BlindObject

My Feedback: (11)

Heya, so I'm finally trying out the electric side of RC and I'd like some links or suggestions that talk and explain about Eletric motors, batteries, what exactly is an ESC and pretty much all this noob stuff lol. I have a basic idea but I'd like more details. A suggestion in a good beginner truck would also be great.

Thanks!

badboy2

My Feedback: (13)

are you lookin for 10th or 8th scale?how much is your budget?

ThunderbirdJunkie

My Feedback: (3)

Blind, depending on how advanced you are in the RC hobby in general would pretty much dictate what you're looking for. Goals for the car and examples of what you already have would also be good. IE if you already have a Savage 4.6, a Savage Flux would be a no-brainer; if you have an XXX-NT an XXX-T CR would be a good stepping stone, etc etc. Most nitro cars have an electric variant, which is good when you're transitioning from nitro to electric.

BlindObject

My Feedback: (11)

I see, my budget right now is around $300. And I've had a Firestorm before, great chassis, but the motor was an absolute nightmare, lol. I've also owned an Ofna Violator, Tmaxx 2.5 which I covered to a 3.3. I was thinking of either a trophy truck like the Traxxas Slash or Blitz, or stick with the stadiums such as the E-firestorm. I'd like to really learn what I need to operate these cars though, like a basic beginners guide. Maybe also learn the difference between brushed and brushless, Lipo batterys, etc.

Foxy

For your budget look no further than the shortly to be released (within the next week) Savage Flux XS... It is designated a mini moster truck, but it is still equivalent in size to most 1/10th cars.

Official page at HPI: http://www.hpiracing.com/kitinfo/106571/

Thread with much discussion here on RCU: http://www.rcuniverse.com/forum/m_10554235/tm.htm

Couple of pre-order options...:
http://www3.towerhobbies.com/cgi-bin...&I=LXBFNA&P=ML
http://www.amainhobbies.com/product_...-w-24GHz-Radio

Although I would normally hesitate to recommend a truck that isn't out yet, I am absolutely confident this thing is going to make a huge impact on the hobby. You will however still need some batteries and a suitable charger. The car just ticks all the boxes, 2.4ghz radio, brushless motor, good quality speed control, standard size wheels and tires, standard size electronics, tough as nails, waterproof, crazy fast, HPI quality. I will be getting one myself as soon as possible.

Foxy

In response for your request concerning info about electric in general, here are some basic guidelines:

Motor

Motors come in 2 basic varieties, brushed and brushless. Brushed motors are older technology and are only really used still, in classes that dictate you must use a brushed motor, and other applications that require very smooth throttle response, and low speed control, such as Crawling and Drifting. Brushless motors need maintenance every so often, changing the brushes when they wear down and sometimes shaving a layer of metal off the commutator (using a 'comm lathe') to provide a better surface for the brushes.

Brushless motors are the newer technology, requiring no maintenance and delivering significantly more speed and power for the same ratings.

Both types of motor are rated in 'turns', with higher turns being more torque and less speed, and lower turns the opposite. Most brushless motors are also referred to as having a specific KV rating. This is a measure of their maximum rpm per volt. So, for example, if you see a brushless 10.5 turn 4000kv motor, it will turn 4000rpm for every volt supplied at maximum throttle. So the max speed of that motor on a 7.4v lipo battery will be 7.4*4000. In general consider that 3000kv or less is a fairly slow motor for high torque, and a 9000kv motor is a very fast, less torquey motor. The current a motor pulls (amps) goes up with the KV.

Speed controllers

Speed controllers also come in the brushed and brushless variety, indicating what kind of motor they can accept. There are many speed controls which can be switched or switch automatically between brushless and brushed operation. Running the wrong type of speed controller for the motor or running the wrong setting will destroy the speed controller and/or the motor in pretty short order.

The next things to look at on a speed controller are voltage and current ratings, which must not be exceeded. Often a speed controller (hereafter referred to as an ESC) will say first how many volts you can pump through it. Though this is often expressed in how many cells you can use (the number of cells your battery has). NimH old style batteries composed of a number of SubC cells are 1.2V per cell, and Lithium Polymer (lipo) batteries are rated at 3.7v per cell. You may see an ESC say '10 cell/3s max' This means 10 nimh cells (10*1.2=12v), or 3 lipo cells ('S' always refers to lipo cells) (3x3.7=11.1). Or the same speed controller may say 12v max. Once you have identified that the ESC can handle your batteries, you need to look at the current rating (maximum AMPS) and make sure your motor draw will not exceed that. Most motors will say how many amps they draw 'under load' and 'burst'. As long as those amps do not exceed the 'continuous' and 'burst' amp ratings of the ESC, you are good to go. As a general rule of thumb, 25A ESCs are for micro scale stuff, 40A ESCs will do for most 1/10th stuff, 60A ESCs are for the heavy duty (very high kv) 1/10th stuff, 80A for light duty 1/8th stuff, 120A for midrange 1/8th scale stuff, and 150-200A for the really big 1/8th scale stuff.

Batteries

Nimh batteries (made up of smaller 1.2v cells) need to be maintained. After a month of being flat, they will rarely take a full charge again, at least not without careful resurrection using a complex cycling charger for many hours, apart from that, decent nimh cells should be fine for almost all your current needs.

Lipo batteries are a little more trouble, but overall lower maintenance. The thing about Lipos is that they will generally start a fire if mistreated. Mistreated means; overcharged, overdischarged, badly damaged. These batteries must never be allowed to drop below 2.9v per cell. If this happens, first of all there is the fire risk if high current is still being pulled through it, but also a battery overdischarged in this way will never take a full charge again, and may visibly 'swell'. Therefore it's critical when using lipo batteries to use a speed control that has an automatic lipo cutoff, ideally one which you can set. When I have the option, I always set my lipo cutoff to 3.1v per cell. (so when a 2s (2 cell) 7.4v battery reaches 6.2v, the ESC stops the power to prevent battery damage). These batteries also need to be regularly balanced to make sure that the batteries stay at the same voltage per cell so that the lipo cutoff works properly. The danger of an unbalanced battery, is that eventually, if one cell in the battery were to fall to 2.6v, yet the other was still at 3.7v, that wouldn't be low enough (combined=6.3v) to activate the cutoff, but the first cell is already damaged beyond repair, having dropped below 2.9v. Balancing your batteries prevents these voltage mismatches. Most lipo chargers include a balancing charge option, which will do this automatically.

The good thing about Lipos is that they charge fast (can be charged in an hour at the most, and many can be fully charged in half an hour), they do not lose much charge over time sitting around, they deliver incredible amounts of current, and last a very long time. Despite the extra care, these batteries are VASTLY superior to the other type, and I strongly recommend getting some and getting used to their idiosyncracies. Dont be put off by the extra care they require, follow these simple rules and they are very easy to own and will serve you well for many many charge cycles.

Charge and discharge rating... When you buy a lipo battery, as well as the number of cells (2S, 3S, 4S, etc, which determine the voltage, 7.4, 11.1, and 14.8 respectively), and the duration expressed in mAh (milliamp hours), you will also see a discharge rating, expressed in 'C', for example, '2s 7.4v 5000mAh 25C'. This means it is a 2 cell 7.4v battery which will last for 5000miliamp hours and the maximum discharge rate is 25C. The C rating is an expression of how much continuous current (Amps) the battery can deliver safely (exceeding this can damage the battery and/or the ESC. The C rating is a formula based on the capacity. So, 25C on a 5000mAh battery is 25x5 (5000mA=5A), so this battery can deliver 125A of maximum continous current. A 40C battery of the same capacity would be able to deliver 200A of continuous current (40x5A=200A). Once again, it is important to match the battery to what your motor and ESC are capable of. To be honest, most batteries of 4000mAh or more at 20C or more are good enough for most applicatoins, it only starts to be a problem in the really high power 1/8th applications, where a 2650kv motor pulls say 150A continuous current. You would need to make sure that the C rating of your battery multiplied by its capacity makes at least 150 in order not to risk damage to the battery and/or ESC

The same applies when charging. You may see a battery say it can be charged at 1C or 2C. Lets take the 5000mAh example again. 1C as we said=5A, 2C=10A etc. So a 'Charge at 2C' battery with 5000mAh capacoity can be charged at 10A maximum.

Hope all that makes sense and helps.

BlindObject

My Feedback: (11)

Thanks for the huge post! Extremely helpful

And the hpi savage does look nice, but Im a bit hesistant on brand new models, defintely going to look at its reviews however. I was looking at probably getting a easy pay vehicle from TH, so I can get the vehicle and its accessories for cheaper at first, hence the ones I looked at.

Any other suggestions?

Foxy

I promise you it won't be a lemon, and to recommend anything else in the current market for your budget would be bad advice. With the littel Savage you are getting $200 worth of electronics (brushless motor, excellent ESC, decent servo, good 2.4Ghz radio) alone. There is nothing else even remotely representing that much value for money at the moment. I don't believe you need to wait for the reviews, it's going to be truly epic. But if you absolutely insist, wait til the reviews, THEN start looking for something else if you don't like what you're hearing, because the next best thing for $300 is NOWHERE NEAR as good, trust me.

Chucksolo69

I just picked up the Associate SC10 RS Lucas Oil truck from Tower Hobbies. Nice 2WD truck, and very sturdy. Price is right too, around $250.00.

BlindObject

My Feedback: (11)

Its definitely an awesome truck, but Ill also need to buy a charger and lipo batteries, right? Do you guys recommend getting a used vehicle?

Mysterious

Everything Savage rocks, it'll be a kick***** truck, guaranteed....

u could build an ofna hyper tt if you increase the budget a tad....

or buy a losi ten-t roller off ebay & do it up electric......check out my builT thread...

http://www.rcuniverse.com/forum/m_10655645/tm.htm

Everyone at my track, even the lifers think its awesome...... i'm a newbie and only driven it 3 times & am rapidly challenging the experienced guys.....almost took 3rd out of 7 last week but I ran out of juice in the last lap on the back stretch....might need to tack $100-200 to your budget but it'll be worth it, guaranteed

BlindObject

My Feedback: (11)

Hmm, buying a roller and installing the goods doesn't sound like a bad idea. I really don't wanna start with Nimh, I rather simply go to Lipos and brushless, and then upgrade the chassis later on. Which is when [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXBBBW**&P=EP]this[/link] caught my attention. It comes with everything I need except the LiPo battery. I did really wanted a Trophy truck though, but I don't see many good deals on them.

BlindObject

My Feedback: (11)

Alright, I'll actually rather wait and buy the little savage. It really does look great, but for now, can somebody suggest me a good charger (nothing too wild please) and LiPo batteries? I like to have them ready when I buy the truck .

SyCo_VeNoM

Well the charger isn't an issue batteries could be depending on the RC. Like some batteries I have fit great in some RC's, but others they can't fit in at all. Then it comes into the discharge rate, mah capacity etc which depend on the ESC's rating that they are for.

Might want to look at the thunder chargers on hobbypartz.com they are kinda decent for the cash, and read most the ppl like them that buy em.

BlindObject

My Feedback: (11)

Well, I'm not sure what the Savage SX flux takes in, I was assuming all batteries were standard sized. What are some good brands for Chargers and Batteries?

TTMT

There seems to be a welcome trend in our hobby toward chargers that can charge multiple batteries at one time.  If I were in the market for one now, that's what I would buy.

There are AC/DC chargers and DC-only chargers.  My preference is for chargers that run off both AC and DC.  If you buy a DC-only charger, you need to buy a power supply to use it off wall current.  You can buy power supplies at hobby shops. 

To get the most value for your money, you want to consider the types and sizes of batteries you expect to be charging.  For example, if you ever think you may use 6S lipo batteries, you need to be sure the chargers you consider can charge them.  There are many battery types you'll encounter in the hobby - Lipo, NiCd, NIMH, LiFe and so on.  You'll want to consider them when you evaluate your options.

My AC/DC charger is the Hyperion 6061i. It can handle a wide range of battery types and sizes, it's full-featured and of nice quality.

Hope this helps.

ThunderbirdJunkie

My Feedback: (3)

Hitec X2 would be a good charger. It'll charge two batteries at 10a each if your heart desires. However, you need a 25a power supply to run it.

Foxy

The battery tray is the only problem with the Savage XS Flux identified so far. Someone got one a couple of days ago (assuming in Asia, since they haven't arrived in the US yet...slow boat), and finally revealed the true battery tray size.

143x47x31

This is a problem because there aren't very many high capacity batteries (4000mAh and up) that are less than 47mm wide. I'm going to have to be cynical and say that HPI has done this on purpose to sell their plazma range of batteries, which, surprise surprise, are an exact fit (both 2s and 3s). There are several cheaper packs on hobbypartz.com that will fit, but they aren't high capacity. The shocker is that most standard 2S hard cases (49/50mm standard width) won't fit either!

My own Zippy 3s packs are only just off (146x50x28), and I will be looking at what I can do to the battery door with a dremel to make them fit.

If you're going to go for the little Savage as a roller, bearin mind you'll need a 60A ESC capable of 3s/11.1v (if you want to do the claimed 65mph), a brushless motor around 4000-5000kv, a 2.4 Ghz radio system, some batteries and a suitable charger.

Having done a quick search, I'd say go for 2 of these... http://www.hobbypartz.com/77p-sl4400-3s1p-30c-3333.html

And one of these... http://www.hobbypartz.com/thac6smbachw.html

BlindObject

My Feedback: (11)

I'll be buying the RTR version of the truck. Will its stock ESC/motor handle the LiPo batteries? And those batteries look good, how long do you think they'll last?

Foxy

Half an hour each I would guess. Yes, the stock electronics are designed for 3S, it will handle it and come back for more. HPI's claimed top speed of 65mph on the stock electrics is definitely with 3s packs, so take that as a green light.

cumminspower5.9

My Feedback: (4)

What about the e-firestorm? that looks like a pretty sick truck.

Mysterious

I have this one... cheap , efffective, robust in coverage......
http://www.hobbyking.com/hobbyking/s..._GENUINE_.html

BlindObject

My Feedback: (11)

The firestorm does look awesome, but I grew a little bored of the 2wd chassis and understeer handling. The package is awesome since it has everything I need, but if waiting a bit means getting a better truck Im up for it. 30 minutes each sound pretty good. Im not really trying to go that fast with the truck, Ive made such memories with my old 3.3 jato..

cumminspower5.9

My Feedback: (4)

lol yea. well if 4wd fun is what you are looking for then the savage flux is the one to go with. balls to the wall with that thing. durable as heck too. but there is also the 4wd stampede. kinda top heavy though. im just throwing out 4wd suggestions cause that seems what you are aiming towards.

ThunderbirdJunkie

My Feedback: (3)

The roller is an option?

Must be a Europe/Asia thing[:@]