What would happen if.........

[Jarius]

While pondering the feasability of buying a second hand Twinstar as the basis for a seaplane conversion, I realised that fitting a water rudder to the proposed design would be almost impossible. I was wondering if a possible solution could be to add another ESC and fit  an elevon mixer between the ESCs and the receiver.  The  throttle  output  of the receiver would connect to the elevator input of the mixer and the rudder output to the aileron input. This arrangement would probably need to be switched so that it was only operational when taxiing perhaps using the retract channel. I have not found any references to this sort of setup anywhere and was wondering if any of the illustrious readership had tried this. I wasn`t sure where to put this thread. Perhaps there should be a Bodging section.

[Andy Harris]

On a JR you could set this up as one of the 'flight modes'

You would set these mixes in the TX only on that mode.  You could choose mode 2 because thats the one that gives you a warning at switch on.

You'd have to be careful about not hitting the switch in normal flight.

The original Twinstar is a bit gutless, you'd need a pair of brushless, I know the TwinstarII has these but I don't have experience of the newer one.

Andy

PS as I look out the window, the dreadful weather forecast has not arrived, could be an early morning whizz round .. 

[Jarius]

Hi Andy, The budget won`t stretch to a new TX. If the idea was feasible any spare cash would go on a couple of brushless motors and ESCs. There are some good deals on Ebay for Mystery motor and esc bundles. Although these are relatively unknown over here our friends over the pond don`t seem to have any problems with them. If the weather continues like this I think a lot more people will be looking at floatplane conversions. This morning on Sky they said they were expecting a months rain to fall in 24hrs. You know it`s summer cos the rains warm.

Jim 

[Phil Winks]

Andy sorry to correct you but the twinstar 2 comes with 2 x 400 brushed can motors according to the multiplex site. not sure gutless is the word for it either though would suggest a power upgrade to fly of water. apart from water proofing electrics I think there's achance the twin star would float as is so a water rudder would simply need to be an extension of the rudder would prob need wing floats though

[Andy Harris]

Phil

 I have the original Twinstar, it has brushed and *is* gutless, perhaps the phrase 'double gutless' is more apt, its very lazy and almost impossible in more than a 10knot  wind (with a 8.4v 3200NiMh).  So much so that I'm eyeing up the servos and receiver for another project .

 You are right, the Twinstar II uses 2 off 400 Permax motors, I assumed it had brushless because I'd seen it with a number of deals, or because the adverts suggest superior performance.

I stand corrected ...

Regards  Andy 

[David Ashby - Moderator]

Multiplex fine-tuned the aerodynamics for the Mk.2 so the 'can' motors are pretty pokey with a 3S Li-Po - careful throttle usage is required to prevent their short term demise though.  

[flytilbroke]

If you want to take-off from water you will still need to put it on floats, or at the least add depth and shape to the lower body to act as a "hull" with tip floats for stability. I think the simplest water rudder would be to add one to one of the floats or the modified hull and drive it from a servo linked to the rudder output from the Rx. You will need more power for lift off from water though.

 One of the Cumbernauld mfc  lads is publishing a cracker of a little twin leccy seaplane plan, maybe has already.