Sunday, November 30, 2008

Harnessing the BugE

It's much easier getting to the inside of the cowl when the BugE canopy is on a table. So, I wanted to pre-wire the cowl in a detached state.

On my first wiring attempt, here were the features I wanted:
  • The ability to wire the cowl of the BugE separate from the chassis to minimize the time I would be bending down while assembling the vehicle.
  • An isolated and reliable DC-DC converter with extra capacity for expansion.
  • A back lit speedometer with status lights for turn signals, HiBeam & brake.
  • An external charge strategy to allow quick change from grid to solar power.
  • Keeping the convenience of a one-plug charger while managing battery imbalance. (using PowerCheq modules)
POST CONSTRUCTION NOTE: This is NOT a guide on doing 12v wiring quickly or inexpensively! Rather, it was exploring the issues I ran into when I finally decided what wiring features I wanted. Several states appear to be fine with the default lighting layout and no changes. However, New York State is a bit more fussy so I re-wired the 12V system (here and here) to comply with the more rigorous NHTSA requirements. Still, it might be worth a read since it discusses why I decided to put the components where I did. Also, some components in the Blue Sky kit such as turn signals and tail lamp did not have the proper DOT markings on them. Most places don't apparently care but New York State did. This may have been fixed but it's probably a good idea to verify the kit lights now have the proper markings.

During this time, there was a great deal of debate in the BugE discussion group of either going for a DC-DC converter from the main battery pack, tapping one battery from the battery pack for 12V lights, having a separate 12V battery entirely for the 12V system with it's own charger or charging a smaller accessory battery from a 12V-DC-DC converter. I decided to go for a simple but nice DC-DC converter for the following reasons

1) No "stranded power" If I went with a separate battery, the 12V battery would either be too small and underpowered or too large and I would be hauling around extra weight.
2) Tapping off a 12V battery would lead to battery imbalance. Range would always be limited by the weakest battery.
3) Mounting a 12V DC-DC converter was much easier than trying to find a place to mount a larger 12V accessory battery.

That decision plus the decision to mount the speedometer on the handle bars (rather than in the dash) , the desire for accessories and finally, headlight placement, drove my first 12V wiring attempt.

I decided to connect the cowl wiring to the controls with molex type connectors so the handlebar controls can be easily moved out of the way for service. I decided to use connectors between the cowl & chassis. This would allow the cowl to simply be plugged in when mated to the chassis.

Pictured here is the first version of the handle bar control system that I considered. This is pretty close to the layout finally settled on for my first tests. The "handlebar" is simply a 1/2"x18" black pipe available at any hardware store.

Of course, just to make things confusing, at my hardware store, "black pipe" is measured by the inner diameter. I found that this type of pipe has an outer diameter of about .84 inches. This is really close to the outer diameter of a 7/8" bicycle handle bars (.875 inches). So, I saved quite a bit of money using plain black pipe rather than using an expensive polished chromed bar that my bicycle shop was offering.

The handlebar clamp is a short-neck type that sticks down a 7/8" (inside diameter) pipe that came with the kit. The clamp was a surplus item on sale at my local bicycle shop. I've been told that straight style handlebar clamps in that style are falling out of fashion so getting another one may be a bit of a search. The controls are arranged such that there should be just enough room for the wiring harness, brake lines and handle bar grips while still hopefully being ergonomic. Since the pipe was a pinch too small in diameter, a few wraps of electric tape on the pipe were used to increase the diameter slightly for the turn signal controls and thumb throttle. The other items had various types of screws that allowed them to be tightly secured to the bar.

In the image of the controls, the lower loop is just three wires that go from the thumb throttle to the DC speed controller. Although there is a male connector on the end, a female end was not provided so the wires will be connected to the speed controller differently. The middle wire bundle is for the turn signal / lights /horn control on the right. It comes with a female 9-pin connector which plugs into the male end of a wiring harness (provided in the BlueSky kit). The upper wire bundle is for the speedometer/odometer unit. The wires with black connectors are for the sensors (provided with the speedometer kit). Other wires are for turn signal indicators, fuel level, neutral status switch, brake, hi-beam and other optional status signals the meter can display.

This is a photo of the motorcycle harness for the controls that came with the kit. For my first attempt at wiring, I tried modifying the harness in the kit rather than building one from scratch. Some wires need to be lengthened to reach where they need to go. Others will be attached to a second chassis molex connector that will allow me to easily attach/detach the controls from the main chassis. Being able to attach/detach is more for ease of assembly than for maintenance. However, if I should need to take off the whole canopy for a maintenance operation or for transporting, it will be nice to have less steps to deal with.

This wiring harness will connect the canopy to the rest of the BugE. It provides 12V from the rear mounted DC-DC converter and 48V for the battery meter. It also passes back a pair of wires for the horn which will be mounted on the chassis on the side of the battery pan.

The instructions do not cover how to connect the speedometer. Since there is such a variety of units, this lack of guidance is understandable. For example, my speedometer has several status lights on it that probably would not be on a simple unit. Normally, such a unit would go on the dashboard since it's much easier to tap into the wire harness there. Since I was undecided on final ergonomics & features, I decided to put the meter on the handlebar assembly. However, there is a significant cost to this decision that I did no realize at the time. Since the canopy lifted up, I figured that a wiring harness would be nice to extend the length of the speedometer wires and allow the handlebars to be detached should the BugE need servicing. These steps could have been avoided if I mounted the meter on the cowl and tapped into the wire harness from there.

Parts required:
-male,female connectors
-40ft coil of 18 gauge wire
-2ft wire wrap
-European style bus bar

To the right is an image of my temporary stand-up soldering station. The handlebar is held on the shelf with "C" clamps so it doesn't fall. A bright light is on the left so parts and colors of wires can be seen easier. The wire diagram for both male and female connectors is on the wall. A "helping hands" device is also held to the shelf with a "C" clamp. Shown just under the wires is the plastic housing and pins that will form the female connector. Perhaps the most important item in my opinion is the wall mount fan that sucks out rosin core fumes to the outside. Originally, it was put there to suck out sawdust from a saw that used to be there. It didn't work very well for the saw, but such a fan works beautifully for a soldering station!

Here is the wiring diagram of the 12 pin connector used with the speedometer wire bundle. Deciding what pins go where was arbitrary. Each wire was 30". The excess wire is coiled up on the wiring shelf in case it's needed later. I wired all wires including ones I'm not using such as oil pressure or water temperature just in case. They might be handy for something else later. for example, I wired up the tail light to the "hazard" indicator so I can tell the stop lamp is energized when I'm braking.

After the female end is assembled, it is time for the male end.
For the male end, I decided to go to a European style bus-bar simply to keep track of what wires go to which pin. Wires are being kept long (30" ea) so mounting options remain flexible. Pin1 is marked on the European connector with marker. The speedometer kit came with some crimp on connectors so tapping into the main harness will be done that way for now.

-8-32 screws & nuts
-drill (for mounting holes in shelf)
-"L" brackets to mount 48V charge meter & fan switch*
*fan switch was recycled from switch that came with the headlights. 48V meter is provided in EVparts BugE electric kit.

Since I'm reluctant to poke holes in the dashboard at this point, I've made a small shelf using some bent "L" brackets and a short section of aluminum to hold the fan switch, charge meter & wiring bundle. The forward "L" bracket is from the bolt that holds on the headlight. The rear "L" bracket is from the mirror. The mirror "L" brackets will now be used to hold up a strip of aluminum I'll be using for a temporary shelf. Eventually, when I decide on accessories, I may finally drill holes in the dashboard to give a finished look. Originally, I was going to use all four "L" brackets to hold up a shelf for wiring & chargers. However, this is no longer needed since the charger and DC-DC converter will now be mounted in the tail.

After the first shakedown cruise, I'll be adjusting placement of these components. For example, the speedometer may move to the dashboard. The analog 48V charge meter will eventually be replaced with something digital and the rocker switch for the fan will be mounted to the dashboard rather than remain on the shelf. Finally, the wiring assembly will be removed from being zip tied to the temporary bar and hidden under the dashboard using screws & zip ties (perhaps such zip ties could hang on the rear of future panel mounted instrument bolts) .

For 12V power, I decided not to use the smaller DC-DC converter from EVparts, Item #DC2415. This component came as an item from the "Deluxe BugE kit" offered by EvParts. Normally, it is sold separately for $35. Since it's non-isolated, there is a potential to fail closed & send 48V through the 12V section. This problem could probably be solved by adding a small 12V battery and a fuse so a 48V surge could be absorbed by the battery in time for a fuse to blow should a failure occur. However, I didn't want to deal with having another 12V battery to manage.

Fortunately, Dan Bushee who is another BugE builder, suggested a 25 amp Sevcon DC to DC Converter from EVparts for $225 Item #DC2430. My hope is that this electronic box will provide reliable 12V power and at the same time negating the need for having a separate small 12V battery. However, there is a problem with this unit. It's large. So, the only place I found for it that made sense was in the rear shock-hump shelf. Mounting it was done by making an "L" bracket mount with some then drilling 4 holes and attaching to the shelf with (6) 1/4-20 x 3/4" screws & nuts

Originally, I was also going to install two 48V-4A chargers in parallel, mounted in the tail to charge the battery pack (since that's what came with the EVparts kit). However, a friend of mine, Jeff Ekross, pointed out a problem with this idea. Unless the chargers have some communication between them (which mine don't), one charger would tend to work really hard and the other will not since it will not overcome the electrical pressure provided by the first charger. So, while using two chargers might be desirable from a reliability in case one fails, it would not decrease charging time much. So, I really only need one charger.

So, the problem seemed to be: Where do I mount one of these? The original locations for the chargers are being used by the reversing switch and the DC-DC converter. So, the solution I came up with is to not mount a charger in the bugE at all! Rather, I will be using a DC CHARGING PORT off the side of the BugE. If I decide I want to carry a grid charger with me, I can just stow one in the cargo area.

This not only solves the space problem but has other benefits as well. One benefit is that I can now see the charge indicator light on the charger to show at a glance that my BugE is ready to go. Another benefit is that I can quickly switch between grid power and solar power just by plugging into the connector. The connectors I've ordered are available at:

Mounting the rear blinkers was rather easy. Draw pencil lines parallel to the rear headrest area & intersect with 2" vertical line from lip. Then, drill with smaller drill bit & work up to width of blinker bolt. If the blinker isn't facing the rear enough, a Dremil could be used to modify the plastic seating to angle the blinker. Once the hole is there, push the wires and mounting bolt through, then secure with the provided nut.

At first, it looked like this would be an easy job. I had the tail light, brackets & all the nuts. However, since all the holes in the little stack of brackets I'm using are just a hair short of accepting a 1/4" bolt, I needed to whip out a drill, bit, vise and oil to expand the holes slightly. Then I felt that one end of each 6" bracket was too long so I trimmed with a grinder. Cut off parts are shown in the photo. However, I later found trimming the tail light bracket was not a necessary step. Also, two wires go out from the lamp socket. A crimp-on spade connector needs to be added to the wiring harness to attach to the body of the lamp for a ground.

Time tasks (to nearest quarter hour)

Prepare the speedometer connector (molex on end of speedometer box) - 1 hour
  • Prepare speedometer tap wires (molex on end of blue wire bundle) - 1 hour
  • Install wiring shelf - size strap stock, attach to "L" brackets, drill some mounting holes for 48V meter, fan switch & places for securing wiring via zip ties - 1 hours.
  • Bend "L" bracket, drill holes for DC-DC charger & mount - 30 min.
  • Drill rear blinker mount holes & install blinker units - 15 minutes.
  • Rear tail light - Make lamp assembly (but not install), should take 15 minutes if properly sized "L" brackets are available. For me, this task took much longer since I needed to drill out screw holes & shortened bracket.
  • Research, pondering & blogging about it - around 17 hours, non continuous.
(1) DC-DC 48 to 12V converter (EVparts kit - not used)
(1) turn signal control EVparts kit
(1) thumb throttle control - EVparts kit
(2) brake handles BlueSky electric & control kit
(1) tail light from BlueSky electric & control kit
(1) 48V external charger from EVParts kit. Second charger not used.
(1) Speedometer & handlebar clamp included in the speedometer kit

Parts used not included in either BugE kit, EVparts kit or speedometer kit:
  • Bicycle handlebar clamp
  • Black pipe for handlebar
  • (2) mountain bike handlebar grips
  • Aluminum stock for wiring shelf / "L" brackets / 8-32 screws & nuts.
  • Fan switch (recycled from the headlight kit) & 8-32 screws & nuts.
  • Sevcon DC-DC charger
  • Scrap metal for "L" bracket for DC-DC converter & (6) 1/4-20x3/4 bolts & nylock nuts
  • (4) 12pin molex style connectors from Radio Shack (2male & 2female)
  • European bus bar (not essential, but it was handy for keeping track of wires)
  • 3-pin DC charging port & connectors
  • solder / heat-shrink tube / matches / electric tape / medium zipties
  • (8) Small "L" brackets for headlights/mirror/tail light assembly
  • (2) Large 6" - "L" brackets for tail light
  • (8) 1/4-20x3/4 hexbolt & nuts to secure 6" bracket to back of BugE.

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