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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Dwayne on September 25, 2011, 02:26:57 PM
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Hey guys, I got everything set up and did a rpm test, when I adust the rpm it goes from 8900 rpm to 11,000 with nothing in between.
Confused again...still ??? :-\
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Well, if you are using the Phoenix ESC programmed to Control Line Set RPM mode that is what might happen. Actually you should get three RPMs which you select during the programming process (one for 0 to 49%, another one for 50 to 99% and one for 100% throttle).
If you want to adjust RPM with the pot on your timer you should program the ESC for Control Line Governor High mode (which is what most fliers are using).
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Hey guys, I got everything set up and did a rpm test, when I adust the rpm it goes from 8900 rpm to 11,000 with nothing in between.
Confused again...still ??? :-\
It is working as it should. In "Set RPM" mode you program up to 3 choices for your RPM setting in the esc. The timer is then a selector for the RPM's that are programmed:
* Turn the timer RPM pot all the way to the left, that is 0% throttle. Anywhere from 0%-49% selects the lowest RPM that is programmed into the ESC
* From 50%-99% travel on the pot selects the middle RPM that is programmed into the ESC.
* Turn the pot all the way to the right against the stop - that is 100% throttle. That will select the highest RPM that is programmed into the ESC.
Set RPM is more precise than the fully variable throttle type timers, but it requires drinking some Kool-aid! Simply put you have to abandon your old IC ways. It also works well with oddball motor set-ups like the 10-pole motors. I even used it with a 3-pole inrunner motor with a 3.29:1 gear drive - the RPM setting came out perfect every time - at least until the gears wore out! I also used Set RPM on the Pathfinder Twin because it would not be possible to synchronise two motors using regular high gov mode. The BAD NEWS is that you need a PC to re-program the RPMs in the ESC. I prefer Set RPM because I think it is more exact. I typically use the middle setting as my "standard" then set the others at +100 RPM and -100 RPM.
There is some controversy over the way it governs. I think it governs better because there is tighter control with less spikey motor response. Some folks have noted - with datalog to back it up - that the the governor responses ARE steeper with regular High Gov mode. Is that a strength or a weakness? Your mileage will vary.
I prefer Set RPM and have not seen any reason to change, the same can be said by those who prefer High Gov mode. Either method works better than the old Fox 35!
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I have been using the "set RPM" mode with my Phoenix 35 for about 65 flights or so. I have the ESC set as Desired Head Speed #1--9,400 RPM. Desired Head Speed #2--10,000 RPM. Desired Head Speed #3--10,400 RPM. I use Speed #2 for normal flying. Motor goes to Speed #1, 5 seconds before quitting to warn me. And if the day is a little windy I go to Speed #3 for a little more punch. Works like a champ. And when I use my tach to check RPM, I'm within 20 RPM of the set RPM. What could be better than this ? I likes it !!! :) Yes I do.
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Yes it is Phoenix 45, I'll try "set rpm" I had it set up as shown in the "cook book"
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Ok I set it up using "set rpm" 9450, 9500, 9600 and headed out to the Field, it seems to be right on the money at 9500 lap times are around 5.3 and there is good line tension overhead, I'm using about 1814 ma so my 2650's are more then enough,.
So here is my set up now
Plane is scratch built using a Twister rib built into a C-tube and added 1 inch inboard so the span is now 49" or 490 sq in
The stab and elev. are built up 20" span
Fuse is hollow aft of the wing using 1/16" sheet around 1/2" sheet in the nose, there are no doublers.
Motor-E-Flite 15 APC 11X5.5 EP
Phoenix 45
Hubin FM 2SR
Zippy 2650 4cell
Weight with batt is 39.5 oz.
I put up 5 flights and so far I'm pleased it was a bit windy so couldn't tell how level the wings were as it was getting bounced around pretty good but seemed ok and it turns on dime.
So, so far I'm pleased with this set up and as I get more comfortable with plane it should only get better. y1 #^
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Nice looking plane.
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Dwayne
Looks great. Glad you made it all work.
Regards
Norm Whittle
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At 39 ounces, you get to run the 012 lines! That will help, too, if you aren't already.
Nice looking ship,
Dean P
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Thanks guys, I'm happy with the way it came out.
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Dwayne
Glad it's working for you ! You will probably experiment with different RPM's as time goes by. I like to have a 400-500 RPM difference (lower) than my normal flight RPM so the 5 sec. cutoff time is very noticeable with the RPM change. I first had only 100 RPM difference, and could not tell when it switched to the lower RPM for the cutoff warning. Good luck to you. And have fun. :)
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39 oz !!! Yee haw, you have great power to weight with that set-up.
Glad you got the Set-RPM going too. Do yourself a favor, and fly it at the high seting and the low seting too. That will affirm that these settings are where you want - no surprises on contest day either!