Tail motor cuts out intermittently

[helirifick]

I was flying my mcpx bl's outside and the tail motor cut out a couple of times during the half a dozen flights I had. This resulted in the heli becoming a 'ceiling fan' and spinning out of control. I wasn't doing anything power-demanding at the time either, so it's not LVC.

Upon inspection, nothing got unplugged or anything in the fall. I have the solid tail boom on these bl's, but they are not stretched. They fly really well -- no vibes, very smooth. I have them blinged out with lynx swashes, lynx barings, and just lubed the main grip bearings, re-did 0 pitch and leveled the swash this weekend.

Anyway, I unplugged and replugged the battery (Pulse 300 mAh 30C) and it continued flying without problem. This is happening on 2 separate mcpx bl's and on one of them, in addition to the tail motor cutting out, sometimes I need to give the main blades a manual start -- the main motor is going back and forth and making a buzzing sound as if the ESC is having issues commutating it.

Are both boards going bad? I am using these bl's as trainers -- inverted flying, learning backwards flying, new tricks, etc.

Is it worth getting something like a 130s or attempt to repair the mcpx bl boards (megasmicros) or even buy new ones? I hate to dump money into these things if the bl boards are going to crap out as soon as I buy them.

[Chris1683]

I put 5 batteries through my BL yesterday and saw the same after a crash. Turned out to be a loose tail motor connector. Double check your main and tail motor connectors. If they become even slightly loose you can get some erratic behavior. Use a dab of liquid electrical tape or hot glue to secure the tail connectors together both at the tail and board. I found that even a small crash can loosen the connectors anywhere on the BL including the servo connectors.

As for the 130S, I have it and love it. It flies very smooth and has a good amount of power. It is a much more relaxed flight than the hardcore power of the BL.

[Indokast]

Originally Posted by Chris1683

I put 5 batteries through my BL yesterday and saw the same after a crash. Turned out to be a loose tail motor connector. Double check your main and tail motor connectors. If they become even slightly loose you can get some erratic behavior. Use a dab of liquid electrical tape or hot glue to secure the tail connectors together both at the tail and board. I found that even a small crash can loosen the connectors anywhere on the BL including the servo connectors.

As for the 130S, I have it and love it. It flies very smooth and has a good amount of power. It is a much more relaxed flight than the hardcore power of the BL.

+1

That connection at the board is often barely hanging in there.

[d12bn]

I had a tail blades slipping doing same thing

[Allan114]

As said check all the connections. If you just clip the tail rotor this can cause the motor to stop. Often it usually points to a dodgy tail rotor motor.

[helirifick]

I double checked all the connections for the tail motor and everything is connected tight. It still cut out today after I did a hard turn. I think it's either the board or the tail motor. Me thinks it's the board, since it sometimes has problems commutating the main motor too. Anyway, I flew my other BL, which flew fine.

Then... I flew my 180cfx and tried some inverted flying (like on the BL), and crashed head into grass. The 180cfx's cyclic turn rate or whatever you call it, is so much faster than then BL's. Anyway, a couple of stripped servos, main gear. The main blades seem fine. Oh well, I'll get it fixed up and try again

[daveapplemotors]

If you have 2 Bls then why not swap tail motors?

[learnedthehardway]

Or try the wire harness from the good one on it. Had a similar issue and it was the wires even though they looked fine.

Servo savers or metal servo gear sets are a must for the 180. Saves a ton of headache.

That and for every 2 torque tubes you break you can make 1 good one out of them. Pull the pin then use needle nose to wiggle the good end till it breaks loose. Then replace the bad end of the other TT with it, use some good CA when you put it on then push the pin in.

Once you get a TT that both ends have been repaired it'll be 5+ times tougher than stock but still break before the other gears. TT I'm using now has survived 4 spills and one hard crash and still going strong.

Like them better than the slippers that cause vibes and other issues quite ofte

[helirifick]

Forgot to mention, that I am using solid tail booms on both of the mcpx bl's. And I have several new tail motors I can try swapping and seeing if this intermittent tail cutout problem persists.

As far as the 180cfx, yeah I know about servo savers -- I even bought a couple Lynx ones (too lazy to make my own).

I took a 1.5 year break from flying, so just getting back into it. I used to fly my 180cfx and 500x in 2014/2015 and I don't remember the 180cfx being such a responsive heli around the cyclic. Now, the 500x was a power-house. It had vibration issues with the tail, though.

Anyway, is the mcpx bl worth putting more money into (e.g. new board, lynx stretch kit), or should I just get a 130s -- I need a trainer to learn backwards flying, for instance. I can sort-of fly my bl's inverted and do funnels. And I can hover my bl's inverted head-in and tail-in. So, would the 130s be a good heli for 3D training (+ it has rescue too, right) ?

By the way, my 180cfx head first crash into the grass (i.e. inverted auger) broke the skids. How????

[Chris1683]

I have no complaints about the 130S other than the short battery life of the stock battery. For such a small Heli, it feels like you're flying a much larger one and it is very predictable and smooth.

As far as your BL goes, I wouldn't trash it. I have the solid tail booms also and they don't make any difference other than not breaking a tail boom in a crash. If it's a bad board I would just send it to Megas Micros and have him repair it.

[helirifick]

Well, I put a brand new tail motor and brand new solid boom on my BL and so far so good -- the tail doesn't cut out randomly. Will see how it behaves in future flights. I still suspect that it's the board.

Btw, is the BL worth stretching by +20 mm using the Lynx stretch kit and adding tail boom holder? Does it improve tail authority?

[JonJet]

Any stretch on any heli will improve tail authority...

So Yes

[helirifick]

Also meant to ask if stretching the BL using the Lynx stretch kit and using their 125 mm blades improves anything??

Currently flying with green and orange blade/eflite bullet blades.

[JonJet]

Longer blades = more lift and more float

[Nytro97]

When I had the BL I used the Lynx tail motor wires. I felt the stock wires were just to fragile and was afraid they would short.

http://www.ebay.com/itm/Lynx-Blade-M...26.m2548.l4275

[Chris1683]

Originally Posted by helirifick

Well, I put a brand new tail motor and brand new solid boom on my BL and so far so good -- the tail doesn't cut out randomly. Will see how it behaves in future flights. I still suspect that it's the board.

Btw, is the BL worth stretching by +20 mm using the Lynx stretch kit and adding tail boom holder? Does it improve tail authority?

Buy yourself some of the Lynx 3-Blade tail rotors. They completely eliminated the tail wag on my BL and it holds perfectly.

[helirifick]

I have the Lynx tri-blade tail rotors. I tried them a while back but didn't notice any improvement -- maybe I put it on backwards.

[daveapplemotors]

I noticed very little difference flying. But a tri rotor is much more likely to break in a crash.

I recently tried some modified Plantraco Tri Rotor blades-- shortened to 40- 45 mm and balanced-- with good results. And they are crashworthy.
Note: although "Tri Rotor" is in their name they have only two blades.
These tail rotors are cheap if you get them in quantity from the factory.

[helirifick]

Yep, the lynx tri-blade tail rotor was very fragile.

Anyway, to me, the BL's rapid tail wag that comes and goes or disappears entirely, is semi-random.

It seems to manifest itself when it's windy, but then again, on subsequent flights, one after the other, my BL's don't exhibit the same behavior. Both of my BL's have the lynx swashplate (v1 and v2) and solid tail boom.

I usually bring 6 charged Pulse 300 mAh 30C packs and fly by 2 BL's one after the other (randomly alternating which BL I choose for a flight). Like I said, the tail wag seems to be worse when hovering and when it's windy, but then again, I think it's random.

Also, one thing I noticed, again, is when I back-flip to inverted, it doesn't flip straight and I have to give it rudder or aileron to correct it. I remember this problem when flying my BL's from 2013 and onward and people said it's because the swashplate's with the anti-rotation bracket is 90 degrees from the elevator servo.

[madeye]

One more possible reason I didn't see anyone mentioning - tail motor overheating.