Just pulled the trigger on a 620 10s combo kit.

[centuryman]

Just ordered a new swift 620 10s combo deal from heliworld . Can't wait to feel the power of 10 and maybye 12s setups. I have the batteries for both and i have a hv85 in my 8s swift 16 that will work with 12s.
Has anybody tryed 12s in a swift 620?
My calculations put it around 2300 to 2400, Sound right?
That headspeed should be safe on the full metal head.I hear of guys running there trex 600e's at that rpm with no problem.
With some luck the kit will be here on wensday and with a couple late nights i hope to have it in the air next weekend:)

[RAV50]

You lucky devil !!

That should be a real powerhouse heli.

[centuryman]

I'm counting the hours till it gets here.
RAV 50 what do you think about 12s?Have you heard of anybody trying it.The motor kv rateing with a 9 tooth pinion or 10 should put it in the ballpark i think.

[RAV50]

I guess it would all boil down to what power the components are designed to safely take.

Like when one soups up a car. Dropping 600 horses into a car that had a 250 hp motor may mean the clutch, the tranny, or differential will fail in short order because they where not designed to take the power....and even after hooking to a trany and differential system that can take it, all of that power has to be transfered to the pavement. And two tires may not be able to properly do so without braking loose, so one may have to go not just bigger tires, but to 4 wheel drive.

A 12S/3300/20C Lipo (not A123) pack can feed a demand for 4336 watts - that is 5.8 hp.

Already you may be pushing the limit of a number of components with the 10S pack at a 2400 rotor speed.

To stay within design limits of the components in question, by using small and light blades, limiting pitch ranges and gearing to the only 2400, the only advantage I can see is longer flight times.

Of course, one can always go to bigger components, and bigger blades (tires) to properly absorb the power, but then you are into a bigger sizes heli.

Just a note on another system of consequence on the heli is the tail rotor. Most helis use tail rotor gearing of about 4.6 to 5.1 to 1 relative to the mainrotor. For this discussion let's use 4.8 to 1. So if you go from 2100 to 2415 on your main rotor, the exponential ratio of the power demand means you have a 15% increase in head speed but have absorbed a 50% increase in power. This also means that your tail rotor has gone from 10,080 to 11,568. Again absorbing 50% more power then it did before.

So as you can see, these two areas are important limiters of the power they can absorb before failure. Of course, putting longer blades on either will allow them to absorb more power, but if they are not designed to do so, it ca become dangerous very quickly.

As it is now, I think you are starting to push the design limits. All manufacturers build components to take higher forces then what they figure their helis will be used for, just to help insure the safe operation of them. I know Century, and a number of other manufacturers, test fly their products for 1000's of flights before putting them on the market, in order to insure their design integrity. This integrity is only insured IF they are powered and used as intended.

So if you add battery power (which is a function of potential watt hours of use) and you are already using the components to the max, then increasing the battery power can only safely be used to increase flight time.

[centuryman]

Thanks RAV50 for your input.These are are all good points and i have been considering these things and have had numerous discussions with knowledgeable people on this subject.Like you said it comes down to how much power can a given heli hold.and how much weight to disk size.As you said this setup should net you more run time.But for more then one reason, I've had conversations with NEU reps on this subject of higher voltage, and basiclly what i got out of it , is your highest effeciancy will be at the highest voltage that your kv and gearing will allow.And the more effeciant your system is the longer everythingin it should last, because it will be pulling less amps and running cooler and also longer run times is a side benifit.I have a phazor 600 running on a 1907 on 8s that is absolutley crazy fast and powerfull and the esc and motor are cool at the end of a hard run.So i put that same power system in a swift 16 with an absolute awesome result.Every thing is cool run times are awesome weight is still at 6 pounds and when i ocasionally need that extra power it's there just waiting.So my experiment continues with the 620 My thinking is with a full metal haed and carbon frame and a good strong desighn, that 620 should be able to hold at leasta s much power as the chinsy built trex's that i know people are putting 5hp motors in all the time, plus they weigh close to 8 pounds where as the swift with the right battery should be atleast1 pound lighter.I also talked to century on this and they tell me that there reps regurally run 16 degrees of pitch with no problems.
So in conclusion I'm very curious to see how this experiment is going to turn out.

[centuryman]

The heli is done just waiting for the weather to clear to maiden it.It's one sweet looking machine.

[RAV50]

I got one sitting in a box here - gotta get my butt in gear and get it built.

I am just having too much fun flying my two other Swifts.

[centuryman]

the weather has been horrible latley thats why mine is done already.

[RAV50]

Well that is one of the reasons mine isn't - the weather here has been good enough to get some flying in - 3 yesterday and 5 today.

[centuryman]

I got in 9 flights yesterday before the blizzard hit.The weather should break tomorrow and the new swift should see some air time.The last battery just showed up this morning so i can try 12s if i feel so inclined.

[centuryman]

Just maidened the 620 on 10s today. power was awesome!! but the chicken dance upon spolling down was not cool. i try loosing the blades. it got worse ,i tryed changing the throttle curve and pitch curves . no difference. anybody got any ideas.I'm thinking it's the esc since the heli flys perfect smooth and vib free and every thing is new.

[JustPlaneChris]

My Swift stopped doing the chicken dance on spooldown when I ditched the stock "bowlegged stork" landing gear and installed some Hirobo Scedeu (sp?) struts and skids.

[centuryman]

now that you mention it.on both my other swifts i have low profile landing gear that are sustatialy sturdier and neither one of theme do the chicken dance.thanks for the idea i will switch out the gear tonight.and on wensday give it a try:)