Do not worry Bob, we will have active controllers soon, and fiddling with the power train will be back … guess how I know 

I mean a device which controlls RPM on base of some measured value. For example if you can measure prop slippage, you can compensate it by higher RPM and so simulate 4-2-4.

And since I flew jurrasic 4-2-4, pipes and 4C engines as well as 3 different systems of active regulators of electric motors (and noone satisfied me yet for 100%  ), then I can tell you that setting of them is minimaly the same amount of work like setting of piped engine (pipe length, prop sisize, nitro% etc)

Igor
How do you define an active controller.  I am new to electric, an I am interested in trying to understand the terminology being used in the electric world.  I know you and Bob are two of the leaders in the advanced world of electric control line flying.  Hey Bob, anything you would have to add would also be appreciated as well.

I look forward to hearing what you two have to say.
Andy Borgogna

Andy,

Here is an example of "Active" throttle control. Note that when the nose rises the rpm increases and when the nose is lowered it decreases.

Kim.

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I mean a device which controlls RPM on base of some measured value. For example if you can measure prop slippage, you can compensate it by higher RPM and so simulate 4-2-4.

And since I flew jurrasic 4-2-4, pipes and 4C engines as well as 3 different systems of active regulators of electric motors (and noone satisfied me yet for 100%  ), then I can tell you that setting of them is minimaly the same amount of work like setting of piped engine (pipe length, prop sisize, nitro% etc)

Of course, it may turn out that the benefits of "active" control don't make up for the amount of fiddling you have to do -- just a solid single-speed run may be more than enough for the Nats.

Note, too, that there is absolutely no reason that you can't make an active controller for an RC glow engine with a throttle.  You could, right now, connect a C/L timer, battery, a glow helicopter engine regulator and a servo to get a single-speed engine run without all the fiddling with props and pipes and venturis and needle settings and all that.  Of course, you'd be fiddling with the electronics instead of all the mechanical parts.  But Bob's quoted advantage of electrics -- that you get a solid single-speed run -- will hold.

Consider: the current state of the art in glow powered stunt is to take a perfectly good 2-stroke engine that by its nature wants to run somewhere between 10000 and 25000 RPM, put a too-large prop on it, then cripple it so that it can only do 8000-9000 RPM.  You're basically purposely making the engine run 'sick' in level flight, and arranging things so that it gets better going up and worse going down.  Because you've made your engine sick you have to constantly fiddle with it to keep it from getting too much worse or better.

Now throw all that accumulated knowledge away (dang but I'm glad I'm doing this on the Internet).  Replace that poor sick engine with a smaller one that's designed to produce some serious power -- look to something like a serious RC pattern (or heli) engine in a right-sized displacement.  Put a low-pitch prop on it of sufficient diameter.  Put velocity feedback on the engine like the helicopter guys do, and either put in the constant-RPM setup that I suggested, or put Kim's active control in there (which is accelerometer based, if I'm not missing a bet).

You'll be fiddling with electronics, yes, but if you size the engine so that the verticals don't demand 100% power from a healthy engine then if you have a slightly bad engine run -- it won't matter.  Instead of needing 90% power on the verticals, you'll need 100%, and the plane will fly just fine.

Just a thought -- were I more serious about this sport I would have tried it a long time ago.  With itty bitty servos and batteries and microcontrollers it's an obvious thing to try.

Kim
That is very interesting.  Are they doing that by monitoring the load on the motor coils or gyros and closed feedback system to the ESC.  My guess the equipment is not the low cost stuff I am using. 
Andy

Tim,

The plane is a modified copy of a Fancy Foam Yak F3P model that we used for fly-by-wire development work during the winter.

Andy,

As Tim was suggesting, we use accelerometers to feed a processor which determines how much, which direction and when to adjust the throttle. The actual cost of the components is just a few dollars.

Dennis,

The processor is a joint development of Pat Mackenzie and myself. It is a prototype and not available for sale.


So lets stop hijacking Bob's thread and get back to the main topic. The consistency of electric models is something all should exeperience. Billy used to say that 80% of this was the power train, the other 50% was the plane and pilot. Imagine if you could eliminate that 80%!!


Kim

Quote Kim: Billy used to say that 80% of this was the power train, the other 50% was the plane and pilot. Imagine if you could eliminate that 80%!!

Kim, I just want to find a way I can utilize the 130%!  I figure if I can get 30% more than everyone else, I will win the Walker Trophy!

Seriously, I have not experienced the *SHOCK* yet, Bob has totally convinced me that electric is the only way to go if you are wanting to contend at the highest levels, and that electric will take over completely one day.  I believe he is right.

So, anyone feeling generous and wants to help a poor, broke, begging brother out, just send me an electric set up, and include the info on what size plane to use it in.  Address available.   (it's a joke, but I am dead serious! I wish, sometimes, I had everything I had given away! LOL!!)

 Big Bear

The simple answer is you can't. It is not even a subject for debate. Just ask Paul.

Paul who?

Whew..........getting back to what Bob said at the start of this thread, he is 100% correct, and there is no engine system or wet set-up that has everything that electric can offer. The biggest single thing holding this progress back was the price (and even the weight) of the batteries. This has now changed and batteries are much cheaper and lighter. Read "cheaper" as many more cycles than before. Mass production for the R/C guys has made the motors and esc's totally affordable right now, so electric stunt is indeed a better way forward.

I am a born fiddler and love experimenting with different idea's and concepts, and I would submit that the closest "simple" engine to electric, is the diesel. My MVVS diesels ran smoothly and gave a solid constant speed, BUT they are messy and the kerosene/paraffin/ether fuel pongs like hell. Electric stunt is just better. All you have to do is to fly one straight after you fly a wet set-up. As Bob says, just put it down, switch it on and fly.......forget about the engine run......what a pleasure! For coaching, just how much of your valuable time is lost when you get a bum engine run??

Tim, the reason for no-one really developing an electronic feedback system for the engine folks, is because it is banned in the FAI rules for international competitions, although I believe that this could change in the near future. Electric stunt can only work properly this way, so I see that this could be allowed in future rules for engines. They already allow the use of timers with shut-off's in stunt, so things are moving that way. I'll leave it there for now, because we could really get carried away with the FAI rule stuff.

Keith R

Kim,

That's basically what I meant when I said that "Electric stunt can only work properly this way". It is this fact as you stated about governors, that has caused many to ask about electronic feedback being used in the wet set-ups. I'm pretty sure that this will be allowed sooner or later. I predict that electric systems will dominate stunt soon like they are doing in pattern, so to level the playing field, the wet set-ups will need active feedback.

Keith R

Paul who?

Tim didn't make it to Eugene.  He's a Seattle guy who used to compete, but has moved up to stunt management.

Keith, are you already working on "Beethoven box"? 

Simple ... it is just serial terminal with 2 lines and keyboard with 4 buttons, so whole menue is always in programmed device ... looks like you have new job for winter 

... if you change mind and come to WC in Gyula, I will tell you 

Hi Bob,
     I got to compete in my first Nats (first contest too!!!) in the open beginner class and did not have my electric ship done in time.I took the old warhorse Top Flite Tutor II with a LA46 installed.It still has the remote needle(Mistake) and was hard to get started after I signaled the judges.I flew many practice flights and thought I had the correct amount of fuel dialed in and my motor would stop in time(Mistake).I ended up in 5th but would have come in 2nd if I did not go over the time limit and did not get the landing points(Mistake).The good thing that came out of all this is OBVIOUS.All I could think of was an ELECTRIC powered ship would have prevented all of my frustration.My hat goes off to all the people who donated prizes for the beginners as I was fortunate enough to get an ARF Pathfinder that I am converting to electric and hope to have done before the contest in Detroit in August and I also received an ARF Strege too!!!!Can't wait to get these electric ships up and flying as I purchased a Genisis kit off ebay right before I left for the nats and want to convert her to electric when I build it this winter.I have a set of articles you wrote in FM back in the 90's about flying the stunt manuvers and I still look at 2 quarters placed side by side in my head when I do my 8's.It helped my flying score but mistakes hurt my bottom line.Its obvious ELECTRIC will fix it.Thanx,Jeff Traxler AMA24950