At this year's King Orange International, noted Electric power-hater Derek Barry flew Jim Smith's E-Tracer model.  The Smith brothers have worked very hard the last two years on their models and have been rewarded with some very good flying electric power planes.  Even Derek was sufficiently impressed with the model to admit that it was not impossible that he might not defect to electric power some day(!)  He landed from his flight with a troubled look on his face because of the model letting him down by not bursting into flames, and handling the cold windy conditions at the KOI field with no difficulty while presenting a very good pattern.
I post this with some regret, knowing that Bob Hunt will not see this photograph proof of e-power triumph and vindication since Derek's earlier barbs resulted in Bob departing this forum.  Perhaps one of the E-power crew could cut and paste this Bob's way?

Now, I did miss the sound of my PA 65 chugging along and powering through the maneuvers. Some of the romance was lost, but it worked very well. Thanks again Jim for letting me fly your plane. I truly enjoyed it!

Eh, with a light weight speaker and 20-30 watts added to the power budget we could fix that.

You'd have to decide between a PA and a P&W, or maybe a Merlin or Allison, though.

They use smudge pots here in the orchards,, I have threatened to create a castor smudge pot to set next to the judges, which would help them, and you at circle center,,

Derek,
If you flutter your lips, you can also make engine sounds!

I will be going electric with the new airplane that I am building. I have been very impressed with several of the latest set ups.

Derek,

Thanks for that kind remark about our electric powered planes.  It means a lot coming from a IC die heart. You are a real Gentleman.

Linheart

Gentleman may be a stretch but thanks just the same.

Derek

Derek sounds suitably impressed, even if parts of the total package were not HIS preferred installation!

All teasing aside, the Smiths have been refining the Tracers from the IC versions through the electrics - they have been working hard and it is great to see their level of success just keeps getting better. 

One thing I did not see in the pix - does that bird have feet???  As I recall the Smiths were working on retract installations too...

 

Derek,
Maybe it is time for you to apologize to Bobby.

Very few of us agree on everything, but Bob is very generous in telling us how he does things. He is very creative, and he never says that his way is the only way.

And I agree with Doc, we would like to see his updates on the twin. Losing Bob on this forum is a loss to all.

I think the Derek/Bob story is history - it is time to move on.  If/when he sees fit, Bob will become active again in the forum.  If not - well its his decision - so be it.

Meanwhile we have an opportunity to pick on Derek - at his and Steve F's invitation.    Ahhhh life is good!        

Thank you Dennis!

Derek

Don't say thanks yet, I am still working on a suitable FLAMBE!     

Eh, with a light weight speaker and 20-30 watts added to the power budget we could fix that.

You'd have to decide between a PA and a P&W, or maybe a Merlin or Allison, though.

Tim,
How much would a sound setup wiegh?
Lynn Weedman VP X47FLYERS

Okay, Derek ...
It's debriefing time.
I am sure that you have taken some time to re-re-refly that flight(s) and since you have not yet drunk the Cool-Aid, your observations might be refreshingly unjaded.
What did (and didn't) the setup you flew do that you liked, or want more of, or would like to change?
This, after all, is where the rubber meets the road.

Thanks in advance,
 Dean P.

Hey Dean,

To be quite honest, other than a few trim adjustments I can't say I would change much. I did have a few questions when I landed though.

Jim is using the reverse rotation that I see most of you doing. I asked him and Dennis Toth if they felt that it made a big difference. (had they flown it both ways back to back) Jim seemed to think it did help and Dennis seemed to think that the vertical CG had more affect on the plane. The plane had enormous pull but I know that a lot of that can be in the way you trim your plane. A plane that is heavy on the end of the lines, to me, feels better than one that is light. I had clocked Jim's plane before he offered to let me fly it. Lap times were 5.55 every time. He said at 5.2 you almost cant hang on to it. The pull was consistant with My PA 65 plane but never let up, unlike an IC that cycles between 2 and 4 stroke. It was a little strange and my hand was shaking at the end from the constant pull. Cannot decide if that is good or bad yet...

Jim's retracts were very cool. With only one flight I could not tell if there was any significant advantage but cool...YES!

One thing that I am still not thrilled about is the cost. Tom Morris was there and for the "package" it was $500, I think. This did not include batteries.
Jim's is using basically the same thing as Paul. I am not sure the cost but he told me the batteries he was using and that I flew were around $55. I could see this adding up quick if you like to practice a lot.

Another thing that scares me and it is directly related to the cost, is prop strikes on grass. I know a few people that have had a strike and it toasted the entire setup. I am sure that there is a fail safe of some sort but I get the impression that it does not always work. I would be pretty upset if I toasted my setup...

I believe that anything can be dangerous if used incorrectly so I will not start on lipo battery safety. What I am curious about is if I were to go practice and lets say I have 8-10 batteries charged. I get to the field and after the first flight a storm moves in. Do I now have to go home and uncharge all the batteries to make them safe? And if so, that would mean a couple hours of charging before I can go back to the field. I know they can be charged easily at the field so just a question.

As I mentioned before, some of the romance is lost with electric. I am old school, even though I am a young competitor in comparison to many in the event. I really do like the sound, smell, and feel if a good ol IC engine. I take pride in being able to get really good engine runs.

Now for the props, despite my opinions from watching people use them I could tell no difference in pull or performance when I put the plane under a load in hard corners. I was sure that the props were the weak link but I may have been wrong.

Dean, thanks for asking my opinion, I hope that my observations help. If I think af anything else I will post it.

Derek

Derek

I guess since I have had a few leak their smoke I can answer the issue about that. You do not loose the entire system if it happens. You only loose the speed control. It seems some speed controls are more resistant to this in their design than others. The Castle Creation ICE esc's seem to have had the most issues. But in the programming there is a setting to control the amount of current before automatic cutout. The default is a medium setting. But you can opt for it to be very sensative. I've found a very good starting point for programmable settings is the medium setting. But this is one setting on the ICE that should be set for most sensitive. I have not heard of an ICE letting the smoke out if its set that way. At any rate, other than the airplane stinks like heck for a few days that is about all I have seen happen. A little ultracoat melted on one plane but that was an rc plane that it turned out had a defective motor that shorted out in the air and caused the problem.

As to the battery issue, you can get by very well with 4 batteries. After you fly just put it on the charger and go to the next flight. By rotating the batteries thru the charger you can fly all day with no problems at all. One of the things that gives you more versatility than you would think going in is that you do not have to do a full pattern length flight every time. If I am working on a particular trim point for instance, I will fly 2 minutes flights and adjust then put up another 2 minute flight to check the adjustment. I can easily get in 3 flights from most of my packs so its not as much battery usage as you might expect. The batteries are lasting longer and longer too and are getting so you can charge them must faster with an appropriate charger. But when you get into electric you pretty much buy a charger and will use it for years. If its doing the job well on the packs you are flying then it really becomes moot about what new charger capabilites are. Usually you only wind up getting a new charger if you go to a larger pack with more cells that your original charger did not deal with. I started with 3 and 4 cell lipo packs and bought a charger for those. Still using it years later and nothing better has come on the market so why buy another for those? I started flying 5 and 6 cell packs also both in CL and RC so I bought a charger that does up to 6 cells for those packs. Of course it also does the 2,3, and 4 cell packs so I can use it on pretty much everything I fly.

If you do not fly the pack you do not have to discharge it until you go to fly again. THAT would be a pain. Learn lipo management form someone who has been doing it a long time and be disaplined about it and always balance charge and its not a problem. I have a lot of respect for lipos. When I started in RC electric they did not have balancing chargers. I have had one go up in flames on a bench back in those days. Since going to balancing chargers and batteries though the problem that was the cause of those stories has pretty much been solved. A crash can cause a battery issue, I have punctured a few. Those I just stop using and after dealing with them per manufacturer's directions dispose of. I have not seen one eignite from a crash but its theoretically possible. If one gets crashed it gets set off out of the way at the field to just sit till its time to go home. By then its usually pretty safe to deal with and it goes in a fire proof lipo bag for the trip home for decomisioning. Safety with lipos is really a disapline issue. If you are willing to do what you should it is not a limiting issue.

One thing I have learned is that more money does not always buy more success. The most expensive gear performs very little different from less expensive gear. And there is a learning curve. If you can get mentorship by someone doing it sucessfully and will listen to them it can shorten it, but its still there. As you learn you will be able to decide for yourself where you want to put your money. Its not always where it is intuitively obvious. There are some mighty fine patterns being flown on not the most expensive equipment out there. I know a number of experienced electric fliers who have used really expensive stuff and have come back to less expensive stuff cause it works as well for them. I don't make any money from anyone so I'm not trying to push any horse here, but if you wind up pricing all the most expensive stuff at the get go, I think you may get scarred off by $ and it really is not essential to get in and do very very well. Ask Dennis how much the motor in the motor in his Mythbuster cost. That plane has won everywhere its flown I think, and in everything from zero to really awful winds. The proof is in the results, not always the theories. 

Prop wise we have had an interesting experience there, and a fortunate one. A major issue with electrics is how many amps do you draw when flying in the air. If you draw more amps you have to carry more battery, more weight... well you know where things go from there. Efficiency is a primary issue. Fortunately for us the APC thin electric props are the most efficient props we have been able to test out there. My electric flying partners and I spent an entire summer doing nothing but testing prop and their draws and performance in the air. Nothing else even came close. We tested everything from Rev Ups we still had or found during the winter, to carbon fiber stuff from glow, to every kind of wood prop or any other kind we could find. Only thing was it was structured as an electric only prop and too many glow fliers were finding out how good they were and in trying to use them were chucking blades not made to absorb the irregular power pulse of a glow motor. APC is currently replacing all their electric props with new designs that are thicker and as we have found perform differently. However, thru Dennis Adamissin APC has been working with the electric stunt community to provide new props specifically for our needs. They have provided us with very useful props and they are still getting better. The proof is in the flying and they ahve been flying very well.

Hope this helps clear up a few questions.

bob branch

Hi Gang,
Hi Derek,
Let's see now ...
Line tension is never a problem, as you said, you can easily trim some out. What would I do if I had line tension to burn and was flying at 5.5? Add a foot, slow a tenth or two, or both!

The thing about the pusher prop is that outsides and the tops of the vertical 8 and hourglass benefit with better tension as compared to the under 45 stuff than with a standard IC prop.

Cost? Depends. If you do a 4-cell setup, then a great 4-cell capable charger is available from FMA for under $60 apiece.
Let's see, two 4-cell CellPros, a Power 32 motor and an ESC and I get maybe $350 before batteries. Add another $50 and you could have a 10-cell charger that will charge 2 5S packs at once.
 In any case, I like the CellPros. You can buy several of them at that price, and they will automatically discharge a fully charged pack to storage-charge in maybe an hour.
These are the guys who introduced balance charging. Everyone else had it wrong (read that unsafe) until they introduced their first product. I am still using two of those!

If you get rained out, and know that you are going to fly in only 2 or 3 days, then don't discharge to storage level (maybe 1/2 charge). Topping up from storage charge will only take 1/2 hour, so it's easy to pop a pair on before breakfast and then charge the rest at the field. Storage at full charge is not at all unsafe. It simply means that the battery cycle life will take a small hit. Store them fully charged all winter and you may lose a meaningful fraction of the cycle life. How much? The pundits say anywhere from 1/10th to 1/2 but temperature matters too.

There is and will always be room for prop development. That's like saying that the sun will rise tomorrow.

The prop strike & ESC burnup issue is largely a matter of poor setups, current sensitivities set to insensitive or OFF. Actually, I have heard of more problems from the folks running the bargain brand cheapie ESCs.

take care,
  Dean P

Line tension:

I noticed Bob hunts model had very solid amounts of line tension, and I liked that, it had more than my .81 has... I wonder if this increase in line tension is common among the Electric fliers.

Line tension:

I noticed Bob hunts model had very solid amounts of line tension, and I liked that, it had more than my .81 has... I wonder if this increase in line tension is common among the Electric fliers.

It did?  I always heard that Bob Hunt hated line tension(!)

Don't get too excited guys, when Derek landed from the electric test flight and walked back up to where we were, I asked him if he would sell me his PA 65s, and he said no.  So, I think it will be awhile till he actually makes an electric plane.

Bob, Dean, and Arch,

Thanks for all of that info. I am sure it is posted all over these forums but it was nice to be able to see it all here in one place. 
 
It is good to know that you don't have to spend a fortune to try something new, and it seems as if you guys are getting pretty good at this stuff.

Steve is right, I am not selling off my PAs but my eyes are now open to other possibilities. This crow taste terrible...


Derek

Derek

A-1... everything is better with A-1 on it.

Electric is just another way to go. Its certainly not the only way to be competitive. For someone who doesn't want to deal with engine issues, or someone who wants the convenience its a big advantage. But many people are happy. As you saw, it can offer some advantages, but I don't think right now its a deal breaker. Just like when pipes came in we are still learning, a lot. Just looking in the post your setup thread will show a tremendous evolution in power systems over the last 5 or 6 years. KV numbers have changed a lot just as an example that you can see in a fast look. Number of cells has climbed in many applications. Lots to learn to get to getting a system that is optimised for how an individual flies... hmmmm, sounds like flying stunt in any other form as well. Someone in a previous post commented about why would you leave what you are doing if its working really well? Its a good question. And one I do not think there is a firm answer to. As I said there is a learning curve, and it can be substantial, though we are getting it shorter now with more folks flying it. But to go from being a top competitor in glow, and to just drop that to go electric? Man that would be a tough one to call. I think it depends on each person's personal goals. It would be tough to decide at your level. It would be more satisfying I would think to parallel fly a glow and an electric system and learn gradually. Plus it would give one to tune against the other. I have done this with electric planes. It was very successful with my T-Rex and my SV-11. One was markedly better, then I tuned the other against it til it was as good, or actually better. Then returned to the other and worked to get it better. Its interesting how much progress you can make doing something like that.

bob branch