RE: Schulze ESCs
[quote]ORIGINAL: OhD Chad, After reading the hints for the aerobatic version, I conclude neutral corresponds to zero rpm at 1.5 milliseconds and the speed is linear between 1.5 and 2.0 milliseconds. I also assume you need to be at 1.0 msec or below to arm the ESC. Given that I would assume that one could set the inflight condition up so the motor would idle at one click up on the throttle stick and brake with the stick all the way back. That would give a curve that jumped from some braking value between 1.0 and 1.5 msec to something just over 1.5 with one click of throttle. I would then expect I could set up an arming and idle condition so I could idle for taxi and takeoff. Have I got it right? How do you set your throttle curve? Jim [/quote] Hi Jim Yes I think you have it, 1msec to 1.5 is brake, and 1.5 to 2 is power. How that translates to operational is strictly up to you! You could have it such that bottom stick to 1/2 stick is braking, and 1/2 to top is power etc. I prefer to have the brake on a switch inside a condition, I find I only use the brake on very specific maneuvers like the Fig 9 in P-09, and no where else. I have a minimum rpm idle the rest of the time. Attached are two shots of my throttle curve. The first is in idle mode, and the second is with the brake switch activated. All the brake switch does is move the bottom part of the curve down. ATV's can be used to adjust the top and bottom ends and subtrim will affect where that transition between brake and power occurs. I usually setup the ATV top first, bottom second, subtrim third, then adjust the throttle curve to get it as close as I like. The benefit of using a condition for the brake is for starting safety. In this situation it is not possible to arm the controller until the throttle stick is at the idle position and the brake switch is ON. With 14MZ the radio will alarm if a condition is on when the radio is turned on, and you are forced to move to the normal condition before the radio will proceed. In this case it makes it far less likely to arm the ESC accidentally even if the throttle stick is at idle. Hope that helps a bit?
Posted on: 11/21/2009 12:33 AM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9269188

RE: Schulze ESCs
Hi Jim Sorry about not getting back to you, new baby, busy at work....I will get you an answer tonite and a pic of my throttle curve which should make more sense.
Posted on: 11/20/2009 8:24 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9268627

RE: Schulze ESCs
Haha, geez, must be winter the comedians are out LOL :) Jim to answer your questions, I have used Schulze controllers (both 32.55KA, and 32.80KA) for 5 years, have always had good luck with them in operation the Pletty's. Pletty and Schulze work closely together so their stuff usually works very good with each other. They certainly are not the fanciest available, but sometimes simplicity has its merits :) The controller when set to the aerobatic mode, has fixed endpoints, a fully proportional brake (that can be set via the transmitter). So yes you can have an idle like a glow motor, and switch activate the brake if you wish. I prefer the 32.80 because it can handle the power we typically use in F3A application with basically no forced cooling, so it gives a lot of operating ceiling since you can't always mount in the most optimum location.
Posted on: 11/17/2009 10:27 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9261679

RE: Composite-ARF Integral, kinda build thread
[quote]ORIGINAL: Rune Hi just started to convert my old Integral to el. the old firewall is removed and found the PDF that shows Chad's firewall with the Pletty. I think I understand correclty that the center off the Pletty is in the middel off the screws that holds it? The engine I will use is a cheap China Axi copy ...if I work it works if not I maybe change it for a Axi ... When you fly with a el. engine you use a bigger prop and remeber the old days with glow that you got change in the need for right thrust , but the rmp on the el.engine is lower do I need to make the right trust diffrent ? With the YS I had 1,5 mm more that the nose indicated and that was perfect. [/quote] Yes, the center of the bolt circle is the center of the motor. One firewall will match the existing downthrust molded into the fuse, the other firewall has the motor offset about 2mm lower, to compensate the spinner location if you reduce the downthrust by about 2 degrees. I used the factory right thrust on my Integrals, but that was with the folding props, maybe its not the same with an APC.
Posted on: 11/16/2009 2:39 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9258027

RE: Regulator Voltage
I have ran 6v last year, and 5.7v this year, there isn't really any noticeable difference between the two. 1/3 a volt is pretty insignificant!
Posted on: 11/14/2009 12:36 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9253201

RE: Plettenberg Xtra 30-10 EVO
Hi Magne, I prefer the 21x15, but the 20.2x17 is also a nice option, but its a bit higher load on the batteries, however its quite fast! I didn't have the 20.2x17 prop when I made those data plots unfortunately. I might have another plot at home on the computer, I will have to check later. If I have it I will post it here.
Posted on: 11/13/2009 9:12 AM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9250619

RE: Is EP ready to downsize to 8s?
[quote]ORIGINAL: 1bwana1 I'm not sure what is meant by ''keep things equitable for everyone''.  Why are we wanting to protect any particular power system?  This is like having a rule to protect those who like wood airframes insead of composite.  It would seem most equitable to have very simple rules.  Size, take off weight, noise, the same for all competitors regardless of power plant, or construction.   What else is really needed?  The better technology will eventually dominate. [/quote] Exactly the problem, the current rules functionally limit the power an electric model can generate to be the maximum discharge current available in current technology. There is no such limit placed on a glow motor, they are functionally limited to weight/noise, but so are electric. Most FAI electric setups are pretty close to the limit already, another 500+ watts and I think a lot of us would fail. ie: If a 10C discharge battery had been all that was ever able to be developed due to tech. limitations, electric models would be functionally limited to approximately 1800 ish watts (assuming the largest battery you can fit due to weight restrictions is 5000 mAh). This is due to the voltage limitation being 42V resting....so under load its really only 35V. Allowing unlimited voltage would open the doors a bit more. I think currently, its pretty even, however if someone were to come out with a glow (or gas) motor that was significantly more powerful (say a 2.5 cu.in.) that could meet weight/noise rules, then I think it would be very difficult for an electric model to remain competitive due to the voltage cap currently in place, as the only way to increase power is to a) increase voltage retention under load, b) increase amperage. A) is plateauing, I dont think we will see major gains in voltage under load in the future (without increases in pack weight)....and B) requires larger batteries, which makes the weight rule very tough to meet. I am not an advocate for removing the voltage cap, just posting some thoughts :)
Posted on: 10/29/2009 12:25 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9212267

RE: Plettenberg Xtra 30-10 EVO
3kW is getting up there, you certainly will never use that much power even in FAI. Typically in flight you will see peaks around 2500W give or take in an FAI routine, you get a little unloading so statically that would translate to 2700W or so. If you feel its too much power, then set back your ATV a bit (if you are using fixed endpoints on your controller and not auto calibrate). Brian, I think the big Pletty outrunners peak efficiency is in the 35-40A range (at the voltages we run), which is right around the average draw that we use during a flight. Pletty has not posted efficiency values on their website for the Evo though.
Posted on: 10/28/2009 10:17 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9210998

RE: Prop choice for a Pletty. What's the background?
In general the two most common APC props are the 20.5x14, and 21x14. However its really personal choice, some props like the 20x15 give lots of speed, 22x12 lots of pull but less speed, etc. etc. A lot has to depend on the sequence you fly, how you like to fly and so on and so forth. Each person has a different feel :) There are also other props, PT carbon props, RASA single blade (20x15, 21x13) and RASA folding blades, Xoar makes some wood props for F3A electric. I think you will find that the 21x14 is the common choice because it offers a good combination of pull, speed and does it quite efficiently. Its not by chance that this particular size of prop has become the most popular :) Hope that helps somewhat.
Posted on: 10/28/2009 10:10 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9210957

RE: 2009 Tangerine Poll
April would be good for me :) I could actually fly down and make that one.
Posted on: 10/28/2009 10:20 AM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9208933

RE: Is EP ready to downsize to 8s?
Hi Volkert et al. I have read (translated by Google!) that report on the 8s Exelent model previously, and I would like to share some thoughts, math and own experience regarding their report on the use of 8s. I am certainly not suggesting it cannot be done, but my opinion on why I feel its not a workable setup for F3A (I am strictly speaking about flying FAI, P/F sequences here!). Firstly, we have to make some generalized statements and assumptions. a) Lets assume for a minute that input power = output power, ie: 100% motor efficiency this simplifies the argument b) As a general statement currently a very large majority of people are using setups that generate at least 2500+W of power (input to motor) c) As a general statement most people are using between 20" and 21" props with between 14"-17" of pitch Those statements should cover off I would guess 90+% of electric models flying today, up to the highest levels of competition. I feel its safe to say that the above is the accepted norm for performance of an electrically powered F3A model. So to the 8s setup, I will use some google translated quotes, [quote]A deployed data loggers supplied current peaks, in the second range of max. 83 amps. The average was found approximately 50 A. Our time limit on the transmitter is set for 9 minutes. Depending on the power battery, this is enough battery reserve. We use one battery of 4350 mAh mAh to 5400th[/quote] Lets do some math for giggles, Peak input power as per above, 8s @3.5v/cell (could be more, but lets say 3.5) = 28V @ peak of 83A = 2324W input power (remember the assumption above). This is as a general statement near or below what is being commonly used today, but not far from the mark. Second point, 50A average, for 9 minutes = 7.5 Ah, seems a little high. Based on their own statement to drain a 5400 mAh pack to 80%, you only have a 5.2 minute run time. Something in their statements does not compute for me. [quote]With wind we fly the larger batteries, in order to have more reserve, with weak winds, the lightweight batteries are used. After the flight of the normal P-09 flight program mAh we consume on average 2900 to 3300.[/quote] If we take the above statement, lets say 3300 mAh used from a pack, and the previous statement of 50A average, they are flying P-09 in 4 minutes flat. I do not think that is possible under any circumstances. To me its more reasonable to say 6.5 minutes at the least, which gives an average of 30.4A which is much closer to the average in flight current that I personally have seen on my own models. From those statements I have a hard time believing the article at face value, it seems like numbers put together without any facts! If their numbers added up and made sense it would be more valuable. Further on in the article, they state they are using a 19x12 propellor, here is my big problem. 19x12 prop at 2324W vs 21x14 at 2500W+ There can be no doubt that the second value provides significantly more performance, 2" more diameter and 2" more pitch. Now there is the weight factor. [quote]thus, the real flying weight varying from 4280 to 4480 g.[/quote] I can buy this, and believe most planes up in the 4800g+ range would be down to 4500g with the 8s packs. However, this is not sufficient weight reduction to overcome the performance difference! Here is where experience comes in, Way back in 2005 I flew an Enigma with a Pletty Xtra 25-13, weight was 4500g, I ran a 19x12 prop on TP 5300 Prolites (10s). Peak was about 70A-75A with the watts in the 2300-2400W range. Essentially exactly the same watt output and weight as what they are flying the Exelent on 8s with. I remember flying that plane very well, and can say with absolute certainty that it would not have enough performance to compete successfully in todays events. In fact before the WC in 2005 I switched to the original 30-10 in order to run bigger props at similar power levels. My experience tells me that on a 19x12 you should be in the 3000W range to have equivalent power to a 21x14 at 2500-2700W (I know Dave L has done a lot of experiments with small props, he should chime in as well! :) ). If thats true, on the 8s setup spinning the 19x12 prop, you are going to see 107A peak, and then higher average draws. If we use their 50A average as per above and a flight time of 8 minutes you need a 6700 mAh pack at 80%, so about 8200 mAh, in other words your weigh savings is really negated. I hope no one views this as being argumentative, I am all for change and progression. However, there are some basic physics at work that cannot be ignored, and no magic wand can violate them! I am always skeptical when I read reports like this and the numbers have to make sense first before I can believe that an accurate portrayal of performance is being displayed! For instance, posting simply watts, and amps, or watts and volts, and prop size [b]without[/b] the RPM that those results were generated at is only telling 1/2 of the story. You are defining the load the battery is under, but not the relative load the motor is under...this is a very important fact to be told. When I see posts of motor performance without RPM I become very suspicious about the information! Ok, enough from me :) Feel free to peel open my logic :)
Posted on: 10/27/2009 6:34 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9207087

RE: Is EP ready to downsize to 8s?
You cannot limit electric without limiting glow....or everyone will simply go back to glow! Electric is already confined to 10s, I am sure that without that limit we would have moved to 12s power pretty quick because it makes more sense. I have no issues with capping power if that's what is chosen by majority, however it must be equitable for all power sources. Competitors will always move to exploit the most advantageous application of the rules.
Posted on: 10/27/2009 10:57 AM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9205744

RE: Composite-ARF Integral, kinda build thread
I go through battery almost that quick, most of my data gathering has shown that I consume 500 mAh per minute. So I don't think you are too far out of the ballpark. The 21x14 or 20.5x14 are about the best you will get in terms of efficient power, the rest will either perform worse, or use more battery to perform the same.
Posted on: 10/26/2009 9:34 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9204581

RE: Ventura- new Quique Somenzini design
What QQ told me was basically this, When he ran the RASA 20.2x17 which is has very little blade at the root, he was happy with the performance but noticed that on uplines the plane was pulling to the canopy (I think he said, but its not relavant anyway).....and when he switched to the APC it was not doing that. I talked to him about it for quite a while and he feels that because of the different blade areas between the two props this was causing some changes in the flow that effected the amount of downthrust required. He felt rather than mess around with modifying the thrust to just run the APC. To get the performance he wanted he modified it, I think its a 21x14, pitched up to 21x15 and thinned out then stiffened with some carbon. Whatever he did it was the quietest plane there in flight IMO.
Posted on: 10/24/2009 7:17 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9199147

RE: RASA Prop Sizing for Neu Motor
Simon, Directly email Manfred Greve Jr., he is the designer of the RASA props and can probably provide you with more information regarding various setups for other motors. I will PM you his email,
Posted on: 10/22/2009 9:06 AM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9193101

RE: RASA Prop Sizing for Neu Motor
Volkert, They wont fold with the brake, I run my blades quite loose and have never had them hit the fuse.
Posted on: 10/14/2009 2:26 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9172928

RE: Benefits of swept wings?
[quote]ORIGINAL: Jeff Boyd 2 [quote]ORIGINAL: can773 Then we should be picking the design by the weakest pilot in order to cover all the bases! [:D] [/quote] Nice one Chad . . SO . . how is the Xigris ??? . . (only kidding, mate [:D] ) Cheers, JB [/quote] [:D][:D] I need all the help I can get! It delivered! [:D][:D]
Posted on: 10/14/2009 9:54 AM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9172318

RE: RASA Prop Sizing for Neu Motor
Hi Simon I don't know the exact loads with a Hacker, but here is my experience in order from lightest load to heaviest 21x14.5 - about 65A on a Pletty 21x15 - 70-75A 20.2x16 - 70-75A 20.2x17 - 80-85A 21x15.5 - about 90-95A on a Pletty I have never used the 21x16 Sorry, I always forget the Mag #'s! Can't comment on the Jeti either, but with the Schulze I use as much brake as possible and have a switch to activate it when needed. Maybe thats a solution for you?
Posted on: 10/14/2009 8:51 AM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9172190

RE: Benefits of swept wings?
I don't think so, I asked CPLR about that he said that he increased the dihedral in the Axiome prior to the WC's. I believe originally it was built with a flat top wing, and they cut it in half and added a couple mm. I think the newer planes have the wing so low in the fuse that they need more dihedral than was common in the past when the wings were closer to the engine line. [quote]ORIGINAL: Rendegade One wonders whether the increasing amount of sweep has some effect on knife edge flight, giving the aircraft more effective dihedral. Maybe it means that you can get away with less dihedral in the wings, which i have to say I'm not sure is such a great thing. It's been proven before that an aircraft with no dihedral doesn't knife edge as well as one with dihedral (just enough, not too much that it rolls out) due to the extra projected side area given by the wings. Food for thought though. I too find it a little hard to swallow that more sweep will aid rolling and stalling. It does however shift the MAC aft which may be desirable. [/quote]
Posted on: 10/13/2009 9:21 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9171146

RE: Benefits of swept wings?
Then we should be picking the design by the weakest pilot in order to cover all the bases! [:D]
Posted on: 10/13/2009 6:44 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9170667

RE: Sebart Wind S Pro Powerplant Options
I am fairly sure he flew his mono mostly, but I think he did change it up a few times. I recall him flying both models. Note: There were a lot of planes to watch, and it was far hotter than my Canadian raised body is used to so the mind gets a little blurry after a while. LOL So I may be thinking of someone or something else!
Posted on: 10/12/2009 7:21 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9167718

RE: 20th Annual Bud Garric Pattern Classic
Hi Tom I really wanted to go, but with Agnes being 38 weeks pregnant I was unable to convince her (of that or anything else for that matter) that I should go [:D] I am still working on timing babies appropriately for model airplanes, so far I am 0 for 2, during the first one I was in Victoria trying out for the team (2006) while she was a few days past due. That didn't go over very well! I still made it back in time for the birth though so it was all good. One day I will be there to have a few beers, and talk motors LOL.
Posted on: 10/12/2009 2:06 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9166878

RE: winter is coming, what about lipo's?
Hi Anthony, I have never tried it, but I know some of the F5D (electric pylon) were using something like that to get their packs hot before flights. Since our packs are so big though I would try to heat them evenly so the inner cells get warm as well. Maybe a couple of those or Brian's idea of bottle warmers in a small insulated cooler would work well I just leave my car running, I figure we need some global warming in this part of the world anyway so a little greenhouse gas is a good thing LOL [:D]
Posted on: 10/10/2009 10:36 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9162735

RE: winter is coming, what about lipo's?
Hi Volkert Yes break in is essentially going easy on the pack for the first few cycles, reducing the depth of discharge and peak amps. The easy way is to prop down or to just fly and practice rolls and such things for a bit :) My experience is that packs mainly heat up from discharge, so by flying a short flight you wont make them very hot. Presumably if you fly in the winter you have a car nearby! The easiest way is to run your car and use the heater to warm up the batteries. I feel that its important to get them hot prior to the flight for best performance.
Posted on: 10/9/2009 9:17 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9160487

RE: winter is coming, what about lipo's?
Avoid flying in temperatures less than 10C-15C with an F3A electric model without taking precautions. If you do fly in temps lower its wise to preheat (to 40C+) your packs and reduce, or eliminate any cooling air so the packs will stay warm during the flight. An eagletree logger with a temp probe helps to identify how warm your packs are staying during flight, and then you can adjust things based on that knowledge. You can very easily over discharge packs while flying in cold weather. As long as you can keep the packs warm, you will not see any reduced performance, except maybe your own flying because your fingers are frozen! [:D] For storage, discharge to about 3.8 V/cell and keep cool around 5C (I keep mine the refrigerator), then do a new break in (low power for 5-10 cycles) in the spring to bring them back to best performance.
Posted on: 10/9/2009 2:40 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9159545

RE: Comp ARF Valiant
Hi Stever Get in touch with Chris Moon at F3Aunlimited.com he has worked out a deal with Pletty to sell Evos in the US. Maybe he can help you to get one sooner!
Posted on: 10/8/2009 10:15 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9157905

RE: 2M Electric only planes...?
Spied this pic, didn't know Hyperion had a Helios 140? It would be another e-only 2m if it is actually in production.
Posted on: 9/29/2009 9:04 PM by Author "can773" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9134369

RE: 2009 Tangerine... 3 days of fun this year
OUCH! Don't remind me of that!
Posted on: 9/18/2009 1:32 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9105774

RE: 2009 Tangerine... 3 days of fun this year
Where am I gonna stay? [:D]
Posted on: 9/18/2009 9:16 AM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9105290

RE: Composite-ARF Integral, kinda build thread
Delro maybe? http://electric-f3a.com/delro.htm
Posted on: 9/11/2009 1:54 PM by Author "can773" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9087130