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[suilven]

Hi all, I have fitted 2 Mtroniks 600s each wired to its own viper 20 esc. The +ve And _ve wires are then connected to a 12v battery. ( one esc has had its Bec wire eliminated). the whole shebang is controlled by a RadiolinkT8FB. The rudder servo works fine. One motor works reasonably well ahead and astern. The other does nothing. What have I overlooked?? Advice gratefully received. S.

[clockworks]

How are you connecting the ESCs to the receiver?

[suilven]

directly, starboard to channel 1, and port to channel  2.

[clockworks]

OK. First thing to do is try swapping the two ESC plugs over, That will prove whether the problem is with the ESC or with the receiver.


If the "bad" ESC works when it's plugged into the other channel, then you need to look at the mix on your transmitter - I assume you have set up a mix to add ch2 as a "slave" to ch1?

[suilven]

I have swapped them around and the issue is not with the escs I think But you've mentioned the mix !! how do I make channel 1 a slave to channel two?

[clockworks]

Depends on the transmitter, and I have no experience of Radiolink kit.


Do you have the user manual?
Is it a computerised radio (with a big LCD display) or a basic one with just sticks and switches?
If it's not a computer radio, you will need an external mixer


edit:  Just googled it, and it's a basic transmitter, so no built-in mixing.


You can either use "tank steering" - put the second ESC on the right stick up/down


or use an external mixer


or connect both ESCs to ch1 using a servo Y lead

[RST]

Have you been round the channels on the Rx with a single servo to match the channels to the sticks? Are channels 1 and 2 the vertical on the sticks? I'd expect channel 1 as rudder, 2 as throttle and can't remember after what order is 3 and 4. I know channel numbering gets messy these days, particularly when instruction manual annotation labels function on the tx, but the Rx is just labelled as the channel.  I got caught out with this when I first moved to 2.4GHz.

[suilven]

Yes, tank steering is what I'm trying to achieve but one motor does not respond at all to channel1, the left stick. its completely dead. swop the escs around  and I get the same response, ie no response to the left stick. ( channel two is the channel with the working Bec, its the PWM signal, whatever that is!!)

[clockworks]

Sounds like either the transmitter or the receiver is faulty. Might be worth putting the rudder servo onto ch1 as a test though.


You can plug the BEC into any channel, as the power and ground pins are all wired up on the same PCB track.

[suilven]

just tried rudder servo in channel 1 - zilch. nothing.

[cos918]

Is the ESC that not working switched on ?
John

[suilven]

yes both Escs have power.

[clockworks]

just tried rudder servo in channel 1 - zilch. nothing.

If you don't have a spare receiver to try, I guess it's time to buy a new radio set.


Before you do though, check the 3 pins in the ch1 receiver socket - it's possible that one of the pins got bent, and isn't going into the plug

[suilven]

Have just tried another receiver -- the same results. Conclusion? --the Tx is goosed!!

[RST]

Channel 1 isn't left/right on the right hand stick? (Don't know whether it's different for surface or air radios)

[unbuiltnautilus]

CH1 is RH Rudder, Ch2 is RH Throttle, Ch3 is LH Throttle, CH4 is LH Steering. Just tried one!

[clockworks]

CH1 is RH Rudder, Ch2 is RH Throttle, Ch3 is LH Throttle, CH4 is LH Steering. Just tried one!

Very good point - channel numbers and stick assignments can get very confusing!


OP:  connect everything up, and wiggle both sticks in both directions, see what works. It might be as simple as moving the plugs around on the receiver so that the rudder and the 2 motors correspond to the desired sticks.

[DaveM]

All multi-channel receivers have labels to inform you which numbered channel you are connecting your device into, but very few have the corresponding labels on the transmitter sticks. So how do you know which set of pins to use'? The answer is to experiment, or try it and see. Plug a servo into Channel 1 of the receiver, switch on the transmitter and receiver and wiggle the sticks until you find which movement of which stick moves the servo. Now draw a diagram of the transmitter in the notes section of the radio’s manual and label it. Switch off the Rx, move the servo connection on to Channel 2 and repeat. Do this for every channel and you’ll end up with an accurate picture of your Tx showing the correct stick/switch for each Rx output. Simple, innit?Dave M

[malcolmfrary]

I have swapped them around and the issue is not with the escs I think But you've mentioned the mix !! how do I make channel 1 a slave to channel two?

Fit a mixer between the radio and ESCs.  Plug the mixer into the rudder and throttle channels, plug the ESCs into the mixer outputs, plug the rudder servo ino either the rudder output on the mixer (if it has one) or into a Y lead plugged into channel 1, the other leg feeding the mixer.  The rudder will work as normal, the ESCs will work together but their power will be modified by the rudder input.
Note that although on 2 channel radios, Ch1 was rudder and Ch2 was throttle, this is not the case with multi channel sets.  See Daves excellent drawing in the previous post.  Using a working servo as a meter is the best way to see if any channel is behaving as it should.
Before I parted with using Radiolink, I had bought some spare receivers.  It was a surprise to find that, although the labels were identical regarding make and model, the actual channel numbering sequence was reversed.  They bound to the transmitter OK, though, even if they did seem to need a lot of re-binding.

[suilven]

After acting upon your collective suggestions I have comprehensively concluded that the LH vertical control aka Ch 3 is Kaput!! -- but I do now have a diagram which, perhaps, RadioLink should have thought appropriate to include in their manual! --its difficult enough coping with what is lost in translation!
So to buy another RadioLink...... or perhaps an alternative since I only need max of 4 channels!!??

[clockworks]

If you feel comfortable with a bit of soldering, it might be worth opening up the transmitter and checking the wiring from the stick potentiometers to the PCB. it might even just be a case of pulling off the plugs and reseating them.


Whether to stick with Radiolink or not depends on how many matching receivers you have - it can get expensive to switch brands, as not all receivers work with all transmitters.


My personal choice is Futaba gear. It's not cheap, but I've never had a failure in getting on for 20 years of flying and boating with Futaba.
Because it's reliable, it can make sense to buy secondhand. That way, you can get a better spec for the same money - a decent 6 or 7 channel computer radio (that'll have onboard mixing, model memories, etc) for the price of a reasonable basic 4ch set.


For twin motors, mixing (either on the transmitter, or with an external unit) makes a lot of sense. A secondhand computer radio with mixing built-in will work out cheaper in the long run. Something like a Futaba 6EX or T7 should do everything you'll ever need for boats.

[HMS Invisible]

After acting upon your collective suggestions I have comprehensively concluded that the LH vertical control aka Ch 3 is Kaput!! -- but I do now have a diagram which, perhaps, RadioLink should have thought appropriate to include in their manual! --its difficult enough coping with what is lost in translation!
So to buy another RadioLink...... or perhaps an alternative since I only need max of 4 channels!!??

Have you googled correct product model and firmware version or looked up the customer uploads to youtube?
Radiolink t8fb shows in my searches as a computerised radio with useful android app.

I've fixed many radios and pinpointed faults over the phone. Here, I'd tweak settings before bothering with a voltmeter check.

[DaveM]

I've just checked my Hitec sets and the drawing I did for that 'Model Boats' article is slightly wrong c/w their stick layout. They are both the same as Alan (UBN) describes with the LH Throttle being Ch3, and I suspect that is pretty much standard for Tx's (if there is anything such as a standard).

Now I have to confess that this "expert" bought a Planet T2+2 for my grandson's SLEC Police Launch and I couldn't get the damned thing to work, so I set it back to Howes with a "I'm bewildered and perplexed" note. They replied that it was working just fine on their bench and would I send the return carriage charge if I wanted it back? Fair do's; mea culpa and all that. When I got it back it still wouldn't work on all channels until I realised the problem - me. I've been using my sets with the little Hitec Minima 6 receivers which have their slots arranged with the Ch6/Battery pins at the lower corner of the case, whereas the T2+2 Rx has them all reversed.

Regarding rudder/motor mixing, I'd just fix up an old P94 and forget about system mixes altogether.

Dave M

[HMS Invisible]

If it's any help :
Distributor page on T8FB

On the bulleted feature list*Supports receivers: R8EF, R8FM, R4FG, R4Fto be followed later by "PLEASE NOTE: The T8FB transmitter ONLY works with the R8EF receiver and NOT other receivers in the Radiolink Range."

[ivorthediver]

I've just checked my Hitec sets and the drawing I did for that 'Model Boats' article is slightly wrong c/w their stick layout. They are both the same as Alan (UBN) describes with the LH Throttle being Ch3, and I suspect that is pretty much standard for Tx's (if there is anything such as a standard).

Now I have to confess that this "expert" bought a Planet T2+2 for my grandson's SLEC Police Launch and I couldn't get the damned thing to work, so I set it back to Howes with a "I'm bewildered and perplexed" note. They replied that it was working just fine on their bench and would I send the return carriage charge if I wanted it back? Fair do's; mea culpa and all that. When I got it back it still wouldn't work on all channels until I realised the problem - me. I've been using my sets with the little Hitec Minima 6 receivers which have their slots arranged with the Ch6/Battery pins at the lower corner of the case, whereas the T2+2 Rx has them all reversed.

Regarding rudder/motor mixing, I'd just fix up an old P94 and forget about system mixes altogether.

Dave M

Totally agree with Dave , personally , if he docent know no body , would , Component Shop  still have my P94 I sent in for repair last June !


I am sure there is a good reason for that but despite many emails and messages left still awaiting a report on how much it will cost to rectify it , shame as its a brilliant bit of kit once installed ....