Desert RC

Im getting there...lol.

ace@

My Feedback: (9)

What spur/pinion are you running? I jusst converted from the Micro T to the Micro DT Truck. I got the DT tires and the stock Micro T spur/pinion. I put the biggest pinion that came with it on. I have 7.4v lipo from losi, Losi brushless spectrum micro reciever ect... it just don't seem that much faster then the stock set up with the lipo.. I guess i need to look into the biggest brushless motor that losi has. I think Mamba also make a micro t motor but i'm not sure.

Desert RC

HMMMM, I dunno think mamba makes a micro motor. I do know that the losi BL has two motors and the smaller of the two usually comes with the combo unless you get it on ebay. I am running the stock pinion/spur. Never changed it....but I will mess around with it after my upgrades. I have heard that the BL system is not THAT much faster than Lipo/BBmotor set-up. Post some pics of your wiring, I would love to see. I want to do this set-up myself. I dont like the way the stock bare electronics look with the graphite chassis.
Paul

mikemcnair

my 10250 kv BL motor is REALLY fast with the new battery i just got (diyminitune.com, BEST place to deal with!!!)

with the losi lipo, it was just weak. now, it is sick. pulling wheelies from half throttle. then i lost a control arm screw, so i headed in to the pit. (the shop i have)

all fixed now, but i am running into ESC LVC issues. if i am full throttle for more then a second, the car stops..... chills..... then beeps as if saying "hey, you can drive again" then it happens again. it is frustrating because the car flies, but i can only do it for a few seconds. when it stops, i still have steering, so i am sure it is the LVC.

oh, and i powered up the lights, and fried all of them, in one shot. it was awesome, for a second. so i will buy another one, and make sure they have the appropriate resistors in them.

i will call losi tomorrow about the ESC and lights.

KRO

Yes , it is THAT much faster ....


mikemcnair , check the wires going into the motors can , I had one get loose and it was doing the same thing yours is ......

Desert RC

Which kv motor are you running with the BL?

mikemcnair

i will check the wires going into the motor to see if that's the issue. i am running the 10250kv motor and it is indeed fast as hell!!!!

i lost a control arm screw, which allowed the right rear wheel to flop out, and i lost my outdrive on that side. thank god i have ~ 6 full trans with all parts, and 2 screw sets. we are already back together and in business (although this trans is totally shot)

i can't wait for the shims to get here so i can make a trans that won't explode in a new york minute like they are doing now.

also, i am going to try to figure out a nice way to get these dam lights to work. i have to order another set, but we shall see what i come up with....

KRO

I am also running the 10250Kv motor , but the 8750Kv motor was really fast too

mikemcnair

ok guys, i am really struggling with the options i have for these (now blown) lights. i was thinking of wiring them into the motor, but A) there are 3 wires going to the motor and B) i want the lights on all the time and C) i don't want to fry another set when i hit the gas due to overload of voltage.

the lights fried with just tapping a 9v battery to them, so that is clearly too much power the stock ESC they are intended for puts 5v to the Servo (which is where the lights tap into on a stock setup)

i cannot find a resistor of any sort on the lighting kit, so i suppose they are OK at 5v.

SOOOOOO, here is my thinking....

i will get a "Y" connector from the servo to ESC, and tap into that with the lights. this in turn will set it up ~ like the Losi guys intended, just without 5 wires. also, it appears the servo has a constant power lead going to it at all times the car is on, so my "on all the time" thing will be taken care of. also, with the "Y" adapter, i can always just unplug it all, and plug the servo right back into the ESC should i ever want to run it without lights.

make sense?

ace@

My Feedback: (9)

i got the 8750 that was all they had at the hobby shop. I see they have the 10250 on Ebay. Will that work with the ESC from the 8750 combo that i got?

I will post some pictures tonight when i get home.

mikemcnair

yes, the losi Xceleron ESC will power that motor as well as the 10250.

mikemcnair

ok, i finally bit the bullet, and ordered the Spektrum Micro Rx for the car. i also ordered another set of the Losi lights, this time i will get them to work properly

also, since i am wheelie'ing at 1/2 throttle now with this new battery, i actually bucked up for a wheelie bar. i do not like them, but it appears it is necessary now since the car keeps flipping over on itself when i hit the gas.

i will call losi today and get to the bottom of the light wiring, and post up for anyone else that is now a 3 wire setup (BL). :thumbup:

edit:

called losi, they are clueless, so please chech this out if you have any ideas......

http://www.rcuniverse.com/forum/m_7784509/tm.htm

gt_man

Hey Guys. Alright I really have a situation. I dont know a whole lot and really need some ideas on whats wrong. First off. I have the regular micro t and had some fun with it. I probably ran it about 10 times on the regular battery. Then i got the LiPo and after about ten runs it started to screw up. In the middle of a run it would just stop all the suddenly. The wheels would still turn but the motor was dead and i would have to turn it off and on again to run it and then it would just end up stopping again. Eventually as soon as i turned it on and pulled the throttle it just stopped the motor. So i was pretty convinced that the motor was shot from the lipo and was getting caught on the brushes. So i went to my LHS and bought a new losi replacement motor, some new pinions just in case, and some desert tires because my were bald. I came home charged up the battery and put on the new tires, motor, and the smallest pinion for the bigger tires. It ran for about a minute and then did the same stopping thing where i had to restart it a few times. Then it wouldnt even go anymore. So I gave up and came back to it a few hours later and the motor will go in reverse with a little delay but no forward at all. Does anybody know what I should do. Please help.

mikemcnair

for starters, you were likely hitting your low voltage cut off on the lipo, causing your car to still have steering, but no throttle.

secondly, your motor sounds like it is shot if you can go one way, but not the other. or, for some weird reason your ESC is on the fritz.

i can send you a perfectly functional motor/Rx/ESC all wired, with the Atomic BB motor already soldered on if you would like since i have no use for it at all. i would need a small fee in return, but nothing crazy.

this (to me) would be the best way to test your system, if you replace all known electronics that could cause an issue. heck, i can even send you a losi lipo (also perfectly functioning, but would need a new connector soldered on it) to test as well.

you let me know if you want to try it.

gt_man

Thanks for the info. Im not sure yet im thinking of just converting to the brushless system before spending any more money but im waiting until i can find it for a little cheaper. Also that motor is a brand new losi and the lipo is a losi lipo thats only been used like ten times and im definitely not overcharging it.

mikemcnair

LVC, not over charge. low voltage cutoff bro.

gt_man

Oh yah I knew what you mean I was just saying that I know that the losi lipo should be good because I havent overcharged it and barely used it. Im thinking it might just be worth my while now to go brushless. Do you think that would solve my issues.

mikemcnair

lol, your asking the wrong guy, cause i think brushless solves all issues the universe is faced with

gt_man

yah it still only goes in reverse. i dont see how its so screwed up. Its almost brand new. I dont have 100 bucks right now to convert to brushless. I wish i could though

Desert RC

Mike that would make my day if you could part with that stock stuff to me...and the bb motor if its cool!! IM me and tell me what you want in return bro. It would really help a fellow member out in getting my stuff running. I am haveing similar issues with my other esc!! LMK, that is if he does not want it...

gt_man

dude i just lost a screw on my micro and got hit in the head with some stuff because of a huge fricken earthquake

Desert RC

DUDE where do you live in cali.....I just had an earthquake!!!!!!!!small world we must live pretty close to eachother. I live in Palm Desert Cali. What screw did you lose...I have replacement screw set, I can send you what you need if you dont have extra...

Desert RC

The earthquake was a 5.8 and the epicenter was in Chino Hills......my wife filled me on this info>

LBRC

Ok since your car will only go in reverse now, what is wrong is that you fried you mosfets (abbreviated FETs) a common problem with the LiPo usually because your pinion was pressing too hard against the slipper spur gear along with other things like the slipper being too tight. Bad when your first motor was cutting out but then once you added the larger DT wheels the poor circuit board couldn’t handle the load. BTW motors are always easy to check by hooking them directly to any odd battery, if a brush ever did get stuck to the commutator you’d know since there would be a noticeable amount of smoke and/or sparks, if you feel like destroying something for fun try stopping a DC motor while it’s still connected to power.

Just for general info its current that kills FETs not voltage, the LiPo’s higher voltage let the motor draw more current and consequently goes faster. Unfortunately that speed and wheelie popping power has a price, the McT CB has 4 mosfets in a 2x2 parallel arrangement, but they SUCK, while the 40,000+ McT current hungry McT motor is a micro monster that can easily draw more amperage those pitiful puny el-cheep’o mosfets can handle, especially with too much drive train friction and/or drag. And to top it all off at 1/36 scale we are like a 180’ Jolly Green Giant trying to adjusting gears on a VW not pretty from the bugs point of view, so what we may think of as loose enough can be well less than adequate. Other evils are sand or other FOD in the gears with a tight slipper, gears bind motor stops with full power applied and something’s got to go so unless the diff gear strips fast enough the FETs die.

Your CB can be fixed by replacing the FETs (recommend using 4 Fairchild FDS8858CZ’s) but since you were using a Losi LiPo and Losi Motor you might as well see if you can get a new CB out of Losi first, even if you plan on going brushless.

About a brushless Micro-T I have two one with the Losi Xcelorin ESC and the other that first used a slightly downsized Castle Creations Mamba-25 but reticently switched it over to their new Sidewinder no contest if you have the money and technical ability, i.e. soldering skills etc., a Sidewinder w/ Castle Link USB computer interface is the only way to go, runs both brushed and brushless motors.

Desert RC

Okay somebody knows there stuff. Nice support. Does the sidewider fit under a stock body...I would love to see your set-up all wired up with the CC stuff. I am sure you must be running spektrum rx.