Which Mega 16/15/X motor for my s400 racers? - RC Groups
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Jul 14, 2002, 01:53 PM
Registered User

Which Mega 16/15/X motor for my s400 racers?


Ive got 2 Adrenalins and 2 Stingers. Im about to buy a few of the new brushless Mega and I had decided on going with the 4 turn version when Sal C (thanks!) kindly tested the 3 turn for me with 7 and 8 cells packs of 600AE cells. The results for the two motors were like this:

Mega AC 16/15/3:

8x600ae's

APC-E 5x5
16.5 amps
110 watts in
15,800 rpm

APC-E 4.75x4.75
15.5 amps
100 watts in
16,200 rpm


7x600ae's

APC-E 5x5
15.2 amps
97 watts in
14900 rpm

APC-E 4.75x4.75
14.3 amps
93 watts in
15,800 rpm


And the 16/15/4:

8X600ae's:

APC-E 5x5
11.5 amps
16,000 rpm
96 watts in

APC-E 4.75x4.75
10.8 amps
16,500 rpm
92 watts in


7x600ae's

5x5
9.7 amps
14,400 rpm
70 watts in

4.75x4.75
9.4 amps
14,600 rpm
65 watts in


The amp draw with the 3 turn motor wasnt as high as I thought it would be. I do not want to use bigger cells than the 600AEs but even with the 3 turn motor (especially if I stay with 7 cells) the amp draw doesnt seem to more than around 12-13A with the 4.75x4.75 when the prop unloads in flight.

Please give me some ideas, I know the 4 turn would give me great speed without lowering the flight times much at all but that should be possible with both motors, I mean, I wont be using an on-off controller, I CAN throttle back

/Erik
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Jul 14, 2002, 04:56 PM
Registered User
Considering the fact that I dont want duration to suffer much by going to brushless, I think the 4 turn might be the best choice after all. With 8 cells and the 5x5 it should give a real speed boost compared to the 6V sp400 and if I can get a decent speed boost and keep the duration above 4 minutes Im very happy. With the increased efficiancy of the brushless setup I might even get longer duration than that.

Also one guy (Waxer) flew the 4 turn in his CSD Twister with 7 and 8 cells 600AE packs and he said it was much faster than the sp400 setup so guess its allright. Its just that the 2200rpm/V seems low. He liked the APC 5x5 better than the 4.75x4.75 on his 4 turn.

/Erik
Jul 20, 2002, 09:29 PM
Registered User
I'd say your 600AE's are amp limited. I just ran up a 16/15/3 with a 4.75*4.75 Cam on 8 CP-1300's with a stale charge and saw 26 amps. Didn't measure RPM but it was screaming
Jul 21, 2002, 11:08 AM
PUGZ RULE!
juantrinidad's Avatar

HMMM......Interesting!


Same prop size (4.75x4.75) on the Mega 3T on two different battery packs. 60% more amp draw. Wow!

I gotta check this out. Sal C over in the "throw your speed 400" thread has been using the 600ae for his tests. I just bought 1300 scrs. I might get different results vs. his using the scrs and blow up my 18 amp speedo.

Thanks.

Rgds, JT
Last edited by juantrinidad; Jul 21, 2002 at 11:23 AM.
Jul 21, 2002, 06:22 PM
Registered User


Seems I didn't look at the prop close enough - it was a cam 5.5*4.3. You should still get more current out of better cells - just not quite that much!
Jul 21, 2002, 06:26 PM
Registered User
rafaelABN's Avatar
Quote:
Originally posted by Chris True


Seems I didn't look at the prop close enough - it was a cam 5.5*4.3. You should still get more current out of better cells - just not quite that much!

If is speed what you are after, the 600 cells are not match for these new speed 400 size brushless motors; perhaps use less 1300 cells to keep the weight the same. Ill be putting an Aveox 27/13/2, six cp 1300 in my Sokol and something like a 4.75*4.75 prop. It should scream! I dont own an elect. calc. program, can anyone punch the numbers for me?
Thanks
Jul 22, 2002, 03:56 AM
Here's My 2
Hitec-Redneck's Avatar
rafaelABN

On line battery calc (flydma.com)

On line motor calc (custompaintjob.com/ezcalc/dma.asp)
Jul 22, 2002, 08:13 AM
Registered User
oldpilot's Avatar
Check out the F.F.X fighters thread for information on what they are doing with Mega 16/15/6 motors and 5x4 thin props. Getting blazing speed with longer duration on 10 of the new Sanyo Hi Amp NiMh cells.
Jul 22, 2002, 05:40 PM
Registered User
Quote:
Originally posted by oldpilot
Check out the F.F.X fighters thread for information on what they are doing with Mega 16/15/6 motors and 5x4 thin props. Getting blazing speed with longer duration on 10 of the new Sanyo Hi Amp NiMh cells.
What size Hi amp nimh cells is it you are talking about? I heard some people talking about a new 1200 nimh that was the size of a 600AE cell and could handle 15 amps.

/Erik
Jul 23, 2002, 08:53 AM
Registered User
oldpilot's Avatar
ERIK

Thats the one!!! Except its 1700mah and up to 30 amps.

Check it out at http://www.flydma.com/batteries/index.html

Cheers. Patrick.
Last edited by oldpilot; Jul 23, 2002 at 09:00 AM.
Jul 23, 2002, 12:10 PM
Registered User
Quote:
Originally posted by oldpilot
ERIK

Thats the one!!! Except its 1700mah and up to 30 amps.

Check it out at http://www.flydma.com/batteries/index.html

Cheers. Patrick.
No its not the same one. The 1700 is the size of the 700AR and much bigger and heavier than the 600AE. If there will be a new 1200 the size of 600AE that can handle 15 amps, Id be in heaven.

/Erik
Jul 30, 2002, 03:51 PM
Registered User
kushal_22's Avatar
yes the new 17004/5 AUP`s are great. You can also use the 800 or 500AR`s to keep wieght down the 500AR`s are the same size and wieght as the 600AE`s

Mal
Jul 30, 2002, 08:59 PM
Carbon fiber is our friend
Steve C's Avatar
Quote:
Originally posted by Erik Johansson

If there will be a new 1200 the size of 600AE that can handle 15 amps, Id be in heaven.

/Erik
There's the purple 1100 that's the same size as 600AE. They work fine at 20A.

Steve C
Jul 30, 2002, 09:30 PM
Registered User
kushal_22's Avatar
And where would you find them?
Jul 31, 2002, 02:13 PM
Lithium Member
Herb's Avatar
Quote:
Originally posted by Erik Johansson


If there will be a new 1200 the size of 600AE that can handle 15 amps, Id be in heaven.

/Erik
The new (red) 1100 NiMH from HP,

https://www.rcgroups.com/forums/show...0&pagenumber=1

they take 16A with no problem and perform more or less just as well as the 500AR's.
(The old (purple) 1000 NiMH from Goldpeak are quite horrible, can't handle currents above a few amps)

I use them with the Mega ACn 16/15/3 & Master controller.