Page 1 of 4
Mini K-Bar
Posted: Sun Mar 08, 2015 4:09 pm
by DOG
Hey everyone. I was wondering if anyone using these Mini K-Bar no name brand that you buy on E-bay. The one that my friend uses cuts out in the middle of the flight and as the heli is descending the heli will run again like nothing went wrong. The Reason I'm asking because he started process of elimination by purchasing first a new Tx "Taranis Plus" second he bought a new ESC "YEP 40a" third he bought a new motor "Align 450mx" the servos are fairly new and still he has the problem of power loss in flight. He switch gyro with a newer gyro but the same kind "Mini K-Bar no name" still the same problem. He lost and so am i so we can use some help to figure out whats going on here. Appreciate any idea. Thanks all!
DOG
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 4:16 pm
by Graham Lawrie
Sounds more like a power failure than a gyro failure. Possible also a break in a cable or an esc set up fault. Get him to take the blades of and try it on a test bed(Lazy Susan), full power up and down:)
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 4:47 pm
by DOG
Hey Graham Lawrie, when you mean power failure, could it be with the batteries connectors? I'll recommend him to check cables,esc like you said. When i had this kind of problem "My Gaui just went dead" i traced it back to the battery connections. He probably didn't check the connections as good as he said he did. Either way thank you for your time and I'll pass your information on to him.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 5:19 pm
by Graham Lawrie
Could be a cable break anywhere on the power supply from the battery onwards:)
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 5:39 pm
by DOG
Thank you again. I agree with you. He just have to check each one of his 12 batteries that he has. Oh well, lot cheaper then buying electronics all the time. Thanks again.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 5:58 pm
by KevG
Think the kbar as with the vbar is power hungry, I could simply be the bec is not quite good enough
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 6:16 pm
by Tony
if your just using the 5 volts from the ESC then Kev could be spot on there, ive had 2 mini Kbars and i know they are power hungry especially with 4 servos going too and the RX. i used a separate BEC, it was rated at 5amp. if you do decide to use a separate BEC then make sure you remove the red wire from the ESC to the rx/kbar
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 6:27 pm
by DOG
Hey there KevG and Tony. I didn't know that the KBar is power hungry. He also has the Turning servos that looks like my KST215 and if his servos are power hungry also, Humm! He did change esc twice from 40a yep to 45a yep then back to the 40a. He mention something about BEC not be strong enough but that was it. I'll bring that up to him. You have no idea how bummed out he is. Especially after buying that TX. It's all in good fun. Sometime it's not all fun but it's all good fun.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 7:10 pm
by Derek
I got your PM's, DOG. I suggested bad solder joints or a faulty ESC. After I finished the PM, I was beginning to think that it could be a BEC issue...just like the others have suggested. I think I would start there. I have a Castle Creations 10amp external BEC on my 450 Pro DFC. It's probably "overkill" but it's never failed. You could probably get an inexpensive 5 amp BEC and hook that up and, just as Tony said, disconnect the red wire from the ESC lead.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 7:19 pm
by Tony
the 40 amp rating isn't for the internal BEC though, that's the rating for the motor driver. The internal BEC that supplies the 5/6 volts to the rest of the electronics has a different rating.. You need to make sure it's enough current to supply all the servos etc... Best thing is to get the spec sheet for the servos, Kbar and receiver, add up all the "Peak" current ratings and see if the BEC can cope.. If it can then that's something to eliminate.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 7:37 pm
by DOG
Thank you all for your suggestion. I appreciate the help and glad to see the old group back together!

Keep up the good work guys and girls? Good place to "Hangout"
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 8:03 pm
by Marius
Check Rx/motor fail safe. Then do a range test.
Also, check all power connections.
Re: Mini K-Bar
Posted: Sun Mar 08, 2015 9:01 pm
by DOG
Hey Marius, we did the fail route and still the same. I'm pretty sure he's going to put the bec he has on and give that a try. It's a CC Bec. Now my question is; should i put one of those bec on my helis? I haven't had no problems with the set up i have. My Tarot 450 DFC/Gaui X3 both have Yep esc. 45a for my Tarot/3s and 60a for my Gaui/6s. Both birds have AR7200BX and also KST 215mg "Power Hungry" servos all around. I'm thinking for my Gaui just go ahead and purchased one of those Hobbywing 50a esc and be done with it or should i just wait since i haven't had no problems with my electronics cutting out. Just asking! Thanks
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 1:49 am
by murankar
Those servos he has, did he pop off the bottom plate and insulate the case?
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 3:08 am
by DOG
Hey murankar. Good question, I have no idea if he did or not. I heard about that, insulate the case. I will bring that up in our next conversation, another good call, i forgot about that. He said something about putting on the CC Bec that he has. Next min. he wants the Hobbywing 50a esc and call it done. Then the next minute he want's to throw in the towel. I'm confuse on what is he going to do next. He's clueless!
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 3:23 am
by Superbad
If the K bar was shutting down the heli would crash before it could reboot
Dose he loose all control of the heli or just the motor
I run the K bar on all 4 of my Helis and the only thing I have had Is one lost its bind after it set for a few months
I would be looking at the plugs for the motor
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 8:38 am
by Tony
I've got the tgy306 servos and had to insulate all 4 of those.. Bloody rediculous having to do that to new parts..
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 11:07 am
by DOG
Tony wrote:I've got the tgy306 servos and had to insulate all 4 of those.. Bloody rediculous having to do that to new parts..
That's why i decided to spend the extra bucks for the KST
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 10:14 pm
by murankar
One more thing. I know the real mini vbar has a power issue . the power bus on the mini is not strong enough for a high demand system. If you have a high demand system you will want a full size vbar.
Re: Mini K-Bar
Posted: Mon Mar 09, 2015 10:52 pm
by DOG
So he's asking too much out of his Mini-v and should move up to full size v-bar? After buying 3 of those mini , he probably doesn't want to here that. Thank murankar, i will pass it on to him. He should be joining the site soon. That way he can ask his own questions and explain it much better then I can.