Looking for some help with computer radios

adzam · 23-05-2006

Ok,
i`ll breifly explain the situation, i have a Hitec eclipse 7 channel rc set,
now this has various functions and custom mixers available,
however !! ........

i have no knowledge of aircraft funcionality in computer radios,
could someone explain how i could create or use an existing mixer function that will allow a twin screw tug to manouvre with differential prop movement on rudder, then when under forward (or reverse) motion operate the rudder without any problems.

the alternatives are..
1. use two sticks like a tank drive set up
2. use a third party external mixer

the problem with option 1 is it s just not comfortable and can get a bit `busy` if in close quarters while towing.

option 2 i have tried but i seem to be much more susceptible to interference, and introduces temprementality to the system, something which i cant/dont want.

if any of the aero boys ( or girls ),or anyopne else can help i would be very appreciative

as it`s set up just now,
i have .....
chan 1.... rudder
chan2.... throttle ( controlling both motors via `y` lead)
chan 3 .... bow thruster
chan 4 ... switching control unit
chan 5 free
chan 6 ... activate jjc fog horn unit.

i would like to try and keep the usual set up for cotroling the boat , ie right stick for rudder, left stick for throttle etc.
Or am i asking too much ??

thanx guys

Adz..

p.s i`ll be posting construction pics of this model in a few weeks

scottie2212 · 24-05-2006

Hi Chris,

I think I can help with this - I had similar concerns when I was building St Columba. I did a tranny mod but I could have used the built-in mixing functions (I've seen this done and it's very effective although a little complex to set up.)

My solution was to utilise the 'dual rate' switch (not required in a boat) and rewire it to allow either 'one stick' or 'two stick' motor control.
To be able to have independant speed control of twin motors you will need (for either suggestion) two speed controllers and two channels from the receiver. See attached pic for schematic drawing of tranny mod. If you need any more information let me know.

I will get detailed instructions for the use of 'V-tail' mixing set-up if you would prefer to go down this road.

Scottie.

Mankster · 24-05-2006

Hi Chris, can I ask which external mixer you had trouble with? I was planning on going down this road with a future model and don't have a spare channel for independent motor control.
Thanks

adzam · 24-05-2006

scottie, more info would be great , thanx m8
the boat electrics are in, there are two electronize Esc`s fitted , i`m using a a 7 channel set

mankster,
te unit i was using was one that appears on ebay every now and again. i`m not saying this unit is rubbish in anyway, in fact when it did work it was very smooth, just the unit has failed. the ebayer name i cant remember but he sells teh units for about £25 , normally buy it now.
it also has a staright out put for a third Esc if required.

scottie2212 · 25-05-2006

Hi Chris,

I have spoken to one of the lads at the boat club and he has given me some info. I have also done some experimenting myself and have found a solution which you may like. I have the Futaba 6EXA computer set which I think has similar, if not indentical functions, to your Eclipse.

First - setting up a mix for the motors only....
If you 'must' keep throttle on the left stick you'll have to set-up a manual mix unless your Tx has a built-in mix for channels 3 and 4 - if you're happy to move throttle control to the right stick you could use the inbuilt 'Elevon' mixing.
Assuming you're staying with the left stick plug your esc's into chan 3 & 4 and set-up mixing these channels according to the instructions in your manual. Once done your stick will work in this manner -
Full forward - both motors ahead
Full back - both motors astern
What happens for left or right stick movement depends on the mix - on my Tx manual mix will only put one motor to stop but the 'Elevon' mix mode reverses one motor.

Next - by experimenting I have added rudder control into the mix...
On my set I can only do this with 'Elevon' mixing (throttle on right, rudder on left). It may be possible for your set to do more than mine but this is what I did, it may help you to experiment with your own equipment.
I set-up 'Elevon' mixing and then added a manual mix using the rudder (chan 4) as the master to the right hand horizontal stick (chan1). Although servo travel is reduced by 'Elevon' mixing I have a sytem which I may suit your requirements. normal motor control is affected by the position of the rudder stick. I will be trying this set-up in Egrete, a pusher tug that I am curently building.

I have just seen that your Tx has 5 programmable mix functions so I think you may be able to set-up just what you want with these. My set has only one programmable mix so I'll be considering an eclipse when I'm looking for a full new set.

I probably don't need to tell you this but it's good advice for anyone else who is reading this and thinking about doing something similar.... set it up 'on the bench' first to make sure it works as planned. I used a pair of servos to 'see' what happens, I'll gave it another test later with the esc's.

I hope this helps, even if it only encourages you (and others) to 'have a go' and see what you can get your set to do. Please keep us informed of how you're getting on.

Scottie

adzam · 25-05-2006

Scottie thanks very much for taking the time to do this .
i`ll play about with mix`es and see what i come up with, you`ve at least set me on the right path to what i`m after.

i`ll let you know how i get on ,

Cheers
Adz..

Mankster · 27-05-2006

Quote:

Originally Posted by adzam

te unit i was using was one that appears on ebay every now and again. i`m not saying this unit is rubbish in anyway, in fact when it did work it was very smooth, just the unit has failed. the ebayer name i cant remember but he sells teh units for about £25 , normally buy it now.
it also has a staright out put for a third Esc if required.

Thaks, I was only aware of the Action kits and Astec ones. Has anyone tried either of these?