Rewinding Emax CF2805 & CF2822 - Page 6

jonesymj · Aug 21, 2009, 07:36 PM

Thread revival!!!

Just tested a 2822 I've rewound similar to MiseryQ's parkjet wind... I did 5 turns first tooth, 4 turns second tooth, 2 strand 24ga, . Used a SS30a for the first run and a Phoenix 25 for the second, just to be sure my numbers were right, and they came out nearly identical. With 460mAh gone (nice and settled) from a 25c 1600 3s, I got 211w, 20.1a @ 10.57v using a 6x4 EMP sport. Should push my Jetset44 Gripen around nicely...
I'm also using a 2805 rewound with 11t 24ga on my BMR-2 with 2s 800's and the same 6x4... Isn't insane speed but it's a ton of fun and the motor comes down cool to the touch after a 10 minute run... Good wind as well!!

Texas11 · Aug 26, 2009, 04:40 AM

I just finished a wind of a 2822. I used 22 AWG and a dLRK scheme. I got 6 turns per tooth on every tooth. I initially wired the motor as a Delta. In testing, the bearings got VERY hot at WOT with no propeller. I lubed the bearings, but I'm wondering if I should go with a Wye instead. I haven't measured the motor directly, but form other's measurements, it seems like the motor would be about 3400 Kv in a Delta and 2000 Kv in a Wye. I'm using a 3s Lipo and I'm trying to get the maximal thrust. Do folks have a recommendation? This is my first motor rewind, so I don't have any experience in these matters.

MiseryQ · Aug 26, 2009, 10:58 PM

If your going for thrust then 2000Kv with a larger prop would be the way to go IMO.
Depends on how much pitch speed you want as well.
My 2700Kv with a 5X5 TGS puts out lots of thrust and a decent pitch speed too.

Texas11 · Aug 27, 2009, 12:32 AM

I was running a 9x5x3 GWS HD on the stock motor. Do you think I'll get better thrust with a Wye or Delta with the same propeller compared to the stock motor?

MiseryQ · Aug 27, 2009, 12:48 AM

Delta will be way to hot for that prop. Go with the 2000kv wye.

Texas11 · Aug 29, 2009, 02:11 PM

OK, I've been playing with the new wind. In Wye or Delta I was getting "slippage" at high throttle. I assumed it was too much work for the motor and the system was failing. I reprogrammed the ESC to "high" timing and both the Wye and Delta can be driven to WOT. At WOT in Delta - the ESC gets very hot very fast. WOT in Wye seems OK with my ESC. I'm using a HobbyKing 30 Amp Super Simple ESC.

My question is this:

If I can drive this motor in Delta at WOT, should I just get a bigger ESC and use the higher power?

MiseryQ · Aug 29, 2009, 02:27 PM

You need a wattmeter. Even a $3 wattmeter.
My motor was measured at 24amps IIRC and it's nowhere near as hot as yours in Delta.
Your going to have to us a small prop to keep the amps down. A prop too large will cause a hi kv motor to pull way to many amps.

If you want thrust as you mentioned then terminate it Wye with the 30amp ESC and try maybe a 7x5 or even MAYBE a 8x3.8.

lukydvll · Sep 14, 2009, 06:44 PM

[quote=MiseryQ]How many MiseryQs can there be? (:
I go more by the also unique name of fr4nklyn now o:

Haha, I've built several Megasquirts with EDIS... like you said, small world.

MiseryQ · Sep 14, 2009, 06:57 PM

My Oldsmobile needs a total rewiring plus code update.
It's been awhile since I've evn been to the sites.
Have an EDIS 8 but never found a good trigger wheel.

grumman5277 · Oct 13, 2009, 02:50 PM

Just finish a volt amp test on a 6t 22g y dlrk.
12.4v and 14.6a using a 4.1x4.1
I used a turnigy plush 25a and lost some throttle resolution over 75%.
I will probably try some reprogramming or do a quick test with my CC45 and see if anything changes. I used 200c magnet wire from Techfixx.com

One thing I did notice about these motors is a little inconsistency in the magnet strength. I have two that are as far as I can tell similar and one definitely different (stronger). Not sure if they have changed these or it's a fluke

Jeremy

MiseryQ · Oct 13, 2009, 07:48 PM

At higher KV the ESC is pretty critical. Only a thunderbird would turn the the first rewind I did, 7t of 22 IIRC.

What's the KV and RPM with the 4.1x4.1?

grumman5277 · Oct 14, 2009, 08:33 PM

The testing was just the volt and amp measurements.When I found the timing issues I never tried another esc. I tried a 5.5x4.5 and it squealed at about 75% WOT. I'm told that they do use specific timing so I'll try it and get the rest of the info at the same time.
The original winds on that motor was 13 dlrk delta and 2850kv. My guess is I'm about 3000kv or very close. I just couldn't get more than 6t of 22ga on it or it would be about 2700kv.

I'll get more accurate info soon.
Jeremy

Quote:

Originally Posted by MiseryQ

At higher KV the ESC is pretty critical. Only a thunderbird would turn the the first rewind I did, 7t of 22 IIRC.

What's the KV and RPM with the 4.1x4.1?

grumman5277 · Nov 04, 2009, 06:13 PM

I agree 100%. My test of a 2812 which is stated as having 1534kv measured 1.1vac. (2580/1.1)/1.41=1663 about 7% different from stated. If i used the whole formula it comes out to 1750kv.I will test the rpm of my press to determine if it's off. I would imagine 150rpm difference from the press stated rpm (7%) is not that unreasonable.

The problem I have with all the testing people have done over the years is that even now there is no standard. We know MFG's or I assume are not ISO ,so why haven't we at least attempted to or agree upon a standard here.

I personally like the Vac method because I'm only testing the motor,which is my only intention. Loses ,esc,props,batteries etc. are not my concern when determining the motor's KV. Efficiency is another aspect of a motor which all those other things mentioned will be addressed.

Jeremy

Quote:

Originally Posted by MiseryQ

1200/.44=2727kv

((1200/.44)/1.41)/.95=2036kv

That's a big difference. It doesn't seem to add up.

MiseryQ · Nov 04, 2009, 08:55 PM

That 7% could easily come from the winding at the factory.
While my 28-22 was consistent the 28-05s were not.

I'm really scared cause I ordered a 2627 and even though it's listed as 3800kv I saw a test that say it's more like 4300 :ugh:

grumman5277 · Nov 04, 2009, 10:46 PM

That's kinda funny. I tested two identical motor's or so I thought. I have 3 motors 2 were 2840kv and one was the 1600kv. I didn't think there was a difference but I guess I was wrong. I rewound 2 of them 7t (y). One measured .5v and the other .6v .
I found that I mismatched the bells. The lower Kv motor had stronger magnets and was the reason I had 500rpm difference between them.

Based on the stated 2840kv I calculated a new wind 7t (y) v's stock 15t (D) = 3540kv
The measured kv based on 3120/.6v/1.41 = 3688kv almost exactly 4% or a factor of 1.04 difference.
Which is closer to actual (measured) or (kv/ new kv x turns).

MiseryQ, I would imagine if there is a factor to use and this is speculation ,but I believe less than 1 isn't applicable as someone else stated .95 .

My press measured 3120 rpm so I know there is a difference.
3120/1.1/1.41/ (factor? (1.3) = 1547kv (stated Kv 1534). without the factor it is 2011.6kv. Not sure why there is a 23% difference in Kv.May just be HC fudging no again.

Has anyone measured the 2840kv motor's vac?
Jeremy

Aug 29, 2009, 02:27 PM	#82
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	You need a wattmeter. Even a $3 wattmeter. My motor was measured at 24amps IIRC and it's nowhere near as hot as yours in Delta. Your going to have to us a small prop to keep the amps down. A prop too large will cause a hi kv motor to pull way to many amps. If you want thrust as you mentioned then terminate it Wye with the 30amp ESC and try maybe a 7x5 or even MAYBE a 8x3.8. Last edited by MiseryQ; Aug 30, 2009 at 11:45 AM. Reason: phone typos

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Aug 21, 2009, 07:36 PM	#76
jonesymj Certifiable E-hole Join Date: Jun 2006 Posts: 390	Thread revival!!! Just tested a 2822 I've rewound similar to MiseryQ's parkjet wind... I did 5 turns first tooth, 4 turns second tooth, 2 strand 24ga, . Used a SS30a for the first run and a Phoenix 25 for the second, just to be sure my numbers were right, and they came out nearly identical. With 460mAh gone (nice and settled) from a 25c 1600 3s, I got 211w, 20.1a @ 10.57v using a 6x4 EMP sport. Should push my Jetset44 Gripen around nicely... I'm also using a 2805 rewound with 11t 24ga on my BMR-2 with 2s 800's and the same 6x4... Isn't insane speed but it's a ton of fun and the motor comes down cool to the touch after a 10 minute run... Good wind as well!!

Aug 26, 2009, 04:40 AM	#77
Texas11 Registered User Join Date: Apr 2009 Posts: 6	I just finished a wind of a 2822. I used 22 AWG and a dLRK scheme. I got 6 turns per tooth on every tooth. I initially wired the motor as a Delta. In testing, the bearings got VERY hot at WOT with no propeller. I lubed the bearings, but I'm wondering if I should go with a Wye instead. I haven't measured the motor directly, but form other's measurements, it seems like the motor would be about 3400 Kv in a Delta and 2000 Kv in a Wye. I'm using a 3s Lipo and I'm trying to get the maximal thrust. Do folks have a recommendation? This is my first motor rewind, so I don't have any experience in these matters.

Aug 26, 2009, 10:58 PM	#78
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	If your going for thrust then 2000Kv with a larger prop would be the way to go IMO. Depends on how much pitch speed you want as well. My 2700Kv with a 5X5 TGS puts out lots of thrust and a decent pitch speed too.

Aug 27, 2009, 12:32 AM	#79
Texas11 Registered User Join Date: Apr 2009 Posts: 6	I was running a 9x5x3 GWS HD on the stock motor. Do you think I'll get better thrust with a Wye or Delta with the same propeller compared to the stock motor?

Aug 27, 2009, 12:48 AM	#80
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	Delta will be way to hot for that prop. Go with the 2000kv wye.

Aug 29, 2009, 02:11 PM	#81
Texas11 Registered User Join Date: Apr 2009 Posts: 6	OK, I've been playing with the new wind. In Wye or Delta I was getting "slippage" at high throttle. I assumed it was too much work for the motor and the system was failing. I reprogrammed the ESC to "high" timing and both the Wye and Delta can be driven to WOT. At WOT in Delta - the ESC gets very hot very fast. WOT in Wye seems OK with my ESC. I'm using a HobbyKing 30 Amp Super Simple ESC. My question is this: If I can drive this motor in Delta at WOT, should I just get a bigger ESC and use the higher power?

Sep 14, 2009, 06:44 PM	#83
lukydvll Registered User Join Date: Sep 2008 Posts: 2	[quote=MiseryQ]How many MiseryQs can there be? (: I go more by the also unique name of fr4nklyn now o: Haha, I've built several Megasquirts with EDIS... like you said, small world.

Sep 14, 2009, 06:57 PM	#84
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	My Oldsmobile needs a total rewiring plus code update. It's been awhile since I've evn been to the sites. Have an EDIS 8 but never found a good trigger wheel.

Oct 13, 2009, 02:50 PM	#85
grumman5277 Registered User Join Date: Jan 2004 Location: Troy ,OH Posts: 1,439	Just finish a volt amp test on a 6t 22g y dlrk. 12.4v and 14.6a using a 4.1x4.1 I used a turnigy plush 25a and lost some throttle resolution over 75%. I will probably try some reprogramming or do a quick test with my CC45 and see if anything changes. I used 200c magnet wire from Techfixx.com One thing I did notice about these motors is a little inconsistency in the magnet strength. I have two that are as far as I can tell similar and one definitely different (stronger). Not sure if they have changed these or it's a fluke Jeremy

Oct 13, 2009, 07:48 PM	#86
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	At higher KV the ESC is pretty critical. Only a thunderbird would turn the the first rewind I did, 7t of 22 IIRC. What's the KV and RPM with the 4.1x4.1?

Nov 04, 2009, 08:55 PM	#89
MiseryQ Registered User Join Date: May 2006 Location: Norfolk, Va Posts: 1,770	That 7% could easily come from the winding at the factory. While my 28-22 was consistent the 28-05s were not. I'm really scared cause I ordered a 2627 and even though it's listed as 3800kv I saw a test that say it's more like 4300 :ugh:

Nov 04, 2009, 10:46 PM	#90
grumman5277 Registered User Join Date: Jan 2004 Location: Troy ,OH Posts: 1,439	That's kinda funny. I tested two identical motor's or so I thought. I have 3 motors 2 were 2840kv and one was the 1600kv. I didn't think there was a difference but I guess I was wrong. I rewound 2 of them 7t (y). One measured .5v and the other .6v . I found that I mismatched the bells. The lower Kv motor had stronger magnets and was the reason I had 500rpm difference between them. Based on the stated 2840kv I calculated a new wind 7t (y) v's stock 15t (D) = 3540kv The measured kv based on 3120/.6v/1.41 = 3688kv almost exactly 4% or a factor of 1.04 difference. Which is closer to actual (measured) or (kv/ new kv x turns). MiseryQ, I would imagine if there is a factor to use and this is speculation ,but I believe less than 1 isn't applicable as someone else stated .95 . My press measured 3120 rpm so I know there is a difference. 3120/1.1/1.41/ (factor? (1.3) = 1547kv (stated Kv 1534). without the factor it is 2011.6kv. Not sure why there is a 23% difference in Kv.May just be HC fudging no again. Has anyone measured the 2840kv motor's vac? Jeremy