Scooter Rebooted Pt. 2 – Heavy Duty Controller Heatsink

January 6, 2013

HS12 1600

A custom, copper heatsink and mount are bolted to the baseplate, extending it to the rear to accommodate the larger, 18-FET controller

Parts

  • 4 pieces of – 100 X 260mm 0.3mm copper sheet
  • 3 pieces of – 60 X 260mm 0.3mm copper sheet
  • One piece of – 60 X 220mm 3mm copper sheet
  • One piece of – 60 X 220mm 0.3mm copper sheet
  • 6 3.5mm countersunk head bolts

Having upgraded both the hub motor and the controller, I thought I’d take the opportunity to incorporate a custom heatsink into the rear mounting plate. The current 1500W hub motor is basically maxed out now, with the 16-FET controller more than enough to give it all it can take (about 4KW), so the controller doesn’t run very hot at the moment, but in order to clear an upgrade path for a more powerful hub motor, as well as address an issue with mounting controller that’s too big for the baseplate, I decided to design a heatsink custom made to maximise contact with the controller casing.

HS03 1600

Most controllers are either 180mm or 210mm from end-to-end of the baseplate. This one, though is 260mm, and as you can see from the picture above it overhangs the baseplate by 50mm or so. My solution to this was to build a heatsink that would also double as an extension for the baseplate. By stacking cut pieces of thin copper sheet of alternating width and bolting them firmly to the base, I get good wide fins that help with heat dissipation. The air being funnelled to the controller area, and the good thermal contact with the base plate should both help draw heat away from the controller.

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Below you can see stage one of the heatsink which acts as the main base for the controller.

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As any of you who have dabbled with controller will know, however, the controller casing has an odd recess underneath that prevents most of the controller case making good thermal contact. Only the brackets at the end, and a section of case running the length either side make contact with the baseplate when the controller is mounted. The recess is about 3.2mm, and I had two special pieces cut to act as a seat that would allow the base of the casing to make near-complete thermal contact with the heatsink.

Below you can see the main item, a 3mm thick slab of copper, and a thinner 0.3mm sheet of the same size that brings the plate almost flush with (actually about 0.1mm proud of) the controller base.

HS05 1600

The tricky bit in mounting this on top of the first stage of the heatsink is to do it in such a way that the heads of bolts are sunk so they are flush with the base of the controller case. Any bolt poking up will stop the case from making good thermal contact.

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After some fiddling with different drill bit sizes, and very gentle drilling I eventually ended up with a second stage plate with six suitably  recessed bolt holes.

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HS08 1600

Finally, six corresponding holes were drilled through the heatsink base sheets and the baseplate. From the underside, you can see both parts of the heatsink now firmly bolted to the baseplate. I cut off the excess lenghs of these bolts with a grinder. You can see how the heatsink adds the extra required length to the baseplate from below.

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The finished product! A nice big heatsink that doubles as a lengthened baseplate for the controller.

HS11 1600

HS12 1600

A final touch before mounting the controller was to remove some instructional stickers that were on the base. Thus, the aluminium of the base sits directly onto its heatsink mount.

HS13 1600

And there you have it. A solid heatsink that helps keep things running nice and cool. You can see a thermocouple I attached so I could monitor its performance. The most striking difference is that though the controller still gets warm when thrashed, it cools down much quicker, with the rate of cooling directly proportional to how hot it’s getting. Definitely a must for people who like to push their controllers to the limits.

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Installing a Speed Control Switch

August 15, 2011

Three-way Speed Control Switch

N.B.: This upgrade is only suitable for bikes with “infineon” type controllers with an EB-206/212/218 board, such as the LYEN Edition Controller and  eCrazyman controllers. Check that your controller type supports speed control settings before going ahead with this upgrade! You will also need the USB/TTL programming lead and software that enables you to program the controller settings.

The Switch

The first thing you need is a suitable three-way switch. A handlebar-mounted, three-way switch exists specifically for this purpose and is now available from my shop. Other similar switches are available from various China-based vendors.

The custom, three-way switch, available here

To fit the switch, you remove the throttle control by loosening the alan bolt that secures it, and sliding it off the handle. You then slide the switch onto handlebar so that it sits next to headlight switch mounting, and secure it by tightening its alan bolt. The throttle is then slid back into place to its right and similarly resecured.

The switch is connected by a good length of cable to a standard three-way mini connector.

To feed the cable through to the rear of the bike, I removed a side panel to route it through to where it was within reach of the controller, using cable ties to secure it.

The Controller

At the controller side, the EB-type boards support three speed settings, which can be set via the Parameter Designer software that is used to program the controller. The speed settings can be found in the “Speed Mode” panel on the right of the settings screen. Three speeds – Speed 1, 2 and 3 – are listed which are all set to 120% default. Modifying these enables you to customise the amount of power that is delivered by the controller in response to throttle movement.

In effect, lower speed setting values decrease the throttle sensitivity, making it so that more rotation of the throttle is required to deliver a set amount of power. In addition to letting you set up an ‘economy mode’ which restricts the amount of power you use, it is also hand for creating a ‘low-gear’ for manoevering at low speed. This is particularly handy if you are running at very high current and voltage, which can make the throttle twitchy and oversensitive.

The Parameter Designer Screen

The key to rigging up a three-speed switch is understanding how the EB board sets its speed mode at a hardware level. The way it does this is fairly straightforward. There are two terminals on the PCB, X1 and X2, which are simply shorted to GND (battery bank negative) to set the controller’s speed mode. Shorting X1 to GND puts the controller into Speed 1 mode, shorting X2 to GND selects Speed 3 mode, while leaving both of these terminals un-shorted keeps it in the controller’s defaul Speed 2 mode. Effectively the bike is always running at the Speed 2 setting, unless it is told to do otherwise by wiring up a switch to short X1 or X2.

In terms of the physical layout of the connector attached to the switch, it looks like as below. The black wire goes to GND, while the green and red go to X1 and X2 respectively.

Adding a Connector to the Controller

The main part of the job that needs to be done is to add a connector to the controller. To do this, the case needs to be dismantled and the PCB carefully removed. The X1 and X2 terminals are clearly marked and simply need a couple of suitable, small guage wires to be soldered to them, These wires can then be fed through the end of the case by threading them through the hole with all the existing wiring. A two-way mini connector can then be added and the case re-sealed.

The EB-212 board seen with the X1 and X2 terminals (here with wires soldered in place)

This is the final arrangement on my bike. A two-way connector feeds through to X1 and X2 on the controller board via grey and purple wires. If you wanted to use a GND (battery bank negative) connection from within the controller, rather than somewhere else on the bike, you could have an extra wire here and use a three-way connector instead. I chose to only run wires for X1 and X2 from the controller, and found a place elsewhere on the bike, to earth the GND wire directly from the switch itself.

The X1 and X2 connector for the speed control switch.

The only thing that remained for me to do was to assemble a short length of cable to join the three-pin male connector from the switch tothe two pin connector I had wired up to the controller. The remaining GND wire was routed to a connector on the loom that served the negative terminal of the main battery bank.

Try it out!

This done, it’s simply a case of programming your controller with suitable speed settings. For testing purposes you should make sure that the settings are far enough to be clearly noticeable when you switch modes. I set mine to 40%, 70% and 120% for Speed 1, 2 and 3 respectively.

You can test it on its stand easily enough by holding the throttle open a set amount and switching between modes. If you’ve got it right, the motor will slow and speed up accordingly.


Shocking…

April 19, 2011

The Ego Scooter with its new, beefed-up suspension

Over the course the last few months, as much as I’ve enjoyed scooting around on an increasingly powerful and nimble bike, one thing that always bugged me was the shaky and bone-jarring ride quality. Some of the road  surfaces in my neighbourhood are in a pretty dismal state of repair, and it seemed that every bump, crevice and pothole would make the bike shake or lurch around drunkenly. The suspension always struck me as limp and wallowy, and yet – oddly – it also did a good job of transmitting road vibration through the handlebars, up my arms and through my teeth. Finally weary of this I took a look at the rather feeble shocks on the bike and considered that, though adequate for pootling along at 25 mph with the smaller, 48V battery bank, it might not be up to the job of charging around at nearly 50 mph with 48 kilograms of batteries on board.

So as I passed my local bike shop recently, I thought I’d drop in and ask the staff there what my options were regarding upgrading the spindly looking affairs currently there with something a bit more substantial. The guy from the bike shop duly came out to take a look at it for me. He asked for the keys, unlocked it, bounced the bike up and down a bit and declared the rear shocks to be knackered. Only the springs seemed to do anything, the hydraulic-type piston didn’t seem to have any discernible effect at all. When I told him that that’s the way they’d been from new, he just said they were obviously rubbish, then, which I had no problem believing given the manufacturer’s tendency to keep prices rock bottom by using the cheapest parts they could get their hands on.

The Scoota’s original shocks – not really up to the job anymore

This said he said he could order a decent set fo £50. I knew I could probably get them cheaper if I researched them and spent a while trawling the internet, but I have less time nowadays and a bit more cash, so I thought I’d just leave it to him.

A none too swift ten days later, I was the proud owner of a new set of MDI brand shock-absorbers. They werereassuringly beefy looking, with a sparkly, chrome and gloss-black finish. They didn’t look much like the one pictured on the box’s lid, but I wasn’t at all bothered about this because I much preferred the on that was actually in it.

The box with its almost-nothing-like-it photo

As you can see below, the new shocks are quite a bit more substantial, with a solid, thick, hydraulic slider that is in stark contrast to the spindly assembly it replaces.

The new MDI shock absorber, next to the original, factory unit

One minor difference that I had to accommodate, though, was the fact that the bushes in the rubber mounts both had wider, thinner sided bores that would require a thicker bolt. For a brief, disappointed moment I thought that this would be a show-stopper for fitting these, as the bore on the corresponding bike brackets needs the original bolt-size. However I quickly realised that the bushes – with a little help – would pop right out of the thick, rubber gaskets surrounding them. Lo and behold, the ones from the original suspension would slide snuggly back in in their place, leaving me with a perfect fit for my bolts! 🙂

The new, larger bushes can just be slid out,and replaced by the smaller bore, thicker ones that came with the original suspension

It was only a half-hour job to remove the old ones and fit the new ones. They’re attached – top and bottom – to the frame by a simple, thick nut and bolt, and my ratchet socket set plus a spanner made short work of it.

All done, and looks great!

As soon as the bike had finished it’s home-from-work recharge, I eagerly hopped on board. Straight away I noticed a differencein that the whole bike didn’t simply flop three inches onto its soggy springs. It sat firm, and with its rear an inch or so higher  – another boon since the ride height was all the better for my six foot frame!

Taking it for a spin over some of the less hospitable surrounding roads, I was delighted to see that it’s handling was much more steady and firm. I was concerned that the stiffer suspension might make the vibration even worse, but clearly the “ISO 9001 certificate” that the box proudly announced did actually mean something, as the ride quality was substantially improved. It had a more solid, ‘big bike’ feel now, was much more sure of itself over uneven surfaces, and the wallowing and lurching was all but gone. Road vibrations, were much softer now, and the lack of bone-jarring harshness to its protests as it negotiated the rougher patches was a blessed relief!

I really couldn’t be happier with this upgrade, and think it’s worth every penny of the money I spent on it. If your suspension pistons are as rubbish as the ones that originally came with my own Scoota, then I’d strongly recommend taking care of this if you plan to upgrade – or already have upgraded – to 72V and/or a more powerful controller. The original suspension, I think, was barely fit for purpose for the bike in its 48V form. With the added weight incurred by an upgrade, and the higher speeds it has to contend with, I’d almost call this upgrade a “must”.

For the benefit of anyone looking for these, it’s been brought to my attention that they are available at the time of writing (and cheaper) from here, where they are referred to as “chrome shock absorbers Suzuki A50 Moped 71-76“.

However make sure that they give you the right size! – The length you need for the Ego Scoota should be 310mm., however an owner of the UK Eco Scooter (which is very similar) reports needing 335mm ones. It’s best to measure these to make sure your replacements match the originals (you take the measurement from the middle of one hole to the middle of the other).



Adding a Controller Pre-charge Switch

February 20, 2011

The Controller Pre-charge Switch: Protects the breaker-switch and controller from damage from sparking at switch-on

Parts

Tools

  • A crimper
  • A pair of wire snippers
  • A soldering iron and solder (optional)
  • Epoxy resin glue

 

So what is this for?

If you’ve been following my blog, you’ll know that I recently had to replace the breaker switch which began misbehaving a couple of months ago, and then completely conked out shortly after I put in a bodge to keep it going.

I originally assumed that the reason it broke down was that these switches were simply not designed for regular use, and that they would mechanically wear out fairly quickly if used with any frequency. However I subsequently heard a totally different explanation from members of the Electric Motoring Forum, and one which was to have implications for the way that the breaker circuit should be set up.

The reason was indeed to do with the fact that these switches are designed for a slightly different job, but has nothing to do with mechanical wear and tear alone. It turns out that while usage of these on an AC circuit poses no problem at all, DC voltages of any magnitude result in a pretty brutal spark every time you turn the thing on. Hence the loud “crack” that can often be heard whenever the switch is engaged.

The spark generated by the DC – particularly on bikes that have undergone the 72V upgrade – will, with constant use, quickly burn out the switch, or – even worse – damage the capacitors in the controller and send it to an early grave. Though a replacement switch is not expensive, modifications to the replacement and an extra hole in the mounting plate is often required to make it fit. In addition, the switch is awkwardly located, and dismantling the bike to get at it can be a tedious and time-consuming job.

Failures of the breaker switch that comes with this bike are therefore quite a common nuisance about which users frequently complain, but, as usual, more electronically literate forum members such as Mike have come up with a clever workaround that avoids this problem, and thus allows people to use this main cut-off switch without fear of damaging it or the controller.

How it works

The way it works is very simple. Usually when the breaker is switched on, power is rapidly drawn by some big capacitors in the controller (which is why there is a big spark and that ‘snick’ noise as it engages). The capacitors are charged almost instantly and ‘equalised’ with the supply voltage whereupon the current flow stops again just as quickly.

But the initial, sudden ‘jolt’ is what causes the problems. To avoid this, a switch and power resistor are connected in parallel with the breaker switch (that is, wired between the front and the rear contacts of the breaker switch). Before engaging the main breaker, this switch is activated, which allows current to be slowly drawn into the controller over a few seconds. Once the capacitors are fully charged, the main breaker can be switched on without any problems (as the voltages are now equalised). The pre-charge switch can then be reset until the next time that the bike needs to be turned on at the breaker.

This ‘soft-start’ to the controller’s main power supply is a great way of protecting both the breaker switch and the on-board capacitors, prolonging the life of both and preventing failures.

Building the switch assembly

Building the assembly is an easy job, requiring only two cheap components, a couple of bits of wire and a pair of spade connectors. It took me less than an hour to make a nice, tidy job of building one, and that was even with taking snaps as I went along. The main components are the 7W, 1000Ω resistor and a small ‘slim-line’ rocker switch (I got these from Maplin for under £2).

A couple of bits of red wire, a pair of spade connectors and some wire sheath for the resistor legs are required to put it together.

Just for good measure, I also stretched out some short lengths of heat-shrink, to cover the bare metal of the spade connectors. I removed the original plastic covers so that I could solder mine as well as crimp them, for a nice, secure connection.

First, I made a wire that would go from the rear of the breaker contact to one terminal of the rocker switch:

I used the red sheathing to cover the legs of the resistor and soldered and crimped one of them to the other spade connector. This will connect to the forward breaker contact.

Connect these to the switch. I’ve connected mine up so the ‘on’ position of the rocker will point the rearwards, like the breaker switch.

Next, you install the finished assembly, connecting it to either end of the breaker switch. You’ll need to remove the seat to access the breaker.

Once fitted, you can test it by reconnecting the batteries and attaching multimeter probes across the ends of the breaker switch (make sure the breaker and pre-charge switch are both in the ‘off’ position). The meter should read somewhere in the region of 72V with the capacitor fully discharged, depending on the charge state of the batteries. If the meter reads less than that, then the capacitors still have charge in them. They can be discharged by turning on the ignition for a few seconds, whereupon you should see the voltage rise and then settle at the proper level.

With the multimeter still in place, you can now turn on the pre-charge switch. The voltage should drop (exponentially) towards zero over the course of ten seconds or so. You can then engage the breaker switch, whereupon the remaining voltage will drop straight to zero. At this point, the pre-charge switch can be turned back to the ‘off’ position.

You can see the results of this test on my YouTube video.

The final assembly: The pre-charge switch is glued to the side of the breaker

Once you’re satisfied that everything is working fine, you can secure the switch to the side of the breaker, or whereever else you want it. I just used epoxy resin to glue it to the side of the breaker.

And there you have it! An excellent little safety feature that should prevent breaker burn-out and even extend the life of your controller!

Acknowledgements: Thanks to Mike and Flexy for the explanation and component details for this fix.


Building a Battery Header Board

October 18, 2010

The Battery Header Board – A handy way of accessing the terminals of the Primary Battery Bank

Parts

Tools

  • A crimper
  • A pair of wire snippers
  • A soldering iron and solder
  • A sharp blade, like a Stanley knife
  • A hacksaw
  • Epoxy resin glue

Battery Balancing

SLA battery banks that are connected in series and then charged via a 48V, 60V or 72V charger (depending on the number of batteries) are not always charged evenly, and when the bike is used, the batteries do not discharge evenly either. This is due to discrepancies in the quality of batteries used. With constant use, and over numerous discharge/recharge cycles these discrepancies become magnified and the charge in the batteries fall out of balance, with some cells having a higher charge level than others.

If the bike is not used very often, and is periodically charged to maintain the the batteries, then they will – over time – naturally self-balance. But if the bike is used frequently, especially on a daily basis, then the batteries will gradually fall out of balance. An un-balanced battery bank means impaired performance, as a serial battery bank is only as good as the charge of its weakest cell. Batteries will therefore periodically need balancing, which means charging them all individually with an ordinary 12V charger to bring them all back up to their peak charge.

Because of the poor accessibility of the bike’s primary battery bank, though, this can be a tedious job. The seat assembly must be removed, and the securing cross-bar on top of the battery bank needs to be detached to allow better access to the terminals. Furthermore, if the bike has been upgraded to 60V or 72V, it also means detaching and removing the extra battery or batteries that sit on top of the original bank.

It’s a nice idea, then, to have a convenient way of accessing the terminals of the battery bank by routing a series of small gauge feed-wires from the terminals of the bank to a suitable board. I’ve spent some time coming up with an elegant and safe way of achieving this via an eight pin connector which sits under the seat, and which can be used to monitor battery voltages, and – if necessary – enable individual cells to be recharged without the need for dismantling the bike.

The principle is very simple – to extend leads from each battery terminal to a suitable assembly – but the actual work is quite fiddly and time-consuming. This is something for a rainy day or two, or else – like I did – to break up into little stages to do in your spare time over the course of a week or two.

Building the Battery Cable

The first stage is to build a cable that runs from the battery heads to the female side of an eight way connector that can be mounted in the underseat storage compartment. I’ve used 10 amp figure of eight cable, which is solid enough to carry a charge current (and even to power things off of), but flimsy enough to act as a fuse if an accident happens and the terminal heads get shorted.

First, you need four lengths of the cable. About an 450mm (18″) length of each should suffice as it doesn’t need to run very far. I’ve split this off at the end into two 75mm (3″) lengths, just far enough for the separate wires to reach the terminals of each battery. For good measure I put a bit of heat-shrink at the junction of the ‘Y’ in the cable to secure it.

Next you need to crimp the connectors onto the ends. I’ve used more heat shrink here, and also soldered the crimp for added strength, as it’s important that these don’t work loose.

The final strand of each connector looks something like this:

And here’s all four of the assembled cables that are ready to be combined into one tidy, larger one.

I’ve used a larger bore length of heat shrink, here, to tie all the cables together.

The other ends of the wires are crimped to the spade connectors that comprise the female side of the eight way connector.

The end result looks like this. Once checked for continuity, it can then be hooked up to the bike’s battery bank.

While you’re attaching them to the batteries, use a continuity tester, again, to check which pins of the connector each battery correspond too, and note it down. That way you can know exactly which battery you’re dealing with. This is helpful if you’re running your 12V battery system or other interfaces (such as a car accessory socket) of a particular battery, and would like to keep track of which is which. Here’s the cable in situ, with its connector rigged up to the battery bank.

The Cable in situ, shown connected to the terminals of two of the Batteries

I’ve cut a small rectangular notch by the hole for the extra batteries here in my 72V arrangement, leaving enough space for the wires to sit comfortably, but making it small enough to keep the connector anchored to the top-side of the underseat compartment base so it can’t fall through. It’s also loose enough pull through a small amount and manoevre into the right position to connect to its male couterpart.

Once this is in place, you already have a useful header that can be used to take voltages, and even to recharge with a basic cable. But I’ve gone the whole hog and put together a posh looking board – complete with template – that can plug into this and be used to directly clip one or more 12V battery chargers onto.

Building the Battery Board and Cable

When I cut a hole in my seat for the 60V and 72V upgrades, I put aside the bits of plastic I cut out in case they came in handing later. One of these was just right for me to fashion a little board for my external connector heads. Mine was 160 x 70mm (2¾ x 6¼”) , but you can make this any size you please. Just bear in mind that it’s desirable if it can fit in the space alongside any underseat batteries you have, but shouldn’t be so small that the terminal heads are in danger of being shorted by any clips that you hook onto them. That would make a bit of a mess out of your fuse-grade wiring.

To accomodate the terminal heads, I simply melted holes at set intervals (about 38mm, here) with a soldering iron, then cut off the goop with a craft knife. You could of course just drill them instead.

For the terminals themselves, I opted to make mine from scratch from a piece of copper plate. I cut out little 28 x 8mm plates with a hacksaw, in which I’d pre-drilled holes to thread the wires through prior to soldering.

If you don’t want to go to all this trouble, then you could just use some bolts, and secure them to your wires by sandwiching them between a couple of nuts on the board’s underside. That was my original plan, but in the end I went for this deluxe solution.

I wasn’t happy with the 4mm holes I originally drilled, so I drilled smaller, 2mm ones closer to the end. The old holes were eventually hidden in the layer of my plastic board, so only the new, corrected holes showed round the back. I made my holes small enough so the connectors were a tight fit, then I used epoxy resin round the base where they connected to glue them solidly in place. Be careful not to get any glue on the connector ends where the wires go, as you need to solder them.

Below is the board shown from the underside, with the little (new) 2mm holes showing where we can thread and solder the cable wires.

The next stage is to hook a corresponding set of wires to the other (male) side of the connector. Your wires can be as long as you need them to be to reach the corresponding heads on the board, but I cut each pair to correspondingly longer lengths to help me keep track of which pins I wanted to go to which terminal heads.

I took more pictures this time, so you can see what I was doing to wire in the pins.  I assembled short lengths of heat shrink that the wire would go through prior to crimping the connectors onto the male pins. I also used little 5mm bits of thick copper wire to reinforce the small wires’ connection to the relatively large crimps.

Here I’ve just crimped them, and am about to add a bit of solder to reinforce the connections.

Next, the solder.

Then I push the heat-shrink up into place and warm it with a lighter to give a nice solid seal.

The pins then go into the connector, in the order of their corresponding terminals on the header board.

And finally, the finished cable assembly:

I’ve added another thick gauge piece of heat-shrink to wrap all the wires into one short stump of cable, but you can make this trunk as long as you need. I was content with just a short length as I wanted the board to just sit by the connector in the underseat compartment.

Next, I glue the neck of the cable to the board and reinforce it with a strip of – also glued – insulating tape. Then the wires are cut and stripped to the right size, threaded through the holes at the base of the terminals, then soldered in place. Then I run two other strips of insulating tape along either sides of the boards base, covering the soldered connections.

For the final step, I’ve beautified the assembly by adding a template to slide over the terminal heads and sit on top of the board, which can then be glued on if needs be. It’s a pretty illustration showing which terminals of which batteries the header points connect to.

Tip: You can print the template image to any dimensions you want from the printer ‘options’ or ‘properties’ dialogue of your software. Under the ‘features’ tab, in the dropdown options for paper size (or elsewhere if you’re not using Windows), there should a ‘custom’ option where you can specify the exact width and height of the printed image. You should make the image slightly (2mm or so) smaller than the board to make room for a border if you laminate it like I did.

Next I printed out and cut out my template before putting it through a laminator. I also cut out the holes in the template first, so that the edges of the holes would also be nicely laminated.

Finally, the laminated piece is cut to the right size, and holes made for the terminal pins.

And voila – a handy, professional-looking battery header board for all your battery checking and maintenance needs!


Removing the Rear Wheel

October 2, 2010

Removing the rear wheel is a little more complex than removing the front wheel, but is still not particularly difficult or time-consuming. It shouldn’t take more than half an hour to remove, and maybe a little more to put back on again.

The main issue with the rear wheel of an electric bike is that this is where the motor is located, and a cable runs from it and back to the area behind the seat where the breaker, connection blocks and controller are all housed.

You can see the end of this cable below, where the phase wires and hall sensor connector come out and meet up with their respective connectors.

The first thing to do is detach the hall connector plug, then unscrew the phase wires from the connector block so that you can free the cable with the wheel. There may also be a cable tie further down that you will need to cut off.

Before we can tackle the nuts and bolts securing the rear wheel, you’ll need to remove those plastic panels that obscure the bike’s innards to the rear. They’re held on by two little screws. Take these off and put them aside. You might want to take this opportunity to give them a good wash, as this is where road muck tends to gather.

You can see below how the cable is run alongside the left side of the frame, and secured by a couple of cable ties. You’ll need to cut these. You can replace them with fresh ties when the wheel is back on again.

Next you’ll need to deal with the assembly that secures the main shaft of the rear wheel to the bike. On the left side of the bike, two large nuts – the inner one flanged – sit side by side. To its left is a retainer bolt which will have to be fully removed. This will allow the shaft to slide out of a slot in the bar. Loosen off the nuts, and remove the bolt to the left.

The arrangement on the right side is more complex, as this is where the rear drum brake assembly resides.

You’ll need to detach the arm of the brake drum from the brake-cable actuator by removing the nut at the bottom from the end of the cable. Next take the little cylindrical gromit out of the end of the brake lever and put it back onto the cable end, re-securing it with the nut. That way the arm will be detached, but all the bits will be together  in one place when it comes time to refit the wheel.

You’ll also have to remove this bolt that secures the drum brake assembly to the frame.

Finally, as on the left side of the bike, loosen off the nuts and remove the forward retaining bolt.

The whole thing – rear wheel, drum and axle – should now freely slide off the slots that hold it in the frame.

To refit the wheel, you just do all this in reverse. However, be careful to ensure that the cable is correctly routed along the outside of the frame (and re-secured with fresh cable ties) before you reconnect the hall sensor and phase wires.

When refitting the wheel, you’ll also notice there’s some free play either side, where the axle can slide one way or the other. To make sure the wheel is on nice and straight, it’s a good idea to take a ruler and measure the distance of the axle either side from the end of the bars into which the ends of the axle are seated.


Adding a Car Accessory Socket

August 19, 2010

A nice feature for any vehicle to have is a power socket. The classic ‘cigarette lighter socket’ is practically ubiquitous in cars, and accessories based on this fitting are widespread. Anything from phones to sat navs are equipped to use it as a source of power. It’s also handy for running a small compressor to put air in your tyres.

The Car Accessory SocketIncreasingly useful in our Gadget-cluttered World

Parts

Tools

  • A drill with a 25mm bit
  • A pair of wire snippers
  • A crimper or needle-nose pliers

This is very easy to do. The only issues are with the practicalities of mounting the socket in a suitable position, and running cable to a suitable source of power.

1. Choosing a Site

I decided to mount mine in the lockable ‘glove compartment’ box, as obviously it should be weatherproof and reasonably secure. The clear choice here was either the left or right recess.

A quick look under the front-wheel recess shows that the horn is directly in front of the left recess, and may risk getting hit by the drill-bit. The space behind the right recess is a little more roomy and easier to reach and work around.

2. Drilling the Hole

The first thing to do is to drill a hole. The hole actually needs to be 28mm if you’re using the connector I list, but a 25mm drill can suffice, as the plastic is soft and the hole can be easily ground larger with the bit.

3. Connecting the Cable and Mounting the Socket

Next, you need to prepare your connecting cable. Crimp the spade connectors to one end of the figure eight cable, then thread the connectors through the hole and plug them onto the terminal heads at the back of the socket. Once this is done, thread the big plastic nut that comes with it up the wire and into position behind the compartment. It’s easier to reach this area if you turn the wheel hard right so the forks are out of the way.

The socket can then be pushed through the hole and secured from the back of the compartment casing by the nut. It’s a good idea to use a large rubber gromit or some silicone sealant here to prevent water seeping through the join during bad weather.

It’s also a good idea to tape the cable to the inside of the bodywork to keep it clear of the forks.

4. Connecting the Cable to a 12V Source

Next, the cable needs attaching to a 12V source. It might seem logical to simply attach it to a live 12V wire in the nearby instrument panel loom, but the problem with that is that this will only be life while the ‘ignition’ is on. I suspect that most people, like myself, will want to be able to charge or power things without the keys sitting in the ignition.

So I have opted to thread the cable to the last battery in my (currently 60V) bank, where it will be available as ‘always-on’. This may raise battery charge-balancing issues with frequent use, so you should occasionally balance your batteries as a matter of course to keep them at peak performance.

I’ve run my cable alongside the existing main wiring conduit along the left side of the bike, so that it emerges into the battery bank under the seat. You can remove the side panel by unscrewing the bolt and screw securing it at either end and releasing it from its retaining clips.

Cut off the wire at a suitable length, attach the ring connectors, and secure the end of the finished cable to the terminals of the battery of your choice. In my case I’ve opted for Battery No.5 of my 60V system, as I charge this battery separately anyway and use of the socket won’t throw it out of balance so easily.

Remember – the positive terminal of the socket (marked on the plastic) goes to the positive terminal on the battery.

And there you have it: A ready power socket for all your rechargeable doodads and other accessories!