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Old May 27, 2012, 01:39 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
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Quote:
Originally Posted by bigroger View Post
All this talk about the hot 2820-750 spinning too fast to run the 14x7 prop, why not just trim down your throttle end points?
Good point Roger, end point adjustment should work ok, providing the ESC doesn't go auto calibrate itself to the reduced end point position.

For me the wood prop was a no-no because it over amped the motor far too much.. but it should be ok with the 680 wind, which is another plus for the 680. I guess end point adjustment could fix that one also, providing your ESC was up to the job because end point reduction does not actually reduce the peak amp value seen by the ESC.

Steve
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Old May 27, 2012, 03:26 AM
Just flitting about!!
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Of course, but most of us running the hot 750kV would use the 60A with 80A peak esc, so it should be able to handle the spikes and reduced end points on throttle should allow reduced load.

I did an experiment the other day on my Edge, I had been running the scorpion 3020-890 on vox 14x7 and 3s with the airboss45A esc.

Never had issues and had healthy 60A wot numbers without issues and 6 minutes flights.

I had nose dumped the previous edge and bent the prop adaptor and shaft so built the new edge with my Motrolfly 2820-950 and tested on vox 14x7. Pulled some 68-70A numbers at wot so thought I fly it.

It was horrible, now where near the punch as the 3020-890, made the esc run very, very hot and short flight times.

Reducing to 13x6.5 lowers the amps to 56-57A and rpm of 8670rpm so I'll try that.

I want to keep the little edge on 3s if possible as really enjoyed the light flying huckability on that set up.
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Old May 27, 2012, 09:05 AM
JKasprak
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Fayetteville, NC 28304
Joined Jan 2010
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Roger - I'm currently flying a MXS with the 2820-950 on 3S with a 13x6.5. No lack of power and punch as far as I'm concerned. Using 2650mah batteries I get about 6-6.5 minutes. I ususally fly 4 batteries back to back. Motor and ESC are warm after the 4 packs, but not hot, as are the packs. I'm interested to hear your assessment of the set up.
John
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Old May 27, 2012, 02:36 PM
Not as Good as The Kid
Aeroplayin's Avatar
South Pasadena, FL
Joined Sep 2009
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Quote:
Originally Posted by bigroger View Post
Of course, but most of us running the hot 750kV would use the 60A with 80A peak esc, so it should be able to handle the spikes and reduced end points on throttle should allow reduced load.

I did an experiment the other day on my Edge, I had been running the scorpion 3020-890 on vox 14x7 and 3s with the airboss45A esc.

Never had issues and had healthy 60A wot numbers without issues and 6 minutes flights.

I had nose dumped the previous edge and bent the prop adaptor and shaft so built the new edge with my Motrolfly 2820-950 and tested on vox 14x7. Pulled some 68-70A numbers at wot so thought I fly it.

It was horrible, now where near the punch as the 3020-890, made the esc run very, very hot and short flight times.

Reducing to 13x6.5 lowers the amps to 56-57A and rpm of 8670rpm so I'll try that.

I want to keep the little edge on 3s if possible as really enjoyed the light flying huckability on that set up.
Plus I think running it to 8400 RPMs static will be fine too. This is where Tom's is at right now with the APC 14x7 on 4S and has been for just under a year.
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Old May 27, 2012, 02:53 PM
Not as Good as The Kid
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Quote:
Originally Posted by propchief View Post
Roger - I'm currently flying a MXS with the 2820-950 on 3S with a 13x6.5. No lack of power and punch as far as I'm concerned. Using 2650mah batteries I get about 6-6.5 minutes. I ususally fly 4 batteries back to back. Motor and ESC are warm after the 4 packs, but not hot, as are the packs. I'm interested to hear your assessment of the set up.
John
Check your RPMs but if you are getting 9,000 RPMs or less, then you are not going to produce more than 560 Watts-out with the 13x6.5e. That's 120 Watts-out less than the 680 on 4S with the 14x7. We have the 950 on 3S and a 13x6.5e on the Velox VR-1 at only 48 ounces all-up and it is considerably less power (522W) than the 4S, 14x7, 683Kv setup on the Edge EXP at 56 ounces.
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Old May 27, 2012, 04:55 PM
Grumpy old git.. Who me?
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56 oz for the 48" Edge.. isn't that a bit porky?
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Old May 27, 2012, 05:17 PM
JKasprak
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Fayetteville, NC 28304
Joined Jan 2010
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Just performed a run and got 8650 rpms. Can't get you a watt/amp reading. I can tell you that the combination has enough power to pull the MXS around ... fast or slow there is no shortage of power.

I'm not advocating this set up. My set up is what it is, as that's the motor and batteries I own. If I had to purchase a motor and batteries I would go lower kv and 4S battery. But until my batteries or motor give out it's what I'll use.
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Old May 27, 2012, 06:19 PM
Just flitting about!!
bigroger's Avatar
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Pretty much aligns with the rpms I got on that motor/prop combo.
Are you using apc or Xoar/vox type 13x6.5 prop?

Will genrate more thrust with the vox type prop over the apc from what I have seen.
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Old May 27, 2012, 07:41 PM
JKasprak
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Fayetteville, NC 28304
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I'm using an APC prop. I'll check the Xoar/Vox when I can get a hold of one. Thanks
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Old May 27, 2012, 10:12 PM
Registered User
Omaha Nebraska
Joined Apr 2008
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Quote:
Originally Posted by bigroger View Post
Ken,
is this modification to the 28xx range going to be ex factory or SubsonicRC only? ( I am referring to the set screw in bearing hub being drilled further into the bearing tube)
This is something we do here in the US only

Ken
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Old May 27, 2012, 10:21 PM
Just flitting about!!
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Happy to report, 4 3s2200 packs through the 48" edge today with the DM2820-950 and Vox 13x6.5 prop and it was fantastic.
Not a bullet by any means but for 3s it really was nice, harrier and hover very easy and gentle tumbles, KE spins, flat spins, etc all very nice.

To compare it to the scorpion 3020-890 on Vox14x7 though, the scorpion set up had a lot more punch and you could feel the prop vectored thrust on the bigger prop a lot more, but the big prop did tend to make fighting the torque in hover a bit more of a challenge.

I've repaired the scorpion motor now with new bearings, shaft and prop adaptor, so I'll swap it over and give it a try as direct comparison before I settle on the one motor.

I must try it on 4s one day, I have the torque motor and could run a 13x5 Vox prop to see what its like. I would prefer a bit more vertical punch that I just don't get on the 3s setups.
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Old May 27, 2012, 10:35 PM
Not as Good as The Kid
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South Pasadena, FL
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Quote:
Originally Posted by JetPlaneFlyer View Post
56 oz for the 48" Edge.. isn't that a bit porky?
That's the weight of both Edges we have... Most of the people I know with the Edge are seeing anything between 52 and 56 oz and you can come in lighter with a 45A ESC, no BEC, light extensions, analog servos, smaller prop, a 2200mAh batt, etc.

Although I am a fan of a light airframe, the 48 Edge carries the weight very well, as you can see in Tom's videos, and I don't start seeing a handicap until I put my 2800mAh GForce batteries in it. The 2200 nano in my 638 is nice and floaty and I still get over 7 minutes from it. I will say that I do like the way it flies better. The problem is that I'm just not a fan of the battery.

I think the 2200 Skys are 195g (6.9 oz) so I may start getting them when it's time to cycle out 4S batteries. but I'm moving to bigger airframes this summer and we'll see what EF has available by the end of August. Tom maidened the 27% Godfrey Extra yesterday on the 10S Q80-7M Hacker (35 oz) and it did produce as advertised. Amazing with the 24x10TH Mejzlik at up around 4400W and 115-116A. I see this light combo easily pulling around any 3D airframe up to 19 pounds.
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Old May 27, 2012, 11:48 PM
VOLTS > AMPS
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United States, MN, Buffalo
Joined Jul 2011
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How did the 5s setup work this weekend

Also ken on my 600kv 2820 5s setup, can I run the 14x7 prop since its custom wound and has the modification in it?
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Old May 28, 2012, 02:31 AM
Just flitting about!!
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Jim,
are you misreading something.... 4s2200 skylipos that come in a 195g, shouldn't it be a bit more then that? Unless you are referring to 3s setup?
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Old May 28, 2012, 12:11 PM
Not as Good as The Kid
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South Pasadena, FL
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Quote:
Originally Posted by bigroger View Post
Jim,
are you misreading something.... 4s2200 skylipos that come in a 195g, shouldn't it be a bit more then that? Unless you are referring to 3s setup?
Yes, my-bad... I was quoting from memory and was wrong, so thanks for the correction. The Sky 2200 30C 4S is 50 grams more than that and the Nano is 44g more.
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