Building a Lightning Powered Murder Board – Part 3

In this third installment, we’ll be discussing ESCs, motors, remotes, enclosures, and batteries.

Electronic Speed Controllers

ESC(s), or Electronic Speed Controllers, are a topic that we could discuss for days and still not get anywhere useful. Its a topic alive with politics and marketing half-truths. Let’s just stay on topic and talk about the most common ESC(s) that are used in the esk8-verse and go from there.

Most VESC type ESCs, including the FocBox, have some characteristics in common. The all have phase leads and sensor leads that connect to the motor, have a power input connector, support PPM/PWM for control, use CAN bus to combine multiple VESCs into a single system and have a UART header for integration of Bluetooth and other alternate control methods.

The most used ESC brand/model is the Enertion FocBox, and for good reason. It’s based on the VESC, is well built, dependable, and small. As of this writing Enertion is no longer selling the FocBox in favor of the upcoming FocBox Unity, but I expect a new version or variant of some type to be released any day.

You can normally buy FocBox(s) at any of the following websites, although some may be out of stock at this time.

A relative newcomer to Esk8 is FlipSky. They make good quality controllers that are inexpensive and easy to install. Its a good choice for new and/or cruiser builds. They have a large lineup of VESC based ESC’s, I’m going to narrow it down a bit for you based on what I have used and know works.

Make sure that if you buy the FlipSky Dual 4.20 that you get the Plus version, it performs better and has less issues than the non-Plus version.

TorqueBoards has been selling their version of the VESC, the TORQUE ESC BLDC Electronic Speed Controller, for a long time. I’ve used many of them in my builds. They are a great low dollar option for entry into the Esk8 arena.

There is a plethora of other VESC based ESC’s available, including VESC 6 & 7 versions. I have listed the ones I use and that I know to be reliable, but feel free to experiment and try new things.

Motors

Motors are another wild frontier when it comes to Esk8. There are expensive motors that are seemingly well built and high performance that are actually nothing but junk. There are relatively inexpensive motors that seem like “base models” but are actually pretty bad ass. What makes this situation eve worse is that those positions can change places in a matter of days. The key here is not what motor you buy, rather who you buy it from. You can do weeks of research yourself or you can buy your motors from a reputable vendor who has experimented and tested until they were comfortable with the resulting motor.

I am going to touch on ‘profit’ for a minute here. The 1st comment I always hear when discussing motors is “but I can get them from Alibaba for half the price!”. By all means, do it. You might end up with a brick in bag, but you saved 20 bucks right…that was sarcasm in case you didn’t pick up on it.

There’s a million ways to save money, but if you want quality gear then buy from quality vendors. They are making some money, a lot less than you’d think, but they are providing you with a known level of quality, performance and reliability.

Here’s some motors that I like, I’m confident you will as well:

I am partial to 6374 motors, I like the extra mass to keep them running cool which also delivers more torque, especially useful in a single motor build. Unfortunately they do not fit on standard Caliber 2 trucks in a dual mount configuration. For this you will need 6355’s, they are smaller and easier to work with.

Lastly, you can buy motors that have sensors or not, sensors are useful but not necessary. If your motor is sensored you have the ability to run it in
sensored FOC mode which is quiet and has a nice startup roll at the expense of a little top end. For our purposes we will be running in BLDC mode, as FOC has some inherent issues that can cause hardware failure at the ESC.

Remote

Remotes are plentiful and readily available. The only real choice is which one do you want, so I will refer you to another article entitled Esk8 Remotes: Garbage or Greatness! to help you decide.

Most remotes have a few thing in common. They typically use the 2.4 GHz band and use PPM/PWN and/or UART for control. Most available remotes are decent, some are absolute garbage, so do your research. The Maytech V2 or the FlipSky Nano are reliable and inexpensive choices.

ENCLOSURE
Enclosures are both incredibly easy and terribly frustrating all at the same time. Here are some individual steps that you need to take to find the correct enclosure for your build…

  1. Measure your wheel base, if it’s approx 26 inches, then your max enclosure size (assuming forward mounted motors) is 22 inches.
  2. Assuming you are using an ABS enclosure, use a block of wood or foam approximately the size of your internal components and clamp the enclosure, at the edges and in multiple spots. Use a heat gun, sparingly, to fit the edges of the enclosure to the surface shape (said concave and camber) of the deck.
  3. However many screws you want to use to secure the enclosure to the deck, use more. Also inserts are a plus but get stainless steel as brass inserts will shatter under stress. You can easily spread the load of the enclosure on the screw heads by using fender washers.
  4. Self adhesive foam insulation, like you use to weatherproof a house door, is a great method for making sure an enclosure has good seal against the deck.

Battery with switch, voltmeter, and charge port

If you want to deep dive into batteries I encourage you to check out ESK8 IQ. Its a 3 part series that delves into the math and science behind esk8 theory, production, and building.

Batteries are a challenge all their own. For the sake of this tutorial we will discuss 10s batteries. You can use 12s battery packs reliably, they are just larger and a little more difficult to work with. They are also insanely fast, so for 1st time builders 10s is typically a better fit.

You will need to take dimensions into account. A Samsung 30Q Lithium Ion cell is 18.4x65mm, with the addition of nickel strip and heat shrink as well as other materials used in battery pack construction you can safely use 25x75m (or 1×3 inches) per cell. Also remember to account for BMS dimensions in the total pack size.

A 10s4p battery pack will average around 20 inches, plus the BMS. If using a charge only BMS you can locate the BMS on top of the pack to keep the length down, but you will need to add about 3/8″ on top. If using a full size BMS, your total pack length will be around 24 inches. You can see how this gets complicated very quickly. I would suggest using a charge only BMS, if you do this you can easily fit the complete battery pack and x2 ESC’s in a 24 inch enclosure.

Voltmeters are handy little guys, you can instantly see how much battery you have left and it’s a quick indicator that the system is turned on. Make sure you add the voltmeter leads after the Anti-Spark switch, XT90-S loop key, or whatever you are using to power on and off the board.

You have to have a charge port, the type of port you use will be dependant on the type of charger you use. Most people use a 5.5×2.1mm waterproof charger port. Most chargers use the the same dimension counterpart.

Charger

My first and last piece of advice about chargers is don’t be that guy that bought a $12 piece of shit charger that broke on day three and is always borrowing yours. Buy a quality charger! A junky charger will likely damage your battery which can in turn damage every powered component in your esk8.

There are lots of really good quality chargers available, most of which are only available from China so be patient. A couple of things to look for when shopping chargers are an aluminum body, cooling fan and replaceable fuse. If the charger you’re thinking of buying doesn’t have those features then start over, it’s junk.

If you want something more local (and you’re in the US) look at this 36v 4a mini charger and this 36v advanced features charger, both. Both are from Luna Cycles and are for 10s battery packs (42v max, 36v nominal), but have XT60 connectors so you will need to solder on a new 5.5×2.1mm DC pigtail. It’s a pain but both chargers are worth the trouble. If you want to find something less expensive, search eBay or Amazon for “10s BATTERY CHARGER”, but don’t say I didn’t warn you.

OK, i just want to say one thing in closing. There are bound to be 100 things I’ve missed telling you about. Most of them are unnecessary but some I just plain forgot. If there is something important that I’ve missed please alert me to it, with links if possible and I will include it ASAP. I bring this up now because Part 4 is gonna be a monster. We are going to take everything discussed up to now and combine it into making an esk8, otherwise known as a Lightning Powered Murder Board.

Check back, it won’t be long. It’s not like you read this whole site already, right?

Mike Maner

Mike is a systems/communications engineer and a dad to 4 kids as well as being a member and forum leader of the electric skateboard building community.Mike is NOT a traitor, screw a damn unicycle!*shakes head in confusion at Damon thinking "why man, just why?"

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