4pk and throttle on hpi baja

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gazzazh

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Hi,

I am new to rc cars, but have been in rc's for quite a while. I have been flying rc planes for a long time now, but i am still getting into rc cars.

I have the bajs 5b 2.0, my wife bought me the 4pk for my birthday.. and a new servo for my throttle. after removing the stock servo and rx. i binded the rc with the my new 4pk. my problem is as follow.

the car would not ideal, it used to ideal with the custom transmitter, now every time i let go of the throttle or brake the engine would switch off. what can i look for to get this right.

thanks
 
If it was running ok before it will be a case of setting up the new 4pk. To get it running ideal there are loads of settings you will have to adjust on the transmitter. End point adjust limits the servo travel so this needs setting to achieve full movement. Have a read through your manual and it will describe each setting. There will also be a built in fail safe that you can set up so that the brake will come on if the signal is lost.

The cutting out sounds like you have a remote engine kill switch fitted and the channel needs reversing so that it is normally off. If it is only on a low setting the revs will probably keep the engine running and it will only cut out at idle. You will be able to adjust the mix up (probably set at 50% as std) so that it cuts out throughout the rev range which is what you want. Im sure somebody who is running a 4pk or 3pk will be able to give you some settings to give you a start point.
 
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Thanks dwarfy, I will take a lot at the manual... i think the problem is with my servo setup.. should the arm be set at 90.. when the servo in centered?
 
gazzazh said:
Thanks dwarfy, I will take a lot at the manual... i think the problem is with my servo setup.. should the arm be set at 90.. when the servo in centered?
Click to expand...

If you turn the servo by hand with everything off it will give you an idea of full movement then you can set the endpoints to suit. When I first got a 2.4ghz set (Code Core RC) I set the endpoint at 110% on throttle but still wasnt achiving full range. There was a setting called Brake ATL that I needed to adjust to give full movement. It was frustrating but I got there in the end!

Here is an old thread and a couple of the lads on there bought the 4pk. Maybe PM them and they will either talk you through it or PM you back the settings they are using. That will give you a good start point to get you running and you can tweak it to suit your needs.

https://www.largescaleforums.com/showthread.php?t=2890&highlight=futaba+3pk
 
what servo you have?

i think the 4PK come in HRS mode (for digital servos ONLY) if you have non digital servos (analog servos) then you need to put the 4PK into PPM mode (for analog servos). you can run Digital servos in PPM mode, they just wont perform up to full digital capabilities, but if you try to run analog servos in HRS mode, you ll get all sorts of issues, as well as a burnt out analog servo in short order.

check all servos are digital, if so, your good to go, but if you have an analog servo (like the stock 5T steering and throtle/brake servo are) you need to switch the 4PK into PPM mode. this can help solve a few issues.

the rest of it is likely just setup adjustments needed on the 4PK.
 
You need to adjust the Neutral position of your servo. Use the Subtrim menu to do this. It moves the servo in very small increments.
 
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