High Speed RC18T

[stereosonics]

hey everyone,

here I will post my build photos for a fast RC18T, the base car consists of pretty normal hopoups:

• GPM carbon chassis
• RPM arms
• RPM towers
• RPM bumper
• BRP rear bumper (also acts as a 'wheelie bar')
• TheToyz CVDs

I have then modied the top chassis plate to accomodate the 60A ESC, external BEC and capacitor. I had to space the aluminum plate 10mm above the standard top plate to clear the battery and motor. I do have some concerns about the higher center of gravity, but it's the only way I can neatly install all the electronics. The car will be mainly used for speed runs so I hope the higher COG won't affect it too much.

The power system will consists of the following:

• Neu 1107/1.5Y 4100kv motor
• 54T Spur and 31T Pinion!!!
• 60A EZRun ESC
• 4S LiPo (16.8V @ full charge)
• External BEC because of the 4S battery

Below are some initial photos of the aluminum plate and standoffs, also test fitting the large 4S LiPo battery, ESC and motor. The motor in the photo is from the Mini E-Revo, the Neu is very similar in size. Gearing is very high, 54T spur to 31T pinion

[stereosonics]

more pics...

[Stoogey]

Good lord, nice rig, barely any RC18T left on it

Vidz nao pleez

[stereosonics]

Good lord, nice rig, barely any RC18T left on it

Vidz nao pleez

I never actually purchased the RC18T kit or RTR, just built from parts I ordered slowly over a few months.

I'll get videos up when it's up and running, still waiting on motor and few small parts.

[Zerosignal]

Hope you've got some nice foamies and some exceptional fine motor skills cause these things are just idiocy at speed trying to hang on to them, and thats running no where near that sort of specs will love to see it in action once its done though

[stereosonics]

Hope you've got some nice foamies and some exceptional fine motor skills cause these things are just idiocy at speed trying to hang on to them, and thats running no where near that sort of specs will love to see it in action once its done though

oh hell yeah! it's going to be a handful but I love a challenge

I bought some 12mm hex adapters, so I will be running some 1/10th scale foams.

[RyeSin]

this thing is gonna fly, i have had about 5 rc18t's and they just seem to take so much abuse, one hell of a car you have, you're only missing the wings!

[Oldskool]

i got a EZrun 7800kv brushless motor 4 sale if ya interested.
its done 1 1800MaH lipo battery cause i then upgraded 2 the losi motor an now have no need for the ezrun motor.
PM me if ya interested.
$50

[stereosonics]

Just a small update...

I've painted a body to see how it looks, but I don't think it has the aerodynamics for speed runs. May need to look at another body or modify this one.

Also installed to some foam tyres to see how it'll sit, it's 55mm diameter. I also have some larger diameter Rustler Jaco foams arriving. The idea is to see how the larger diameter tyres will affect speed runs. On one hand it'll effectively increase the gear ratio for higher top speed, but it will also increase ride height and spinning mass. Will be a fun experiment

[stereosonics]

I've also invested in a Mamba Max Pro ESC, it supports 6S LiPo without the need for external BEC. It's capacitors are also built into the one unit so it will make the ESC easier to install.

The EZRun is nice and works very well, but having an external BEC is annoying.

[stereosonics]

So I received my Neu 1107 motor today, below are some photos of it installed using the stock motor mounts and using a 31T Traxxas pinion gear.

The motor doesn't spin as freely or smooth as my other motors though, like when in neutral it's like I'm hitting the brakes. It works fine though, spins up fast and has a lot of torque. Like a lot and a lot of torque.

If anyone else has a similar motor, could you let me know if yours spins smoothly?

[BIG-block]

So I received my Neu 1107 motor today, below are some photos of it installed using the stock motor mounts and using a 31T Traxxas pinion gear.

The motor doesn't spin as freely or smooth as my other motors though, like when in neutral it's like I'm hitting the brakes. It works fine though, spins up fast and has a lot of torque. Like a lot and a lot of torque.

If anyone else has a similar motor, could you let me know if yours spins smoothly?

I had a NEU in a heli once (i trashed that poor thing) and let me tell ya that its all normal. I know exactly what you mean. It feels very notchy and when mounted to the car it feels like there is binding in the drive train. Nothing to worry about. Its due to the magnets that NEU use in their motors. They are stupidly strong and will cause ton of drag when you back off the throttle. Set your ECS to the lowest brake setting and even that will probably be to much. Its a pain but the magnets are a big part of why these motors are so powerful.
Also I think you can go much higher with the gearing. One guy on the Traxxas forum is running a 1112 1y 3900Kv (the newer 1Y is 3500Kv) and he is running with a 35 tooth pinion in his mini Revo (biggest that will fit standard motor mount) and no issues with heat what so ever. The standard motor on 4s will fry even with a 18 tooth pinion.
I know that the final ratios in the mini revo and the rc 18t would differ a lot but being a lot lighter than the revo I think you could go a lot higher on the pinion. Anyway soon you will be able to test that.
I hope you are running metal diff gears as the NEU will make dust of the plastic ones. LOL. Also I recommend locking the front diff. Try running it the way it is first but I found that locking the front diff in my 18R was the only way to get some control at high speeds. Anyway see how you go.
That thing is going to be crazier than squirrels down your pants. I hope you can get a vid together so we can see it in action. It would probably just be a blur across the screen though. LOL

How long did it take for you to get your motor from CC from when you placed the order? I want to get me self a NEU 1112/2.5D which is 2600Kv. I want to try it out on 6S as I have a 6S capable ESC so why not. I think I will have to go past 35 tooth pinion so I will have to make a custom motor mount.

Ever since I got onto this brushless thing I have been obsessed with speed. Just love that jet like sound when it flys past ya. Its a drug I can't seem to get enough of.
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[stereosonics]

I had a NEU in a heli once (i trashed that poor thing) and let me tell ya that its all normal. I know exactly what you mean. It feels very notchy and when mounted to the car it feels like there is binding in the drive train. Nothing to worry about. Its due to the magnets that NEU use in their motors. They are stupidly strong and will cause ton of drag when you back off the throttle. Set your ECS to the lowest brake setting and even that will probably be to much. Its a pain but the magnets are a big part of why these motors are so powerful.
Also I think you can go much higher with the gearing. One guy on the Traxxas forum is running a 1112 1y 3900Kv (the newer 1Y is 3500Kv) and he is running with a 35 tooth pinion in his mini Revo (biggest that will fit standard motor mount) and no issues with heat what so ever. The standard motor on 4s will fry even with a 18 tooth pinion.
I know that the final ratios in the mini revo and the rc 18t would differ a lot but being a lot lighter than the revo I think you could go a lot higher on the pinion. Anyway soon you will be able to test that.
I hope you are running metal diff gears as the NEU will make dust of the plastic ones. LOL. Also I recommend locking the front diff. Try running it the way it is first but I found that locking the front diff in my 18R was the only way to get some control at high speeds. Anyway see how you go.
That thing is going to be crazier than squirrels down your pants. I hope you can get a vid together so we can see it in action. It would probably just be a blur across the screen though. LOL

How long did it take for you to get your motor from CC from when you placed the order? I want to get me self a NEU 1112/2.5D which is 2600Kv. I want to try it out on 6S as I have a 6S capable ESC so why not. I think I will have to go past 35 tooth pinion so I will have to make a custom motor mount.

Ever since I got onto this brushless thing I have been obsessed with speed. Just love that jet like sound when it flys past ya. Its a drug I can't seem to get enough of.

Thanks for clearing that up for me! I was getting a bit worried there, because Neu motors aren't cheap, and it's a long wait to get one.

I will definitely want to try higher gearing, the only problem I can forsee is is that a higher teeth count pinion will push the motor out more and will require a custom motor mount. With the 31T pinion, the stock motor mount is pushed out the most it can. Unles I can find a lower count spur, currently have a 54T spur. Higher gearing is the only way to get more speed because with 4S and this 4100kV motor, it is running just above the maximum 60k RPM limit.

The motor took just over 3 weeks to be built, then about another week to arrive to my door. I also bought a Mamba Max Pro It's great because of the 6S, but I can also use 4S without the external BEC.

And you're not wrong about the addiction! I can't get enough of it!!!

[BIG-block]

Don't worry too much about the 60 000rpm limit. A lot of guys have tested these motors to way above that. The little bit that you will go over is nothing to worry about IMO. Also with a little bit of load and some voltage drop I think you will be under the 60 000rpm limit that NEU state.

Did you have to shorten the shaft on the motor? Could you tell me roughly how long it is?

I want to get the MMP as well (mainly for the fine tuning ability) but it being a new ESC I will wait and let guys like you be the test guinea pigs (sorry. LOL) just in case there are issues with it. Anyway my Quark is doing an admirable job at the moment but even on 4S I had to use the CC external BEC.

With your motor mount would it be possible to drill new or extend the mounting hols on the chassis so the motor mount would move further away from the spur? Just a though.

[Homer]

Mate im interested to see what sort of speeds you get, i had an rc18r that i put a 9200kv Losi brushless in, Running 2100mah 40c lipo. Best i got was 100k's but the thing kept leaving the road, Literally started to take off. The tyres start seperating from the rims and it torque steers like a bastard.!

[BigKev aka The Frog]

Dont know if you have seen these clips....
This is with Homers RC18R before we went to lipo..

http://www.youtube.com/watch?v=JGgwK-c97Lc

http://www.youtube.com/watch?v=PuQexVAhXos

[stereosonics]

Don't worry too much about the 60 000rpm limit. A lot of guys have tested these motors to way above that. The little bit that you will go over is nothing to worry about IMO. Also with a little bit of load and some voltage drop I think you will be under the 60 000rpm limit that NEU state.

Did you have to shorten the shaft on the motor? Could you tell me roughly how long it is?

I want to get the MMP as well (mainly for the fine tuning ability) but it being a new ESC I will wait and let guys like you be the test guinea pigs (sorry. LOL) just in case there are issues with it. Anyway my Quark is doing an admirable job at the moment but even on 4S I had to use the CC external BEC.

With your motor mount would it be possible to drill new or extend the mounting hols on the chassis so the motor mount would move further away from the spur? Just a though.

The shaft is 18mm long but it clears everything so didn't have to shorten it.

I do hope the MMP will work well! It also cost a bit of money, good thing is that I alreayd have a Castle Link so that's handy.

It is possible to extend the mounting holes, but it would be very difficult. There is this custom mount, might try it later on:

http://www.rccustomzone.com/rccz_Pro...otorMount.html

Mate im interested to see what sort of speeds you get, i had an rc18r that i put a 9200kv Losi brushless in, Running 2100mah 40c lipo. Best i got was 100k's but the thing kept leaving the road, Literally started to take off. The tyres start seperating from the rims and it torque steers like a bastard.!

Man I'm a bit worried once this thing gets on the road too! I think I will try using some weights for the front. Vertical stabilisers also considered to keep it under control.

Will be using various foam tyres so balloning won't be a problem.

Dont know if you have seen these clips....
This is with Homers RC18R before we went to lipo..

http://www.youtube.com/watch?v=JGgwK-c97Lc

http://www.youtube.com/watch?v=PuQexVAhXos

Yep seen those videos. I'll try take a video of my one running suspended. The torque is crazy and the car tries to shake around in my hand, and that's with small diameter tyres.

[stereosonics]

So here's a youtube video of testing the Neu 1107 in the RC18T.

http://www.youtube.com/watch?v=bpF2wtCPHpQ

You can see how much torque it has because it's like pulling around when I hit the throttle. This is testing on a 3S battery with a Mamba Micro Pro.

[stereosonics]

Some good news, I found a spur with less teeth Stock spur is 60T, I currently have a 54T and the new spur I've ordered is 51T!

Because I'm limited by how far I move the motor outwards, I'm also limited by how large my pinion can be. By using this gear diameter calculator I can workout what the maximum gearing I can use: http://stereosonics.com.au/mestuff/R...gear_calc.html

My current gearing (31T/54T) has a distance of 23.55mm between motor shaft and centre shaft. If I put in a 51T spur, the largest spur I can fit is a 34T.

[Homer]

See how quick the motor brakes when you back off, Thats going to be a problem!. Mate i run foams and the low 350z body and the thing was 10kmh slower, It was actually faster with the rubber tyres and stock body!.

The fastest we clocked it was 100kmh, But it was still winding up, when i rolled off the throttle to slow down it started to tail whip then flipped and slid upside down for 30+metres.


Here ya go, same setup i run!

http://www.youtube.com/watch?v=1zfl_vu-1Ss