Kalameja

Upgrading to 2.4ghz transmitter and receiver questions.

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It's probably time to stop being so nostalgic and let the old Futaba 70mghz RX and TX stay on the shelf. 

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Ok. So here is my attempt to untangle and present my wiring situation. 

  • Servo for steering plugged directly into channel 1 of RX with no adapter.
  • 104 ESC plugged into channel 2 with J to G adapter. 
  • Red and black wire from BEC plugged into red and black wire of ESC
  • red and black wire from BEC plugged into Battery port or RX with J to G white, red and black wire adapter. I know that's one extra wire in the adapter and into the RX batt port, but that shouldn't matter, right? 

Not sure why the throttle now cuts off when max forward is applied. The set up was working better with the TBLE-02 ESC. 

Suggestions?

image.jpeg

image.jpeg

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6 hours ago, Kalameja said:

Man I have so much to learn. How do I do that? 

Its a tricky combination that requires a bit of agility in some instances.  With the transmitter turned on and the truck powered off, hold down the setup button on the ESC, then turn on the truck (plug in the battery/flip the switch on) The LED flashes every 3 seconds.  Release the setup button while the led is ON to turn off low voltage.  The ESC will "long beep" to acknowledge that the low voltage is off. The LHS told me this was the reason my NiCAD battery had such short runtime.  10-15 min and the truck falls on its face at full throttle.   I have included a pic of the instructions for the TEU-104BK  and a handy chart to show what the beeps and flashes indicate.

TEU-104.jpg

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@Kalameja it looks like your BEC and your ESC both have hot wires going to your receiver?  The red and black wire coming out of your BEC is connected to the receiver, and the red/white/black wire coming out of your ESC are connected as well.  It almost looks like your sending double power to your receiver which should fry it if you turn that truck on.  Have you ran the truck like its currently wired?

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Sorry for the rapid fire posts, I should have had my thoughts together before posting.  Here is my wiring with a better view.  The blue BEC gets is power directly from the battery lead.  I can't tell where your wire runs.  The other end of the BEC is connected the the battery slot of the receiver.  Since the ESC is trying to send power to the receiver also, the red wire was pulled from the ESC connection and taped off.  The red battery lead off the ESC is not used in this setup.  Someone correct me if I am wrong, but I have had no trouble with this setup.

BEC Wiring.JPG

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29 minutes ago, Macinnis said:

@Kalameja it looks like your BEC and your ESC both have hot wires going to your receiver?  The red and black wire coming out of your BEC is connected to the receiver, and the red/white/black wire coming out of your ESC are connected as well.  It almost looks like your sending double power to your receiver which should fry it if you turn that truck on.  Have you ran the truck like its currently wired?

I do have it set up just like that.  I thought that was the point of the BEC.  i did run the buggy like that and it did not cry anything, but I did have the full throttle problem.  

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17 minutes ago, Macinnis said:

Sorry for the rapid fire posts, I should have had my thoughts together before posting.  Here is my wiring with a better view.  The blue BEC gets is power directly from the battery lead.  I can't tell where your wire runs.  The other end of the BEC is connected the the battery slot of the receiver.  Since the ESC is trying to send power to the receiver also, the red wire was pulled from the ESC connection and taped off.  The red battery lead off the ESC is not used in this setup.  Someone correct me if I am wrong, but I have had no trouble with this setup.

BEC Wiring.JPG

So the red wire is always the power wire? Like I said, I'm learning.  I see in your picture that your pulling power from the plug to the BEC and then have the 3 wires from the BEC plugged into the battery port of the RX. But nothing is attached to the red/black wire coming out of your ESC. What would be the use of the unused red/wire from your ESC in your set up? To power r something else? 

In my set up, I have the red/wire from the ESC connected to the red/wire of the BEC. Then then on the other end of the BEC the red/black wire is connected to the battery port of the ESC. I thought this completes the circuit and regulates the power from the ESC through the BEC to the RX

And yes, I then have the red/black/white wire of the ESC connected to CH 1 on the RX.  I did not realize the red wire is power wire and I'm now giving too much power to the RX. It hasn't fried. 

So you're suggesting that I just snip the red wire that is coming from the 3 red/black/white wire from the ESC to the RX? 

 

Hmmmm, I'm totally scratching my head.  

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On February 13, 2017 at 6:43 AM, WillyChang said:

Be careful, TEU101-104BK don't have BEC afaik... they have a separate 2-pin red JST plug to go into RX 'batt' port feeding it full input battery voltage - it expects RX to have BEC builtin there instead.

You can tack on a BEC inline, between red plug & RX.

TRO-01-BEC-System.jpg

 

Hey Willy, when you have a moment would you take a look at my recent post on this thread and give my wiring a once over? McInnis and I could use another set of eyes on this BEC and ESC set up for my Hornet. 

Am I supplying too much power to the RX? 

 

Thanks man. 

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Don't cut the wire.  Take a hobby knife and lift the tiny black tab on the connector and pull the red wire out.  Be careful as it's fragile.  Try to run the buggy and see if it works with that wire disconnected. May save you some trouble later. 

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Thanks man. I'll give it a whirl. I too noticed short run times on both my Nicad and NiMH. 

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25 minutes ago, Macinnis said:

Don't cut the wire.  Take a hobby knife and lift the tiny black tab on the connector and pull the red wire out.  Be careful as it's fragile.  Try to run the buggy and see if it works with that wire disconnected. May save you some trouble later. 

I'm going to run it with the low voltage first and then decide whether or kit to remove the red word from the ESC. 

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TEU doesn't supply any power to RX via its signal lead, that's why they put the separate power lead to the RX. (if it did, wouldn't NEED the power lead)

Havent triggered LVC before afaik... I don't have many 104s in use though, mainly 101s... although a 105 just arrived on bench. 

With other ESCs, triggering LVC leaves a telltale - there'll be some LED flashing urgently etc whilst the motor is cutoff

Also the 104's LVC is set for LiFe... 5.0V says LiFe specs, in others real life testing supposedly only kicks at 4.5V.

Does it consistently just cutoff at full throttle (I assume your car is stationary on blocks?) all the time, even with a freshly charged battery?

Check voltage of battery, got a multimeter? 

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btw have had 1 odd incidence involving TEU101BK and my ancient KO EX1 AM from 1981. (It too needs external BEC as KO's RX predates such modcon)

ESC gets all confused when KO's throttle trigger is fully pressed :o sometimes it aborts the programming too.

Only bandaid that has worked is to limit the throw of the trigger lever - I jam in a stop 4-5mm thick under lever. Then the ESC programs & operates just fine.

I'm blaming KO though, suspect there might be something non-standard about their signalling (eg 1.55ms neutral pulse, vs usual 1.50ms? Dunno!).

Every other ESC worked fine to date though... except same thing happens with a Futaba MC330CR when I tried using the KO to run a Bruiser. (I have feeling Futaba helped T design their ESCs, though haven't tried looking for confirmation) Just limit the lever throw, the 330 programs fine too.

 

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2 hours ago, WillyChang said:

TEU doesn't supply any power to RX via its signal lead, that's why they put the separate power lead to the RX. (if it did, wouldn't NEED the power lead)

Havent triggered LVC before afaik... I don't have many 104s in use though, mainly 101s... although a 105 just arrived on bench. 

With other ESCs, triggering LVC leaves a telltale - there'll be some LED flashing urgently etc whilst the motor is cutoff

Also the 104's LVC is set for LiFe... 5.0V says LiFe specs, in others real life testing supposedly only kicks at 4.5V.

Does it consistently just cutoff at full throttle (I assume your car is stationary on blocks?) all the time, even with a freshly charged battery?

Check voltage of battery, got a multimeter? 

With a full battery it will run for about ten minutes without a problem then the problem will start.  When applying full throttle it just stops.  I release throttle and try again, inches forward and then cuts off again. 

I have a multi meter. But these same batteries with same RX with the tble-02s would run about 40 minutes before showing signs of power drain. 

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If it doesn't do it when battery is full, sounds like LVC kicking in.

Older batteries will have increased Internal Resistance, when you draw high current load the voltage will drop more than from a brandnew pack.

Another possibility is the voltage drop is browning-out the BEC. I'd try adding a StutterStopper after the BEC... just get a bigass capacitor (eg 4000-7000uF 10V) and jam it into any of the red plugs, -Ve leg into black of course.

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That's very typical 101/104 behavior, to cut out at full throttle when the battery gets low. It will go if you give it gentle throttle, but cut out if you "floor it." Then the cutoff starts happening at lower and lower speeds until the battery finally calls it quits entirely. I always assumed it was supposed to work like that, to let you know "hey, the battery is getting low."

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I appreciate the help gents!!!! 

Whay can I say? "Zen and the Art of Motorcycle Maintenance", I'm more of a BMW kinda guy than a Harley guy. 

I threw back in the Tble-02s and a 2.4ghz receiver. No more BEC, no more extra adapters and spaghetti. Clean and runs great!

 

 

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Just so you know about 70 mhz and why you may be getting interference.

These links should pretty much give you the answers -

http://www.arrl.org/news/fcc-turns-down-petition-to-create-a-4-meter-band-in-the-us

https://www.iaru-r1.org/index.php/spectrum-and-band-plans/vhf/4-meter

I would be careful using 70mhz to be honest. You could get your ham radio license,they are practically giving them away and entry level license will allow you to use 50 mhz (6 meter band) for your own personal RC frequency if you wanted to.

https://radiocontrol.fandom.com/wiki/List_of_RC_frequencies

Jim

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