RunRyder RC
 8  Topic Subscribe
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 1811 views
Scorpion Power Scorpion Power
HelicopterScale Model RC Helicopters › scale blade balancing
12-17-2013 06:25 PM  3 years agoPost 21
Mojave

rrElite Veteran

Palos Verdes, Ca.​USA

My Posts: All  Forum  Topic

Hi Sandy, it looks like you have a good solid set up. I have only used this method to correct the CG on root biased CG blades with a lighter tip weight. It's a simple solution given that the root biased CG blade has a lighter tip weight (which is the more common situation). I have not tried it with respect to correcting a heavy tipped blade. So, is your CG location close in this blade set (within 1/8 inch from blade to blade)? If so, you may want to leave it alone, as I would not want to chase my tail on this one by creating demons.

As I said when I started this thread, it's an ongoing experiment. So your findings may lead to situations where this set up won't work. I'm thinking that with the different manufacturing techniques and materials used in making the blade sets, that unless they are autoclaved and pre-preg materials used (like spin blades) with a bleeder ply, any combination of weight bias is possible. This would hold true for all "wet" lay ups of FG or graphite cloth.
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
12-17-2013 07:10 PM  3 years agoPost 22
Phoenix NOTAR

rrApprentice

State College, PA​USA

My Posts: All  Forum  Topic

Barry,

The "balance point" CG of these blades are currently very close. The set is within .028" (0.71mm), and two of the blades are within .003" (0.08mm) of each other.

So my plan is to get the overall weights matched by adding weight to the lighter blades at the current CG, and ignore the "tip weight" variation at this time.

For what it is worth, I checked my Starwood Lama blades while I was playing with the jig, and all three blades were less then 0.1 gram in overall weight AND "tip" weight, as they came with the kit, no adjustments needed. Very cool.

It has been an interesting test, as you noted.
Thanks for the feedback.

Sandy

PM  EMAIL  GALLERY  Attn:RR  Quote
12-17-2013 08:14 PM  3 years agoPost 23
Mojave

rrElite Veteran

Palos Verdes, Ca.​USA

My Posts: All  Forum  Topic

Hi Sandy, I think your approach is wise. I like when the blade sets are super close, there's much less work involved in getting them spot on.

I know that the Funkey and rotor tech scale blades come to century in a bulk shipment and they have to mix and match them into sets based in OAW and CG points. This has got to be very time consuming. Thanks for your input with this project, it's much appreciated.
Barry

All helis and planes have an expiration date stamped on them...you only find it after you crash!!

PM  EMAIL  GALLERY  Attn:RR  Quote
12-18-2013 12:00 AM  3 years agoPost 24
doorman

rrProfessor

Sherwood, Arkansas

My Posts: All  Forum  Topic

Experiment!!

I got my set from Barry and hopefully will get to give these a test soon.

I have a few sets of blades to try this on.. actually this is a up to date version of what we did in the good old days, when it took longer to build your blades then the heli!!
Will let you know what I find..

Thx Stan

AMA 2918-Team JR, Spin Blades, East Coast Scale Helicopter,Castle Creations

PM  EMAIL  GALLERY  Attn:RR  Quote
12-19-2013 04:10 AM  3 years agoPost 25
jusrap

rrNovice

Asia

My Posts: All  Forum  Topic

Great thread.. Very interesting

In a previous thread, some five years ago now, it is argued that the overall weight and cogs can be different, but it's the moment that is the most important factor.https://rc.runryder.com/helicopter/t445787p1/

I'm not trying to start an argument, but I would be interested to know the definitive views and answers based on experience

Life's sweet

PM  EMAIL  Attn:RR  Quote
12-19-2013 05:08 AM  3 years agoPost 26
R.J.

rrVeteran

SF bay area, CA USA

My Posts: All  Forum  Topic

The issue is that the 451.5 gram blade is also the 278.0 gram "tip weight" blade. There is no way to add the 1.7 gram overall weight without also increasing the tip weight even more.
Sandy,

You add the 1.7 grams at the root of the 451.5 gram blade. The tip weight is unaffected, the overall weights are the same, so the spanwise CGs must also be equal.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-19-2013 04:49 PM  3 years agoPost 27
Phoenix NOTAR

rrApprentice

State College, PA​USA

My Posts: All  Forum  Topic

R.J.

What you state is true, I can add weight to the root, and not effect the "tip weight" (much). And this is what I did with a set of Vario aluminum blades for my R22.

But, the other factor of the blade set referenced in my post, is that the "actual balance point" CG of this set is extremely close blade to blade. I did not want to mess with that condition. So I corrected the overall weights to be the same by adding weight to the lighter blades AT the balance point CG. This had the unfortunate effect of increasing the "tip weight" delta even more then it was.

I used tape for this correction, just so I can experiment with flying the heli with this condition, and then remove the tape and try again with a overall weight correction made at the root. I may then make another test by adding additional weight to all blades to try to get a matching tip weight and overall weight. The goal being to see which method will have the same heli fly smoother.

Sandy

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 1811 views
Scorpion Power Scorpion Power
HelicopterScale Model RC Helicopters › scale blade balancing
 Print TOPIC  Make Suggestion 

 8  Topic Subscribe

Wednesday, November 22 - 1:31 am - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online