tinosasso

recently purchased the redcat volcano epx pro brushless. i have 2 batteries, both charged. and my truck constantly stutters, especially when i start it from stop, b/c of this i have broken parts twice b/c its no responsive at some times. i charged the transmitter batteries and its only a little better. any suggestions, this is very frustrating..................the antenna is not broke.

Willystylz

what kind of batteries are you running, and do you know how many kv or turns the brushless motor is?

proanti1

My Feedback: (2)

You need a BEC... sounds like voltage spikes are overloading your receiver.

tinosasso

hello, thanx for the help, the motor is Electric Brushless 3300KV 540 Novatech
i'm using rechargeable rayovac batteries for the receiver and i have the standard 7.2 nimh batteries, one is 2000 and other is 3000.
whats a bec?

i noticed yesterday, that after charging everything, the truck actually ran really good for a few minutes using the stock battery. i then changed it to the replacement, and same thing happened, so i then put in the first battery (which wasnt dead) and same problems occurred. i also  tried picking up the truck and holding it in my head, i could get it up to full speed (very gradually), but it would cut out after a few seconds ?

john01374

I've seen this problem several times over the last year. What you're seeing is cogging from the brushless system. The Novatech system is actually pretty good setup for the price you pay. The problem is not the motor, receiver or ESC. It's the batteries. The stock battery those cars ship with is JUNK. With it you will get about 5 mins of run time without cogging then the voltage drops and you start running into issues (exactly what you described). I'm going to guess that the 3000mah pack you have is possibly an off brand or lower quality pack as well but I would only be guessing.

A couple of good NiMh packs from promatch racing would solve the problem and give you a decent amount of run time but you will need a better charger if you are still using the stock charger that came with the Redcat. If you need a new charger and new packs it's a good time to look at LiPo batteries. The packs are much better for less moeny but you will need a charger that can charge LiPo, a balancer and a LVA to tell you when the pack gets low. The Novatech ESC has a build in cutoff but I've seen them fail more than once so a separate LVA is a good idea.

mrgoodbar

Nimh batteries are your problem, what you're experiencing is called "cogging." A problem typically experienced by BL users not using Lipo packs, and instead trying to get by using inferior nimh packs.

tinosasso

thanx again for all your help, i'm not an experienced rc user, i dont think i want to start with the lipo's just yet, i know there harder to maintain and more dangerous, i think i'll try promatch for a decent nimh pack and charger and eventually mayb upgrade to the lipo's. ...........................thanks again and i'm glad its not my transmitter or ecu.

mrgoodbar

Not true at all, just a rumor as the total opposite would be more accurate.

midntpumkin

the problem isint the batteries its the brushless system if its not sensored it will cog and act like that if its sensorless (without the sencored wires comming from the motor ) it will alway cog
this brushless system wont cog because of the extra wires
http://www3.towerhobbies.com/cgi-bin...?&I=LXYDM6&P=7
the black plug comming off the back are the sencor wires that plug into the esc with the main wires to the motor

mrgoodbar

Study up, and try again.
Sure, sensored systems are much smoother - but cogging can and will happen regardless of if it's sensored or not if your batteries aren't up to snuff.

john01374

This is only semi true. A sensorless motor will always cog a little regardless of what battery you use but in most systems the cogging is so little it isn't noticed IF you're running a good battery. I don't own a sensored system and I don't notice cogging in any of my cars or trucks unless I'm driving extremely slow. Like Rock crawler slow.

Also Lipo's are not harder to handle or more dangerous. The complete opposite is true. What you've been hearing is bad info. It is true that they can catch fire if you do something stupid like try to charge them with an extension cord plugged directly into the wall or stick them in a microwave like the idiots on Youtube are so fond of doing. In all seriousness I'd place and order with Hobby king for the Lipo's, charger, balancer and a couple of LVA's and spend a few days doing homework on care and handling. I've been using Lipo's for close to 4 years now without any problems. I'll be more than happy to give you all the instruction you need and answer any questions you have. While the NiMh packs from Promatch are some of the best NiMh packs you can buy they really don't compare to a Lipo pack. NiMh is in my opinion old and dying technology. LiPo and LiFe packs are the future.

Feel free to PM me if you want info on handling LiPo packs. I also have a Vortex EPX so I'm familiar with your truck.

midntpumkin

unless you can post pics of your brushless systems dont answer , i have both and i have used both batteries in tests , the sencored system has 0 cogging the sensorless stuff as alot of on and off throttle responce at slow and i mean like barely throttling speeds . if you want pics i can provide evidence can you

midntpumkin

here are the pics , the kyosho lazer and a sc10 that i both race , where are yours[X(]

qoisdhc oqina

My Feedback: (-1)

Some whining baby pic he found on google most likely.

tinosasso

i appreciate all the info, i guess right now i'm more concerned with cost, i didnt realize that after buying the truck, i'd spend hundreds more to run it. I definitely consider the lipo's but right now it seems like they will b much more costly. If i can get a couple good nimh's from promatch, i think i'd b happy for now, i dont race the truck or abuse it, i just want to use it w/out it stuttering and bogging down. Sounds like the lipo's have a higher cost to set up, and i dont have hundreds more to spend, so for the time being i guess my ? is would the truck b ok with a couple good nimh's?     thanks again all

midntpumkin

yes a new nicad or nickel metal hydryed will be better than an old one , brushless systems run more efficient than brushed systems and will use the power more efficently. radio shack or i buy batteries here
http://www.all-battery.com/nimhbatteriesforrccars.aspx
i had one or 2 fail after 40 or 50 cycles but for the price there fine

tinosasso

can i use an 8.4 or 9.6 volt in the truck w/out any mods?
the extra battery that i had purchased is the same as stock, but 3000mah's not 2000. i see some batteries on the site that i hope would b better than what i have.  thanks again for helping me as i am new to this hobby, but am anxious to finally use my truck w/out problems.

midntpumkin

a 8.4 yes , but i am not sure about the 9.6 will fit

mrgoodbar

A moron, newb, rookie ANDsupposed expert all wrapped up in one. ROFLMAO

Willystylz

msgoodbar what good is this supposed to do? You are apparently the wise one...

cowana

A 9.6v works fine in that truck - you just need to make a new battery mount.

Do verify that all the connectroes are soldered on properly - after a crash I found that my motor would only stutter and not run properly - it turned out ALL the motor connections (both on the motor and ESC) were dry solder joints, and making a very poor electrical connection.

If you pull on the wires, see if the plugs come apart, or the plugs come off the wires.

Andrew

tinosasso

thanks again everyone, well i charged everything (including the transmitter battery's )yesterday and decided to give it a shot (obviously i havent purchased the new batterys from promatch yet. I was pleasantly surprised that the truck worked awesome with the stock battery. i got about 5-7 minutes out of it and had no problems at all until it started to get weak. I decided to put in the 3000 mah battery that i had charged also and the truck did not work properly, would not budge. So i'm guessing what everyone said is right, in that its the battery in the truck that is my problem. i'm guessing the soldering job on the 3000mah battery wasnt up to par b/c it will not work the truck. I will invest a few dollars and get 2 good nimh batterys until i have the dough for the lipo set up. thanks again
and i'm guessing an 8.4 volt would do the job just fine, but can i have too much mah's ?
i found an 8.4 v 5000mah from promatch.................thanx again all

mrgoodbar

how many volt's your running relates to power, more cells is more volts, so more volts equals more power. but more power/volts also means more stress on the motor/esc, so keep a good eye on your motor temps.
how many mah's your running relates to runtime, higher mah is higher capacity of the cells, so more mah equals longer runtimes. but longer runtimes also means more stress on the motor/esc, so keep a good eye on your motor temps.

Shenanigans

My Feedback: (12)

what kind of radio do you use?  AM/FM radios with brushless systems also cause "coglike" interference.  should upgrade to 2.4 ghz if you dont already have it in the kit.

Does the esc have a lvc setting?  I know nothing of your esc, but the vxl for example has a setting for lipo, and a setting for nimh.  if you try to run your car with nimh on the lipo setting it will shutdown when it stops receiving adequate volts...which with nimh's will happen very quickly.

Slo-V Flyer

As others have suggested, the answer to your stuttering problem most likely is better NIMH or LiPo/LiFe batteries and good solder joints and connectors (gold 4mm-5mm bullet for motor/ESC and Deans Ultra or similar for battery/ESC).

Also please keep in mind that a good charger is also an investment you should be looking for. The stock wall plug in chargers or timed chargers are not very accurate, which they have their limited uses for Nimh. This will GREATLY help in the future. I would suggest you spend wisely right now so you don't end up spending unnecessary amounts of money. A good lipo/nimh capable charger is something vital for your r/c stable as much as good batteries and motor setup.

While it may seem like it's a good idea to just get better Nimh for now... you can for the same cost get a couple of 2s lipo batteries (2 cell = 7.4v) 4000 or 5000 mah 20C batteries. (20 C means 20 x capacity e.g. 20 x 5000 ma, or 20 x 5 amp = 100 amps discharge rating). A good balancer/charger for lipo/nimh would cost about $50 off Hobby King or maybe $90 if you get some other models/brands. A low voltage alarm, or battery voltage monitor can be $3-$10 on Hobby King or ebay.

However, with that said, it's always better to be informed and understand the lipo battery stuff before you buy it, so for now enjoy your truck as it is with your new Nimh batts.


Geek moment:
The cogging and stuttering people are talking about happen for at least 3 reasons I can think of, battery related, motor/esc related, and radio related,.

1. The Nimh battery or any battery for that matter cannot provide enough amps when the motor is accelerating, usually from a stop, causing it to STUTTER badly or momentarily. Often this can just result in the motor stuttering for a short moment, OR worse case, the voltage drop and amp spikes from the load can also cause the total system including the receiver to lose power, which lets off the battery some. This causes the voltage and power to come back on, (resulting in a stutter) and the cycle to repeat until the load/amp draw steadies off and or the battery meets the demand of the motor amp pull.

2. The batteries are fine, and you are running a sensorless brushless system (your Volcano EPX, or Mamba Max system for example). From a stop, or at low low speeds, the sensorless setup ESC does not know the position of the motor's rotor. This causes a momentary COGGING/stuttering effect until the motor spins fast enough for the ESC to do its magic and keep it going. Or you are driving around very slowly, almost to the point of stalling the motor. Same deal, the ESC (depending on several factors and how sophisticated its motor driving algorithm is) will have a hard time keeping the timing on the rotor and some times send the pulse of power at the wrong time/position causing you to stop or sometimes just stutter a little.

3. The intense amp draw that happens momentarily from the motor wanting to accelerate, causes a lot of RF interference to be generated in the motor/battery leads. If these are next to your AM or FM receiver on your mode truck/car, that CAN and has for me caused a lot of stuttering. Usually I was unable to drive more than 50-100 ft away from me depending on the area.
EDIT: As mentioned above, using a 2.4GHZ radio system can solve this type of stuttering/inteference. It worked like a charm in my case, and I can drive my truck 200-300 ft away or more until I can barely tell where it is.

Hope this helps. Or didn't explode your brain.