I decided I wanted some kind of mode of transport for mostly short journeys, like from the house to the train station, from home to school and back for the school pick-up. Yeah lazy I know but I want it to be fun too!

The board above is the one that I ordered online (eBay) for a steal! and is the one that's going to become a power board...
FYI, I was amazed at the quality of this board for the price! Most longboards start at around £100 for a decent board, but this one was just £35!! and glides along as smooth as a Gillette Mac 5! (or whatever they're up to nowadays, I don't know 'cause I don't shave any more!) soaking up all the bumps the extremely bumpy pavement down my road could throw at me.

Below are some specs of the board:

• Deck length: approx 104 cm (41")
  
• Deck width: about 25 cm
  
• Deck: 9 ply maple wood (9 ply maple)
  
• Deck-top: black grip tape
  
• Total height: about 12 cm
  
• Castors material: PU (Polyurethane)
  
• Castors Ø / Width: about 7 / 5 cm
  
• Hardness 85A
  
• Bearings: ABEC 9
  
• Axles material: Aluminum
  
• Axis mounting: Drop through
  
• User weight: recommended rider weight up to 85 kg
  
• Max. load: up to 100 kg

If you're going to make your own powered longboard, you really only have to worry about a few things...

1. The wheels need to be a minimum of 70mm diameter, preferably 80mm
2. The wheels are made from PU (polyurethane) and are no harder than 85A
3. Your motor has a low enough KV rating to haul your fat ass
4. Your ESC (Speed Controller) has a high enough AMP rating for your batteries

The reason for the diameter stipulation and for the material the wheels are made from is basically so that it'll glide down the road or on the pavement with ease and not get stuck in any cracks or get snagged up on variations in height of paving slabs.

I started by doing a whole load of research... Some long nights! If you search for 'electric longboard' on YouTube, you'll find a myriad of vlogs from people who've powered their own boards either from kits or a custom bespoke hand-made system.

Thanks to those videos I've been able to use the best features from all the different electric longboards and am now aware of all the pitfalls I may have encountered should I not have done my research first.

I'm not trying to take anything away from those guys powering their own boards, but almost every one was very poorly finished with perhaps some poorly made wooden boxes to house radio & electric gear, or Tupperware boxes screwed to the underside of the board, or even just strapped down with some aluminium, and motor mounts that are extremely rough and look unfinished, and that's just too ugly for me. So I'm setting out to make my powered board as 'pretty' as possible and as close to a shop bought electric longboard as possible. I'm basically testing out my engineering skills.

Thanks largely to an accumulation of tools over the years and more recently my awesome Dad for lending me some of his, I'm able to stretch myself technically in an attempt to produce something hopefully exquisite!

I decided to go with a chain driven power train, rather than the more common method of a toothed belt and two pulleys. The reason for this was strength and durability. Lots of people who'd built their boards already complained that sometimes the belt slipped, or snapped or that it ran off the pulley, and I didn't want that so a chain and sprocket was the only way for me.

I found a great company on the web (after an exhaustive search), who supply all sorts of different steel sprockets and chains, there's a link to their website at the bottom of this paragraph.
I chose a 6mm pitch steel chain sprocket for the motor and the hub, (no need for any bigger), and a tiny little 6mm pitch chain to connect it all up with. You literally only need a few inches of chain but they only sell it by the metre, but they're really inexpensive, so you can't complain. 

The size of chain and sprocket you'd need is 04B and the pitch is 6mm, oh and simplex (single) not duplex.

Source: http://www.technobotsonline.com/

Here are the (from left to right); pinion (goes on the motor), main drive sprocket (on the wheel) and chain.

These are the sprockets I ordered:

As you can see from what I ordered (above), I  paid to have the pinion tapped with an M4 grub screw, but they didn't do it.

Below is a diagram of how the electric motor will be connected to one of the wheels via a small chain.

I placed the sprocket on the wheel (once I took it off) to offer it up, the hub of the sprocket wasn't quit big enough to make the outside diameter of it sit far enough away from the wheel to accommodate the chain, so I found a couple of 30mm x 1mm (8mm bore) washers which did the trick and fit perfect!

Whilst waiting for all the other components to arrive, such as the motor and speed controller etc. I thought I'd get started with fitting the collar to the axle and the under-try to the underside of the deck, which will house all the electrics.

Here is the collar. It was only £11.50 (link at the end of the paragraph), and arrived quite quickly. It's made of stainless steel. Now that might be a little overkill, but I couldn't find an aluminium one so this had to do.
The one I bought has turned out to be a little bit too small so I've linked to the one the right size for my trucks, but yours might be different, luckily they do all sorts of sizes. Needless to say I had to modify mine slightly to get it to fit properly and actually as an added benefit of this slightly odd fit, it kind of eats in to the truck when it's clamped, so it's got great grip and shouldn't need a locating pin to keep it from sliding.

Source: http://simplybearings.co.uk/

Here's what I had to do to make it fit the shaft of my truck. Basically I just shaved off a small amount of the inside edge of the collar on both sides of each half to allow it to have a larger bore using a milling bit in the drill press.

Once that was complete, I moved on to clamping the collar to the axle. For this the axle needed a little modification because there was part of a brace getting in the way of the collar sitting flat and at a 90 degree angle to the axle itself. I offered the collar up and eyed where I needed to grind the metal away to make way for the collar as you can see in the photos.

Once complete, it looked pretty good and was ready to take the motor mount!

Here is the tray. It is in fact just a simple drip try for a flower box! This was the shortest one I could find. To be honest I could get away with one half it's size and in fact, I'll keep my eye out for one to replace it with, but for now I'm going with this one... (fitting a smaller one will be a doddle). If you see the last photo in this series, this is how it will sit underneath the deck to house all the electrics.

I thought about running some bolts vertically down from the underneath of the board which poked out the bottom of the tray to secure it with nuts, but then I didn't really want something metal poking out so much, just in case it got snagged on something, it may damage the board or get burred and then I wouldn't be able to get the nut off easily.
So I thought about it and decided to go with an internal angle bracket, screwed to the bottom of the board, drill holes in the side of the tray and then screw bolts or some kind of finger tightening screws in through the tray and in to the brackets on the inside, to keep protrusion to a minimum and to be more pleasing aesthetically.
See the series of photos below on how I did it.

I started by marking out where the brackets needed to go on the underside of the board...

I knew I needed to make four brackets exactly the same, so I made up a crude jig to bend them all to the same angle...

Then I needed to grind down a few screws I had because they were too long and would've protruded out the top of the board... drilled pilot holes and screwed in the brackets...

 

Once all four were on the board, I drilled holes in from the side, inline with the existing holes in the brackets and then screwed in four M4 bolts to secure it.

I think you'll agree, it doesn't change the profile too much or look too ugly. I think it's quite aesthetically pleasing if I do say so myself. I'll swap out those bolts before completion for four the same and probably ones that I can finger tighten easily, although, I shouldn't be needing to get in to the electronics very often once the board is complete because there will be connectors for battery charging and a power switch mounted nicely from the inside facing out.