MMM availibility date dropped!

[johnrobholmes]

Efficiency and amp draw are not tied together directly. Amp draw creates heat with resistance, but higher wind (higher voltage) motors also have more resistance to go along with the reduced amp draw. So, without dyno graphs and specs of a specific motor the ideal voltage and KV cannot be determined for a particular situation.

Of course buying more batteries is an inconvenience. So is buying a new motor and ESC. I would prefer a wind that was great on 6s and outrageous on 8s for battery amp draw reasons. The MMM is a 6s controller so a 4s mild, 6s wild motor just makes sense for the first release.

[glassdoctor]

I really don't want to talk motor theory, but keep this in mind when studying motor specs... on the Neu site I think the amp draw specs are max amps at the max rated voltage. The watts should be basicly equal on all winds. Lower kv motors will naturally have an efficiency advantage due to the lower currents they use to make the same horsepower.

[ssspconcepts]

Sure I'd like to see more CC MMM motors offered....but the fact that they are only going to initially offer a 2200kv motor is not going to sway me (or other enthusiasts) one way or another. Neu 1515 motors are "cheap" right now...$245 on Neu's website! These are proven motors and that's some of the best pricing I've seen in a while. The way I see it is that if folks want more selection in kv, they will buy it directly from Neu. After all, we always have in the past...why should anything change now? The "genuine" Neu motors (not the CC version) are certain to still be better in terms of quality...which is what I use as a guiding principle for most of my purchases. If I am building a special rig or if I have a special application, then I will still probably go with a Neu.

I am not going to sit here and beat up CC for not offering more kv motor selections. I can control that myself by purchasing the very best motor money can buy from Neu. However, what I will beat up CC for, is not cowboying up and getting the MMM product to market before the foreign competition got theirs out on the street. But its not just CC...there are others that in my view that are also guilty and have been asleep at the wheel. I have to tell you...the expectation is pretty high at this point and time for the U.S. market to come up with something truly spectacular...namely a HV ESC that blows the competition away.

[lutach]

Originally Posted by ssspconcepts

I have to tell you...the expectation is pretty high at this point and time for the U.S. market to come up with something truly spectacular...namely a HV ESC that blows the competition away.

I think an HV MMM would've been the perfect controller. Like I said before, have it handle up to 12S lipos and I know a controller that handle 12S can also handle 6S. Then the choice for a motor would've been huge. Just picture a Mega ACn22/50/2E running 12S of the little 2200 or 2500mAh cells. A few guys would probably a Plettenberg Bolido n a 5th scale. It's funny how Schulze has a huge array of controller and Castle has the ability to do that, but they are lacking behind. Yes, Castle has better programming and awesome features in the controllers they make, but where is the HV version for vehicles?

[SpEEdyBL]

Originally Posted by Just go Play

The spec sheet that I have for Neu 1515 motors shows the 1Y rated at 110 max amps with an internal resistance of .006 while the 1.5Y is rated 70 max amps and .011 internal resistance. This equates to the 1.5Y having 1.83 times the resistance of the 1Y.

Based on the spec sheet the 1.5Y would have a power loss of 53.9 and the 1Y 72.6. While they are close the 1.5Y appears to be noticeably more efficient. Like I mentioned it is entirely possible that there are other considerations that make this not as simple as I think it is.[/COLOR]



Based on user experience this sounds right but I cannot find any reliable documentation that proves it. (for that matter who has 6000mAh cells available today?) The discharge graphs proved by many pack builders seem rather questionable if there are any available at all. Whats worse is that there does not seem to be any standards when it comes to testing or rating lipo cells from one brand to another. Could you point me to any reliable data on cell discharge rates that confirms this claim?



I really don't think that this is a valid argument. Both motors are capable of creating almost the same amount of power at simular RPM's. I also don't think that anyone can reasonably argue that low voltage high current is more efficient than high voltage low current setups. If this was the case then everyone would be building rc's with ultra high kv motors to run on 7.4v packs right?

To answer your questions:

1. From those specs it looks like the the 1.5y isn't ideally 1.5 turns in comparison to the 1y. An ideal 1.5 turn would have wire that is 1.5 times the length has a 1 turn and 2/3 the cross sectional area (to fit in the same space), making it have 1.5 x 1.5 = 2.25 times the resistance and 2/3 the kv. That said, the motors cannot be considered "equivalent" with the 1y on 4s and the 1.5y on 6s.

2. http://www.enerland.com/product/p1.php?num1=1&num2=4 These are considered to be some of the best cells in the industry. It's quite obvious that bigger cells hold their voltage better under a load than smaller cells when you look at the discharge curves. True that there seem to be no 6000 cells available, but that has nothing to do with my point. I was comparing 4000 mah cells to 6000 mah cells for the sake of simplicity.

3. I never said that lower voltage was more efficient than high voltage. In fact i never even said they were equal in reality. I said that a neu 1y on 4s is efficient enough for it not be necessary to use a slower motor on 6s. So how can a 4s setup that a.) that still runs cool and b.) has all the power you need, be inadaquate?

[starscream]

Originally Posted by SpEEdyBL

To answer your questions:

1. From those specs it looks like the the 1.5y isn't ideally 1.5 turns in comparison to the 1y. An ideal 1.5 turn would have wire that is 1.5 times the length has a 1 turn and 2/3 the cross sectional area (to fit in the same space), making it have 1.5 x 1.5 = 2.25 times the resistance and 2/3 the kv. That said, the motors cannot be considered "equivalent" with the 1y on 4s and the 1.5y on 6s.

2. http://www.enerland.com/product/p1.php?num1=1&num2=4 These are considered to be some of the best cells in the industry. It's quite obvious that bigger cells hold their voltage better under a load than smaller cells when you look at the discharge curves. True that there seem to be no 6000 cells available, but that has nothing to do with my point. I was comparing 4000 mah cells to 6000 mah cells for the sake of simplicity.

3. I never said that lower voltage was more efficient than high voltage. In fact i never even said they were equal in reality. I said that a neu 1y on 4s is efficient enough for it not be necessary to use a slower motor on 6s. So how can a 4s setup that a.) that still runs cool and b.) has all the power you need, be inadaquate?

1. I don't have an opinion on the motor choice as I certainly won't be buying a 1515 2200kv motor.

2. I'm not sure which discharge curves you're looking at but if you take a look at the charts for a 2S 4500mAh and compare to a 4S 2000mAh you'll see that the 4S pack holds its voltage just as well or better than the 2S pack. With this kind of performance you'll get more efficiency from the higher voltage system.

3. This question is relative to the end user. Cool to you may be hot for me. My ESC's typically don't run much over 100F. I equate efficiency just as high as power. In other words, just because a system can put out 4hp doesn't justify its usage especially when there is a more efficient system available that can produce the same power using less resources.

[Cain]

I personally am excited for the ESC. I run 4S right now and won't be doing more than that, so I am not too concerned. Main thing I am looking forward to is the fact that I don't need all the fans, and external UBEC like before.

[pipeous]

I am with you on that one Cain. I can use my MM in something else and just grab the mmm esc for my 4s buggy, and then a combo for truggy.

[DrKnow65]

Would there be an issue if the MMM/2200KV had torque and rpm limiting software?

[strodedawg]

i understand that using a higher voltage lipo yields less amp draw, which yields lower temperatures. what i am cofused on is that i can use a lower C rating and less mah and still get the same run time?
any info would help
can't wait for the mmm

[suicideneil]

Thats about right strodedawg. Personally I think you could sacrifice one or the other but not both C rating and capacity, just to be on the safe side in case of large peaks of current draw. I know the outrunner guys have used some much lower capacity packs -3000mah or so- with great runtimes still.

[lutach]

Originally Posted by strodedawg

i understand that using a higher voltage lipo yields less amp draw, which yields lower temperatures. what i am cofused on is that i can use a lower C rating and less mah and still get the same run time?
any info would help
can't wait for the mmm

I run 20 minutes on my 6S 2200mAhpacks without an issue. One of the reasons why it would've been good for Castle to just do a 12S capable controller. They have the MM that can handle 4S so why not have the MMM handle 12S. I think they would finally have a complete line of ESCs. The math is simple. If you have a 2000 Watt combo you would draw 90A on 6S, 54A with 10S and 45A with 12S to get the same amount of power. With higher voltage you will also have to go with a smaller pinion and/or larger spur. Another option would be to use the 4.3:1 diffs that some truggies have in your buggies.

[strodedawg]

cool, i have a crt with the HB ring and pinions and a neu 1515/2d (2050 kv). waiting for the MMM and a 6s lipo (2 x 11.1 in series)
thanks for the info

[kulangflow]

So, I'm guessing that the MMM will go on sale on April 1st, the day after the March 25% off sale ends. Thoughts? :-)

[jnev]

I bet you're right in the sense that it won't be out during the 25% off sale, but I doubt it'll be out April 1st. More like..... late April to May I'm thinking.