This is an account of how the conversion is going. The plan is to use as many
parts as possible from a 1999 Suzuki Swift (including mounting points) and
to create a light-weight frame onto which aerodynamic bodywork panels can
be attached.
The goal is to create a driveable road-legal prototype that proves that the
aerodynamics design is viable, and that the vehicle can achieve reasonable
speeds using the PMG226. It would also be nice to meet the weight target of
350kg, but due to the weight of the Suzuki's suspension and steering
assembly that might not be possible on this prototype.
This will be the first prototype, as an important learning curve. The
second prototype will most likely involve the use of an Aixam or Ligier
Microcar, as the parts for those cars are designed for 400kg vehicles:
the Suzuki's parts, including suspension, are designed for a 750kg vehicle
(which will make for a spectacularly bumpy ride, as well as being overkill).
23 May 24 May 25 May 26 May 27 May 28 May 29 May 30 May
01 Jun 02 Jun 03 Jun 04 Jun 05 Jun 06 Jun 07 Jun
08 Jun 09 Jun 10 Jun (Break for a bit...) 16 Jun
With one of the doors on it's finally possible to work out where the mirrors are going: directly *behind* the tops of the front suspension, with a tunnel over them to give the illusion of bulk and form and to smooth the airflow. The reason why the position of the mirrors hadn't been decided is because it is very tricky to gain direct line of sight to the rear of the vehicle. In the CAD/CAM drawings the line of the door along the length of the vehicle rose up from front to rear: that hasn't happened in the prototype - instead the line is pretty dead flat, such that the outer air box on each door will be underneath a direct line of sight from mirror-height, over the back wheel. The only thing that is now slightly tricky is where to place the lights. The MSVA document states that rear indicators must be a minimum of 250mm off the ground (and stop lights a minimum of 350mm), with a minimum of 600mm and 500mm between them, respectively. So that leaves quite a lot of places they can go, which is good.
Arse! The welder has packed up. I had already had to redo the cables, both on the croc clip as well as the electrode holder. That's fine - it's annoying but to be expected. What was *not* ok was opening up the welder and finding that the thermistor was no longer sitting in contact with the coil via thermal paste, and these hard blue bits (with thumb-prints on them) had come off. As I can't find the multimeter right now I can't do tests, but when switching it on and then off the transformer gets warm, so the primary coil is clearly working. Darn it - there's not enough components in a transformer-based welder to actually go wrong: it's not like it's comprised of moving parts or anything (ok, actually the transformer does move quite a bit if you know anything about iron core electromagnets...)
Ok, I gave the details about the welder to SIP and they are kindly arranging
collection and generally sorting it out.
So, that done, it was time to get some expensive bits. I phoned
canev.com and spoke to a very nice lady,
Bonnie. They're kindly going to check against electricmotorsport.com's
mechanical drawings for the Zero-X MARS motor (which is a slightly RPM-uprated
version of the ME0708, apparently). The adaptor required is the
Geo Adapter and it looks like it'll be the 8in version.
Motor and Controller, I chose the motor from the
Zero-X Motorbike
because the volume of sales of this bike has pushed prices down so much that
companies like kellycontroller.com have stopped selling comparable units!
So I picked the
Electric Motor Sport Zero-X Kit
because it comes with cables, controller, Potentiometer, small circuit for
the thermistor (that's already attached to the MARS EMC-R "Zero-X" motor):
all in all it's just an easier option, and the power? Well... it's not going
to be spectacular: the EMC-R is rated at 6kW (but can be pushed to double
that for short durations, hence the reason why the thermistor is so important).
My main priority is to get the vehicle moving, and to find out how close the
design is to the expected aerodynamic efficiency.
Next will be the batteries - I've chosen Headway 10Ah cells, because they can
actually be found in the UK because they're typically used for electric
bicycles. The continuous current for such a small cell (300g) is huge:
100 amps! However, doing that would kill the cells ($1000 of cells) within
a very short time-period, so instead I will be putting 4 parallel sets in
a 16 series array, to give 48v and a continuous current of over 400 amps.
Have spoken to a company in China that has a suitable BMS, to look after the
cells. It's all good clean fun...
Well... whoops, it turns out that canev.com don't have a Geo Adaptor kit which
can go with the MARS ME0708 motor, which is a 7/8th in output shaft. So
after a bit of searching I accidentally encountered everthing-ev.com and
this Taper Lock Weld-on Hub and matching
Taper Lock Bush which they're looking up for me to
see if they can get a 7/8in bush. I think what I will do is get some
aluminium plate (Suzuki Swift Gearboxes are aluminium) and make the adaptor
plate myself. I promise to not do a bodge-job. Also I am considering making
a mild steel light-weight flywheel to weld the Taper Lock Hub onto, because
the existing flywheel is amazingly heavy
So, by saving $900 including shipping on not buying an adaptor plate, that
means there's enough funds to get the batteries. I've found a company that
has some surplus Headway cells on clearance: they have 75 in stock, and 64
are needed, yaay!
Thank you to Electric Motor Sport for the discount on the EMC Zero-X Kit - very grateful to you.
The laser-cut disc and plate arrived from LaserMaster (thank you!) and the Zero-X kit from Electric Motor Sport has been shipped. Also the adaptor bushes from EverythingEv are on the way. Batteries have yet to be ordered from EVAssemble as we need to arrange getting the funds off to them in China.
Ok, the new welder arrived so work continues.
12 Jul
| Ceo1shop | 300A shunt |
| Ceo1shop | 300A meter |
| Ceo1shop | 75V DC meter |
| Everything EV | Taper Lock Bush and 7/8in bush |
| Electric Motor Sport | Zero-X Kit |
| EVAssemble | 48v DC-DC 12V 10A Converter |
| EVAssemble | Elcon TCCH-48-25 |
| EVAssemble | Headway 38120 10Ah
cells in a 16-series, 4-parallel arrangement. EVAssemble also have BMS systems up to 300A (a 150A one was chosen here) |
| Laser Master | Laser-cut steel for flywheel and gearbox adaptor plate. |
| The Metal Store | Mild Steel rectangular and box section. |
| Mr Gasket | 3/8-16 1in bolts from a really nice guy, runs a USA Car parts company, had these sitting on the shelf, which is fantastic. I actually got part 917 from him instead, which is the 1in long bolts. Thank you! |