Ivan V

Hello all, just wandering if it is possible to to fly a model by controlling the air speed as opposed to controlling the turbine speed.
Merry Christmas to all and may your wishes be fulfilled.
Ivan

ZB

Yup with Jeti radios we do it all the time. Simple use MSpeed sensor, dial your speed at the transmitter and create logical condition.
We have guys control all kind of functions, you wish for automatic slots or flaps simply done.

Zb/Jeti USA

Ivan V

Thanks for the reply,
would this be achievable with JR 10X radio and the MSpeed sensor? Here in Australia I have not seen a Yeti radio, looks niece and it looks a lot easier to keep clean than my JR.

Jeti USA

Unfortunately no, the 10X is 2 generations behind.

http://www.espritmodel.com/jeti-model-cz.aspx

mr_matt

My Feedback: (10)

JetCat turbines can use a speed sensor that is integrated into the ECU. It takes the state of the turbine into account within its control law so it can provide optimized control of airpseed. It not only allows for a "cruise control" speed hold mode but also allows the throttle stick to be used as a "speed stick", directly controlling the airspeed

mr_matt

My Feedback: (10)

Can the Jeti provide a function assignment between the input and the output? Like a scale and offset? Or is it just a threshold setting?

I saw a set up for airspeed based gain control on a gyro and it was slick.

Jeti USA

You are describing Cortex gain input using Jeti MSpeed sensor. Yes I think it has been done, you can set up very easily logical switches.

Zb/Jeti USA

wojtek

My Feedback: (73)

I have done this with a p200 and using the aux channel to engage "cruise control mode" effectively turns the left stick from "thrust" control to "speed' control ... the JetCat ECUs allow you to set a low and high speed value, and then proportionally the stick sets the speed in between. Its pretty awesome for scale routines ... I wish other bran ECUs also had this option. With all the turbines these days being reliable and many choices better than JetCat in some size categories( to me at least) this is the one feature which would still make me get a JetCat for some applications


Voy

stevekott

Ultimate Jets Sells an "ASSI" device that is exactly what you are looking for. It uses a Pitot tube to set up an auto-throttle. It is made by Corsten Groen in Europe and they work great. I have two of them.

RCISFUN

My Feedback: (44)

That's because Yeti's are usually found in cold climates....
sorry couldn't resist...

Bob_B

My Feedback: (11)

Rich did you get your Yeti Yet?

flycatch

My Feedback: (26)

I find it interesting that this company does not list the selling price for any of its' products. It appears that they are appealing to the elite and not the ordinary modeler. So be it and I wish them well.

VF84sluggo

My Feedback: (55)

What would be sweet is if the 'autothrottle' could be programmed to fly a steady approach speed for landing, but allow the throttle to be pulled to idle in the flare. I know, I know, you'd still need to be proficient in managing speed and glidepath in case the gizmo starts acting up, but, boy, it sure would be nice to normally just focus on glideslope and let the speed take care of itself.

Carsten Groen

Sluggo, check the ASSI device, it does exactly this and much more (and supports Futaba SBUS2, JR XBus and Spektrum )

VF84sluggo

My Feedback: (55)

Will do...Thanks much!

RCISFUN

My Feedback: (44)

Sure Did my Christmas came early in October this year

And now I have the perfect weather for it!

stevekott

Sluggo, the ASSI is very well thought out for auto-throttle. You have five different airspeeds you can set up depending on flap position, I only use 3. You flip a switch(3-way) that arms it. Then you drop your throttle to zero and that engages it. If you come up with the throttle at all it disengages it and you are back to manual.

It's nerve-wracking at first doing an approach with your throttle stick all the way down but I find it corrects airspeed and sink rate as fast, if not faster than I could do it myself. It also has output for bright LED's that I have mounted like AOA lights on the front strut. Solid green .. to fast .. flashing green - perfect .. flashing red - a little slow .. solid red - go around!

I find when using it, that I land so much slower than I usually do. I have it programmed for 1.3x stall speed. I think all of our natural tendencies are to land a little hot. So it really gets your attention when you look that slow but it really shortens the roll out.

I had one landing where I carried all the way down to a full landing and then never gave it a throttle bump (to disengage). During roll out it throttled up to maintain approach speed and I wound up making an unintended but uneventful touch and go. I just hit the coals once I realized what it was doing.

I did set up the Angle of Attack function as I know that's how most fighter jets do their approaches. But I just set all the warnings and lights based on airspeed alone (it can use either). IMHO a simple pitot tube for airspeed alone would get 90% the job done with this device. Then you don't need to mess with making an AOA sensor. An AOA sensor is less complicated than you think. It is basically two tubes in the air stream, One 45 degrees up and one 45 degrees down. But a pitot tube is VERY, VERY simple. Just a tube stuck into the uninterrupted air stream and possibly a static port 90 degrees to the air stream. And there are a lot of ready made pitot tubes out there (Eagle-Tree, etc...).

Happy Flying,

Steve

Ivan V

Ultimate Jets Sells an "ASSI" device that is exactly what you are looking for. It uses a Pitot tube to set up an auto-throttle. It is made by Corsten Groen in Europe and they work great. I have two of them.
My electronics knowledge is fairly limited, so if I understand it correctly I would need an ASSI gadget and a more modern radio to control air speed instead of engine throttle.
Ivan

stevekott

Well ... sort of. You will need a limited knowledge of hooking up the device via a USB cable and running the software to set up your desired airspeeds based on flap (or any other channel) settings. I don't know how modern you radio needs to be but you will need an available channel with a 3 position switch. If you have an 18mz or Fasstest Receiver you will be able to hear call outs of the airspeed into an ear bud (along with all the engine parameters as desired). There is also a new Android Phone app that will bring all of the turbine and airspeed information into a smartphone with with most 'old school' non-telemetry radios.

You would like to designate a 3 position switch to engage and dis-engage. Position one .. Disengaged Throttle control as usual. Mid position .. Throttle control as usual but the output for the Red and Green indicator lights (Airspeed Lights) are active. Position 3 .. Device is armed and will become active once the Throttle is dropped to 0. It will stay engaged until the throttle is raised above 0 or the 3 position switch is flipped from position 3.

Airspeed set points can be programmed to up to 5 different flap positions or can be assigned to a knob or slider.

I would recommend setting up the bright LED's first and practicing a few approaches using those to guide your approach. Then try engaging the auto throttle at altitude and fly around to get the hang of engaging and dis-engaging. It's pretty easy. Just be conscious that if you advance the throttle you will disengage auto-throttle and go to manual throttle immediately.