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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Horby on October 10, 2016, 12:41:45 PM
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Now that the Eflite timer is NLA, it there another alternative? The KR and Hubin are too expensive for a basic set up. I need something basic to get some beginners into the sport.
Warren.
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Some discussion of that question here
http://www.rcgroups.com/forums/showthread.php?t=2260561
There are a few suggestions, including Hubin timers with a pot that don't seem to need the Jeti Box. KR is an easy beginner set up and you can save some of the cost using less expensive ESC and share a programmer. Sounds like you know that already.
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$20 is too expensive? At the production quantities that can be achieved for timers, I think that's about as low as things are going to get unless someone hand-builds them with donated labor.
The production volume thing is a sad dilemma -- you could probably sell a Hubin-esque timer for a street price of $5 a pop if you could make them 10,000 at a time. But if you make 100 at a time then you need to sell for $20 ea, and you'll still lose your shorts.
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Hey Warren
the hubin timer fm-9 from Brodak looks like it may fit.
Has all three adjustments.
Some one may need to pony up for a programmer for initial setup.
http://stunthanger.com/hobby/product_info.php?cPath=25_38&products_id=101
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Can you buy a fuel tank for a slimer for less than ten bucks? Just get the Hbin timer. They work well.
Just sayin.
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I know hubin timers are cheap on thier own but picky on the esc you use and the programmer is not cheap. I want to teach a few cadets how to fly and a few want to build planes but don't have the money for the initial cost of electric. I had suggested the IC route but the kids don't like the idea of starting motors. The Eflite timer was perfect, dial the rpm needed then bumped for flight time.
Warren
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I know hubin timers are cheap on thier own but picky on the esc you use and the programmer is not cheap. I want to teach a few cadets how to fly and a few want to build planes but don't have the money for the initial cost of electric. I had suggested the IC route but the kids don't like the idea of starting motors. The Eflite timer was perfect, dial the rpm needed then bumped for flight time.
Warren
You might want to contact Will.
First, the Hubin timer isn't picky about the ESC you use -- it's pilots who use it. If you don't mind the airplane running out of poop a bit as it flies, any Hubin should be OK. As far as I know (someone correct me if I'm wrong here!!!) you can use a less expensive ESC that still has a "helicopter mode" and still get the governing.
Will used to sell a timer that would boost the throttle command as time passed to compensate for the battery running low -- that would work well for sport flying with a wide range of ESCs.
Again -- talk to Will.
As a complete alternative, Hobby King and other importers sell a RC car radio for $20. You get a transmitter and receiver, no servos. You can use the receiver in place of the ESC with the bonus that you can play with the throttle -- this is nice in a trainer, because once you start flying fairly well a typical trainer gets b-o-r-i-n-g, and the throttle helps.
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My grandson's Ring Rat came with an Eflite ESC and timer in the kit. The timer quickly died and I installed a Hubin timer. It works fine.
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Can't one of you programming geniuses clone an E-flight in an Arduino Nano, mini, trinket or something?
Yea yea, roll your own button, soldering, wires, pot, wrapped in heat shrink and all that.
The point is the Arduino platform will likely never go away in the foreseeable future.
Phil
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Castle Creations seems to have a pretty good following too.
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How about a ZTRON Simple CL Timer for $20US:
http://www.bsdmicrorc.com/index.php?productID=880
Paul
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Can't one of you programming geniuses clone an E-flight in an Arduino Nano, mini, trinket or something?
Yea yea, roll your own button, soldering, wires, pot, wrapped in heat shrink and all that.
The point is the Arduino platform will likely never go away in the foreseeable future.
Phil
If a Hubin timer is out of his price range, so is an Arduino -- and the Hubin works.
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Warren, Tim has the idea! Use the R/C transmitter.
That is what Larry Renger and the rest of us at the Knights of the Round Circle use in our ET1 flight program. It is very inexpensive and works like a charm. All you have to do is have a person outside the circle in control of the transmitter. That person can control the rpm (speed of the model) and shut it off in the event that the kid on the handle starts to get crazy or if he starts to get dizzy. Also much safer as the kid never has to get near the prop as the transmitter guy starts and stops the motor.
Since you want to get the kids involved with the hobby but do not want to incur the cost of individual ECL systems Tim's suggestion is certainly the way I would and have gone. Once they get good on the handle and want to graduate to their own system that's when you should get them into the ECL full system using the KR Governor Flight Manager.
Eric Rule
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Hubin still sells the FM-2SR timer for around $15-20. This timer does not require the external programming box. The flight time and motor start delay settings are configured by adjusting potentiometers that are located directly on the timer. You only need a small Philips screwdriver. Couple this timer with a castle Talon 35, which is around $45, and you could have a very capable setup for most any 600 square inch or smaller model. The Talon esc provides all of the CL software features as the more expensive Edge line of esc's, but does not include the data logging features.
Jason
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I don't know what the KR Timer retails for in North America/Canada but it's worth every cent.
Works with cheap non governed esc's, is easy to setup and very reliable. I'm utterly sold on electric power due to my own experiences with the KR Timer.
Just my two cents worth.
Dan.
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If a Hubin timer is out of his price range, so is an Arduino -- and the Hubin works.
Arduino clones cost about $3 shipped.
http://www.ebay.com/itm/MINI-USB-Nano-V3-0-ATmega328P-CH340G-5V-16M-Micro-controller-board-Arduino-T1-/181846906547
A simple timer for one would be pretty simple to write, just need what sort of spec is required.
Any thought on what such a spec would be?
Pat MacKenzie
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If a Hubin timer is out of his price range, so is an Arduino -- and the Hubin works.
Arduino clones cost about $3 shipped.
http://www.ebay.com/itm/MINI-USB-Nano-V3-0-ATmega328P-CH340G-5V-16M-Micro-controller-board-Arduino-T1-/181846906547
A simple timer for one would be pretty simple to write, just need what sort of spec is required.
Any thought on what such a spec would be?
Is there a user guide for the eflite available online?
Pat MacKenzie
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Yes there is an eflite manual online
it is on this page:
http://www.e-fliterc.com/Products/Support.aspx?ProdID=EFLA172
Phil
I originally suggested this route not because of cost (as clones are very cheap, although licensed Arduino boards are around $25) but instead about availability, and future availability.
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Arduino clones cost about $3 shipped.
http://www.ebay.com/itm/MINI-USB-Nano-V3-0-ATmega328P-CH340G-5V-16M-Micro-controller-board-Arduino-T1-/181846906547
A simple timer for one would be pretty simple to write, just need what sort of spec is required.
Any thought on what such a spec would be?
Is there a user guide for the eflite available online?
Pat MacKenzie
The throttle signal is a pulse train. Pulse rate should be 50Hz (20ms between pulses), give or take a bit. Low throttle is 1ms, high throttle is 2ms. On power-up, you need to send out low throttle pulses so the ESC will be happy. You need to have a way to set the speed and flight duration -- if you can do this via USB and a smart phone that would be adequate. If you can do it via a button that would be better for anyone poor enough or non-techie enough to have a smart phone.
There. Now you know everything.
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Controlling an ESC is super simple* with the Arduino (even I figured it out!). By including the Servo library in your sketch, you can create a Servo object and simply set the throttle position by calling a function and passing in a parameter for the ms. This only takes a few lines of code. Of course, I know you guys already know this.
*super simple if you only want to run a constant RPM...if you want the RPM to react to the environment, then you are on your own...
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Controlling an ESC is super simple* with the Arduino (even I figured it out!). By including the Servo library in your sketch, you can create a Servo object and simply set the throttle position by calling a function and passing in a parameter for the ms. This only takes a few lines of code. Of course, I know you guys already know this.
*super simple if you only want to run a constant RPM...if you want the RPM to react to the environment, then you are on your own...
I know nothing about Arduino specifically. So -- it's nice to know it's so easy.
Do they make it easy to talk to it with a cell phone over that USB interface? Looking at the board it should be pretty easy to cable it up to plug into an ESC -- so the problem is coming up with a physically rugged and inexpensive user interface that won't either make the thing weigh a ton, or leave the user helplessly puzzled.
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The throttle signal is a pulse train. Pulse rate should be 50Hz (20ms between pulses), give or take a bit. Low throttle is 1ms, high throttle is 2ms. On power-up, you need to send out low throttle pulses so the ESC will be happy. You need to have a way to set the speed and flight duration -- if you can do this via USB and a smart phone that would be adequate. If you can do it via a button that would be better for anyone poor enough or non-techie enough to have a smart phone.
There. Now you know everything.
I actually know all that, I already make my own timers for F2B. PW used mine when he first started flying electric. :)
I was more interested in the user interface on the Eflite, and how that could be implemented with as few buttons/switches as possible.
The Arduino clone is cheap, buttons are expensive and have to be wired up.
Everything could be done via the Arduino programming interface, that would be the lowest cost option.
Pat MacKenzie
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I know nothing about Arduino specifically. So -- it's nice to know it's so easy.
Do they make it easy to talk to it with a cell phone over that USB interface? Looking at the board it should be pretty easy to cable it up to plug into an ESC -- so the problem is coming up with a physically rugged and inexpensive user interface that won't either make the thing weigh a ton, or leave the user helplessly puzzled.
Looks like there are Andoid apps for talking to an Arduino. That might be an option. Might have to look into that.
Of course not everyone has a cell phone (I don't :-[), but I could probably get an old one just for this.
http://www.allaboutcircuits.com/projects/communicate-with-your-arduino-through-android/
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Hey Pat:
I'm not the one to ask about the eFlight dingus -- what I know is what I've seen in its pictures. Here's the instructions (http://www.e-fliterc.com/ProdInfo/Files/EFLA172-Instructions.pdf). Looks pretty basic, but basically it has a button that starts it or programs the duration, and a knob for throttle.
I just poo-pooed the idea of making a PCB to go with an Arduino just for the sake of a knob -- now I wonder if maybe mating it with some perfboard that has the requisite knobs & buttons might be the way to go. I can see considerable value in making a project that any talented Boy Scout could solder up and download to. If you stick to PC-mount switches and knobs the price shouldn't be too bad. A switch can be had for a bit over 50 cents in onsies from DigiKey, and a decent-looking trimpot for a bit under -- so figure about $1 for the data-entry hardware.
For my timer I just followed Howard's orders and made it talk to a JetiBox. It also talks serial on a USB port, which means that you can talk to it with a smart phone (apparently people who work in server farms all have terminal apps on their smart phones, so they can talk to the servers). No buttons, no lights, and the "programming box" options are common to other things.
Does the nano have a button? I could see setting both flight duration and speed using one button and one or more blinky-lights (or eFlight's method of pinging the motor). It'd be a pain for the user, but you could do something like long presses to enter programming mode and go from one item to the next, with short presses to cycle through the available choices. Two buttons would be better, giving you "up" and "down".
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No, nano does not have a button. Very few Arduino have a button. They software debounce pretty well with a delay.
There are blinky lights already on the board (pin 13, used in "blink" example).
There is also ready made code to adjust the PWM output ("Knob" example under the servo examples.)
I was messing with this stuff about a year ago... I worked through a book I bought and a bunch of other examples but still don't grasp programming well enough to do this. I'll admit to not grasping programming in any language very well.
Buttons are cheap in bulk Under $2/100 from ebay. 10K trim pots are about $4/100, also on ebay. Slow boat from China though.
Perfboard is also pretty cheap. Price is all over the place depending on what thickness and geometry.
I think clear 25mm shrink tube is the expensive stuff on this list, $4/meter on ebay.
Soldering skills are thru-hole and reasonably spaced. Since most pins are not needed soldering some leads directly to the board might be better than installing the headers. This would make it heat-shrink easier. A servo end on some wire to connect the ESC instead of header pins might make things easier still.
Phil
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What about TUT?
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What about TUT?
Too spendy for this application.
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Oh, I forgot, there are design costs, and cool factory to consider.
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Great stuff, I like the idea of using Arduino. I didn't think of it and wasn't sure if was possible. That would be the biggest bang for the buck to get someone started in our sport. Keep us posted if it gets done.
Warren
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As Tim rightly says, you can make your simple timer for a few dollars. The costs go up when you start making them more user friendly and when you want extra features. In the case of my timers I started out with one of Igor's basic timers which Igor kindly gave me. It does not get simpler, BUT it is not easy to change any of the settings. Then mine popped and Igor posted me a new one and that took a few weeks, so I could not fly until it arrived. The next step was for me to buy some PIC chips and get a programmer. At the time, although I had been an electronics technician for most of my life, I had never used digital processors and could not write programs. Igor sent me the firmware and explained how to get it into the chip, but then I wanted to make it easier and improve it as well so I had to learn to program. When I got one to work reasonably well, then someone else wanted one and then everything changes and you have to make something that others can understand and set up. The simple Igor timer and JMP timers have no buttons or one button, so it's quite a challenge for anyone non-technical to change any settings. Igor soon used the Jeti box programmer which made programming easy, but that is costly. I started out with one button then added another one plus a pot for the rpm, after finding that 3 buttons made it easier, then the pc board became too big so I removed them all and made a plug-in programming card and the rest is history. To cut a very loooooong story short, I ended up with my governor timer that keeps the rpm constant and stops the motor when you have a prop strike. The simple timers are not constant rpm either and slow down and speed up as the load varies.
The higher price comes in when you need to make quantity and if you have huge quantities then this too costs peanuts, but if you order 100's instead 1000's then it is quite costly. The next cost is in distribution and shipping, so now all the costs are added in and that's how everything works. My system became popular and I could not sell directly one at a time, so I ended up with agents like RSM and some others in a few countries. It all adds extra costs but in relation to buying all of the other stuff, the system is still relatively cheap..... and it works! If you do indeed find kids that are interested enough, then train them with a basic trainer using a $20.00 Hobby King car R/C system like Larry Renger does with his simple Coroplast trainers used in Kid Adventure. That is the cheapest way......period! You keep the trainer, and IF(?) the kids stick around then try to get them to build a .15 size simple stunt trainer with electric power. That is the smallest practical size model to get involved in some decent stunt flying. I'm actually now busy with my SST (Simple Stunt Trainer ;D) designs for .15 and .40 size electric motors for exactly this type of program. They are not modified existing glow powered designs but designed especially for e-power. I will fly the .15 size version on Spiderwire lines because it is cheaper and easier to get out here in Darkest Africa, and they work as well as cables. I intend to post the plans here once they are done. I'm busy now with my .40 size version.
So sure, some kind soul can make a few dirt cheap basic timers, or you can learn to make your own, but once you start to make a few more, and a few more, then you will go down the same road as the rest of us. The thing to remember is that as soon as you start flying the pattern even in a basic way, the non-governor systems do not work well. It's great to share the hobby with others and what you are venturing into has been done before, so consider all that has been said here and go for it!
Keith R
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<snip>
So sure, some kind soul can make a few dirt cheap basic timers, or you can learn to make your own, but once you start to make a few more, and a few more, then you will go down the same road as the rest of us.
<snip>
+1 to everything Keith said. I think there'd be value in a "Popular Electronics"-style webpage on how to make your own timer, either with an Arduino or from scratch. The value would be to enable Keith's "some kind soul". But whatever you do, unless you don't value your labor very much, it's going to cost bux. So you're either down to trying to find a market that can absorb thousands of timers, making them in onsie-twosies with donated labor, or buying what's available.
It might be worth asking Igor what price he's asking for his simple timers. I have no clue how easy it'd be to import them, but Eastern Europe is pretty famous in technical circles for having low wages compared to the West, and damned good technical people (like -- Igor). I'm not sure if Slovakia still counts as "eastern" by that measure, though.
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You can still buy Will Hubin's FM-Oe or FM-Oc simple timers from Will or Brodak and that does not require the FM-9 LCD programmer. They sell at around $20.00. Igor's simple timer needs the Jetibox so that will cost more. The Hubin FM-Oc is a lot better than the E-Flight timer and it has been around for a long time so it has a great track record. So for a basic timer as per the original requirements from Warren, this would be ideal.......and no extra work is necessary to create something new! I was going to say something about re-inventing the wheel.....but I won't! #^ Sure it costs double the price of the old E-Flite $10.00 timer, but that is a bargain!
Keith R
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Sorry, little later, but better later then never :-P ... I was in Spain for some time.
so few comments:
Keith is right, I had timer on 8 pin 12F PIC controller which did not have any other elements only PIC and connector, worked well, but programming by ON/OFF switch was difficult to explain to some not-techie people (one of my Czech friends did official ECh flight in teaching mode), so that is why I decided throw it away and use JETIBOX ... and all were happy :- )) ... so I fullly agree with Keith, simple solution is may be atractive, but sonner or later ... :- P ... I think Will Hubin can have that my program, I think he sold it for some time. (and then happened what had to happen :-)) )
Yes, I have simple timer, it costs 15E (one piece - if you want more, we can speak about it), and needs programmer fro 35euro. However we use it for teaching kids, that programmer costs 2x price of timer, but you need only ONE for whole class, so no problem, and it is universal programmer for all Jeti devices (including ESCs) and it is also signal generator and signal monitor, so it is not lost money
Arduino is good thing for amatheur timers, beside that piece mentioned by Pat, there is even smaller arduino for 1.5$ or so but it is still enough for trivial program like timer. Programming is by USB and compiler is free, so such program can be delivered as source code and so values (delay, flight time and throttle) can be hard coded, so they can be easily programmed on PC by USB cable. I know, pretty dirty solution, but will work well. I remember Bob H. programming his timers on field by notebook, so what?
If you want really on firld programmable arduino, the simplest programmer we used was simple potentiometer - if you connect it to arduino, program can recognize it is connected and trigger learning mode, so you can set RPM automatically stored to EEPROM - then disconnect and fly .. simple :-P no special hardware needed ... the difference to Jetibox is obviouse, jetibox (or any other digital, easy to set) solution will allow store and recall tested values in case you use it on different models, or in different conditions etc, while pot wil not gove chance precisively set values, but it is still good enough for beginners.