Hi All, As Many of you know, my governor timer system was developed as a simple way for beginners and sport fliers to get into e-stunt at a low cost, and also as a non-technical system and one that will not burn out anything when the prop gets snagged or the model crashes. It soon developed into something that I felt as being good enough to compete with in serious competition, but it was never really tested at international competition level. Percy Attfield and myself decided to enter the 2012 world champs with my system. Percy built his own variation of the Impact using a high-end motor, the MVVS 8.0/680 running on a 5-cell Thunder Power lipo. I'm always looking for simple and low-cost methods of offering competitive stuff to newcomers, so I designed a very simple take-apart model called the Newtron based on Igor Burger's design principles. (I think that maybe Igor is now going to start charging me seeing that he is the world champ!)

I do have some MVVS motors but opted for the simple Arrowind/E-Max 2826 to see how well I could do with such a basic system. The cost of my power package was around $148.00 for the motor, ZTW 50A esc and my timer. I used the APC 12 x 6.5 EW pusher prop from Dennis. The other competitor using the same power package as me, was Loren Nell (ex South African) from New Zealand. He used the 12 x 6 thin blade pusher prop. Loren placed 35th and I placed 38th and this "middle of the pack" placing was in no way due to any poor performance of the systems. It was due to piloting skills and a distinct lack of decent practice. Our systems worked flawlessly for the 2 weeks or so that we were there. We all flew in the world cup competition a few days prior to the world champs as well.  On the "cheap" motor story, both Loren and myself had magnets come loose. I believe that it could be due to the heat. We were flying in heat of 37~40 degrees C (98~104 F) and I measured 65 degrees on my motor's can a few times. I also used a Cobra/Pulso 2826/10 motor to test and it also threw a magnet. Even the label came off! I liked the Pulso motor because it only costs a little more and it has 3 bearings. It is also better made than the E-Max. Just by the way, neither Loren or me actually noticed any difference in the flying performance when the magnets came loose. There was no extra noise either, but when we spun the prop after we landed, you could feel that something was a bit rougher and it made a slight noise. We glued the magnets back with some cyano and flew the rest of the flights without any hassles. I reckon a dab of JB Weld between each magnet will cure this evil. I put the E-Max back because it was 20 grams heavier and my Newtron felt a little tail heavy to me.

Last year I felt that I should do one more world champs before quitting serious competition. I would push hard to make the top 15 fly-offs. I knew that this would take plenty of work and practice to polish up my patterns. As they say "life got in the way" and things just didn't work out. I then decided to just go and see how well I could do with my system and simple model. This would be my 8th world champs and every time I've been there was always some or other equipment failure and lack of performance from the model. So my target was to see if I could just go and fly the qualifying rounds with everything working and do the best that I can with minimal practice. I also need to explain that neither Loren, Percy or me had the energy to put in more than one or two practice flights in a day. We could simply not cope in that sort of heat. I take my hat off to those guys that had one flight and then just kept putting their name back on the list and doing this for the whole day. I reckon I could have put in a top 20 flight if the weather would just give me a gap. This would be when it is overcast, and a gentle breeze blows directly from the judges for the whole flight i.e. "stunt heaven"! This was never going to happen. When the wind was not howling at way over the 9 meters per second limit, we would have either no wind or that breeze that keeps changing all the way around the circle. Added to this was the fact that the sun (as we all know) is a wind magnet, so most of the time you had to fly with the sun directly in your face. Anyway, excuses aside, I came off feeling great with my 38th place out of 66. In my last round two of the judges came me a score 1004 and 1006, while Serge Delabarde gave me 893 or something. For the record I believe that Serge was the accurate judge this time. I flew all the rounds in the world cup and world champs without any technical hassles. My system was tested to the limit and I can state categorically that my system performed as well or better than any other power package there, barring the active rpm system from Igor as used by the top 3 pilots. In fact Igor flew my Newtron afterwards and said that although he could not feel any kick from my differential gain system, it felt like the other good governors. We did not have time for me to set it up to demo it properly for him to feel, so I took his comments as a compliment.

Loren Nell did a great unintentional demo of the way it shuts off when the prop gets snagged. The grass circle was lousy with lots of bumps and lumps. I held the model until the rpm was full on with the governor, but after rolling a short way, it went into a dip and snagged the prop. It shut down immediately. The judges offered him a re-flight, and because there was zero damage to the motor, esc or prop, he just reset everything and flew the flight. I saw a few others break props and stuff on that field.

Dive Fitzgerald saw Loren's model of his Thundergazer fly and commented that it sure looked like it had plenty of power and control in the bad conditions. I've added some pics below. I was thinking that maybe we should re-name Loren's model the "Quiet-Gazer"! I also pointed out to Dave that you can get a kit of his excellent design for a good price and Loren's performance shows what can be done with such a simple power package. You don't have to mortgage your house to get this sort of power and control. In the ongoing debate of does electric stunt have an unfair advantage over IC engines, I would state that it certainly does when it comes to the price/performance/reliability issue. You really have to have a pro-stunt engine system to get near the performance of a simple electric low cost package like we used, and then when it comes to ease of use, setting it all and flying in all weather..........then there is no competition at all. Having said all that great stuff about electric power I must admit to getting caught with something really basic. I would fly a round in the evening with a great setting in rpm, thinking that I have now optimized everything, only to find that my next flight in the middle of the day had slower lap times with just that much less line tension to cause me to bounce a few pull-outs. Boo-boo, I just did not consider that fact that the air density changes and should have just added a few hundred revs. I suppose that's called experience! Overall I had a great experience and I'm really happy about the performance of my system.

Keith R

In fact Igor flew my Newtron afterwards and said that although he could not feel any kick from my differential gain system, it felt like the other good governors. We did not have time for me to set it up to demo it properly for him to feel, so I took his comments as a compliment.

for others ... I flew it, and Keth asked me AFTERWARDS if I did hear motor regulation, and I simply did not, because it worked  ... so I said NO :- P

BTW now I know why your model was too nose heavy for me :- )))))

Hi Keeth, Kieth, er, Keith,
Now, all you have to do if you want more people to use your system is to make it available for 10 pole motors!!

Great World's eh, my Bandolero made it back safely by freight...yay!!

These South African guys were great, say "hello" to Percy for me.

Hi Russel, it was great to meet you and Peter Angelberger as well. Your Bandolero is a great model, and I will be working again on getting my stsem working with those Pletty's! Percy is running around Holland somewhere and then he goes to family in Canada, but I'll send your greetings to him when I mail him.

Keeth, Kieth, Keith or how about Kees (the Germans call me this), and then some of our Afrikaans speaking folks out here that battle with the "th" sounds call me Keef........so I just can't win hey! How about Keefff wiff free F's??

Hah.... thanks Igor, it was a bit of a problem for me because we did go down to sea level before we came to Bulgaria, then I tried the lighter motor in thin Johannesburg cold winter air at high altitude. I will also try again up here with moving the lighter motor again. I can also move the battery forward if it's too light then. I just think that I need to figure out why it wiggles on the pullouts with me and when you fly it then it pulls out flat........any idea's?? Maybe it knows that you designed the wing??

HI Keith,

I think it is great that your system worked so well!  I rally appreciate the fact that there will be less expensive options for the really good pilots and even those like me.  AS you know, I have not been able to try out your system yet, but my recovery is getting better each day.  It might be a while for me to get much more electric stuff, too many hospital bills still left to pay, but I will get a very good system when the time comes.

Hopefully you will attend the next World's with an even better outcome!

Thanks for your help!
Bill

Thanks for your instructive comments, Keith.
A comment: (I reckon a dab of JB Weld between each magnet will cure this evil.) JB Weld has iron filling, could it interfere with the magnetic circuit in any way?
Regards

Luiz

Hi Luiz, mmmmmm.... I did not know that so thanks for the info. I'll do some tests and see if it is a problem.

Keith R

Hi Keeth, Kieth, er, Keith,
Now, all you have to do if you want more people to use your system is to make it available for 10 pole motors!!

That would lead me to ask the question.? Has any one other than myself has even tried the Timer/Gov with 10 pole motors such as the Pletty's. I didn't want to start this until Keith was back and I could include him in the discussion
I've tried it simply to give my Turnigy ESC's a second chance at being used. When I first started electric I bought components mostly from Hobby King Including the ESC's and their governor couldn't keep the same RPM from start to finish. So I put them aside and used Castle ESC's for the majority of the time.
When the Keith's timer came along I thought I would give it a go. I put together a setup on my motor stand as if it were going into a model and started to learn about it. With the timer I can set up a shorter run. So I keep things at 30 secs. I set the RPM to about the same as if I were flying. I check things with a tach ( more on that later) Everything goes back into the airplane set the timer for about 2 mins the delay for 25 secs left the gain alone for now. Off to the field Ill admit I used a stooge for the first few flights just to make sure I had it set right. After that it wasn't needed again. The spool up felt different it rolled slowly then did a quick ramp up to the set RPM. I'm flying a converted from RC highly modified Eratix 3D and without any input from me the tail lifted from the ground like a real aircraft. But the gov works great alone I was able to run the same RPM from start to finish. Then after another short flight I went to full time 5 min and 20 secs. And it performed flawlessly
the rest of the day. I never felt or heard the GOV Differential I knew I had to find that setting since then I've tried every setting and it would never work with either motor. Ive even slowed the motor lap times to nearly unflyable levels. The motors I've been using are the Plettenberg 20-16 and 25-14. I've also used the Castle
Ice light 50 also the results were the same with the GOV off of course. Ill describe my adventures with my 14 pole motors soon. Thoughts everyone  

Later,
Darrell.

Thanks for your instructive comments, Keith.
A comment: (I reckon a dab of JB Weld between each magnet will cure this evil.) JB Weld has iron filling, could it interfere with the magnetic circuit in any way?

strange, I thought it would be aluminum, but now I tested it and it really does stick to magnet, so looks like it is really iron ... however, until that glue is used only to fix the magnet on iron ring, it can even help, however if the glue will really up to height of the magnet, so it will completaly fill the gap, it can make magnet little bit weaker, what can make KV higher, but I do not think it can affect efficiency or heat or so as the magnetic field of rotor is permanent

I use a plett 20-12.
Soon I will get my KR timer.
I didn't now that there might be issues with a 10 pole.

If you use your ICE 50 switch on the logging.
You can see what the input from the timer is and also see the respond in RPM.
The power will give you an indication what and were you are flying.

Greetings Robert-Jan (Holland)

strange, I thought it JB Weld -- TaW would be aluminum, but now I tested it and it really does stick to magnet, so looks like it is really iron ... however, until that glue is used only to fix the magnet on iron ring, it can even help, however if the glue will really up to height of the magnet, so it will completaly fill the gap, it can make magnet little bit weaker, what can make KV higher, but I do not think it can affect efficiency or heat or so as the magnetic field of rotor is permanent

I don't think that JB weld has enough magnetic permeability to significantly affect the Kv, but if it did it would also affect efficiency (and thus heat).

Torque in a DC motor comes from the coil current; coil current generates heat through resistive losses.  When you raise the Kv of a motor by rewinding it, you do so (if you are smart) by using a shorter length of thicker wire: as long as you pack the same amount of copper into the motor your efficiency will be pretty much unchanged.  However, when you raise the Kv of a motor by weakening the magnetic field, the motor can only make up the lost torque by flowing higher current -- which creates more resistive losses.

Old-style wound-field DC motors got used a lot in factories and mills because you could control their speed fairly easily by running the armature at a fixed voltage and varying the field current (thus varying the magnetic field).  You could only do this over a limited range of field current, though, because if you dropped the field current too much the motor efficiency would drop to the point where the motor would overheat.

I don't think this is an issue with JB Weld -- like I said, I rather suspect that it can't really change the field all that much.  But someone would need to check to know for sure.

I use a plett 20-12.
Soon I will get my KR timer.
I didn't now that there might be issues with a 10 pole.

If you use your ICE 50 switch on the logging.
You can see what the input from the timer is and also see the respond in RPM.
The power will give you an indication what and were you are flying.

Greetings Robert-Jan (Holland)

Hi Robert-Jan, The 10 pole Plettenberg does not get enough pulses to be useful to my timer unfortunately. I am working and a way around this and I will post the results when I get this done. The other motors are 14 to 16 pole that we normally use.

Keith R

Hi Darrel,

Thanks for the feedback and tough luck on the prang.........ouch! As I said to Robert-Jan, I will see if I can find a way around the Pletty motor problem. I does work but only at lower rpm than you need because of the lower pole count. I just never bothered about this before because most users of my timer system don't buy that sort of very expensive motor. I've always considered AXI to be very good motors and they are still a lot cheaper than the Plettenbergs. I feel kinda flattered that folks want to use my simple system with the highest quality motor around.

Thanks also to the guys that commented on the JB Weld. What other high-temperature epoxy could I use? Araldite comes to mind.

Keith R

Thanks also to the guys that commented on the JB Weld. What other high-temperature epoxy could I use? Araldite comes to mind.

The best for magnet I heard is UHU endfest 300, but if you want filled glue like JBweld then you can try Loctite 3450 which is resistant till 100deg C and it is not magnetic

Hi Robert-Jan, sounds like a good reason. I remember you posting something about the noise before. I have one Scorpion that is also noisy but only at a lower rpm than I use, so the noise is only there momentarily. You could the whole E-Max factory for the price of the Pletty

The other quiet motor is the MVVS 8.0/680. I saw that Jiri Vejmola was using one in Bulgaria. Percy Attfield in our team uses them and so do I in some of my other models. The other motor that I've tested in my Newtron is the Pulso 2826/10. It is a well made copy of the AXI of the same number and also has the 3-bearing setup. You also get them as Cobra in the USA.

BTW.....could you please send me an e-mail on krenecle<at>netactive.co.za. then I have your details on my database. Thanks

Keith R

I run a APC EP 12x6 at about 9700 ... 9800 rpm. 

Greetings Robert-Jan

Hi Darrel,

Thanks for the feedback and tough luck on the prang.........ouch! As I said to Robert-Jan, I will see if I can find a way around the Pletty motor problem. I does work but only at lower rpm than you need because of the lower pole count. I just never bothered about this before because most users of my timer system don't buy that sort of very expensive motor. I've always considered AXI to be very good motors and they are still a lot cheaper than the Plettenbergs. I feel kinda flattered that folks want to use my simple system with the highest quality motor around.

Thanks also to the guys that commented on the JB Weld. What other high-temperature epoxy could I use? Araldite comes to mind.

Keith R

Ooops!........I just read my own post above, and sorry about stating that the motor will only work at lower rpm. It will only run properly at HIGHER rpm to get a decent governor resolution, because of the lower amount of pulses coming from the lower number of magnets.

Keith R

Yes, he was that one having problems with noise with AXI and then he changed to MVVS 8 so I guess MVVS is somewhere else with that RPM .. he uses APC 13x6.5 cut to 12.5 or someting like that if I remember well so yes he was close to those 9700 rpm. But every motor with such bell has some RPM which is not good for longer time, the only question is where it is. Also Zbynek Kravcik fly MVVS and also at that rpm, and also without problems, so I guess MVVS is OK at 9700. MVVS 6,5 is smaller so it will be far over (at higher RPM) so I think also safe.

Maybe the 16 poles also makes some difference??

12000 RPM is only 200 Hz, and 200Hz is pretty low frequency for a bell as small as these motors.  So I suspect that the resonance that's being hit is higher, and could well be excited by the rotation frequency times the poles, or 1/2 the poles, or maybe some harmonic of 1/2 the poles.

A good musician might be able to thump the motor and tell us the note; we could work backwards from there to the resonant frequencies

I was thinking of the opening bars of "Smoke on the Water".

Come to think of it, that may not be the right thing to play on a prototype device...

Zappa

Keith, you certainly mean Mozart 

No Igor..it was Beethoven.......ask Kim!

could be ... but I affraid of Betthoven, I heard somewhere about some thicking bombs ... I think he likes to make bombs, at least his music souds like bombing ... my best helper in such work is always Mozart ... Mozart has balls, he knows what is good :- ))))))))))