R2104GF receiver ISSUES

[the.ronin]

I've got an R2104GF receiver in an Axial Yeti Jr rc rock crawler and a Futaba 4PL radio.

I have channel 1 to the steering servo and channel 4 to a servo holding a micro camera. This setup has worked great for me. Just yesterday it's as if the 2 channels are getting crossed with the camera servo stuttering and jittering and moving when I move the steering wheel. The steering does the same. I did the following:

* redid the connector for the steering because the wires looked to start getting frayed and coming out of the connecor.

* switched channel 3 and 4

* put in new batteries into the radio / fully charged 2S lipo on the car

* in case this was a mix issue, I reset the model entirely.

Same issue.

I was using a new higher torque steering servo with an aluminum servo horn. The servo was getting caught so it could not turn its full extent. I believe this would cause the servo to draw higher current. Since everything is getting power through the receiver, could it have overloaded a BEC on the received or something? These are not cheap receivers so I will be highly annoyed if this is the case.

 

[brimdogg]

I've got an R2104GF receiver in an Axial Yeti Jr rc rock crawler and a Futaba 4PL radio.

I have channel 1 to the steering servo and channel 4 to a servo holding a micro camera. This setup has worked great for me. Just yesterday it's as if the 2 channels are getting crossed with the camera servo stuttering and jittering and moving when I move the steering wheel. The steering does the same. I did the following:

* redid the connector for the steering because the wires looked to start getting frayed and coming out of the connecor.

* switched channel 3 and 4

* put in new batteries into the radio / fully charged 2S lipo on the car

* in case this was a mix issue, I reset the model entirely.

Same issue.

I was using a new higher torque steering servo with an aluminum servo horn. The servo was getting caught so it could not turn its full extent. I believe this would cause the servo to draw higher current. Since everything is getting power through the receiver, could it have overloaded a BEC on the received or something? These are not cheap receivers so I will be highly annoyed if this is the case.

It does sound like a brown out situation is possible.

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[the.ronin]

Ok so this does happen.

Thank you. I am new to rc cars but have built drones for years. We normally have a separate power distribution system but I realize now with rc cars, aside from the ESC, power is driven off of the receiver. Man this sucks lol. These are not cheap receivers.

 

[brimdogg]

Ok so this does happen.

Thank you. I am new to rc cars but have built drones for years. We normally have a separate power distribution system but I realize now with rc cars, aside from the ESC, power is driven off of the receiver. Man this sucks lol. These are not cheap receivers.

If you run a separate BEC, it should be fine. A $20 Castle BEC should be plenty to smooth out the issues.

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[ninja turtle]

If it is fried check out the R2106GF. They work with the 4pl and are about $30.

 

[the.ronin]

Thank you ninja!! That's a huge help.

So do you guys normally run your servos off a separate BEC? Just seems so short sighted to power these things off a receiver. Talk about a single point of failure lol.

I have a bunch of Pololu 5v step-down regs was just going to use those. Of course they dont list the amp draws on these servos lol wow. (Looking at the Savox SH-0255MG).

 

[the.ronin]

Sorry quick follow up question. If I run the servo off lipo through a BEC I can have just the signal wire running to the receiver right? I don't think I need the ground running to the receiver also do I?

So basically ...

Lipo +/- ==> BEC 5V 3A ==> Servo +/-

Servo (Signal) ==> Receiver (Signal)

Thanks again guys. You know what they say ... learning the hard way is the only way lolll.

 

[mikemcE]

You need to understand what is happening. Your receiver gets a voltage input at a fixed amperage. This is supplied by the ESC which has a built in bec.. if you change components like a servo, your servo could not have the EP set and is sucking power, causing a brownout or glitch. I always run an external bec with MOST ESC and servos, set the internal bec at 6v first if set at 5.1v
You can also get an external bec and rx bypass. I doubt if the rx is at fault.


Hang up and Drive

 

[brimdogg]

Sorry quick follow up question. If I run the servo off lipo through a BEC I can have just the signal wire running to the receiver right? I don't think I need the ground running to the receiver also do I?

So basically ...

Lipo +/- ==> BEC 5V 3A ==> Servo +/-

Servo (Signal) ==> Receiver (Signal)

Thanks again guys. You know what they say ... learning the hard way is the only way lolll.

If you're using the same battery to power the BEC and the rig, I'd tie the grounds together. If using a separate battery for the servo BEC, then yes only the signal wire is fine.
Holmes Hobbies actually makes a harness to do this, for like $8 I think.

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[mikemcE]

. All get grounded


Hang up and Drive

 

[the.ronin]

Super helpful. Thank you guys!!

So do most people run servos off BECs or powered right through the receiver?

 

[brimdogg]

Super helpful. Thank you guys!!

So do most people run servos off BECs or powered right through the receiver?

Low end servos can be run off the receiver generally, but any serious servo really should be run directly to a BEC or battery power.

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[mikemcE]

Low end servos can be run off the receiver generally, but any serious servo really should be run directly to a BEC or battery power.

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Unless you have an ESC that HAS the power, like a Mamba X or HW 1080


Hang up and Drive

 

[brimdogg]

Unless you have an ESC that HAS the power, like a Mamba X or HW 1080


Hang up and Drive

Ehh, the 1080 is still only 3a. That's marginally better than most stock ESCs. You are right about the Mamba X though.

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[the.ronin]

Thanks again guys.

These issues started happening when I replaced a Savox SH-0255MG with a Hitec HS-5065MG High Torque servo. I had also replaced the plastic horn with an aluminum one but had the nut on the wrong side. I had my end points maxed out (figuring that would give tighter steering) and that nut was catching onto the frame. I suspect this was causing the servo to draw more amps than the receiver could handle. The ESC is a 25A Dynamite Tazer Mini rated for 25A continuous (90A burst) so I don't think it's the ESC. (Not sure it matters but I am using a Dynamite Fuze Mini 4500Kv motor that so far has not exceeded temps of 160-ish F under heavy load as measured with an IR thermometer.)

Notwithstanding, would these servos qualify as "low end" that can be run off the receiver? As an aside this is for a 1/18 scale Yeti jr.

 

[brimdogg]

Thanks again guys.

These issues started happening when I replaced a Savox SH-0255MG with a Hitec HS-5065MG High Torque servo. I had also replaced the plastic horn with an aluminum one but had the nut on the wrong side. I had my end points maxed out (figuring that would give tighter steering) and that nut was catching onto the frame. I suspect this was causing the servo to draw more amps than the receiver could handle. The ESC is a 25A Dynamite Tazer Mini rated for 25A continuous (90A burst) so I don't think it's the ESC. (Not sure it matters but I am using a Dynamite Fuze Mini 4500Kv motor that so far has not exceeded temps of 160-ish F under heavy load as measured with an IR thermometer.)

Notwithstanding, would these servos qualify as "low end" that can be run off the receiver? As an aside this is for a 1/18 scale Yeti jr.

I am not really familiar with that ESC, but yes it very well could have been because of a binding issue that caused it.

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[Xx Losungen xX]

The ESC is a 25A Dynamite Tazer Mini rated for 25A continuous (90A burst) so I don't think it's the ESC.

That is for the motor only.

The bec is rated to handle a 1 amp load at 6v.

The stall Current of that Savox mini servo is 1.4a at 6v per it's specs.

 

[the.ronin]

That is for the motor only.

The bec is rated to handle a 1 amp load at 6v.

The stall Current of that Savox mini servo is 1.4a at 6v per it's specs.

Shoot thanks for that. I also have another micro servo powering off of the receiver and hence the ESC. Don't think it draws any amps but I also have a switch plugged into the receiver (to power LEDs - which themselves are powered directly from the lipo).

In the end, it was NOT the receiver. Thank goodness for Amazon returns, I got another receiver and experienced the same issues. It was BOTH the servos. In both cases, I did not use the "servo saver" horn that came with the Yeti Jr. I used an aluminum horn hard mounted with an M2 screw. So I'm back to the stock analog servo that is came with using the servo saver and everything works fine. I will try one more time with a metal gear digital servo but this time will stick to the servo saver.