David VS. Goliath!!
 

Did some speed runs today.

The first runs were with a Lehner XL1600 and 6s kokams. Gearing was set at 12/51 with the center diff. The best speed was 50.2 mph.
The little lehner XL makes good power but the small motor runs HOT. I just don't think the motor was made for these high watts. It has a small amount of cogging on slow take off. When floored will wheelie the truck about 6 inchs in the air but will not flip the truck over. Not a bad motor weighing in at 216 grams but would need fans to run cool in the summer.
Now for the BIG BOY!
Speed runs with the Lehner 2240/10 using 6s Kokams. Started out with 14/51. This gearing is used for bashing and runs stone cold. The speed was over 54 mph with temps not breaking 100. Using 16/51 gearing temps were around 125 and the best speed was 59.7 mph. The combo will run 60 mph plus easy.
The road in front of my house had stone chips and tar put down not that long ago. It's real hard to keep a 60 mph monster truck strait skating on pea gravel. The Truck went for some crazy cartwheels and flips but came back begging for more.
The 2240's are my favorite motors. They are very costly but run cool and make big power. The motors weight is 480 grams. This motor has no cogging at all and can do the "drift backwards slow take off" trick with no cogging. The 2240 will wheelie and flip the truck(can't beat the Nitro boys on you back:L: ).
Sorry for the book but felt like passing some info along.
Thank you,
Promod

The truck

One more

Well, I guess it is only right that the big motor put out more power. Still, 50 mph is pretty impressive for the xl1600. That 2240 is some beast of a motor. Nice truck, too! I may try some speed runs with my 1940/8 some day. The xl2400 runs plenty strong on 5s Lipo for me, and on 6s lipo, it can pull wheelies at most any speed up to about 30mph(no center diff, though), but this is too much for the track (5s is too much on most tracks!). I have a nice, paved road in front of my house, so I can get some speed without fear of the truck wandering(though traffic can certainly be an issue!). Thanks for the Info. That is one heavy motor, huh! More than enough for an e-maxx.

Awesome!! i was thinking about getting a 2250, but i guess the 2240 is more than enough motor for the maxx/savage..

did you hang your eagletree in that car? (i am curious about the current it takes from the kokams)

are those HB tires?

Promod what diff is that ?.


Serum i think those tires are either hpi nubs, or the new panther boas.

It is an Ofna diff.

It are HPI NUbz allright.. makes me wonder.. What 17 mm hub Promod uses..

Yes it is an ofna diff. From an mbx buggy. It uses the same spur as the strobe slipper clutch. Yes they are nubz and I really like them. HPI did a good glue job because they stayed on for all the speed runs an still look great. The nubz are heavy. Here are a few weights.

Nubz 216 grams each
Bowtie,firm foams,veliocity wheel 208 grams each
Traxxas response on revo wheel 192 grams each

The 17mm hubs are from ofna. I've had them for a few years. But Towerhobbies still sells them http://www2.towerhobbies.com/cgi-bin...?&I=LXXE06&P=7

The 2240 is giving the Kokams a work out but everything seems fine so far. The 2240/10 6s peaked at 110 amps and pulled 70 normal. Peaks watts was 2300. I also tried the 2240/12 with 9s. The watts with this combo peaked at almost 3500.

Thank you,
Promod

3500 watts is almost 5HP! That is just palin rediculous for an e-maxx! I wish I could have seen it!

more hp than my lawnmower

What kind of run times you getting with that 2240? It sound awesome. I like the sound that you could run at that speed and the motor kept cool to. I wonder if mike can get one of them.

Hi,

It's a very nice truck...
A video of the monster ?

I am assuming that you favor Lehner motors, like how I like Hackers and Plettenberg Motors, hehe

What controller are you using for the 2240s?

Never really checked the run time but it is over 15 miniutes. That being said run time is greatly affected by driving surface and driving style. I'm just a Backyard Basher so the truck is run on mostly grass and driveway. My driving style is ON/OFF don't need a radio just a switch:D .

Guile, I can shoot a movie might take a few days to get the time.

Chase023, It's not that I favor Lehners but the 2240s WORK! I've tried almost every motor type out there starting with the old Model Tech. The speed control used for tests above was a Schulze 12.97. But the warrior 9918/9920 work just fine.

I hope from the tests above that everyone can see you don't need fast turning motors to get speed. Some people on these boards still think you need to push a BL motor to its RPM limit to get speed. That is old thinking and just not the case. There is nothing worse than a hot running BL system. What good is 10 or 15 miniutes run time if the motor is smoking HOT in 5 miniutes. If anyone is on the fence as to which BL motor to get. Get the slower turning motor and use gearing to get the speed. You will be much better off.


Thank you,
Promod

Sound advice, Barry. Slower motors are the better way to go. Send me a copy of the video, if you don't mind!

Thanks Promod, that really helps confirm what I was thinking as well. I wanted to use the Bolido with its slow 810 kv but I think with proper gearing it could be fast and very smooth.

Chase023, how many cells are you planning on running with the Bolido.

Thank you,
Promod

I am thinking of running 30 - 32 Nimh Cells or 10s Lipoly pack.

The first Bolido I am thinking of running is on my FG 1:5 scale Car, then maybe two of em on my Custom Juggy but I think the Two BigMaxximums on their now is enough,but who knows.

That 2240 is a beast on that E-Maxx.

Promod, i am digging up this topic again, i find it very informative, considering some users here wanted to power up their trucks with such motors as well. (incl me)

Did you shot a movie of this monster in action?

I am also very interested in this topic.
The 2240/10 and the 2240/12 motors are great prospects for higher voltage applications. I believe that you could reduce your amp draw/efficiency by increasing your voltage and gear reduction a bit. From what I've read the amp draw (current) will increase if you are below or above the motors efficiency range.

I would be very interested in your results with the 2240/10 at 9s with a 10/51 gearing. This should give you similar speed to the 6s with 16/51 gearing but with less amp draw.

It would be awesome if you could test this :cool:

Thanks

Hmmm, wonder how 2 of those motors would run in my truck? j/k.....I think.
Anyone know the weight of that truck? Looks pretty light.

starscream;

With higher voltage systems, your better of using a lower kv rate, and gear up , than the other way around..

Hey Serum,
I guess the appropriate question I should ask is what's the efficiency range of the motor (say the 2240/10)?

Here's a quote I received from an electrical engineer:
Higher voltage allows a stiffer gear ratio and thus requires a lower current to make the same power that lower voltage and higher current produces.
Higher efficiency comes from running cooler at the lower current....if the current is high enough to be in the max efficiency range of the motor.
Since you're racing, you can relate to Formula one cars. They make power with small, very high revving engines. They rev to 19,000rpm on a V10! The same approach applies to electrics. A small high revving motor geared properly will be more efficient overall that a larger, heavier, lower revving motor.

This is also what I have recently read, if you are below or above the efficiency range of a motor, the current will increase so max efficiency should be somewhere in the upper limit of this range.

So, it seems that Promod should be able to add enough voltage to the 2240/10 to be in the upper limit of the efficiency range of the 2240/10. 9s should put him at 49284rpm which should suffice thus achieving the same or more power with less current. I think if Promod tests this the numbers will tell us if it is correct. I believe the amps will drop and the motor will be more efficient if he runs 8s or 9s with the 10/51 gearing.

We really need to know what the specified efficiency range is to be completly accurate.

I would love to get a 2240/10 but I'd like to see some numbers first.

Thanks

You can't compare gas motors to electric.

the theory behind electric is that the higher the voltage, the more efficient the motor gets. A bigger motor has got more torque, that's why it doesn't need the rpm's to make the torque by gearing it down, like smaller motors.

It's very simple;

to produce 1500 watts with 100 volts requires 15A to make 1500 watt with 10 volts require 150A. Mostly, the higher the current, the less efficient. the more the internall resistance of the system becomes relavant.


Overall, a large lower KV motor runs less hot than a small high reving one. it is not said that a smaller high reving motor is more efficient. Far from that. (assuming it are both motors from the same serie)

I like a bigger low KV motor over a small high reving one. less heat means more efficient. A big motor has got more magnetical energy to power a car with more ease. resulting in less heat as well. When a magnet becomes hot it becomes less efficient as well, because of the magnet getting less efficient, it gets hotter etc etc etc..

The most efficient range of the setup depends on the gearing ratio, voltage and the resistance of the vehicle (mass etc)

Efficiency of electronics has got more to do with the high frequency of the electronics and the speed that the controller has to build up a clean as possible pulse. That's what makes a BL setup efficient. It's not about high rpm reving setups. . A setup certainly knows his sweetspot, mostly this point is under the 38000 rpms

It depends on so many factors.

I agree Serum,
I am really interested in the 2240/10 and would like to see where the sweet spot is. It would be cool to see the numbers between the lower voltage 15/51 gearing and the higher voltage 10/51 gearing :cool:

Thanks

The Star Screamy Screamin Screamer ;)

I am a little confused by what starscream was trying to say in his earlier post. But here are some tables that make for some interesting reading

Lehner BASIC XL 1200, http://www.lehner-motoren.de/diagram....18v_liste.txt

Lehner BASIC XL 3600, http://www.lehner-motoren.de/diagram...6.7v_liste.txt

These 2 links show data from lehner's website. Both motors are doing 21-24krpm. One can cleary see that the XL 1200 is a good 4-5% more efficient than the XL 3600, it has about 50% more torque, and 50% more power (output). Lastly the XL 3600 is pulling double the current of the XL 1200 ( and yet the XL 1200 has 50% more torque!! ). I hope these figures prove to everyone that slower turning motors are more efficient, more powerful, far more torquey and draw much less current.

Ps. in the links, you see the bit that says 'basxl-12.18v' and basxl-36.7v', do you think that they are the more accurate kv ratings of the lehner motors. ie the XL1200 is infact 1218kv and the XL3600 is infact 3670xl? Seems likely......

Right on maxxdude, I'm not sure why I didn't see those graphs before (my german's not so good, actually really bad :o )
I'm not sure what the differences of the following are:
TIMING 15ø
STERN TIMING 15ø
TIMING 15ø STERNSCHALTUNG
"STERN"-GESCHALTET TIMING 15ø

So I took a look at the STERN TIMING 15ø for the 2240/10.
http://www.lehner-motoren.de/motordia.php
http://www.lehner-motoren.de/diagram...22s_grafik.gif
http://www.lehner-motoren.de/diagram...26s_grafik.gif
http://www.lehner-motoren.de/diagram...33s_grafik.gif


Correct me if I'm wrong, but those graphs for the 2240/10 show that both 26volts and 33volts are higher efficiency with lower current versus running on the lower 22volts.

Thats to do with what Serum was talking about; the sweetspot. All motors (and engines) have a certain RPM range when they are most efficient, known as the 'sweet spot' (I'm sure it hs many other names). The sweet spot varies for all different motors, but for motors of the size we are using it is just under 40krpm. At 22volts the motor is only doing 19000rpm, but at 33volts it is doing near 30000rpm, nearer to the sweetspot, hence higher efficiency.

Cool, it looks like I was correct without looking at the graphs. 8s or 9s would be closer to the sweet spot (higher efficiency). Higher voltage being 7s to 9s and geared lowered (such as 10/51). I think it is very clear what lower kv motors are capable of. My point of clarification is where the sweet spot is. It seems that the sweet spot is toward the upper limit of the efficiency range (which requires lower gearing which is relative to the application). If these graphs are any indication of the efficiency range of this motor it seems that it is around 22 to 33volts (33 volts being closer to the sweet spot).
I would still like to see what numbers Promod would get from his 2240/10 on 8s or 9s with 10/51 gearing. Thats the only way to know for sure :D

Promod, how big are the vids that you have?.... and how many?... i would love to see this motor run in action....

x2 i dyeing to see them:) . hopfully there huge and high Quality :p

I think I've seen one of his vides, he was playin' in his front driveway and front yard... It looked wickedly fast.. but I would like to see MORE>> :)

I havent seen Promod around in a while. I'd love to see the soda can in action also.

I pmed promod a while back. Has not replied yet. Must be on vacation. I like to see some video as well.

either on vacation or he went to Lehner to pick up a 3080 to test out on his maxx and come back to us after he has celebrated for breaking a record....... It could happen.....

well, when the 2080 comes in.. I will definetly post some pics up.... I just got a 42 teeth spur and 24 teeth pinion made for it.... Maybe witht he 2080 I can directly mount it on to the Rear Diffs.. :).. hahaha
hhaha.. I wonder if that motor is powerful enough to do that.. maybe I'll need a 25 turn brushless with 400 kv rating...
Hey, mike.. what's the highest Turn you can get for the Faeigo XL motors.. ?

That'll be something different...

hmm... How does a quad brushless maxx sound...

One brushless for each wheel.. it would be easy to do..... I just would have to make the truck wider...

That would probably be stoopid.. can this work.. I would like to try this..

I think I would try the triple motor mount deal first. By the time you do all that you be better off getting a 3080 your self. Mount it to the chassis and put a ue 8mm drive cup with a dog bone to the rear. Direct drive. It would not be hard to do. Get the mounts like for a boat to mount to the chassis. Thought about this a little bit.

yeah that's true.. Guess that idea's out the window...

I wonder how much is the 3080, i can't seem to find a price anywhere...