aflipz

My Feedback: (10)

Good call that looks like a really decent system.

Well typically we use regular cheapo 3 and 5mm "ultra bright" LED's and wire them in series or parallel with resistors to keep them from burning up. I power them from a spare channel on my receiver this way it doesn't matter if I use 2 or 3 cell lipos; the voltage to the receiver is regulated to 6v regardless. As an added bonus; when you switch off the esc the lights turn off as well. Of course, no extra batteries... This works great and all but I'm rarely one to leave good enough alone; I'd just like to do something different this time around; I need a LED driver that can run on anything between 6.5V and 12.6V that can drive four 1W led's at once, and of course four led's Did some digging at dealextreme but it seems I only found drivers that either run on much lower or higher voltage ranges.

4W worth of LED lighting in front would literally mean DAYLIGHT in front of the car, that would be sick!

Khar00f

Is there anything i should look out fro for the servos?

size limitations, gear type etc...?

aflipz

My Feedback: (10)

Not really;

metal or plastic almost any standard size servo will do as the mount is adjustable to a point, there's a servo saver included (it's a bit sloppy but it does the trick) so you don't really have to worry too much about gears stripping.


What I look for in a servo, for such a light car I favor speed over torque; the faster the servo the better the steering response and the faster you can countersteer when the tail swings out.

I'm a weight reduction NUT so I went with a futaba 9650 which is a bit too small but I managed to bend the mounts in it and cram it in there. I used it because it's digital and insanely fast, and is very light compared to a standard servo. it's pricey though, stick with the one that comes with your radio system for now.

MD6

If you're going to be running on a wet track or snow you want to consider the servo that comes in the Traxxas Slash. It's high torque and water resistant.

aflipz

My Feedback: (10)

Well; unless your RX and ESC are both waterPROOF (NO SUCH THING I assure you, some make that claim but none deliver) there's no point; you'll be covering the whole chassis to protect everything from water anyway.

I've had a HORRENDOUS experience with traxxas crap; never again. Their "waterproof" servo failed on me; overloaded the BEC and caused radio shutdowns. fortunately I found the cause before the BEC fried. My friend wasn't so lucky; it took out his ESC at the same time. Then, running in "misty" not even fully wet conditions, the esc took in a drop's worth of water and fried on the spot.

This is gear from a 1/16th slash and a 1/16th revo, 66.6% failure rate on all the traxxas electronics we got, and after 30 days we were basically told to stick it; pay 40$ to repair an out of warranty esc... bite me traxxas! I can get a SUPERIOR esc for less, brand new thank you very much..


that was my rant of the day... and for what it's worth; we deeply regret buying mini slashes, all around the crappiest RC vehicles we have ever had the displeasure of trying. Such a waste of time and money, for something that handles like a garbage truck and breaks when you look at it funny...

Khar00f

Ok thanks for that

does any1 knows what's the max current for this bursless motor <span class="headingb"><font face="Tahoma" color="#336699">EZ-RUN Brushless Motor 9T 4300Kv?</font></span></p>

MD6

My experience with the Traxxas servos in the Slash has been excellent. I have had my Slash for over a year. I have run it on dirt, carpet and in parking lot races. I have three friends that have had a similar experience and none of us have had a problem with our Slash servos. I have never really tested it's water resistance. I work with a junior high R/C club. For over year the kids have run Slashes. We had no servo problems.

aflipz

My Feedback: (10)

EZ-RUN Brushless Motor 9T 4300Kv current limits, can't find it anywere but I'm guessing 30A continuous 50A bursts.

why do you ask? (i'm asking this in case you fear using a battery good for 100A would fry a 50A motor, or the 60A esc would fry a 50A motor etc... when it doesn't work that way at all)

Khar00f

well the way i see it, if the engine say is rated at 100A and i get a 3600mah 30C battery then my batteries can supply more than my engine can request, which is good.

But if on the other hand my engine is rated say 100A and i get 3600 15C/20C then my engine will request more Amps than what the batteries can provide and that can't be good.

So by knowing what the engine requires, we can make better judgement on batteries

And I'm guessing this is most likely applicable to the ESCalso.

Any1 correct me if I'm wrong

aflipz

My Feedback: (10)

You are close... A 3600mah pack good for 15C/20C means 54A continuous and 72A bursts. That will be PLENTY for your needs especially on 2 cells. Elecrtric motors are funny that way; the faster they are going the less current they draw, every acceleration starts off with a very short but high spike of current followed by a rapid decrease to almost nothing as the motor spins up, if my runs last 12 minutes on a 2200mah pack that means average current draw of 11 amps, of course some of that time (very little) is around 70A and a lot is nothing at all or close to it but all combined that's an average of 11A.

ESC; higher the better until it becomes a size/weight issue. The farther you stay from it's current limits the more efficient it is (less power turned to heat and more used to crank your "engine" (which is a motor really...)



Edited the video again, removed a good minute of footage to make the action more concentrated and changed the music;


http://www.youtube.com/watch?v=YlnXU3OLDzQ

Khar00f

ok now when you say for the ESCthat the farther you stay from it's limits the better, are you talking about motor current draw or battery discharge?

like the turnigy ESCyou recommened is rated 60A, you said the motor is about 30A (i don't know how you got that, but we'll use for example's sake) and the battery is at 108A/144A (3.6 30C/40C)

which amp has to stay furthest from the ESC? I presume motor since the Packs' Amps is what it can give, not what it does give constantly, and since it's the motor drawing 30A, then the ESC is barely being pushed to half it's limits

correct?

Good edit on the video, not a big fan of the music, but I'll live

aflipz

My Feedback: (10)

Motor/gearing/drivetrain drag/aerodynamic drag/ surface drag/ vehicle weight and driving behavior all dictate current... Pack has to be able to provide it or it overheats, ESC; must be rated for at least what the motor will be using, and the higher up above that it's rating is the better.


I use an eagletree datalogger which records volts, amps and mah used in real time (10 samples per second) and puts it on a nice graph for me to look at and see what goes on during any given run. I only did this once, not worried by what I saw. I will have to do it again this summer as high grip aggressive driving might draw a bit more.


These are the specs from a Traxxas velineon 380 brushless motor, which is very similar in KV rating, diameter and length (except its lacking about 4mm of heatsink all around the can)

Velineon 380 Specifications:

* Type: Sensorless Brushless
* RPM/volt: 4000 (8-Turn)
* Magnet Type: Ultra High-Temp. Sintered Neodymium
* Connection Type: TRX 3.5mm Bullet
* Wire Size: 16-Gauge Maxx� Cable
* Current Ratings: 25A constant / 50A burst
* Max RPM: 50,000
* Weight: 140g (4.94oz)


I'd feel safe in affirming that the ezrun can take more than this one can or at least that it can be pushed harder before heat becomes an issue.

aflipz

My Feedback: (10)

Oh, and no matter what song you put, their will always be some who don't like it... but I had to use something otherwise the soundtrack would be quite bland

CWHFSR

That right there is the quote of the century. All anyone can do is give you a recommendation, and hopefully you will get more than one. You then have to look at that information and try to make the best decision you can. I would give you mine but since I know less than dirt when it comes to stuff I would probably give you all bad ideas. I'm following this thread myself to try and understand what is going on.

Casper06

The old shell was beat to hell so I decided to try out the Celica. I have been drawn to flat black a lot and it came out ok with the color of the stickers. Let's see how long this shell last now.

tamiyafan4ever

Oh man Casper!!!! That is just sick, I love the look of flat black. I am so jealous right now. Keep up the good work. Robert

MD6

You might enjoy this video.<div>
</div><div>http://www.youtube.com/watch?v=MwHVvld5hmY</div><div>
</div>

tamiyafan4ever

MD6,
Thanks for sharing that video, they look like they were having a blast. I like the chase car view, rally cars are just so awesome. Robert

Casper06

Again awesome vid MD6!

aflipz

My Feedback: (10)

Awesome video!

MD6

Thanks for the kind words. Here's another you might enjoy.<div>
</div><div><span style="font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif; font-size: 13px; ">http://www.youtube.com/watch?v=Ikv8k8fZveQ</span></div><div><font size="3" face="verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif"><span style="font-size: 13px;">
</span></font></div><div><font size="3" face="verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif"><span style="font-size: 13px;">
</span></font></div>

Willystylz

Thanks MD6...........now i want a rally car![:@]

That is a genius idea to shovel a track on the lake for some ice racing!

alexchen86

Ok I lost a rear dog bone yesterday while the car lost control in the wet rain and flew into a pool of muddy water.

So I went to my LHS and found a pair of replacements from HPI. They look like they will fit but then I saw this online:

http://www.rcmart.com/catalog/rc-ta0...s-p-27979.html

Has anyone used these for the rear as dog bones have been popping out of the cups quite frequently...do I need any special adapters or anything as there are two cups for each side of the dog bones.

MD6

I always like cvd's like the ones you listed or HPI makes them also, but they are probably more expensive. You can also take the dog bones you have an paint them a bright color.

alexchen86

Ok so seems like they fit. If the HPI dog bones pop out again I will go with CVDs. But does anyone know if the drive cup on the axle needs to be removed?