CompetitionX

A Web Site for the Serious Racer

[competitionxrc]

Tuning Haus Precision Onroad Setup Wheels

Vehicles settings like camber and toe can be a difficult thing to set if both sides of the car are not spot on to begin with. Variances in the wheels, insert or mounting can cause the setting to be off slightly, even when your tuning gauges say they’re both equal.

Check out these cool aluminum setup wheels from Tuning Haus. These wheels thread on to any 4mm threaded axle and are perfect for setting up your touring car, F1 or drift car. Because they are made from billet aluminum, they allow a much more precise setting on both the left and right sides of the car.

These setup wheels are anodized black and include a durable rubber o-ring and storage case.

TUH1102 Precision Thread-On Setup Wheels (4)

[source: www.tuninghaus.com]

Tuning Haus Precision Onroad Setup Wheels was originally published on CompetitionX

[competitionxrc]

Integy 23-Piece Competition Metric Tool Set

Having the right tools for the job makes the job much easier. If you believe that, then you’ll want to check out Integy’s new 23-piece competition metric tool set.

All the wrenches and screwdrivers feature a cool, lightweight ‘hollow’ design handle with a clear, molded end cap. Tips are replaceable in case you damage one during use.

This set includes the following tools: Straight Tip Hex Drivers • 1.5mm • 2mm • 2.5mm • 3mm

Ball-Tip Hex Drivers • 2mm • 2.5mm • 3mm

Arm Reamers • 3mm • 3.5mm • 4mm • 5.8mm

Phillips Screwdrivers • Long-reach 3mm (medium) • flat tip tuning screwdriver • 5.8mm (large)

Flat Tip Screwdriver

Nut Drivers • 4.5mm • 5mm • 5.5mm • 7mm • 8mm

Fingertip Turnbuckle Wrenches • 3mm • 4mm • 5mm

Multi-Use Shock Shaft Pliers • 3mm • 3.5mm • 4mm)

Tapered Reamer

As you can see, you get alot in this kit!

[source: www.integy.com]

Integy 23-Piece Competition Metric Tool Set was originally published on CompetitionX

[competitionxrc]

Common RC Screw Types and How to Measure Them

When I first started out in RC, I didn’t have much of a background in building things. Sure, as a kid I disassembled all my toys to see how they worked, but rarely ever put them back together and, when I did, never put the sames screws back where I got them from.

Then I encountered my first race-level RC kit; Team Associated’s RC10T. This kit came with a pretty detailed instruction manual that required me to know about screw types like SHCS, BHCS and FHCS as well as understanding measurements. I didn’t know much about any of these so I’m not 100% sure that my RC10T went together correctly, but I soon found that I needed to get familiar with these terms and how to correctly measure screw lengths.

So let’s get down to some terminology first. There are three common screw types in RC; SHCS, BHCS and FHCS. This is actually fairly easy to learn and remember so let’s break it down:

The common letters in these three terms is ‘HCS’, which stands for Head Cap Screw.

The first letter designates what type of screw head it is: S for Socket head. B for Button head, or the shape of a button. F for Flat head, for the flat top.

So knowing that, a SHCS would be a Socket Head Cap Screw, a BHCS would be a Button Head Cap Screw and a FHCS would be a Flat Head Cap Screw. Pretty easy, right?

These screws come in a slew of different lengths and even sizes, the most common being a 4-40 or 5-40 size. So what does this mean? Good question.

Let’s take a 4-40 screw as an example. The first number (4) designates the size of the screw, in this case a #4. The larger the number, the larger the screw. The second number (40) relates to the number of threads per inch (TPI), in this case 40. The larger the number, the more threads-per-inch the screw will have. So, if you see something like 4-40×1/2″, this is telling you that you have a #4 size screw with 40TPI and a length of 1/2″.

Other common sizes you might see in RC are 2-56 screws or 5-40 screws; these use the same definition as that above. A 2-56 screw will be a #2 size screw (smaller than a #4) and have 56TPI, meaning the threads will be a finer pitch than a 40TPI screw. A 5-40 screw will be a #5 screw (larger than a #4) and have the same 40TPI.

Now that we’re familiar with the sizes, let’s move to how you measure length. Common sense would say to just measure the overall length, but that’s only true for the FHCS. Because the FHCS is countersunk (meaning it sits flat to the surface once installed), you need to measure its entire length to get an accurate reading. To get an accurate measurement on both the SHCS and BHCS, you need to measure the threads only, as the diagram below shows.

As you can see, all three screws are the same length, just measured differently.

Hopefully this article will help clear any confusion about screws, lengths and how to measure. If you don’t have any yet, I would suggest picking up a set of digital calipers. They come in handy for measuring more than just screws and can be a pretty helpful tool in your toolbox.

Good luck!

Common RC Screw Types and How to Measure Them was originally published on CompetitionX

[competitionxrc]

Balancing Your Offroad and Onroad Wheels

Many of you put in countless hours of preparation and maintenance in your offroad and onroad vehicles, but how many of you actually take the 5 minutes to balance your tires? Unbalanced tires can cause that corner to bounce off the surface, resulting in inconsistent handling and lots of vibration. Vibration, in turn, can lead to screws falling out, overworked shocks or even bent parts.

The process of balancing tires is a pretty simple one and only requires a few tools. For this exercise, we’ll be working with GridRC‘s sweet new BalancePro V2 and BalancePro ZERO.

The BalancePro V2 is CNC-machined from aluminum for a precise construction and features a cool tri-foot design. Each foot has a screw running through it that allows you to adjust the balancer to achieve a perfectly flat surface. This is key and means you can be confident that the balancing process is a result of the tire and not an uneven surface. The V2 comes with three Delrin adapters; a 12mm, 14mm and 17mm hex. A precision ground, 4mm shaft rides on four micro bearings for ultimate precision. During this How To, it was extremely sensitive to the amount of lead tape I was putting on, but I actually found that to be a good thing; if it wasn’t sensitive, my work could be improperly balancing the tire and I’d still have issues.

Since touring cars roll at much higher speeds, I decided to go with the BalancePro ZERO. This unit uses a pair of parallel twin-blades that give a continuous, zero-friction contact area, something a bearing-supported system can’t offer. It is constructed from aluminum and also features the same tri-foot design. The balance rod is precision ground and has a Delrin adapter pressed on.

To achieve balance, I’m using some Gamma Lead Tape I found on Amazon for about $4. This tape features a sticky backside that allows you to trim to size and stick anywhere on the wheel you need. You can also use something like Racers Edge Wheel Balancing Putty, a good alternative that allows you to pinch off a piece and apply to the inside of the wheel.

Step 1: Set Up The first step, after acquiring the proper tools, is to make sure the location you are going to balance your tires on is completely flat. As I mentioned above, both balancers come with three adjustable feet to level things out. You will need to supply your own bubble level and I found these Darice Mini Level Picture Hanging ones to do the trick. They’re tiny enough to work on both balancers and only cost a few dollars. So, adjust the feet to get everything level and let’s move on.

Step 2: Install a Wheel We’re going to be using a 1/8 scale wheel, so I’m grabbed the 17mm adapter. Install it onto the 4mm balancing shaft, then press one of the two remaining adapters onto the front of shaft, essentially ‘pinning’ the wheel into place. Now press the shaft through the wheel, leaving about 5-7mm sticking out (see the picture for reference). Slide the final adapter onto the backside of the wheel and press it up against the 17mm adapter. Place this assembly onto the BalancePro V2; make sure the shaft sticks all the way through both bearing sets and does not rub against the bearing screws. You may need to adjust the 4mm shaft to get the spacing right. It seems more complicated that it really is; you’ll see what I’m saying once you put it together.

Once you have the wheel on, give it a spin, letting it rock back and forth until it comes to a stop. Take note of this stopping point.

Step 3: Apply the Balance Install a little tab of the tape (or putty) to the high spot on the wheel. Usually this is done on the inside but I did it on the outside so you could see it. Give the tire another spin, watching to see if it rocks back and forth to a stop. The idea is that we want the tire to slow to a stop without rocking back and forth, preferably stopping at different points as well. Continue to apply tape (or putty) to the high spot until the tire slows to a stop without rocking back and forth. This may require a little or alot, it depends on how unbalanced your tires are.

Don’t be afraid to put larger chunks on, you can always remove some tape (or putty) if your balancing is getting out of hand.

Additional Balancing I also balanced a 1/10 scale buggy tire using the same process. This took a little less tape since the tires weigh less and they weren’t all that unbalanced.

BalancePro ZERO As I mentioned before, the BalancePro ZERO uses a little different method of balancing, however the overall process is the same. Once you’ve attached the wheel to the balancer, set it in the groove and give it a light touch. It should automatically start rocking back and forth, showing you just how unbalanced they were. This was a set of pre-mounts and I was amazed at how off they were. Apply tape (or putty) to the inside at the high spot to balance things out.

You’ll get very quick at doing this after the first few tires, but the rewards on the track will be well worth it. It’s also good to note that if you’re one of those that likes to trim your treads to meet the track conditions, you’ll probably want to balance your tires after you do this.

Good luck!

[source: www.gridrc.com]

Balancing Your Offroad and Onroad Wheels was originally published on CompetitionX

[competitionxrc]

What Does "C" Rating Mean on a LiPo Battery

In this entry in our Beginner’s Guide Series, we’re looking into another one of those magical numbers on the outside of every LiPo battery; the “C” Rating.

Simply put, the “C” rating is the cell’s maximum safe continuous discharge rate. Let’s put some numbers down from a LiPo pack for reference: 5000mAh 20C 7.4V (2S).

Before we calculate the discharge rate, we need to convert the mAh to amps. There are 1000mAh in 1amp so, in this case, our 5000mAh pack is equal to 5amps. Now, simply multiply the capacity in amp hours by the packs C rating (in this case, 20C).

5000mAh = 5amps 5amps x 20(C) = 100amps continuous discharge

Using this calculation, you can see we can safely pull up to 100amps continuously from our 5000mAh 20C LiPo without doing any damage.

Let’s check out a few more scenarios:

4500mAh 40C 7.4V LiPo 4500mAh = 4.5amps 4.5amps x 40(C) = 180amps continuous discharge

7200mAh 90C 7.4V LiPo 7200mAh = 7.2amps 7.2amps x 90(C) = 648amps continuous discharge

You can plug in your own numbers from any LiPo pack and to see your safe discharge rate.

Here are two other articles you might be interested in; Understanding LiPo Battery Voltage and LiPo Battery Safety. The LiPo Battery Voltage article is an interview with one of my good friends that works in the LiPo industry. It has a lot of great info on LiPo batteries as well as squashing some misconceptions about this battery type.

Enjoy.

What Does “C” Rating Mean on a LiPo Battery was originally published on CompetitionX

[competitionxrc]

How To: Clean Your Bearings

I’m like most of you; I love getting my ride out in the dirt or mud and having some fun! I always say, though, that even though you spend the day getting your car dirty or muddy, you had BETTER spend the day cleaning your car as well!

Clean cars are happy cars; that is my mantra when it comes to my rides. That brings me to one of the most neglected parts of any RC car – the bearings.

Almost the entire bearing is made of metal, which means if you get it wet, it will rust. Since it’s also has moving parts, if you get it dirty, it will just continually grind the dirt into the metal until it finally fails … and then you have to replace it anyway.

A little maintenance now will save you a headache later as well as a few bucks.

CompetitionX has put together a quick and easy method for cleaning your bearings. It requires a can of electric motor spray (I like Performance Plus 4 from T.A. Emerald), RPM’s Bearing Blaster and, of course, your dirty bearings.

1. Get Ready to Blast

First gather up your dirty bearings. You can do them all at once or only a certain few at a time. RPM’s Bearing Blaster will accept most wheel bearings, diff bearings, steering bearings and transmission bearings. If you need a Blaster that will handle larger bearings, check out RPM’s Mega Bearing Blaster.

2. Prep Your Parts

Since you’re about to spray the dirt out of your bearings, I suggest taking a paper towel and folding it over a few times to act as the liquid catcher. This will keep mom (or wife, or girlfriend) from slapping you upside the head when you get dirty spray all over her table.

3. Blast Away

Set your bearing into the lower Blaster half and dtop the other Blaster half on top. Using the tube that came with your RC motor spray, insert it into the hole and blast away. Use short bursts to help loosen the dirt. You may have to do this a few times on each side depending on how dirty the bearings are.

4. Admire Your Work

Pull the bearing out and check its condition. As you can see from this picture, there was only a little dirt in this particular bearing. I’ve had some that look like they’ve been sitting in mud for years.

5. Just Add Oil

Once you’re satisfied with the condition of your bearing, add a single drop of LIGHT bearing oil. This one drop will lube the bearing as well as help protect it from further contamination.

Now re-install your bearings and watch how much faster you car goes! Just don’t tell your friends your speed secret!

How To: Clean Your Bearings was originally published on CompetitionX

[competitionxrc]

How To: Change Connectors on Your Battery and ESC

One of the ways manufacturers help keep costs down is to supply their batteries and ESCs with inexpensive connectors. On the plus side, these connectors can cost fractions of what the good, high end connectors cost, allowing them to pass that savings down to you. Because these connectors are so inexpensive, it also makes them massively abundant when it comes time to buy additional batteries or upgrade to a new ESC. In addition, most chargers come with at least one type of these connectors.

These connectors can have a pretty substantial downside, however. When powering your RC car or truck, the juice from a battery flowing through the wires to the ESC can generate heat. This heat can cause two problems: 1) The heat is basically wasted power and can be a reason your vehicle seems slow. 2) This heat can melt the connectors, fusing them together and potentially causing a serious situation (ie, fire!).

Changing to a good, quality set of connectors is a cheap way to both reduce heat (providing more power) and help prevent a meltdown that could destroy more than just your vehicle.

In this How To, we explain how to change the connectors on your ESC. The same steps apply when changing the connector on your battery, however you’ll want to take these additional precautions:

1) When removing the connector from your battery, DO NOT cut both wires a the same time. Doing so could create a bridge that WILL create a pretty spectacular spark. Cut one wire, bend it out of the way and cut the second wire.

2) Make sure you attach the wires to match the connnector on the ESC. If you attach them backwards and plug it into the ESC, you’ll be in for a big, smokey surprise when you turn your vehicle on.

For a explanation on the most common connectors in RC, check out this page: Battery Connectors and Balance Plugs Explained

That’s about it, let’s get on with the How To.

1. Tools Required

To change the connectors, you’ll need your ESC (or battery) with the not-so-great connector. You’ll also need a new set of connectors, shrinkwrap (color-coded is suggested), a soldering iron, solder and something to clip the wires with (scissors, side-cutters, hobby knife, etc).

2. A Set of Helping Hands

I would suggest, if you think you might be soldering quite a bit, to pick up one of these Pro’sKit Helping Hands Soldering Aid. This thing works great for holding wires and connectors while soldering.

3. Snip the Tip

The connector pictured is extremely common and referred to as a Tamiya connector, one of the most widely used connectors in RC. Snip that connector off and toss it in the trash. Take your scissors (or hobby knife, or whatever) and trim a small amount of the shielding off of both wires as shown. If you are working on a battery, trim the shielding off of one wire and fold it out of the way before working on the second wire. DO NOT LET THE EXPOSED WIRES TOUCH! If you’re still concerned, wrap a piece of tape over the wire and proceed to the second wire.

4. Prep Your Wires

Tin both wires with a little bit of rosin-core solder as shown. Make sure to coat the wires completely.

5. Check the Connector

All high-end connectors have the positive and negative terminals designated on the connector itself. You want to inspect the connector carefully to make sure you’re solding to the correct terminals. This Deans-style connector has the + and – near the tabs themselves; I’ve highlighted them in black so you can see them better.

6. Tin the Tabs

Apply a small amount of solder to the tabs on the connector.

7. Final Soldering

Slide a piece of shrink tubing onto each wire (I use Reedy’s pre-cut #650 Shrink Tubing). Carefully solder each wire to the new connector, again making sure you attach the red wire (or positive wire) to the + terminal (positive terminal) and the black wire (negative wire) to the – terminal (negative terminal). You can see so far how handy the Pro’sKit Helping Hands Soldering Aid is!

8. Seal the Solder

Slide the tubing down and over the connector terminal and use a heat source to shrink it to size. You can use your soldering iron, lighter or even a hair dryer. Just be careful not to burn yourself.

So there you have it, eight easy steps to change your connectors out. Your electronic system will waste less energy, your car will have more power and your connectors will make you look like a Pro. Great job!

How To: Change Connectors on Your Battery and ESC was originally published on CompetitionX

[competitionxrc]

Understanding LiPo Battery Voltage

Although LiPo batteries have become the norm in RC, a mild explanation of what they are or how they work is not so common. In this article, we’re going to take a look at LiPo battery voltages and how they relate to your car or truck.

LiPo battery voltage is quite different than that in a NiCd or NiMh; that is, a LiPo cell is rated at 3.7v per cell, while the older NiCd and NiMh cells are only rated at 1.2v per cell. As you can see, because the LiPo cells are rated higher, it takes less of them to make up a 7.4v pack (the standard rating for most RC car applications).

Most standard LiPo packs consist of 2 cells hooked up in series; larger packs will have more cells to boost the voltage. A typical, 1/10th scale vehicle (ie, Touring Car, Short Course truck, 2WD buggy, etc), will use a LiPo with the designation 2S, or a 2-cell pack. Packs that are designed to extend capacity will have the designation 2S2P, or 2-cells wired in parallel (instead of series). LiPos constructed this way (in parallel – 2S2P) is a good way to turn less expensive cells (lower capacity, lower C rating) into good performing packs.

Let’s take a quick look at the standard LiPo battery definitions normally seen in surface vehicles: • 3.7 volt battery = 1 cell x 3.7 volts (1S) • 7.4 volt battery = 2 cells x 3.7 volts (2S) • 11.1 volt battery = 3 cells x 3.7 volts (3S) • 14.8 volt battery = 4 cells x 3.7 volts (4S) • 18.5 volt battery = 5 cells x 3.7 volts (5S) • 22.2 volt battery = 6 cells x 3.7 volts (6S) • 29.6 volt battery = 8 cells x 3.7 volts (8S) • 37.0 volt battery = 10 cells x 3.7 volts (10S) • 44.4 volt battery = 12 cells x 3.7 volts (12S)

The number in parentheses (1S, 2S, 3S etc) is the number the manufacturers provide when stating the number of cells in a LiPo pack. This is the standard industry designation; all manufacturers will use this same ‘code’. If your vehicle states that it can operate on a 4S LiPo pack, then you can see from the chart that it can run on a 4-cell LiPo (or 14.8v). Because of the large jump between voltages, it’s not a good idea to exceed that cell count unless you want to damage your car’s ESC (or motor, or both!).

Understanding LiPo Battery Voltage was originally published on CompetitionX

[competitionxrc]

Battery Connectors and Balance Plugs Explained

Battery Plug Designations

NiMh and NiCd batteries were pretty easy to charge and use; hook the clips up to the positive and negative terminals and hit charge. There were no balancing ports (except during discharge) and we didn’t worry too much about overcharging; the chargers did a great job of keeping track of the pack’s condition.

LiPos, on the other hand, require a bit more during the charging process. Not only do you have to make sure your charging plug is correct but, ideally, you want to make sure that you have the right balance plug as well (you are balancing your LiPos, aren’t you?). Since there isn’t really a standardized plug, you could have one of several different types of plugs attached to your pack. This can be confusing, but thankfully CompetitionX is here to give you the lowdown on the most common connectors and balance plugs on the market.

There may also be a chance that you have several different balance ports on several different batteries. This can be problem when charging unless you purchase several different balance boards that match the balance plugs you have. There is an excellent solution, however. You can pick up one of Hitec RCD’s Universal Balancing Adapter. This balance adapter (or balance board) works with all the major brand of LiPo batteries and can charge from 2S-6S packs. It also has ports (in the 2S-6S range) for JST-EH, Thunder Power, JST-XH and Hyperion (or Polyquest) plugs! I have 3 of these and absolutely LOVE them!

Below is a list of the most common connectors and balance plugs on the market right now. Hope this helps.

Balance Plugs

JST-XH Plug

JST-EH Plug

Polyquest Plug

Thunder Power Plugs

Battery Connectors

Traxxas Connector

JST Plug (AKA Mini JST)

Deans Connector

Tamiya Connector

EC3 Connector

HexTronik XT-60 Connector

Links www.hitecrcd.com www.wsdeans.com www.traxxas.com www.tamiyausa.com

Battery Connectors and Balance Plugs Explained was originally published on CompetitionX

[competitionxrc]

LiPo Battery Safety

Learn from our mistakes before you make yours!

I consider myself a pretty knowledgeable RC enthusiast/racer. I’ve raced at every level of competition, driven everything from 1/18-scale to 1/5-scale motorcycles and travelled all over just to play with toy cars. I’ve worked with NiCd, NiMH and LiPo batteries and been around every form of brushed and brushless motors. Even with this kind of resume, things still happen that can be considered a ‘newb’ move.

A couple months ago, I had a LiPo battery catch fire while working on one of my cars. I did everything right; used a high-end charger, had it set on the correct mode, positive lead to positive plug on the battery and had a balance board correctly connected. Even with all this, it still went up in flames and burned my race-ready Tamiya F104X1 into a pile of molten plastic. Thankfully I was able to get it out the back door before it burst (which it actually did as I was throwing it out…arm hair doesn’t smell very good), but this made me think about getting a real experts opinion and sharing with you my experience.

I contacted my good friend Ling. He worked in the product development department of a company that deals with medical devices. During his time there, he was in charge of developing a wallet sized device that was designed to vaporize liquid insulin. For those of you that don’t know, this type of device requires a ton of power in a tiny package. His research led him to the understanding of battery construction, failure analysis and audits of many battery manufacturers. To say that he has some knowledge of LiPo batteries is an understatement. After he heard about my LiPo woes, he contacted me and we had a chat. We decided that this was probably a good time to clear the air about LiPo batteries and this little interview is the result of that chat.

TONY: Ok Ling, what exactly is inside a LiPo battery? How similar is it to the older NiMH cells?

Standard LiPo Battery

LING: A LiPo cell is a classic battery construction. It’s composed of an anode, a cathode and a separator. These components are inside the aluminum pouch and it’s filled with a liquid electrolyte. Oddly enough, the “Polymer” in modern Lithium Polymer cells refers to the electrolyte – which isn’t a solid polymer at all. The anodes are composed from a copper foil current collector coated with a fine particle graphite slurry. Most cathodes are composed of a LiCoO2 (lithium cobalt dioxide) coated onto an aluminum foil current collector. There are some other mixtures that they throw in there, but for the most part – it’s LiCoO2 based. The polymeric separator does just that, it physically and electrically separates the anodes and cathodes.

Surprisingly, RC LiPos are the exact same chemistry used in your cell phone or laptop. There is a tradeoff between Li-Ion cells: high energy vs. high power. Laptops and cell phones fall into the high energy category and RC LiPos fall under high power. The difference is really just the architecture of the cell.

The high energy type of cell generally uses a single anode/cathode pair with a separator between the two. This sandwich is generally rolled up in a “jellyroll” format to create either a cylindrical cell or a prismatic (rectangular) cell.

The high power type of cells are made of a multitude of anode cathode pairs. This is a stacked cell configuration. A typical LiPo is composed of 20-30 pairs of anode/cathodes. The separator is either a “Z” shaped accordion or a spiral wrapped between the anode/cathode. Think of an RC LiPo as a whole bunch of smaller cells where all the anodes are all welded together and all the cathodes are welded together. The actual thickness of a one Lithium Polymer cell (typically under 10mm thick) is actually limited by the number of anode/cathode pairs that are ultrasonically welded together. If there are too many parts of anode/cathodes, the ultrasonic weld will fail.

TONY: Good to know about the high energy vs. high power. Guess I won’t be hooking up a 6500mAh 65C rated battery to my iPhone. Speaking of that, what does the C rating mean?

LiPo Compatible Charger

LING: Technically, it means the relative charge and discharge capability. For simplicity, take the capacity in amp hours and multiply it by the C rating. So for a 5 amp hour battery, 1C = 5 amps, 2C = 10 amps etc. The discharge C rating is the maximum continuous discharge rating that a cell can handle. There are no industry standards which define when a cell fails a C rating, whether it’s the number of cycles, ending temperature, capacity, etc.

In the RC world, the C rating means next to nothing. I can pretty much guarantee you that just about every RC LiPo would self destruct when discharged at the C rating on the label unless it’s a short burst. For a 5000mAh battery, a 40C discharge is 200 amps. A complete discharge at 40C would last exactly 1.5 minutes There is absolutely no RC application that dumps the battery in just 1.5 minutes. A genuine Deans connector starts melting at 80 amps continuous – a fake Dean fails at even less.

TONY: Well, I always figured some of those numbers were a bit exaggerated. I’m assuming sticking to a quality, brand name battery is probably the best way to get an accurate C-rated pack. Other than that, is there any way to determine a quality pack vs. a cheap pack besides price?

LING: For the average consumer, it’s very hard if not impossible. High quality packs are distinguished by higher safety and abuse limits, higher cycle life, better cell to cell consistency, longer shelf life etc. Higher quality cells have higher standards for incoming material inspection, more in process inspection (high pot testing, X-ray detection of stack etc), and generally a much cleaner production line that limits the amount of impurities that can enter the cell. Once the cell is pouched, pretty much all cells look alike (high quality vs low quality) on the outside. The raw cost of a cell from a high quality manufacturer can cost about 4X more than a cell with the same specs from a low end manufacturer. Any high quality pack WILL cost more to produce, however, all expensive packs are not guaranteed to use high quality cells.

TONY: So, as far as LiPos go, it can be a ‘get-what-you-pay-for’ situation. Are there any benefits to hard cases vs. soft cases?

LING: Absolutely! Remember the copper anode and aluminum cathode layers I mentioned before? They are separated by a very thin polymer. A dent (especially along the edges) will cause the sharp edges of the copper and aluminum to damage and start eroding away the thin separator. This is exasperated by the naturally expansion/contraction of the battery during charge and discharge. Eventually, the eroded hole will lead to an internal short circuit. Best case, the cells short out internally and no longer hold a charge for an extended amount of time. Worst case, the short builds up temperature and leads to thermal runaway – ie. fire. So yes, absolutely, hard cases are beneficial.

TONY: Good to know…I’ll be placing all of my soft-case packs in a case! Hard-case packs from here on out! Let’s talk about charging them. Are there any basic charging guidelines?

LING: There is not much to it. Almost all chargers follow the standard CC/CV charge profile pretty well. With higher charge rates (like 2C and above), there is almost always a big drop in cycle life associated with it. The exception is Lithium Phosphate (LiFe), which does very well at higher charge rates, but those aren’t too common yet…

TONY: So stick with the standard charging guidelines as far as charging amps?

LING: For LiPos, I’d recommend charging 1.5C or under with a charger designed specifically for LiPos.

TONY: A question I’m sure everyone wants an answer to…is it necessary to balance a LiPo pack every time you charge it?

LING: This is a loaded question. For a high quality 2S pack (7.4V), it’s highly unlikely that the batteries will ever need balancing. For higher cell counts, 3S and above, it’s a good idea to balance charge. For cheap packs, it’s always a good idea to balance charge.

TONY: Well, for the sake of safety, is it a problem to balance LiPo packs regardless of their ‘supposed’ quality?

LING: Balancing is an insurance policy. It prevents a cell from getting overcharged. Overcharging is a surefire way to get a LiPo cell to erupt into flames. Unlike NiMH or Ni-Cd, Lithium Polymer batteries cannot tolerate or absorb any overcharge.

TONY: What does it mean when the battery pack looks puffy or bloated?

LING: It just means that the electrolyte has started to break down. A lot of things can cause this: over-charge, over-discharge, over-heating, cell contaminants, internal corrosion, poor material purity, etc. It takes very little liquid to form a whole lot a gas. Unfortunately, puffing is very bad. The anode/cathode layers are vacuum sealed in an aluminum pouch. This vacuum seal helps prevent the anodes/cathodes from shifting around and shorting out on each other. Once puffy, the vacuum is gone and the cell is much more likely to internally short out and, as mentioned before, an internal short may lead to fires.

TONY: So, let’s say I’m going to take a short RC break. Are there any good storage tips?

LING: Shelf life is largely determined by temperature. A rule of thumb is with every 10 degrees, the C is double the degradation rate, so keeping the cells in a cool spot is the good idea. Also the cells like to be partially charged – usually between 20-80% of full. A fully charged cell stresses the internal chemistry and degrades the cell much faster. Think of it as compressing an overstressed spring – if you hold the spring momentarily, it pops back in shape. If you hold it down for a long time – it tends to take a set.

TONY: So a springy LiPo cell is a bad thing. Check. Well, I actually have a few puffy cells here that I’ve been hanging on to for, ummm, whatever reason. What is the correct procedure for destroying a LiPo pack?

LING: I’ve read about the salt water type disposals. The salt conducts and drains the battery; the water is there in case there is a fire. That will work just fine, but I think it’s cumbersome and overkill. Personally, I just discharge the cell at a low amperage rate, usually as low as I can get it. You can run it in your RC car, but I would turn off the low voltage cutoff. You definitely want to go well below the LiPo cutoff. A drained battery has no stored energy. A cell with no stored energy cannot ignite.

TONY: I’m assuming you’ll want to run it at a slow speed so as not to stress it out? I’d hate to have ANOTHER car catch on fire as I do this.

LING: If you have a discharger, I’d use that and a LiPo sack. This way you don’t have to risk a RC vehicle. A discharger can easily take down the energy in a LiPo. If you don’t have a discharger, you can run it at low speeds to bleed off the stored energy, though there is still a little bit of risk.

TONY: Ok, well, that should just about do it. Thanks Ling, I appreciate your time in helping with this article.

LING: No problem buddy, I’m here to help. Just let me win the next time we race – OK?

TONY: You got it!

WRAP-UP As you can see, there’s quite a bit going on with LiPos but, if used correctly, they are just like any other cell. I’m sure there are a TON of other questions that could be asked so, in the name of safety, I will be answering any additional questions you might have about LiPo battery safety on this web site.

LiPo Battery Safety was originally published on CompetitionX

[pixelpolitics-blog]

…with a surprise!

Do your Wednesdays feel joyless and empty now Parliament’s in its summer recess? Does 12 o’clock pass without event, leaving you deflated and depressed?

Prime Minister’s Questions is every political nut’s favourite time of the week and we all deserve to enjoy it whenever we...

[oatmeal]

Dear Tumblr

If you’re going to go down, you might as well blame it on an imaginary animal like Twitter did with their infamous Fail Whale. I’ve taken the liberty of creating this animal for you:

Please use it. 

Please oh please. 

-The Oatmeal

Update:  Tumblr used the TumblBeasts!  Check it out :D

[conorwhelanwork-deactivated2012]

An illustration for the 2011 Trinity Ball Magazine

[nefffy-deactivated20120318]

Nobody tells this to people who are beginners, I wish someone told me. All of us who do creative work, we get into it because we have good taste. But there is this gap. For the first couple years you make stuff, it’s just not that good. It’s trying to be good, it has potential, but it’s not. But your taste, the thing that got you into the game, is still killer. And your taste is why your work disappoints you. A lot of people never get past this phase, they quit. Most people I know who do interesting, creative work went through years of this. We know our work doesn’t have this special thing that we want it to have. We all go through this. And if you are just starting out or you are still in this phase, you gotta know its normal and the most important thing you can do is do a lot of work. Put yourself on a deadline so that every week you will finish one story. It is only by going through a volume of work that you will close that gap, and your work will be as good as your ambitions. And I took longer to figure out how to do this than anyone I’ve ever met. It’s gonna take awhile. It’s normal to take awhile. You’ve just gotta fight your way through.

Ira Glass (via nefffy)

[competitionxrc]

Review: Tamiya TA05 VDF Gold Edition Drift Car

Living in Southern California, you are exposed to quite an array of motorsporting events. Indy and GT-cars, short course, drag racing, motorcross and, of course, drifting. I’ve driven drifters before (well, SCALE ones!) and even built one for a project, but nothing prepared me for the uber-coolness that Tamiya’s Gold Edition VDF has. Carbon fiber and gold-anodized aluminum are everywhere in this kit, and its front-ish motor and twin belt design provide the optimum balance for drifting. While I’m sure I have the skill to drive the full size versions (uh, ya), I was pretty excited to get behind the wheel of this baby for some slide-time.

[competitionxrc]

Helion Animus 18TR

The second Animus platform derivative (after the Animus 18SC), the 18TR continues the next generation of 1/18th scale performance with an unprecedented set of features and value. The premise behind the Animus is to offer something revolutionary: value AND performance. Helion R/C design engineers optimized the Animus platform for the latest generation of bashers and enthusiasts.

[competitionxrc]

Review: TrakPower RC TK-950 Soldering Station Review: TrakPower RC TK-950 Soldering Station

When you mention the words ‘soldering iron’ to someone, most people think about the cheap, $15 setups you get at the local hardware or electronics store. I know I did when I first started this sport. But I soon found out that those $15 units were junk and couldn’t compare to the high-end soldering stations that were on the market. But, at a price tag upwards of $250, it was a bit out of reach on my low-end budget.