Yep in order to get the same amount of power (watt) Id have to increase the voltage on a low KV motor, since it have more windings/turns and thus draws less amps.

This also ansvers my question. With the same voltage available the low KV motor should be easier to handle - if geared for the same top speed - since it will have a lower power output. Cheers... KB45-10/11XL here I come :)

Hi Aqwut,

How about a KB45 10xl in an E Revo?

Let's gear it 20/40 using mod 1 gears, then put in on 6S with a MMM ESC.

How do you think this setup will do, according to your experience with the KB45?

Geared for 44mph according to BG's speed calculator, and spins up to 26,640 rpms.

Also, Where can I find a heatsink/fan for this beast of a motor?

I think you have a solid (cheap $) setup there man... that should do you really good..... I use a 40mm x 20mm fan, and just zip tie it around the motor... 20/40 gearing comes up to only 36MPH.. for my revo 3.3.. Wouldn't you need 22/36 for 45MPH..?

and that motor is plenty powerful for that revo.. Awesome!

Thank you for your reply.

Here are the values that the speed calculator gave me. It LOOKS correct.........hmmmmm.......... :yes:

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.8333333333333332
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 20
Total Voltage: 22.2
Motor KV: 1200
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2 : 1
Total Ratio: 10.4359 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Rollout: 1.73:1
Total Motor Speed: 26640 RPM
Vehicle Speed: 43.67 mph (70.15 km/h)
Effective KV Value: 1200
KT constant: 1.13 oz-in/A

The difference is probably in the transmission gear ratio.

Oh you're right.. I misread, I just assumed that E-Revo means a converted Nitro to Brushless.. :lol:

Here's an interesting tidbit of information:

http://www.castlecreations.com/products/cc_blower.html

"A must have for any hardcore basher or temperature freak. Includes, fan, shroud, and two (2) black zip ties. Fits on motors with outside diameters between 1 1/2" and 1 7/8"."

1 7/8" = 47.625mm

The KB45 motors are 45mm in diameter! :yipi:

This could be a GREAT solution to keeping temps in hand. :yes:

Would the KB45 10XL work on 4S geared for 40mph?

This would mean the setup would look like this:

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.8333333333333332
Other Ratio: 1
Spur Tooth Count: 36
Pinion Tooth Count: 25
Total Voltage: 14.8
Motor KV: 1200
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 1.44 : 1
Total Ratio: 7.51385 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Rollout: 2.40:1
Total Motor Speed: 17760 RPM
Vehicle Speed: 40.43 mph (64.95 km/h)
Effective KV Value: 1200

I wonder what kinda Amp spikes we would be look at?

That's some pretty tall gearing.

Sure it would...! ... if it's cogging at the start, then it's geared too high..

I would do a little bit higher RPMs though.. that's a tad bit low..

if running wanting to use 4S, I would do the 1700KV...
My opinion, Gear it high with the 1000KV KB-45XL...

Had time to play a bit with my 08XL yesterday.

Drive shaft is 4.99mm now.

Front and end bell is modified with four 9mm air vent holes.

After assembling the motor again I was thinking about attaching a 40mm pc fan to the end. This would allow me to force air through the motor... internal cooling FTW :yipi:

One of my colleagues came up with another idea. Attach some wings on one end of the magnet in order to create turbulence... this would then hopefully force air through the motor (or maybe it will just sound like a siren :lol:)

If I can force the rotor itself to act as a fan thats a winner... just have to figure out how to attach a dust filter to the "air intake end".

Hmm... I need to make some tests and see what gives the best results.

Any bright ideas or additions?

kb45 L and xl
 

Hello. i have been running those babyes for 4 years now.
i always pick the top kv rated ones so i play with kb45 2300kv l can. and the bigger one kb45 1700kv xl. i bought them way back before they changed the kv to 1600kv for the xl version.
and the biggest problem people do is that they gear them to low and the will overheat because they have nothing to do.. you all know that running a brushless motor unloaded is a no go right ?
i run 10cells lipo in series trough 2300kv kb l version for speedruns and 5-6cells lipo for offroad and bashing. never has any problems.
i run twinforce and rustler and 1:8 buggy and truggy and revo and cen gst with those motors..
the big hw heatsink cooler for the 2000kv motor is great and the holes in the front and back is also good.
No offense but i think you guys in here run weak setups :whistle:. but its the place with the most info in one place. i run up to 9cells lipo in series in the neu mamba 2200kv motor. stil dont think it is as sharp as the kb 2300kv L
the bigger 1700kv xl is easyer to handle because of lower rpm and it really does a nice job in rustler as a speedrunner.
i prefer hobbywing plane esc and i dont run the pistix as it gets to sick. i use rubber band and gets a full travel on the remote and then its easyer to handle.
the 40k rpm limit is for the nitro guys.. we run eletric and the fun starts at 70.000k rpm :party:
so please put some more lipos in your rc cars :)
best regards from denmark

ok, so one guy says to aim for around 25k rpm and one guy says up to 70k rpm. and according to you, the 2300kv L motor is better than the CC/NEU motor? are these motors really THAT underrated? i've only run my 1600kv less than an hour before the rotor separated from the shaft and my 1400kv for about 2 seconds (5 minutes if you include spinning it while grindhing the shaft to 5mm)

also, how did you mount your KB motors to your rigs? i'm especially curious about the rustler.

is there any way to make an adaptor to mount these motors where normal 25mm bolt pattern motors go? that would definitely help make these motors become more popular. the 6mm shaft is easily ground to 5mm, but the bolt pattern is the real problem. i know it can be done, all you need is either a new front endbell or an adaptor that screws into the endbell, kinda of like that one RCM medusa plate thing.

mounting holes for kb45
 

Hello. i dril new holes to motor on rustler gearbox.
but you can take of front of motor and drill and tap new stock 25mm apart screw holes. that i have done to some of my motors.
yes i think the 2300kv L is more powerfull than castle/neu. but castle/neu 2200 runs cool on 8-9cells lipo and have a huuuge margin for sweetspot so its really a much better motor. but for speedruns i wil always put my money on the kb45 2300kv.i have actually downgraded my rustler to the castle neu because it kept wheeling at 140kmt because i run out of space and had to push harder on the trottle to max it out. with the neu its a bit lighter and its easyer to control on trottle.
here is some of my cars. remember im in to speed and not bling bling. dont care how it looks it just have to be fast and do the job :
http://www.rcgalleri.dk/html/alb_vis.asp?AlbumID=4486

http://www.rcgalleri.dk/html/gal_vis...8100&ipc=96645
i have added much more downforce to the speedrun rustler but havent gotten pictures yet
this video is with a smal motor that i also put in alot of lipos : and it gets to free rev at a time because it loses the pinion. it spins at 90.000rpm
its the turnigy 2600kv 36/56. when i get more time to get my rustler dialed in with the castle neu and then with the kb45 2300kv i will do a record attemt
http://www.rcgalleri.dk/html/vid_vis.asp?VideoID=8217
best regards from kristian

wow, great car!

I once had a kb45l, but getting the axle down to 5mm was not that easy.

a feigao 580l would be an alternative, with a 5mm axle. supposed to have a higher efficiency then the kb. but, in my opinion, the kb have at least a much better quality then these cra++y kd, eg. the magnet is balanced.

getting the shaft was pretty easy for me and i'm practically a novice. all you need to do is run the motor while filing the shaft down.

maybe they have different shafts. I tried it that way... brought it to the shop later and had it done. the guy said it was not easy, as the material was very hard...

I just acquired a couple of 25 tooth Mod 1 gears with the 6mm ID. :yipi:

This NEW KB45 10 XL had just been sitting around waiting for some action.

Here is my proposed setup now:

E Revo
MMM
Apogee Limn 3800mah 6S or 6S Turnigy 5000mah
KB45 10XL geared 25/40 using Mod 1 gears

Now the only thing I'm missing is those m4 screws to mount the motor with.

Where can I find those pesky things?

How well will this setup work?

i got my m4 screws from ace hardware. not too hard to find......

Today, I ventured out into the snow and went to the local Lowes. I couldn't find the hex head countersunk m4 screws, but they did have some phillips head. So I got those.

After much work on the aluminum motor mount in the E Revo, things began to fit.

The 25 tooth Mod 1 pinion needed about 1/8" of metal removed to clear the teeth with the motor in position.

This motor is HUGE! :yes: KB45 10XL 1200kv

Geared 25/40.

This is geared for speeds like:

4S = 36 mph
5S = 45 mph
6S = 55 mph

I have a feeling it will work well with anything from 4S to 6S, but we'll have to see about that.

Everything fit tight, but it did fit like a glove.

Check this out!

http://i160.photobucket.com/albums/t...m/DSC07858.jpg

my 8xl 1600kv on 6s lasted about 5 minutes in a heavy e-maxx before it got hot and demagnetized.

It was only geared for 60:whistle::surprised:

It was frickin awesome till it died.

Was it cogging at all?

That's a bummer. Do you think you got a dud?

Some people have had luck with the KB's, some haven't.

I'm hoping to be one of the ones that do.

I think we'll start with 5S and closely watch temps. The Castle Blower would be a good addition, but I don't think there's room. LOL

I could drop back to a 46 tooth spur. That might help temps also.

We'll see how it does. :yes:

It's pretty cold out, so maybe it won't go poof.

No cogging whatsoever. The smallest blip of the throttle ended in a backflip on grass. Throttle control was paramount!

I was just dumb about it. After 1 min of running I felt the motor and it wasn't too hot. I should have been watching temps better. Then I handed the controller to my son and told him to give 'er hell. He's a natural behind the remote. I didn't check temps again and it just gave out.

I had read that you really needed to load the motor and the only pinion I had resulted in the formentioned 60mph gearing, I just went with it. My own stupidity.

I hope you have good luck with yours. It was insane power until it died.

Hmm, try overgearing a neu next time. You think the kb has power... I had a 1521 6s rig geared for 60, broke stuff, had fun, motor is fine. Damn 250 dollar motors are gangsta....

This is one of the motors I got from you Linc. :yes::great:

Well I never actually ran a kb motor... They just sat in the boxes.

Edit, never ran a XL kb, I did run 2 of the L can motors in my gtp. I never had heat issues there, geared for 50mph on 4s lipo.

i have the 1200kv xl sitting in a box now awaiting a nice heavy project one day.

Hi Tash. What are you calling a "heavy project"?

The 6mm id motor pinion I'm using is stainless. Are they any good?

It snowed here before I got a chance to really test this out.

Just a few short bursts on my cleaned off drive, shows a little cogging at startup/crawling speeds. But WOT results in a quick spin around. It was kinda wet out.

I'm thinking about replacing the 40 tooth spur with a 46 tooth version.

25/40 changed to 25/46

Short tests were done on 5S. In about 10 minutes, the motor got up to around 130 degrees.

something that needs all that torque to run. i had an l can in a ext flm emax and it was plenty, so i'm thinking this will do in something larger if needed.

The weather finally permitted some testing and testing I did!. :lol:

I set the timing to low thinking that might help tame temps. Hmmm............maybe it helped. At the end of the run, the motor was probably 160 degrees or so. About 2 or 3 seconds of fingertip action is all I wanted. LOL

That run should have been recorded for Beat Your Truck.com or something.

On 5S it's crazy! I couldn't grab WOT for more than 1/2 a second at any time. 40mph backflips are kinda hard on a truck.

We have carnage!

The rear wing mount broke off.

This truck really looks funny running around with half of it's butt missing. LOL

Incredible Power though! I'll try it again after I get some parts in. LOL

Maybe drop the timing to lowest. It seemed to like the lesser timing with the tall gears. It starts up better and does low speed better.

Overall, I'm very impressed with the Power output!