Steering Servo - Activating Kill Switch (SwitchBlade)

[CecilB]

Hi All,

 

Thought I would post this to see if anybody else has had this issue in the past and to see peoples thoughts and ideas.

 

I have a "New" KM Baja with a Futaba 3PV and I fitted a "Switchblade" Kill Switch and two new batteries.

 

The Problem

When steering (just slight turn) CH1 the kill switch activates hence cutting the engine, I can use throttle which is fine.

 

The Tests

1. When I remove the CH1 (Steering) servo from the receiver I can start and use the throttle all good and it will not cut out.

2. When I connect another servo (smaller) for testing I can move Ch1 (Steering) no problem and the Kill Switch doesn't activate.

I tested 2 new batteries both fully charged this still did the same in both scenario 1 & 2

 

 I then used a spare FlySky 3CH controller/receiver where it worked a little bit differrently, it would cut out at a very short distance away from me and again when steering.

 

The Theory & Possible Issue

I have spoken with Roger from Switchblade (great bloke) and from what he seen on the video I sent him, when I activate the Steering (Ch1) the switchlade led flashes to the pre_Arm state as if the voltage has dropped below its threshold making the killswitch enable, he asked me to test a fully charged battery as mentioned above and still did the same, many people from the FB Group WMRC Bashers (West Midlands) all seem to think along the same lines that the "Steering Servo" is at fault, which is even more emphasized by the fact of me changing the servo (not fitted) just for testing and I could steer fine.

 

I also tried a different (cheap and nasty) Killswitch where this also cut out at random, obviously the receiver may work of different tolerances of voltage ?

 

The Question

Have any of you had this issue ? where your servo was at fault ? dropping the voltage low enough for the Killswitch to activate ? I have ordered a new servo and it should arrive tomorrow, I have also contacted the shop I got my KM Baja from who said they will test the servo and replace if it's at fault, I think I have covered all bases on testing and parts I've ordered so fingers cross as from tomorrow I should have a working KM Baja with Killswitch :).

 

Please do give input as I welcome any words of wisdom, experience and general thoughts on this.

 

Many Thanks

 

Kind Regards

Cecil Bergwin

WMRC Bashers

 

[evssv]

tbh any stock servos should b swapped out for a decent one imo....as they don't last long and r generally crap....what new servo did u buy??

[CecilB]

It was a default servo on the KM, not sure what as not removed yet but sure there branded as model shop name.

 

[evssv]

so u got the same one coming for it??if so use it till that dies.....probably wont b long if its another stock one.....then got for a decent one....savox.....hitec....multiplex.....ect ect........I run a hitec jumbo in my Baja...and a savox jumbo in my dbxl......

Edited August 14, 2017 by evssv

[CecilB]

No I have ordered a Turnigy, not the same as stock.

[evssv]

ahh fair nuff...hopefully it`ll out last the stock one.....

[evssv]

is it this one....

https://hobbyking.com/en_us/turnigytm-s8166m-high-torque-servo-33kg-0-21sec-154g.html

 

[CecilB]

If it arrives and works fine with the Switchblade it will prove the servo was faulty, fair enough it maybe a poor stock one but nevertheless if it's pulling down the voltage/load like I think it is, certainly faulty - Fingers crossed.

[evssv]

yeah def sounded like a dodgy servo...esp when u ruled out everything else....

[CecilB]

https://hobbyking.com/en_us/turnigytm-tgy-1270hv-ball-bearing-ds-mg-servo-w-heat-sink-40kg-0-18sec-170g.html

 

this one I have ordered.

[evssv]

that was gonna b the nx one I linked.......40kg`s  is plenty...

Edited August 14, 2017 by evssv

[CecilB]

++Update,

 

It was the servo bringing it down but I fitted a Dynamite with the same servo and worked perfect, so must be some form of tolerance level on voltage/amp pull with the switchblade.

[evssv]

Glad u sorted it.  ..and reported bak 

Edited September 1, 2017 by evssv

[Jolly_roger_uk]

Brownout occurs when the battery voltage at the receiver takes a large dip.

I say 'at the receiver' because it doesn't necessarily mean that the voltage at the battery is dipping.  

As we 'instantaneously' pull large currents from the battery through the power switch and cables to the receiver a voltage drop occurs across the cable.  The larger the current the bigger the drop.

Under normal conditions this is fine, but throw a faulty servo in the mix that pulls excessive current, or a worn power switch with touch of black wire corrosion we can expect the drop to be excessive and 'should' active the kill switch.

 

I have known some setups with Dual high current steering servos cause this problem, an anti brownout capacitor will help but if the power switch and cables are in good condition and capable of handling the current it should never be an issue.

 

I hope his helps

 

 

 

 

 

[CecilB]

Hi lee, again I'm having this issue on a second Baja (same make servos etc.) it came with a switchblade.

This brownout link you say Capacitor? is this something we can do on  a DIY method? not sure if you would give that advice as it's a product you sell but I'm tempted to ditch and go with a different sort if I can't do the switchblade fix ?

Any help appreciated.

[Jolly_roger_uk]

On 23/05/2018 at 18:34, CecilB said:

Hi lee, again I'm having this issue on a second Baja (same make servos etc.) it came with a switchblade.

This brownout link you say Capacitor? is this something we can do on  a DIY method? not sure if you would give that advice as it's a product you sell but I'm tempted to ditch and go with a different sort if I can't do the switchblade fix ?

Any help appreciated.

Hi Cecil,

I have replied to your PM.

 

 

 

[babylon]

Had the same problem a while ago, This sorted it for me.