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Old Apr 17, 2014, 03:22 AM
Life begins at transition
Australia, WA, Perth
Joined May 2007
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Yes. Tamjets is about the only RC place I've heard of that dynamically balances fans.
Just because it's balanced while spinning doesn't mean it's dynamic.
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Old Apr 17, 2014, 08:41 AM
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Australia, VIC, Melbourne
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Of course 'just spinning' DOES mean Dynamic. Dynamic only means its balance is assessed when in motion of a speed 'resembling' its operation. (eg not a simple 'rock to it higher weight side', as per Static balancing does)

Tamjets balancing only the rotor is not the ultimate way to balance it anyway - it has to be the complete assembled unit... not a part of a unit.
You can say it is a Dynamic balanced ROTOR then, but that is all.... which does not help achieve a compete EDF that is Dynamically balanced. Every single moving item of it would have to be balanced, as well as perfectly aligned (eg shaft adaptor, motor shaft), for that Rotor to be of real use in it.

The best way for 99 % of people is to Dynamic Balance the whole built unit. Even if you DID get a set of 'perfect' parts from some source. The sum of 'perfection' (doing a fan, with every part supposedly perfect) never comes out as 'perfection' once assembled anyway.
And balancing per item of the unit can only be done well enough by...... almost no one. Seeing almost no one has the equipment (bought or home made) to do so.
Dynamic Balancing a whole unit is at worst, as good as doing it item by item (you can two plane balance a whole unit too - but it is hardly of any great use really).

And the HobbyKing claim is just rubbish..... At best the CS/XRP stuff is a "Static balanced Rotor - done mediocore well"... as per every CS/XRP rotor. Some are ok, some are pretty bad.

Wemo Static balance "To 0.01 of a gram".. or some claim like that. And they are actually nothing great and need balancing anyway - if you want a truly good balance. Which again, has to be done Dynamically anyway.
Throw one together as it comes and it can be "OK", but well short of "excellent" that Dynamic Balancing a whole assembled unit can achieve.
And they are far better than what CS/XRP come 'balanced' as.... and as mentioned, even the Wemo 'balance' is of little real use. (if you want an excellent balanced EDF)
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Old Apr 17, 2014, 10:28 AM
chuck
santa barbara, CA
Joined May 2009
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there is balanced and then there is balanced, it boils down to time, effort and maybe money


enough said.

chuck.
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Old Apr 17, 2014, 12:09 PM
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Quote:
Originally Posted by Odysis View Post
Yes. Tamjets is about the only RC place I've heard of that dynamically balances fans.
Just because it's balanced while spinning doesn't mean it's dynamic.
tam uses dual plane balancing machine, not single plane :-)

IMO, if the rotor and spinner balanced, good inrunner, good built adapter, and
good installation then it should be "good enough", not perfect though. There is
a little to worry about it, (just me anyway)

also, donsrc does dynamically balancing the whole edf unit, not only
the rotor and spinner . Extremerc of australia is my first choice when it come to balancing.
Effluxrc of california. EDFhobbies of texas ... all provide balancing service :-)

And some folks at my flying field did great job on balancing with only
some tape and a very simple procedure ... and it is amazing :-)


.
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Old Apr 17, 2014, 03:18 PM
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I'd spend the $15-20 to have them balance it any day.
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Old Apr 17, 2014, 07:36 PM
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Puerto Rico, Carolina
Joined May 2011
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Hi guys ,

I have a V1 Changesun 10 blade edf on which I installed a 3300Kv Cyclone Power motor. Just by accelerating only the motor inside the housing without the fan I can feel vibration through the housing. I am using a 3 cell battery with 3.85V per cell. This vibration can be felt from low to high throttle. So when I installed the fan and rotated it slowly step by step trying to see if the vibration was reduced until I completely turn it 360, I did not have any luck.
Today I received the V3 Changesun and installed a less costly Dr. Mad Thrust 3000Kv and without any special procedure and when I accelerated the motor and fan, this combo was silky smooth! No vibrations at any range.
Are outrunners more prone to vibrations? Is there anything I can do to improve this? Will this vibration damage the fan? Will it shatter into pieces?
Thanks in advance!
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Old Apr 17, 2014, 08:36 PM
FireHawx
United States, FL, Jacksonville
Joined Oct 2011
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Those Cyclone 3300 outrunners had a few runs of bent shafts. I had 2 myself and have read of many others having the same problems. Inrunners do run smoother especial if you get a HET, MEGA, VELOCITY.
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Old Apr 17, 2014, 08:58 PM
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Madison, MS
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Quote:
Originally Posted by kizashi View Post
Hi guys ,

I have a V1 Changesun 10 blade edf on which I installed a 3300Kv Cyclone Power motor. Just by accelerating only the motor inside the housing without the fan I can feel vibration through the housing. I am using a 3 cell battery with 3.85V per cell. This vibration can be felt from low to high throttle. So when I installed the fan and rotated it slowly step by step trying to see if the vibration was reduced until I completely turn it 360, I did not have any luck.
Today I received the V3 Changesun and installed a less costly Dr. Mad Thrust 3000Kv and without any special procedure and when I accelerated the motor and fan, this combo was silky smooth! No vibrations at any range.
Are outrunners more prone to vibrations? Is there anything I can do to improve this? Will this vibration damage the fan? Will it shatter into pieces?
Thanks in advance!
Take the fan and adapter off the cp3300 shaft and spin the motor up. Very lightly touch the shaft while it's spinning with a permanent marker until you see a little color show up. Shut the motor down and see where the maker contacted the shaft. If it's all the way around then the shaft is fine, if there's a spot where it didn't contact the shaft or a very light spot then it's bent.

If the shaft is straight then check out this video and balance the motor. You actually don't even need the phone you can hear the imbalance.
Motor Balancing (2 min 16 sec)
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Old Apr 17, 2014, 10:25 PM
Life begins at transition
Australia, WA, Perth
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Quote:
Originally Posted by PeterVRC View Post
Of course 'just spinning' DOES mean Dynamic.
That's the commonly held misconception. Dynamic balancing must be able to remove a dynamic unbalance. That needs two planes, minimum.
The terms are defined by the International Standards Organisation, in ISO 1940 for rigid rotors for example.

There is a lot of information on how to balance things if you know the correct terms to google. Why should modelers use different words to the rest of the world, and therefore shy away from the lessons learnt before?
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Old Apr 17, 2014, 11:14 PM
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Puerto Rico, Carolina
Joined May 2011
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If the shaft is straight then check out this video and balance the motor. You actually don't even need the phone you can hear the imbalance.
Motor Balancing (2 min 16 sec)
[/QUOTE]

Thanks to both for the advice.


Wow impresive! thats what I can say! Tried the tape balancing and it is getting there. Just like you mentioned, no need for the phone. Just by holding the edf housing you can notice the improvement. Not 100% yet but much better. I can estimate about a 60-70% improvement, with the added tape.
Once I finalize the balance, what could I use to substitute the tape? Could I drill out a small hole on the opposite side and slowly continue drilling until it balances? Or is it to risky? Please keep in mind I have never done this.
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Last edited by kizashi; Apr 18, 2014 at 01:31 AM.
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Old Apr 18, 2014, 12:37 AM
chuck
santa barbara, CA
Joined May 2009
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Quote:
Originally Posted by kizashi View Post
If the shaft is straight then check out this video and balance the motor. You actually don't even need the phone you can hear the imbalance.
http://m.youtube.com/watch?v=Q_yigvysspo
Thanks to both for the advice.


Wow impresive! thats what I can say! Tried the tape balancing and it is getting there. Just like you mentioned, no need for the phone. Just by holding the edf housing you can notice the improvement. Not 100% yet but much better. I can estimate about a 60-70% improvement, with the added tape.
Once I finalize the balance, what could I use to substitute the tape? Could I drill out a small hole on the opposite side and slowly continue drilling until it balances? Or is it to risky? Please keep in mine I have never done this.[/QUOTE]

weight inside the bell is the best ,,,,,, med ca between the mags works well as does epoxy .
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Old Apr 18, 2014, 12:53 AM
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Quote:
Originally Posted by FireHawx View Post
Those Cyclone 3300 outrunners had a few runs of bent shafts. I had 2 myself and have read of many others having the same problems. Inrunners do run smoother especial if you get a HET, MEGA, VELOCITY.
never had one such CP inrunner myself, but from what I read, it seems that in some cases at least it is not so much a bent shaft (why would a shaft bend before use, they are not so fragile) but rather the shaft is not turned down correctly from the higher diameter (in the motor) to the 3.17mm where you put the adapter on (well, the end result is identical, the adapter won't run true...)

Don't know about the 4mm versions, but if thorse have 4mm throughout, then that kind of problem should disappear...
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Old Apr 18, 2014, 03:58 AM
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Sweden, Gävleborg County
Joined Jan 2004
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The CP outrunners have a 5mm shaft, so all versions have the shaft turned down.
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Old Apr 18, 2014, 02:16 PM
Youtube: TomRi25
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Croatia
Joined Aug 2010
667 Posts
does HET 2w23 (4mm shaft) fit in CS70 without a hassle?
(because I see 4x 90°holes on CS70 for standard motors but HET has only 2 that could be bolted in, as it looks to me by looking the web photos of both items)

and would it be a good choice for HK Vampire 1100mm model? not asking for speedie, rather stable and affordable drive.
(power: 4S highCrating LiPo)
https://www.hobbyking.com/hobbyking/...arehouse_.html

thnx
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Old Apr 18, 2014, 02:25 PM
FireHawx
United States, FL, Jacksonville
Joined Oct 2011
935 Posts
Yes, the HET will work on two screws with blue loctite.
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