information on kb45 motors?

[aqwut]

Originally Posted by Nixpus

At the moment my savage is powered by a Hobbywing 4465... its way too powerfull for the truck.

Was hoping the KB45-08XL would be easier to controll. However, when I read Scarlets conversion thread it seems like its just as impossible as the 4465 :)

If 25K rpm is the limit for the KB's then the 10XL sounds just about right - 26.600 on 6 cells.

Will a lower KV motor be easier to controll (wheelie/backflip wise) or will the increased torque mean that it wheelies more. I mean if I geared for about 45mph will a 1200KV motor then be easier to handle than a 2000KV? And why?

25K is not the limit, I have ran the 1700KV motor on 8S, and it was insanely fast... I recommend somewhere around the 25K mark.

Example, 1200 KV and 2000 KV motors of the same size.. Powering a Monster Truck...

They both have the same power output.. with the lower KV you have to gear higher and use more voltage, and with the higher KV you'd have to gear lower and use less voltage.

I prefer to use lower KV and higher voltage & less RPMS.. but there is a limit..

Lower KV motors can't take as much amps as the higher KV.. the Lower KV relies more on Voltage.. whereas the Higher KV motors relies on Current. know what I mean?

[Nixpus]

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 :)

[sikeston34m]

Originally Posted by aqwut

25K is not the limit, I have ran the 1700KV motor on 8S, and it was insanely fast... I recommend somewhere around the 25K mark.

Example, 1200 KV and 2000 KV motors of the same size.. Powering a Monster Truck...

They both have the same power output.. with the lower KV you have to gear higher and use more voltage, and with the higher KV you'd have to gear lower and use less voltage.

I prefer to use lower KV and higher voltage & less RPMS.. but there is a limit..

Lower KV motors can't take as much amps as the higher KV.. the Lower KV relies more on Voltage.. whereas the Higher KV motors relies on Current. know what I mean?

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?

[aqwut]

Originally Posted by sikeston34m

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!

[sikeston34m]

Originally Posted by aqwut

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..........

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.

[aqwut]

Originally Posted by sikeston34m

Thank you for your reply.

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

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..

[sikeston34m]

Originally Posted by aqwut

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!

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!

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

[sikeston34m]

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.

[aqwut]

Originally Posted by sikeston34m

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

This would mean the setup would look like this:

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...

[Nixpus]

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

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 )

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?

[sikeston34m]

Originally Posted by aqwut

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...

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

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?