spartan117

Hi everyone,
I decided to make a post about my new brushless conversion I did on my AE TC4. The brushless conversion I did uses a Turnigy 35-42D 1000kv outrunner from www.hobbycity.com and a 30 amp speed control from www.ehirobo.com . I was driving my TC4 earlier today with a 13 turn brushed motor and I decided it was too weak for my taste. I started looking around the shop and found an old turnigy outrunner and a 30 amp esc just lying around that never made it onto the intended foam 3d plane (yes I fly planes). I though I had a problem with the fact that the motor is only 1000kv and when I drilled out a pinion gear to fit the shaft I quickly discovered the motor would give me about 15 mph and insane amounts of torque. This seems like it would be a problem right, WRONG I simply decided to hook it up direct drive as it is supposed to have enough power to replace a 30 size nitro motor on a plane. I simply mounted the prop adapter on one side of the motor and cut the shaft for the car in half and drilled a hole in it at the cut end so that the motor shaft could be inserted. About 2 hours and loads of epoxy later, I came up with this final result. ENJOY!!!

Parts list:
5 minute epoxy
dremel
Turnigy motor: http://www.hobbycity.com/hobbycity/s...idProduct=3884
Any 30 amp brushless speed control
At least a 2200mah 3 cell lipo

I strongly urge anyone to do this as I would guess it does about 50 mph in my TC4.

Video coming soon. Sorry for bad photo quality as it was a cell phone since the camera ran out of charge. I will get better photos and a video tomorrow.

justinep

is this just rwd now? Nice work with laying around parts! I was always interested with the outcome of using plane/heli electronics in a car. I have a few planes and helis and a ton of old cars... you got me thinking.

Please post a video of this asap!

thanks

spartan117

Hey Justin,
It was originally RWD, but the car in the pictures is infact still 4WD. I cut the drive shaft in half and then drilled it out so I could fit the motor shaft into it. I will def get video and it should be up at like 3 or 4pm central time. My favorite part about this is the fact that I used up an old motor and esc that were just sitting around.

Spartan

justinep

The car was originally RWD? Did you buy it used from someone that F'd with it? Eitherway... nice mod and can't wait to see it in action.

Is the shaft attached to the motor through the endbell? Its hard to see but, what it looks like. Nice work

spartan117

Yes I bought the car used and the front diff case had nothing in it, as in no gears etc. The yoke for the rear diff is connected to the endbell with the prop adapter. The front diff is connected with a driveshaft that I drilled out. So the drive shaft it pressfit/epoxied onto the actual motor shaft. Strange setup I know but it works well, which is all that matters to me. Video and new pics to come.

Spartan

spartan117

Well looks like the 30 amp ESC didnt cut it as it let out the magic smoke. I was about to grab the camera as I was doing some runs down the street it fried. I will need to get a new 40 or 50 amp esc as the motor is rated at 40 amps.

Spartan

ASSOCIATED_DRIVER

I am not an expert, but heres what I think.

Plane/Heli motor/esc combos are designed for more RPM with low load, having to spin props to create thrust to propell light weight aircrafts.

I think its much safer to mount it just like the stock motor, with a smaller pinion gear to lighten up the load.

A direct shaft mount would have a huge load for the motor and esc compared to one that uses gears (spur & pinion).

Thats just my opinion.

spartan117

Your have a good general idea of how it should be except one vital point, this point is that a normal helicopter or plane motor is a high Kv inrunner brushless motor used in a gearbox. Outrunner brushless motors rotate pretty much the entire motor can, minus the endbell, which means more rotation mass, therefore resulting in more torque. The increased rotational mass of the outrunner type motor means that in order to spin the greater mass and overcome inertia the motor needs to be wound in a lower Kv rating. The Kv rating is a simple fraction of RPM over voltage, so for instance a 1000kv motor will spin at a theoretical 11,100rpm at 11.1 volts. The lower the Kv rating means the lower the rpm, but the converse is true for the torque the motor produces. The outrunner motor needs greater torque to spin the rotor and would draw more amps than physically possible for the wire if the Kv was too high. This 1000Kv brushless outrunner is slightly shorter than a 540 motor and about the same width. The motor has the mounting hole spacing as a 540 motor so I originally bolted it right in place of the old motor and drilled out a 30 tooth pinion and discovered that I could get no more than maybe 20 mph at most. The amusing thing with running the motor in gearing was that the tires would spin endless due to the amazing amount of torque the motor generated. I did some simple math and figured out this 1000kv motor would be much more efficient in a direct drive setup with no gear reduction. The Kv is so low that I draw maybe 30 amps at most while at full throttle. This setup is also vastly more efficient than a gear reduction as there is no loss due to friction of various other forces. This setup also makes for a very very very quiet car. I would say this car now makes a third of the sound the original car made with a 13 turn brushed motor. The motor after running for 30 minutes doing top speed runs remains at room temperature. So your assumption that a direct shaft drive would make it more inneficient and place unnecessary load on the equipment is false, although that is what many would think and immediately assume. This brushless setup is many times more efficient than a geared inrunner as little energy is lost through the drivetrain and more of the electrical energy used by the motor is completely used to its potential with not much loss. The low temperatures caused by the low Kv high torque outrunner actually improves efficiency as magnets lose strength as heat increases and the same is true for the electromagnetic coils in the motor. The gauss field becomes much more unstable and unpredictable as the temperature increases.

Sorry for the lengthy and technical details.

I also hope I did not insult you in any way by disproving you.

Have a good one,
Spartan

team carpet fire

do you think that would work with a xxx-t

spartan117

As the Losi XXX-T is 2wd, it would proably not make the best candidate out there. It will be very difficult as you will have to find gearing to make it 1:1 gear ratio which will also entitle drilling out a steel pinion gear to fit the shaft of the motor. I wouldn't recommend this mod for your truck unless you have the 4wd mod or you are willing to do quite a bit of custom work. I would recommend picking up a Tamiya shaft drive buggy or stadium truck as they are cheap and shaft drive. The shaft drive feature is pretty much a needed prerequisite if you are going to attempt this. This motor also has a great deal of torque, and even with my foam tires, I could barely get it to stop spinning the tires when it was only RWD. I would recommend a Feigao 540 size inrunner if you are planning on modifying your own. It will not be as cheap but it should still perform well. I chose this outrunner as I already had all the ingredients lying around the house from my planes. In the TC4 however, this setup gives great performance and amazing handling (smaller, lighter battery). I think I may get some Tamiya Rally Block tires and try this out as a rally car. I now have a a 25 amp TowerPro ESC that I stacked some old FETs from a partially cooked speed control (actually it was the original 30 amp one). I will attempt to get some video within the rest of this week.

Best of Luck,
Spartan

team carpet fire

there is a 4wd mod for the xxx-t ????

spartan117

Nevermind sorry I confused myself. X-Factory made a 4WD conversion for the Associated RC10B4 and they also made a Belt Drive Conversion for the XXX-4. Sorry for the mistake. I didn't mean to get your hopes up.

Heres the Feigao brushless motor you could go with for a cheap BL setup in your truck:
http://www.hobbycity.com/hobbycity/s...idProduct=5345

Sorry About That,
Spartan

Vic Nyce

any updates???

spartan117

Sorry I have been out of town on a competition for school. I will update pictures and hopefully video tomorrow. I have just been so busy at the moment.

Thanks for the Interest,
Spartan