too much work so forgo the hub balancing ang tracking but still balance the prop horizontally and the spinner.
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Old 04-09-2012, 09:08 AM
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Default RE: How important/ critical is Prop Balancing?

IMHO - I think that using both velcro and CA is kinda dumb. Why use two materials ? I balance the hub by just adding some Sigment or Ambroid, old fashion glue. It is even wood colored, and blends in beautifully.

ed
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Old 04-09-2012, 09:25 AM
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Default RE: How important/ critical is Prop Balancing?

Your props must be pretty close to start with. I have had some of the lower quality wood props, in the 20+ inch sizes be severly out of balance. Using CA or clear coat would not work. I ended up drilling a hole in the hub and adding a piece of 1/4" lead rod to make them balance. Basically how full sized props are balanced. Commonly found cheaper wood props from big retailers are the worst. Shipping them back is not an option due to shipping fees.

Maybe someone can enlighten me? Using clear spray finish to balance a prop.... The solvent has weight. To get an accurate reading you would need to let the solvent evaporate. It seems to me it could take days to get the prop dialed in using spray finish.
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Old 04-09-2012, 10:15 AM
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Default RE: How important/ critical is Prop Balancing?


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ORIGINAL: Scota4570
Maybe someone can enlighten me? Using clear spray finish to balance a prop.... The solvent has weight. To get an accurate reading you would need to let the solvent evaporate. It seems to me it could take days to get the prop dialed in using spray finish.
That's why they invented sandpaper!
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Old 04-09-2012, 11:56 AM
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Default RE: How important/ critical is Prop Balancing?

One convent thing is my LHS has a display DuBro balancer next to the rack of props.
Anytime I need a new prop I mount them up at the store and buy the best ones of the size I need and fix them at home.
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Old 04-09-2012, 11:59 AM
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Default RE: How important/ critical is Prop Balancing?

I also find it interesting that people will take great strides to balance their props.

And then will let bugs, grass and dirt stay on the props and never try to clean them.........;0
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Old 04-09-2012, 12:03 PM
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Default RE: How important/ critical is Prop Balancing?


Quote:
ORIGINAL: Scota4570

Your props must be pretty close to start with. I have had some of the lower quality wood props, in the 20+ inch sizes be severly out of balance. Using CA or clear coat would not work. I ended up drilling a hole in the hub and adding a piece of 1/4" lead rod to make them balance. Basically how full sized props are balanced. Commonly found cheaper wood props from big retailers are the worst. Shipping them back is not an option due to shipping fees.

Maybe someone can enlighten me? Using clear spray finish to balance a prop.... The solvent has weight. To get an accurate reading you would need to let the solvent evaporate. It seems to me it could take days to get the prop dialed in using spray finish.
yes it does take time as it has to be left till dry - however prop balancing is never a 5 minute job. i spray a coat each night, check the following night and add till its right. and yes the cheap props tend to be the worst. they do work, but the better ones work better
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Old 04-09-2012, 12:05 PM
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ORIGINAL: ROGER RUSSELL

I also find it interesting that people will take great strides to balance their props.

And then will let bugs, grass and dirt stay on the props and never try to clean them.........;0
yeah - i always have foam blocks that slide on to my tips too, transporting and moving the planes around its so easy to nick the tips....
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Old 04-09-2012, 02:58 PM
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Default RE: How important/ critical is Prop Balancing?

"however prop balancing is never a 5 minute job"

True, maybe 15-minuets. Put the prop on the balancer. Mark the high point (light spot). Drill a hole as if it were for hub bolt such that the prop washer will hide it. Insert lead wire. Lead pencil weights for fishing are good for this. Try balance. Adjust the balance by trimming or adding to the the lead until it balances. Secure with a couple of drops of CA.

I spent way too much time spraying, drying , sanding and generally fussing around before I figured this out. This is how full sized props are balanced. The trouble with using spray finish for weight is that as the solvent dries it looses weight. Unless you let it dry really well it will go out of balance as it dries out more.

Thre are lots of ways to do things, I understand. I do think what I am doing has real advantages for wood props.
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Old 04-09-2012, 03:55 PM
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Default RE: How important/ critical is Prop Balancing?

I not sure that I like the idea of drilling another hole in the hub ? ? ?
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Old 04-09-2012, 05:17 PM
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Default RE: How important/ critical is Prop Balancing?

Just two holes, one for the stud and a second for the balance weight. None of my engines use multiple small prop mounting machine screws. If I had and engine that required half a dozen holes to mount the prop I would not drill any extra holes either. I would also convert that engine to use a single big nut or bolt.
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Old 04-09-2012, 07:49 PM
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Default RE: How important/ critical is Prop Balancing?

I am not very sure of the larger wodden props but atleast in the GRP ones, especially the S2 type with swept tips seem to be more balanced, both in MAS and APC. With the wooden ones, I would use a layer of laquer or epoxy to balance. I feel they dont need to be absolutely balanced, just very close. So far I have used only the GRP props though (DLE20 16X8 and OS 120AX 18X6)

There is a youtube video by Redwing's Tim regarding how to balance the prop and hub which may be very useful to some

Regarding the spinner, best to get a properly balanced one to begin with. I found that the nylon ones with the nylon backplate from most brands never are balanced and after opening and closing a few times, the backplate bends out making them even more unbalanced. But nylon offers the best impact protection. So I now use the GP nylon spinners with aluminium backplate and those are fairly balanced and dont bend or anything

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Old 04-09-2012, 09:31 PM
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Default RE: How important/ critical is Prop Balancing?

Xoar 17X6 prop hole is not big enough to slide through the crank of DLE20. Do I have to use a drill bit to ream it or do I have to use a reamer to make the hole bigger in order to fit in right? If I got to use reamer so what size reamer do I have to use?

Thanks


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Old 04-10-2012, 12:56 AM
  #41
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Default RE: How important/ critical is Prop Balancing?

You should use the drill bit as a reamer. Its the same thing because you already have a pilot hole in the one in the hub. Just keep the drill as straight as possible

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Old 04-10-2012, 02:55 AM
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Default RE: How important/ critical is Prop Balancing?

Hi!
Problem with using a drill bit to enlarge a hole in wood (or any material) is that it can wander sideways a bit!
Best way to enlarge a hole in a prop is to use a stage reamer!

And balancing is soo easy to fix with just a file and sandpapper! Adding anything to
(spinning) prop scares me. We are dealing with props spinning at high rpm here, not full size props at low 2000-3000rpm!
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Old 04-10-2012, 07:46 AM
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Default RE: How important/ critical is Prop Balancing?



And I do not balance my props! Probably not a wise thing to say here! Why don't I do that. Well, mainly because of lazyness, but it is also very time consuming on models that tend to use a lot of props, like a dogfighter etc. I have been balancing props before whenI had only one or two aircrafts and then it was onhigh rpm racing engines.

Somewhere I have an old high point balancer, maybe I should try to balance a prop again for comparing.

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Old 04-10-2012, 08:16 AM
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Default RE: How important/ critical is Prop Balancing?

I buy both xoar and vess props and both brands require very little balancing. Since their wood line of props are already clear coated all you have too do if remove some of the clear coating material. This is done by using a piece of fine grit sandpapaer removing some of the clear coating from the backside of the heavy blade. Simple process and takes less the five minutes to accomplish.
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Old 04-10-2012, 08:54 AM
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Default RE: How important/ critical is Prop Balancing?

Why the back side ? Isn't that the side that's pushing all the air rearward, and doing all of the work ?
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Old 04-10-2012, 08:56 AM
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Default RE: How important/ critical is Prop Balancing?

Quote:
ORIGINAL: troasb@online.no



And I do not balance my props! Probably not a wise thing to say here! Why don't I do that. Well, mainly because of lazyness, but it is also very time consuming on models that tend to use a lot of props, like a dogfighter etc. I have been balancing props before when I had only one or two aircrafts and then it was on high rpm racing engines.

Somewhere I have an old high point balancer, maybe I should try to balance a prop again for comparing.

I did that as well, I quit balancing and went bact to balancing and tracking my airplane props. I see what a difference it makes on my helicopter so I started balancing again. I now see the results on my planes as well. I feel the tracking is even mor important than the balance. An untracked prop is like a wobble wheel on a car with a bent axel.
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Old 04-10-2012, 09:06 AM
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Default RE: How important/ critical is Prop Balancing?

the FRONT side is doing all the work, the air foil is on the front of the prop.
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Old 04-10-2012, 09:11 AM
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Default RE: How important/ critical is Prop Balancing?

And the undercamber part of the same airfoil is on the back. The total of the airfoil is the back and front combined.
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Old 04-10-2012, 09:17 AM
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Default RE: How important/ critical is Prop Balancing?


Quote:
ORIGINAL: Ed

And the undercamber part of the same airfoil is on the back. The total of the airfoil is the back and front combined.

True, I gues I do not know the correct answer for you, I just know I sand the back of the prop, maybe its a convex vs concave issue.
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Old 04-10-2012, 09:40 AM
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Default RE: How important/ critical is Prop Balancing?


Quote:
ORIGINAL: goirish


Quote:
ORIGINAL: armody

Hi y'all,


I see armody is learning the language
Welcome to Texas! I've lived in Texas for years and I don't say "y'all" and don't feel the need to say "y'all". Paula Dean, the woman from Georgia with the cooking show says "y'all" and sounds just terrible when she says it!!
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