General SR120 questions??

[zeeland rc addict]

well im new to the hobby and purchased the dx6i and the 120 sr bnf, very satisfied with the progress i have made in two weeks, I can fly the heli left to right back and forth and now getting used to flying it facing towards me! very good begginer heli and would recommend to it to any newbs!! enjoy all your training and customization of the dx6i tony. cant wait to get my trex 450!!

 

[gravybird]

Hey zeeland, Do you get to do any of your flying outside with your 120? Mine has been 98% indoors because of the wind where I live. I really like doing the banked u turns. I have a long narrow basement, so I get a lot of back and forth practice.

 

[zeeland rc addict]

gravy i do in fact fly it outside when i can, if its 5 to maybe ten mph its flyable anything above thats a challenge. It does great outside can really crank it up and have some fun, lol just look out for powerlines when you get it outside hahaha. Its kinda hard to get nice weather to fly here in michigan, but we have been getting spoiled this winter

 

[gravybird]

hahaha, yeah. us too in minnesota, the best winter ever! right now not a spec of snow to be found on the ground except the plow push piles

 

[zeeland rc addict]

ya its not a good thing though in my opinion. Lived here for 23 years now and never seen a winter like this, last year at this time we had 3 feet, so far we got about 20inches all together.

 

[gravybird]

I know there is ill effects gonna come from this, but I drive for a living, so I'll be obliviously happy about the road conditions this year

 

[Tony]

what do you mean "ill effects gonna come from this"? I said I had to drive in this crap, but only if I got caught in it. If it was already icy, I stayed home and didn't drive. I'm not putting myself or others in danger because someone is about to run out of fuel lmao.

 

[gravybird]

well I am thinking of odd weather patterns, and drought, however I know virtually nothing about the weather. but ya, I dont stop driving unless the roads are closed, and even then I look for a way around if possible

 

[gravybird]

well I had a relatively good morning with flying my 120sr. but I did learn a couple things... You can't fly a heli with the battery lashed to one of the landing legs with zip ties I was able to tuck the battery up in the belly of the canopy, but it still affected the flight, and made forward flight a little akward. my battery cradle was a casualty in last weeks crash, and the new one won't be here until this afternoon in the mail. also I had a couple times where the tail rotor went crazy on me, and the heli started spinning in circles, all of the wires seem to be in tact, any clues what could cause that kind of behavior? cant wait for the battery cradle to get here, and try it again if the wind stays down, but I doubt it will

 

[gravybird]

I also switched it to the "advanced swash setting" where the linkage rods hook onto the longer of the two sets of links on the swash plate.

 

[Tony]

one thing that goes bad on these 120's is the tail motor. If all of yoru settings are correct, check the motor, it may be time to replace. That's the bad thing about tail motors...

 

[murankar]

order a couple battery trays. They get weak rather easily. along with a few landing skids and a swash for good measure. it's good to extra, you never know when you will need them.

 

[gravybird]

tony, you were spot on with the tail motor. I just replaced it not too long ago, so yeah, they don't last long at all, maybe ten battery cycles or so. Murankar, I will definitely be ordering more of those battery trays. I just got the one in the mail a bit ago, and WOW what a difference that makes having just that little bit of weight in the right spot.. who da thunk it. I'm enjoying watching your 450 progress murankar, I am hopefully soon in your footsteps with my own 450, but I want to get really good with my 120, and mcpx first.

 

[murankar]

I have had many growing pains with this. It is my first build so I am having many first timers issues. It has been fun to this point I hope to continue on with the fun. Good luck with your 120sr, I need a new fly bar. I am considering the RKH upgrade, its out of stock and is $35. RKH is Rakon Heli and their site is http://www.rakonheli.com.

 

[Dodge DeBoulet]

tony, you were spot on with the tail motor. I just replaced it not too long ago, so yeah, they don't last long at all, maybe ten battery cycles or so. Murankar, I will definitely be ordering more of those battery trays. I just got the one in the mail a bit ago, and WOW what a difference that makes having just that little bit of weight in the right spot.. who da thunk it. I'm enjoying watching your 450 progress murankar, I am hopefully soon in your footsteps with my own 450, but I want to get really good with my 120, and mcpx first.

Can you clarify what you mean by "ten battery cycles or so?" I'd ask you if that was a typo, but there's a big difference between say, "ten" and "one hundred" . . .

I'd say I put between 150 and 200 flights on my 120 SR before the first tail motor started to die, and I've had close to 100 on the second tail motor. That one's still going strong.

In my experience, there are 4 failure modes for the tail motor:

1. Tail rotor pressed too far onto shaft, causing binding between the blade hub, thrust bearing and motor housing; the rotor should spin relatively freely
2. Insufficient protection of the power leads where they exit from the motor housing (a narrow band of heat shrink tubing carefully shrunken onto the butt end of the motor cage works wonders)
3. Chafing and eventual shorting of the tail rotor wires in the tail boom
4. Wear and Tear (i.e. "natural causes")

Taking care of #1 and #2 will dramatically improve the life span of the tail motor. #3 isn't anywhere near as common, but it does happen.

 

[murankar]

Most people do the heat shrink route i believe. that one mod has quite a lot of videos on it. I have had a few motors myself but that was due to poor piloting on y part. This motor is the longest running one I have had. Not sure how many operating hours are on it, but it is quite a few at this point. It is starting to ware a bit and should consider getting a new one soon. first I want the new flybar because mine is broke at the ball link for the rotor head. The rkh flybar should do the trick. I hope they are in stock by payday.

I am adding the review of the rkh upgrades for those who care lol!
http://www.youtube.com/watch?v=G9NlrI37GP0

 

[Dodge DeBoulet]

Most people do the heat shrink route i believe. that one mod has quite a lot of videos on it. I have had a few motors myself but that was due to poor piloting on y part. This motor is the longest running one I have had. Not sure how many operating hours are on it, but it is quite a few at this point. It is starting to ware a bit and should concider getting a new one soon. first I want the new flybar because mine is broke at the ball link for the rotor head. The rkh flybar should do the trick. I hope they are in stock by payday.

I've heard mostly negative reviews about the RakonHeli flybar; an awful lot of people seem to be getting severe TBE. On the other hand, their swashplate sounds pretty good as long as you get the metal shavings purged from the hub of the thing.

Before spending the money on the RKH flybar, I'd recommend you try stiffening the stock flybar (start with a new one if the one you already have is worn) with some 2mm CF rod. It fits right into the groove on the bottom of the flybar; just make sure that you do it in such a way that the flybar remains perfectly balanced.

 

[Tony]

Actually, the #3 you posted, if it shorts out, it will fry the board, and not the motor. Shorting out the motor will effectively apply a brake. But you have some great points to look into if motors are dying all the time. Welcome to the site.

 

[Dodge DeBoulet]

Actually, the #3 you posted, if it shorts out, it will fry the board, and not the motor. Shorting out the motor will effectively apply a brake. But you have some great points to look into if motors are dying all the time. Welcome to the site.

I agree with you 100% on the shorting issue, but I think some portion of the reported tail motor problems weren't actually motor problems. Intermittent shorting might cause something that seems a lot like a bad tail motor . . . and is therefore worth investigating.

 

[Tony]

Exactly, signs would be that of a bad motor and major reduction in power. So what are you waiting for, go to the new member section, post up and let us know what you fly. Seems you have done it for a bit.