Hi guys,

I have a Futaba 18MZ and I am busy setting up smoke.

First - What I want to achieve is to control the smoke with my throttle, but only have it switch on above 35% throttle. In other words I don't want the smoke pump to work when my throttle is less than 35% open.

Second - I want to be able to switch the smoke complete off from a two position switch.

Third - I want to control the amount of smoke with a normal end point setting.

Reason for all this; I fly a turbo prop and don't want smoke oil injected when the turbine is at less than 35% as it may choke the engine at low rpm. Also I cannot have the throttle always switch on the smoke above 35% as I need to open the throttle during the start-up of the turbine and then don't want oil being injected.

So as an end result I would like to do the following:

- Start my turbine as per normal and pull back to idle.
- Then switch on the smoke function without the smoke pump starting up.
- When I now advance the throttle past 35%, the smoke pump should switch on and deliver the volume of oil that I had set as maximum, using an end point for the smoke function.

I hope my explanation is sufficient, but please ask me to clarify any confusing bits.

Thanks for your help.

Jan

Jan,
I do more or less the same on a Sprint, here is a picture of the mixer I made for it

Hi Carsten,

Thanks, I'll try your suggestion. Here is the answer from Bax on the Futaba support forum

http://www.rcuniverse.com/forum/fb.asp?m=11503481

Cheers,

Jan

Hi guys,

OK I've worked it out. Here is what I can now do. I can switch the smoke pump on and off at any time. When it is switched on, I can then get my throttle stick to start the smoke pump at 45% throw and it will run all the way up to full throttle. When I bring the stick back towards idle the smoke pump will switch off once the position goes past 45% again.

This is how the programming work. First set up smoke as a function, but with NULL control and NULL trim. Then go to program mixers and set up the first mixer. Click INH to become ON, set the button next to that to the switch you want to use for the on/off. Pay attention to the direction that you set as 'on'. Now set throttle as Master and smoke as Slave. Go across to the RHS of the screen and set up a spline curve. Move the throttle stick to where you want the pump to start and set up an opposite flat line to what you have before the start point. In other words (like in my case, the section before the switch point is at the top of the screen and then after that all the points are at the bottom of the screen). Next go again to Program Mixers, now set up a second mixer, but this time with the same switch having it's 'on' position opposite to the first mixer. Master and slave stays the same. For the spline curve, now keep ALL the points as you had them before the switch point for the total curve.

Basically the mixer now has what you want as a relationship between throttle and smoke when the smoke has been switched on, and when the switch is switched the other way, the mixer does not allow the throttle to start the smoke as it never switches on due to no switch point in the spline curve.

Works like a dream - thanks to my mate Shane (Bart on here).

Cheers,

Jan

Very, very late update....

I almost followed your instructions. I’ve a 18mz and a Dualsky DP1000 smoke pump. I had to use a line graph (easier for me and my brain ). I had to put my curve at +150% at the start and then full flow was at -60%.

Thanks for the post, it got me in the right direction

The idea is a good one but what if in a emergency you need to go to full throttle when the turbine is at idle . Like a go around. The engine would not be spooled up and smoke will be applied ? I'm not sure a person would think about flipping the switch to turn it off. I use a slider to turn smoke on and off. Dan