Production Electric ESC Timer for C/L Available

Excellent news for those interested in electric control line. A commercial ESC timer is available from a company named JMP. His screen name on Ezonemag.com is JMP_Blackfoot. He just shipped me a prototype for $25. Check out the pics. I have some questions for the group:
1. He has it set up to manually set the time in 10 second increments. Is this fine enough, or is more resolution needed? 5 seconds? 1 second?

2. He has it set up to "sag" three times at the end of the run and then 5 seconds later, quit cold. I can see the value for the sport flier like me, but what about the contest flier? Is it a detriment? He said it can be inhibited by adding a jumper. Or by different firmware, of course.

3. The timer can run from 1 second to 1000 seconds. I think about 8 minutes is a pretty good maximum, but the 16 minutes gives more flexibility, I think. Thoughts?

He has asked for feedback and I thought I would ask the group for some more expert advice than I can give him. Thanks for any help you can give.

later,
Mel Duval

edit: having some trouble uploading the pics. The controller is about the length of a dime and about half as wide. It is TINY!!!-mhd

Hello

A few questions.

For brushed motors or brushless? Maximum current? Maximum voltage? Any throttling capability?

Hi Isky,
This is actually a DRIVER for a standard electronic speed control. It just puts out a pulse about 1.5 ms or so wide, with about a 10-12 ms frame rate that looks like a standard R/C receiver. So depending on the motor you have, just pick the right speed control and plug it in to the driver. And the newer ESCs can handle li-poly batteries too. That way, you can have ALL the bases covered, brushed or brushless, nimh/nicad or li-poly.

Edit: Forgot about the throttle question. When you program it, you push the button to start and wait for it to slowly go to full throttle. If let go before you get to full throttle, it will stay at that setting for the designated time. Do it with a tach and you have a repeatable setting.

later!
Mel D.

Does this mean that an RPM can be set and it will be maintained for the designated time?

My preference would be for a speed controller that doesn't need a radio signal that shuts off at preset time, or at a designated battery voltage if using Li-Poly. This would mean two would have to be manufactured, brushed and brushless.

For competition the cutoff being set around 6:30 to 7:00 (390 - 420 secs) should be adequate. I would think that 10 second intervals should be fine enough for our needs.

Except for a timed shutoff nothing is needed for a brushed motor, they can be directly wired to the battery. Only problem is the motor slows down toward the end of the flight and lands with the motor still running.

AHA! Sounds like just the thing - it'll work for everything from the small GWS setups to the huge, 40-50A brushless motors. Not only that, it should be capable of controlling multiple speed controllers (just nice for that Lancaster 4 engine project! )

Such an electronic timer is precise enought just to cut at proper time. I did many flights and it not needs any warning. If you have stop watches you can flight to last second much better then we are used with piston engines.

Here is how I did it and it will also answer some other questions.

I was working on a similar unit that would give you 30 seconds or so to get to the handle before it started (why waste the best part of the battery with it hooked to a stooge?). Maybe I'll try one of these first.

helper can start it whenever you want

Or if you fly solo a simple infra red switch, TV remote style, will start and stop the motor whenever you like. No need for a timer, though of course any form of remote control will be illegal for most C/L competition. Not a problem at my standard of flying, the chances of me ever entering a competition are very low indeed .

One timer I made a while ago had what I thought was a useful add-on. I used an insulating pin on a string to hold a pair of contacts open. Pull the pin out, the contacts close and the timer (and motor) starts. Maybe the JMP timer can be started like that ? The electric version of a stooge .

Igor,
What helper?

Helper is a guy who will help you save your model if you hit something on groud at start by prop from burning your expensive battery or motor ... because unlike piston engine, electric engine does not stop after accident.

... guess how I know

Stage whisper: Igor doesn't realize that, to most Americans, "Igor" was the name of a very famous helper..

Now I am curious (about delaying the motor start).

In a contest situation, you signal the judge, and then start your engine, and walk out to the lines. What constitutes starting an electric motor? I assume it is pushing the start button. So you could still have the delay or a very slow start for the motor as to not waste battery power until you need it.

Maybe this isn't a big issue with the newer batteries we have these days.

Hi Alan,
With the program as easy to change as these new microcontrollers are, setting one up to start 30 seconds after you push the button would not be an issue. I also believe that the 30 seconds or so would not be an issue for the new batteries.

later,
Mel D>

Mel,
I'e emailed JMP via Ezonemag.com and get no answer. Do you have a direct contact address for him. Seems strange that their forum doesn't give email addresses.

Check the CLASSIFIEDS on SSW for my ASTRO 25 geared electric cobalt (brush-type) motor. Good way to get into electric C/L at a good price.

A timer has been available for quite some time now. The one I use is designed by Sergio Zegras. It has worked flawlessly so far. You can contact him for more info or to purchase one. This is from memory, but I belive it weighs 6grams, and is adjustable from 5-7min by turning a speed pot mounted on the timer. You can also e-mail me with any questions.

I think I will purchase this new timer myself. I would like to compare them and see which I like better.

These are my feelings on your questions. 1) 10sec incriments is more than adequate 2) The sag at the end is fine for sport flying, but in competition it may cause bobbles or many other problems. 3) 16min is fine. As long as you can adjust it to what you need.

Mike Palko

Hi Mike,
As the ranking expert on electric C/L, that is high praise! I will forward your comments on to Jean-Marie. Check this link out for some pics of the timer:
http://www.rcgroups.com/forums/showthread.php?t=37609
I thought I had Jean-Marie's email, but I have only his EZone PM.

later!
Mel D>
EDIT: Thanks, Len! Saw your advice about the personal firewall. THAT was it!--mhd

Mel, I didn't realize you post on the E-Zone. I used to check the forum a lot, but finally admitted i was more or less talking to myself. It's very slow over there.

How do you adjust the timer? In the pics it doesn't look like it can be adjusted manually. Can you adjust it at the field (on the go) or do you need change the softwear each time?

I will have to start frequenting the E-Zone to keep up with you guys...

Hi Mike,
I actually lurk mostly on Ezone, but post when I can contribute. It turns out that I have just about converted all the way to electrics. I have a garage full of Parkflyers and a few others like my Kadet Senior (1100 sq in, 6 foot wing!!) The only nitro planes that I fly that are left are my C/L ones!

On the time, you set it by going into the program mode by pushing the button .5 sec, then waiting .5 sec, then holding the button down. When you are ready to set the time, you let go of the button, then push it when the desired time divided by 10 has expired. It rounds to the nearest 10 seconds. (thus the 10 second resolution).

The throttle setting is done in the initial start-up in normal mode. You push the button to start the motor and hold it. When it reaches full speed it will "burp" the motor for .2sec. Time then starts when you let go of teh button. If you let go of the button before full throttle is reached, it freezes at whatever rpm it is when you let go of the button and runs out the time. I guess it may be a good thing to set the speed duriong programming and have it do the same speed every time.

I am going to post some things tonight or tomorrow night on the support equipment you need for electrics, like the Astro Whattmeter that measures the current and voltage during operation, chargers and other stuff. And a little about care and feeding.

All,
Just got this from Jeam-Marie :

"Hello,

This is an interesting thread, from which useful feedback is coming.

One query I am not very keen on is the delayed start for one-man operation. From a professional point of view, I would not let loose a device which can be seen to cause unexpected motor start when standing unattended. On the other hand, there is the rightful concern of using up the battery unnecessarily when walking to the handle.

Maybe the answer to this one would be for the motor to run at a chosen low speed during the "wait" period, so as to save precious mAh (as well as definitely and obviously showing that the timer is armed), then go to the chosen flight throttle setting for the timed schedule.
( Should the transition from wait to flight motor speed be immediate or over a couple of seconds? )

I can write software which allows one to freely set four parameters :

- Wait time in seconds.
- Motor throttle setting during wait time (0 to 100%)
- Total run time from motor start to motor cut in 10 second steps (1000 s. max)
- Motor throttle setting during flight (0 to 100%)

These are all settable at the field with the help of a watch (and tachometer for the more organised) and performed by distinct button pressing sequences. It seems the warning sag option is not an advantage for the competition flyers, so could be forsaken.

Does the above sound right ? Thanks for your feedback to help finalise the specifications."

WOW, what customer service!! He is obviously interested in providing the best possible product for our needs.
I can definitely see his point, especially from a safety view. On the "sag", I understand about it too, for competition fliers. I for one, would like at least a "burp" to tell me that it is coming close to time. I have never been very good with running a stopwatch and flying at the same time. I can't hear most high pitched watch "beeps" either. I would gladly trade the delayed start for being able to switch the the "burp" on and off.

What do you think?

later!!
Mel D.

I just ordered one from him, but it might take a few weeks to get here. I fly electric RC airplanes, so next I guess will be an CL. Maybe an Arf Oriental with an Axi and Li-polys?? Don't know yet.

Rather than have a timed startup, how about a microswitch connected to the controls, so that the start button gets pressed when you apply full up (or full down)? Walk to the handle, pick it up, put tension on the lines and apply full up for the plane to start. Perhaps have it run slowly for 1 or 2 seconds so you get a chance to set the controls to neutral again.

I still prefer the simple "start switch" operated by a small plug on the end of a line. Very similar to operating a stooge, doesn't suddenly burst into life when you're not expecting it (unless you trip over the line) but without having the motor running as you walk to the centre.

>Rather than have a timed startup, how about a microswitch
>connected to the controls ?

You can set the slow speed delay to say 2 seconds (1s. to 1000s. possible!) and wire the microswitch in parallel to the existing button.
To operate, pull up elevator for 2,5 seconds, the motor starts at a slow programmable speed. Release up elevator and the motor will accelarate to the programmed flight rpm after 2 seconds.
The only problem is that further action of the microswitch will stop the motor. I made it that way as an emergency stop feature.
I'll try to figure something around this problem...

Getting a little more complicated, but what about a two line stooge. One lets go of the airplane like usual. The other one would act as J-M has indicated but by acting on the switch (or one wired in parallel with it placed so a lever can get to it). Pull the switch line to start the motor. Then pull the stooge line.

BTW, I've been doing some looks at battery capacity relative to some of the modern motors (like the NeuMotor from Steve Neu) and it appears to me that if you set it up so you have full power available for the clover, a 30 seconds or so run at the start won't make any difference......

later,
MelD.

I have been following this thread and wondering why so many people wanted a delayed start? I Have flown the full PAMPA pattern on both NiMH and Li-Poly cells. There is no longer a capacity problem if you are running a brushless motor. If you are using a brushed motor which is much less efficiant then I do see the advantage of the delayed start. On the other hand if you are just sport flying flight time is probably not an issue either. There is no time requirment for sport flying, other than enough time to make it worth while 3-5min most likely.

From day one of my experiments with electric power my goal has always been to equal or surpass glow power. So for me to use a delayed start is out of the question! Along with a modified pattern, batteries in your pocket ect...

If it were me I would use a stooge. I don't trust a timer or any other device that is subjective to a glitch or meltdown. I would think we risk enough injury or loose enough airplanes do to pilot error let along a faulty release sytem. I haven't had one single problem with the conventional start the airplane and walk to the handle method yet....

Just my thoughts....Mike Palko

Mike,
My comment was primarily focused towards a contest. If I understand the "rules", the contestant must start the engine (-motor in this case), not the helper. This constitutes pushing the button I guess for an electric.
My only interest was to conserve power as long as possible, since the motor running on the ground must be one of the heaviest loads (heaviest ampere draw) on the battery, since the rpms are probably at the minimum at this point.

I am looking forward to gain information on this timer. Is it propgramable? Can you handle 2 engines? Can it handle more than one chanal independently for example power and landing gear. I woul like to develop a retractable landing gear and plug it in the same timer.

>I am looking forward to gain information on this timer. Is
>it propgramable? Can you handle 2 engines? Can it handle
>more than one chanal independently for example power and
>landing gear. I woul like to develop a retractable landing
>gear and plug it in the same timer.

The timer is programmable. In its present state of development, it does not have provision for a servo, but it is a distinct possibility I had thought might be required. I have developed a free-flight timer which independently controls the motor ESC and a servo for rudder and dethermaliser, so it would be fairly simple to adapt that to your requirement.
With an ESC per motor and a Y lead, two motors can indeed be controlled simultaneously.

What I would love to have is a programmable timer that I can set on intervals on a lap top. Say has a timeline for each channel. And set certain parameters for each channel in parallel. For example engine timeline delay start then 30 sec later power to 65% for take off then 10 sec later have the engine set to run in flight mode then after so many min power down to 30% for 5sec and finally shut down. And gear timeline 40sec gear up same time as power down to 30% gear down.
The coolest part of this is that you can customize the run for different flying conditions and download then before flight. Like high wind setup or good weather setup or high altitude versus sea level or you need an extra 7% power or etc. This is so flexible that you can make it do everything. What do you think? Wouldn't that be cool?
Food for thought. How can you create a cruise control for the plane to keep the speed constant and cycle the power to achieve constant speed? I am thinking a Pitot tube pressure sensors. I am throwing ideas butt think how cool could that be?
Imagine you go to flight line hook laptop and download flight plan in the plane. Take off, gear up, power to flight preset and cruise control takes over engine function flight done power down gear down land shut off engine and the CROWD GO CRAZZZZZZYYYY

>>>How can you create a cruise control for the plane to keep the speed constant and cycle the power to achieve constant speed?<<<

Simple, constant rpm regulator. It will give you power excactly when you need it, preserve battery exactly when you fly level. It is the same like a tuned pipe.

>>>>How can you create a cruise control for the plane to keep the speed constant and cycle the power to achieve constant speed?<<<
>
>Simple, constant rpm regulator.

No need to build anything. Most upperscale ESCs like Hacker, Castle, Kontroniks and such have a heli mode. In this mode you can use the governor function. Whatever RPM you set at launch, the ESC will try to maintain. Of course as the battery depletes below the governor setting your RPM will drop but you'll have regulated RPM up until that point. If your at say... 80% throttle to achieve your launch RPM when you pull into a loop and load the motor, the ESC will throttle up to allow more power to maintain RPM. As you come down the backside the ESC will throttle down and decrease power to maintain RPM.

Speaking of which.... Has anybody heard from JMP Blackfoot. The last I had contact with him was on RCgroups early last month. I would really like to get one of these timers so I can start my own project.

Thanks,
Mike

That is true, but only some of them are usefull.

There are 3 problems:

1/ some of them are limited to heli prop rpm because they work with external sensor on prop. (I know you spoke about something else)

2/ Most of them use slow heli response and thus acceleration is too slow (30s till launch) and they do not support break, so it will land with rotating prop - that is difficult and not legal (new FAI rules)

3/ Some of them "remember" actually adjusted rpm and try to keep it. It means it depends on condition what is initial on-ground RPM every time. Next problem is, that after launch rpm can not grow anymore, it means you can really get only some 50% of real power - or you need much stronger setup for that power you will really need.

I tested several of them but I found only one which stores the RPM range to memory after setup. So you can start the engine and it will get wanted rpm only after unloading in air. And what is important, it is everytime the same.

4/ Some of them are too slow in regulation. The time is typically 0.1 - 0.2s and that can lead to oscillation ic corners.

Do not take me wrong, I do not say it is impossible to buy it in shop, but I warn others that it can be disapointing - as was for me before I got that "proper".

Here is that my model with true pulsewidth/rpm regulator. It is not pulsewidth/PWM and then fix rpm like most of them do.

My tuned engine increases RPM when the plane goes up and decreases it when it goes down the RPM are not constant. If RPM is constant then the plane flies faster down than when it goes up. Am I wrong? It is simple physics because the force of gravity.

It is question. Many say that yes, but when we measured rpm on microphone; reality was that it just changed the sound but not frequency (means rpm). For example you can hear higher frequency in 4-2-4 switch. But rpm can make jut opposite - drop in 2 cycling. You know engine typically go to 2 cycling because it is loaded - means rotates slowly and thus gives good condition for ignition, combustion and pipe can better fill the cylinder – it leads to 2 cycling.

But I do not say "never". That 4-2 reaction has positive feedback and so it can over regulate. For example also piped engine can work in level on second baffle and after load jump to front baffle and make strong acceleration at really higher rpm.

The question is if it is anything good or not. From MY experience I can say that large engine on typical model not need such power boost and I use pipes with only one baffle. It does not jump on and off - it is rich and lean, does 4-2-4 switch but without too much rpm differences. On opposite side I fly also piped OS MAX .46 in similar model which has 1/4 volume less and 2 blade instead of 3 blade prop and it is clearly happy with two baffle pipe and stronger 4-2-4 switch - probably with higher rpm uphill - I do not know, I did not measure.

I do not think that dead constant speed to air is what we want. It will well keep speed in maneuvers, but it will slow down against the wind and accelerate down the wind. Constant speed to ground is also not the best – same just opposite reason.

I think it needs something between and I think constant rpm is good compromise. It looks that power train with smaller power can still handle the same model well if accelerates little bit uphill.

If you have large prop, and if you load it by gravity of model, it will get higher AoA because of lower speed and it will pull more. The same downhill. Bigger prop, more stable speed. So I just think that if you have prop, which is large enough, then constant rpm mode of regulation is what we want.