START HERE |
|
Register | FAQ | PM | Events | Groups | Blogs | Calendar | Mark Forums Read |
Unregistered
|
Electric Motors Winding and Repair Electric Motors Winding and Repair Discussion |
|
LinkBack | Thread Tools | Display Modes |
05-17-2012, 08:02 AM | #61 (permalink) |
Registered Users
Join Date: Sep 2008
|
Let me give my 2 cents to this topic here.
Before we can agree to any pros and cons, we have to define our target. Let's say our target is very clean 3-D flying: Lots of figures, where a certain stick input has to give me a known result. Tail has to be very firm. Changing pitch direction and result has to occur at the same stick position etc. etc. That all needs a very predictable and firm head-speed!!! Raw power does not help here. The power has to be tamed and governed and let lose where appropriate. In order to get to our target we have to have a balanced setup: A sound and healthy relationship between motor RpM (cooling), pinion (head-speed) and battery power (the only limiting factor in the equitation here) If this setup is balanced and enough motor power is available, which of course depends on the available battery power (c-rating) the governor has do its work without getting to its limits. When the PWM is a good part of the flight time at 100% (like in the second half of Don's flight and not counting very short spikes) then the setup has to be re-evaluated. The fact, that the ESC has more work to do and converts more of the available power into heat is undeniable and unavoidable for getting to our target. Totally different scenario, when we are talking about speed runs. Ralph stated the requirements for this above already.
__________________
Kind Regards ZT - TDR, No problem can be solved from the same level of consciousness that created it.(AE) |
Sponsored Links | |||
Advertisement |
|
05-17-2012, 08:09 AM | #62 (permalink) |
Registered Users
Join Date: Oct 2004
|
The gearing was optimized for the ESC makers recommendation of 10% overhead in governor mode. The logs confirm that the average PWM during the flight was 91%. After reveiwing the logs again, the ESC did not spend much time at 100% (16 seconds over the entire flight), and most of this was during the latter part of the flight when the packs were drained.
I think that headspeed loss is difficult to avoid if using a reactive governor when doing aggressive flying. The problem with overgearing on this setup is that this ESC does not freewheel very well so although it will have more headroom to maintain the headspeed during the to peak demands, the ESC will be less efficient during the non-peak times leading to extra heat being generated in the ESC. I tried overgearing on another machine (Synergy E7) while running a 4525LE. PWM never got above 95% but the logs still showed the headspeed dropping by as much as 100 RPM.
__________________
fly big, fly fast, fly hard.... |
05-17-2012, 08:11 AM | #63 (permalink) |
Registered Users
Join Date: Jul 2009
|
Ralph you are correct with speedflying you want max thr , I have my tdr in I'd2 at the max thr , i.e.100% for the last quarter of the thr. But for 3 d it's a different story you want as little possible variance in headspeed for max consistency.
@kimmik why do you think we pay mega bucks for jive controllers, because they have the best governers, your argument about bogging giving feedback.....sorry makes no sense! A heli that doesn't bog flies better than one that does, off course I'm referring to a3 d heli, speed flying you actually turn the gov off |
05-17-2012, 08:14 AM | #64 (permalink) |
Registered Users
Join Date: Sep 2008
|
That reaffirms the point!
The battery is the limiting factor!! Imho we can't avoid some of the head speed drops, but we can limit them by a taking the governor limit out of the equation.
__________________
Kind Regards ZT - TDR, No problem can be solved from the same level of consciousness that created it.(AE) |
05-17-2012, 08:22 AM | #65 (permalink) | |
Registered Users
Join Date: Jul 2009
|
Quote:
you can fly the way it is no problem, but you are robbing yourself of the perfect setup |
|
05-17-2012, 08:43 AM | #66 (permalink) |
Registered Users
Join Date: Oct 2004
|
I'm using new Gens Ace "60C" 4800Mah packs. The packs are only 6 flights old so the IR is probably still coming down. I will do a few flights at 2200 and report back.
BTW, I am not experiencing any weird side effects that are usually caused by RPM fluctuation. No tail kicks, no bogging. The machine is very consistent and the power delivery is very smooth.
__________________
fly big, fly fast, fly hard.... |
05-17-2012, 08:56 AM | #67 (permalink) |
Registered Users
Join Date: Jul 2009
|
Sorry dd I didn't read all your posts, you did mention I see the packs.
I'd say log some flights on 2100 as well 2200 may still be too high for headroom. Your packs and that motor can do better I assure you! |
05-18-2012, 05:40 AM | #68 (permalink) |
Registered Users
|
Stolla i like to fly mine with the governor maxing out near the end of pack, so i have a feel of the battery draining and bring it in for softer maneuvres towards the end. Makes great sense to me. This applies even when i'm already using high quality governor.
|
05-18-2012, 07:54 AM | #69 (permalink) |
Registered Users
Join Date: Jul 2009
|
look what works for you I'm not here to tell you what to do, we all have our own way but here's my viewpoint, I want to have the same performance throughout my whole flight routine, from start to finish, I don't want to feel my batteries loosing power towards the end of my routine. The batteries should deliver my governed headspeed till I land. My flight routine exists of very high and very low headspeed, on my 7 hv between 2250 and 1750 at any time I switch between id1 and id2 I get that exact speed throughout my flight routine. In the old days when we didn't know jive had to run at such low thr percentage I remember how we loose power towards the end. Now with correct headroom its like having stronger motor, better lipos etc. read how dekker mentions in the 4035 thread how he heard in video his monster 4035 on 1.6 mmyy bog. Now that's definitely running too high pwm, or in other words not enough headroom. all I can say to you is try it out, you won't go back.
|
05-20-2012, 09:04 PM | #70 (permalink) |
Registered Users
Join Date: Oct 2004
|
Here is a video of the rewound Quantum. Headspeed was 2200 with 14 degrees of pitch.
[ame]http://www.youtube.com/watch?v=6PfNuaPpgq0[/ame]
__________________
fly big, fly fast, fly hard.... |
05-21-2012, 07:58 PM | #71 (permalink) | |
Registered Users
Join Date: May 2009
|
I'm in complete agreement with stolla regarding headroom.
If you really think about how an esc function in relation to our throttle, RPM, motor,gear ratio it will all make sense. There are many variables at play and finding that sweet spot for your heli combination will be very rewarding in the end. I personally have always setup with correct headroom. If anyone ever inclined you can do the math to work out headroom allowance. Basically you would need 15% headroom as a base. Quote:
|
|
05-22-2012, 12:54 AM | #72 (permalink) |
Registered Users
Join Date: Jul 2009
|
nice flying dd but is it only me hearing the motor dropping quite a bit of rpm during load? , I'm convinced you don't have enough headroom for gov, but hey if it doesn't bother you don't mind my opinion. my first hand wind a 4025 with 1.4 mm. yy in logo seriously disappointed till I lowered headspeed for headroom, changing pinion to allow for headroom on higher rpm gave me the best flight ever till I landed and saw my hyperion destroyed, was only 35 c though. Now on jive with jlog I watch my rpm decay more than anything, its the way to a perfect setup.
I'm keen to do one of these motors, just want to see what the thick wire 5+5 4035 does. Did you log this flight dd? |
05-22-2012, 01:18 PM | #73 (permalink) |
Registered Users
Join Date: Oct 2004
|
Your ears confirm what the log says. I really think the headspeed loss is more the do with the packs than the PWM and governor. The reason I say that is because reviewing the logs show that the voltage drops significantly during load. The packs should be able to maintain voltage of above 41V even when at 100% PWM. The logs show voltage as low as 39V when loaded. That 2V difference equates to over 100 RPM drop. I have a larger pinion on order but I am doubtful I will see much improvement with regards to RPM drop.
Do you have any logs that show your voltage when you hit 100%. Another thing to factor in is your experience is based on using what is considered the best internal reactive governor with the Jive. The governor on my Scorpion ESC is much better than what I'm currently using in the Castle but I chose to use the Castle so I could see the logs.
__________________
fly big, fly fast, fly hard.... Last edited by don-dadda; 05-22-2012 at 02:25 PM.. |
05-22-2012, 04:26 PM | #74 (permalink) |
Registered Users
Join Date: Aug 2009
|
don-dadda
I think large voltage sags under high loads are common, even for good packs. What you really want to look for is how much your headspeed decays under that load. |
05-22-2012, 05:21 PM | #75 (permalink) |
Registered Users
Join Date: Oct 2004
|
Yes, but how high of a drop in voltage. I would like some actual data. If the packs drop to 39V simple math will tell you that there will be decay in headspeed even with additional overhead.
39V x 525KV x .9 / 8.86 = 2079 That's inline with the minimum RPM that log is showing. Maybe Ralph has an opinion on this since this is not specific to helicopters.
__________________
fly big, fly fast, fly hard.... |
05-22-2012, 07:29 PM | #76 (permalink) |
Registered Users
Join Date: Aug 2009
|
Edit: Nevermind
Last edited by NRPY; 05-22-2012 at 08:53 PM.. |
05-22-2012, 10:25 PM | #77 (permalink) |
Registered Users
|
__________________
Henseleit TDR, TDR2, TDF, TDS, TDSF Kontronik, Scorpion ESC, iChargers, VBar, VControl Old hand at Planks Peter |
05-22-2012, 11:37 PM | #78 (permalink) | |
Registered Users
Join Date: Jul 2009
|
Quote:
|
|
05-23-2012, 10:17 AM | #79 (permalink) |
Registered Users
Join Date: Apr 2007
|
wiring diagram?
would this be the wiring diagram used for this motor?
http://www.powerditto.de/schemamodus12N_YY.html |
Thread Tools | |
Display Modes | |
|
|