Which Controller for My Application?

Originally posted by luihed
I dont get it..... the 9L and 13s are smaller motors than the 7XL and I thought the 7XL is too hot for 20 cells:C: .... I have a 7XL right now, can I run 22.2v on it?

Im definately gonna run 22.2v lipo too but I still dont have a clue to what motor will give me the fasted speed..... I know its 2400 or 2000 for teh lehner or 8XL for the feigao, but for some reason 2000 or 2400 is not the same as 8XL..... Im too confused.....:C:

The problem w/ choosing a voltage, amperage, motor, speed control, yadda yadda yadda is that each of the aforementioned (and many more items like weight, resistance, ambient temp, final drive ratio, etc.) factor in to how your truck/car will perform.

The motor has several factors alone that you may consider when choosing the correct one. Such as its efficiency at a particular voltage/rpm, the amount of torque it puts out, max rpm's, total horsepower, etc.

I have some data for the 7XL at 14.4 and 22.2 volts. I'm still working on this calculator and it definately needs some input/output tuning, but maybe the following numbers will give you an idea of what these motors can do. For comparison purposes I put the Feigao 7XL @ 14.4v and 22.2v. Also listed is the Plettenberg MAXXimum @ 22.2v.

Remember that these are just numbers, your mileage may vary.

btw, I believe the Feigao's are rated at 50000 max rpm's. You'll see that 22.2v puts you just above that. Of course depending on many factors you'll probably not get to 50000 rpm's.

If something looks fishy about the numbers below lemme know. I haven't looked at my calculator in a while, but I know that it can use some improvements.


Feigao 7XL @ 14.4v
~~ [14.4 volts, 30 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33900.6240
powerin: 432.0 watts
powerout: 362.9160 watts
HP: .4864
efficiency: 84.00%
torque: 13.44 oz-in

~~ [14.4 volts, 40 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33767.2320
powerin: 576.0 watts
powerout: 503.2480 watts
HP: .6745
efficiency: 87.00%
torque: 19.20 oz-in

~~ [14.4 volts, 50 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33633.8400
powerin: 720.0 watts
powerout: 642.4600 watts
HP: .8612
efficiency: 89.00%
torque: 24.96 oz-in

~~ [14.4 volts, 60 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33500.4480
powerin: 864.0 watts
powerout: 780.5520 watts
HP: 1.0463
efficiency: 90.00%
torque: 30.72 oz-in

~~ [14.4 volts, 70 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33367.0560
powerin: 1008.0 watts
powerout: 917.5240 watts
HP: 1.2299
efficiency: 91.00%
torque: 36.48 oz-in

~~ [14.4 volts, 80 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33233.6640
powerin: 1152.0 watts
powerout: 1053.3760 watts
HP: 1.4120
efficiency: 91.00%
torque: 42.24 oz-in

~~ [14.4 volts, 90 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 33100.2720
powerin: 1296.0 watts
powerout: 1188.1080 watts
HP: 1.5926
efficiency: 91.00%
torque: 48.00 oz-in

~~ [14.4 volts, 100 amps] ~~
voltageconstant: .0060
Kt: .0080 (oz-In/I)
rpm: 32966.8800
powerin: 1440.0 watts
powerout: 1321.7200 watts
HP: 1.7717
efficiency: 91.00%
torque: 53.76 oz-in



Feigao 7XL @ 22.2v
~~ [22.2 volts, 30 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 52480.2240
powerin: 666.0 watts
powerout: 561.8160 watts
HP: .7531
efficiency: 84.00%
torque: 13.44 oz-in

~~ [22.2 volts, 40 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 52346.8320
powerin: 888.0 watts
powerout: 780.1480 watts
HP: 1.0457
efficiency: 87.00%
torque: 19.20 oz-in

~~ [22.2 volts, 50 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 52213.4400
powerin: 1110.0 watts
powerout: 997.3600 watts
HP: 1.3369
efficiency: 89.00%
torque: 24.96 oz-in

~~ [22.2 volts, 60 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 52080.0480
powerin: 1332.0 watts
powerout: 1213.4520 watts
HP: 1.6266
efficiency: 91.00%
torque: 30.72 oz-in

~~ [22.2 volts, 70 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 51946.6560
powerin: 1554.0 watts
powerout: 1428.4240 watts
HP: 1.9147
efficiency: 91.00%
torque: 36.48 oz-in

~~ [22.2 volts, 80 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 51813.2640
powerin: 1776.0 watts
powerout: 1642.2760 watts
HP: 2.2014
efficiency: 92.00%
torque: 42.24 oz-in

~~ [22.2 volts, 90 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 51679.8720
powerin: 1998.0 watts
powerout: 1855.0080 watts
HP: 2.4866
efficiency: 92.00%
torque: 48.00 oz-in

~~ [22.2 volts, 100 amps] ~~
voltageconstant: .0093
Kt: .0125 (oz-In/I)
rpm: 51546.4800
powerin: 2220.0 watts
powerout: 2066.6200 watts
HP: 2.7702
efficiency: 93.00%
torque: 53.76 oz-in





Plett HP 220/40/A2 @ 22.2v
~~ [22.2 volts, 30 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 47567.2500
powerin: 666.0 watts
powerout: 625.5517 watts
HP: .8385
efficiency: 93.00%
torque: 17.28 oz-in

~~ [22.2 volts, 40 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 47239.2000
powerin: 888.0 watts
powerout: 837.2376 watts
HP: 1.1223
efficiency: 94.00%
torque: 23.04 oz-in

~~ [22.2 volts, 50 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 46911.1500
powerin: 1110.0 watts
powerout: 1045.9234 watts
HP: 1.4020
efficiency: 94.00%
torque: 28.80 oz-in

~~ [22.2 volts, 60 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 46583.1000
powerin: 1332.0 watts
powerout: 1251.6093 watts
HP: 1.6777
efficiency: 93.00%
torque: 34.56 oz-in

~~ [22.2 volts, 70 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 46255.0500
powerin: 1554.0 watts
powerout: 1454.2951 watts
HP: 1.9494
efficiency: 93.00%
torque: 42.24 oz-in

~~ [22.2 volts, 80 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 45927.0000
powerin: 1776.0 watts
powerout: 1653.9810 watts
HP: 2.2171
efficiency: 93.00%
torque: 48.00 oz-in

~~ [22.2 volts, 90 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 45598.9500
powerin: 1998.0 watts
powerout: 1850.6668 watts
HP: 2.4807
efficiency: 92.00%
torque: 53.76 oz-in

~~ [22.2 volts, 100 amps] ~~
voltageconstant: .0101
Kt: .0135 (oz-In/I)
rpm: 45270.9000
powerin: 2220.0 watts
powerout: 2044.3527 watts
HP: 2.7404
efficiency: 92.00%
torque: 59.52 oz-in

[Serum]

Great info!!

How did you calculated it?

What numbers are exactly used?

Originally posted by Serum
Great info!!

How did you calculated it?

What numbers are exactly used?

I wrote a "program" (if you will) whereby I can enter the voltage constant, no load current, internal resistance, and desired voltage (it also has an amp iterator which I arbitrarily started at 30I and ended at 100I).

I've checked the specs on the main players in r/c brushless (hacker, lehner, plett., etc.) and verified the aforementioned values and plugged them into my "calculator." You can find a grid w/ those values of the motors I listed (and many many many more) at the following link -> (http://www.motocalc.com/data/motor.html).

Interestingly you won't find the same values for Lehner motors. :( I'll hopefully be calculating at least the 2400XL in the very near future. Kinda funny that I've spent so much time looking into various motors but will end up purchasing a brand that seems to have an excellent name recognition for quality. Go figure.

Anywho, its really simple, just collect the motor constants for a given motor (see the link above) and complete the formula's on which you'd like more information.

For the most part all the information you need is out there (the web and search engines are the best thing ever)...well to at least make an educated decision. Including formula's for mass, velocity, and the like.

I've not played w/ my calculator in a while (I want to expand on it) due to work (being so darn busy)...like I am tonight posting on the forums. ;) With regards to expansion I want to integrate a gearing calc and mass/velocity calc into this to help find the elusive sweet spot.

Its geeky fun.

[Serum]

Nice!!

How did you get the unloaded rpm/v range of the plettenberg if i may ask?

It would be nice to have a convertor, that allows you to type the mass, gearing ratio and the motor information based on your calculator, among with the amount of power available, to see what the load of the controller would be like.

I don't exactly know what you mean, is it the information you need on the lehner motors or is the calculator showing different numbers?

here is the link to the lehner motors but i am sure you allready found it.

Are you willing to share the program with us? Sounds very interesting!

It would be nice for you to have an eagletree car data recorder to compare the practice with the theory..

Originally posted by Serum
Nice!!

How did you get the unloaded rpm/v range of the plettenberg if i may ask?

It would be nice to have a convertor, that allows you to type the mass, gearing ratio and the motor information based on your calculator, among with the amount of power available, to see what the load of the controller would be like.

I don't exactly know what you mean, is it the information you need on the lehner motors or is the calculator showing different numbers?

here is the link to the lehner motors but i am sure you allready found it.

Are you willing to share the program with us? Sounds very interesting!

It would be nice for you to have an eagletree car data recorder to compare the practice with the theory..

Schnikes!

I forgot you linked that for me earlier. :-)

Maybe you can help me w/ the translation?

From the "grafik" ;)
http://www.lehner-motoren.de/diagram...13v/grafik.gif

U=voltage
I= amps
N=RPM?
M=Time or distance?
W=Efficiency




Raw numbers
http://www.lehner-motoren.de/diagram....13v/liste.txt

I believe the headers are;

"Spann. Volt" = "Volts In"
"Strom Amp." = "Amps Drawn"
"PEing. Watt" = "Watts In (Power In)"
"Drehz. U/Min." = "RPM's"
"Moment Ncm" = Not sure about this one
"PAusg. Watt" = "Watts Out (Power Out)"
"Wirk. %" "Efficiency=Power In/Power Out"


The raw numbers and the charts are basically what I would be able to plot w/ my calculator, provided I have the correct information. It appears that Lehner will provide the result of the formulas but not the data within them. I supposed I can solve for the missing variables w/ the data given.

Originally posted by Serum
Nice!!

How did you get the unloaded rpm/v range of the plettenberg if i may ask?


. . .

Ah, I almost forgot to answer this.

Check my linky (http://www.motocalc.com/data/motor.html). Scroll down, you'll find the Plettenberg information you so desire. ;)

Originally posted by Serum
Great info!!

How did you calculated it?

What numbers are exactly used?

I'm tired... been up for 40+ hours.

The link that I gave has the source data. The formulas which utilize that source data are pretty easy to find on google.

This link has a fairly decent first read on the subject -> http://www.slewin.clara.net/elec/tmotor.htm

[Serum]

okay, Thanks!

I will dive in to it later this evening, i am working on our kitchen for our new house...

The n/cm value is newton/cm (torque)

Rough numbers;

100 oz/inch = 7112 gram/cm = 71ncm

Originally posted by Batfish
I don't know what your timing is like, but I plan to have 2 Kokam 3s 3200 packs with that low voltage cut-off device on or before next Thursday, 5/26. I'll install and report back after that.

Hey, did you get your LiPo's? Huh? Did ya? Did ya? :D

btw, what voltage are you going to run? ...guess that'll answer my question about whether you're going serial or parallel.

[Batfish]

I'll have the lipo packs in about 4 hours; I'm picking them up today.

With my current controller issue (9918 losing brakes) I won't be able to test them in my buggy, but I do plan on putting one in my XXX-T MF with the MGM 12012 and xl5000 to see what 11.1v will do to it :)

In my 1/8th buggy I'll be running the two 3s 3200 packs in parallel for 11.1v and 6400 mah to get through 15-minute races.
Once I get a solution from Mike regarding my 9918, I'll get the lipo packs into the buggy and get some results.

[RC-Monster Mike]

Well, 11.1 volts and the xl5000 is gonna be on the crazy side in your xxx. Stock up on diff parts (and be ready to rebuild). 60+ mph is not out of the question at all with that setup.

Originally posted by Serum
Nice!!

...

It would be nice for you to have an eagletree car data recorder to compare the practice with the theory..

The Eagle Tree is ordered, should be here this week. Got it w/ the hall effect sensor...can't wait to begin collecting data.


_

[Batfish]

I'm hoping to have my 12012 hooked up to my 8L in my 1/8th buggy for this weekend. Once I do, I'll finally be able to let you know how those Kokam 3200 3s packs do.

Because I'm a d0rk...here are constants for a Lehner 2400xl;

Rm=.0043
Lo=4.7
Kv=2400 (duh)