Stuart's Work in progress

Post by **stuartri** » Mon, 05 Mar 2012, 05:49

Created both the longitudinal and Lateral sections and combined them. I have noticed a couple things that I will have to clean up now before creating the slotted sections. Also I will have to create some finer detailing to ensure the form is maintained.

As mentioned in an above post I have fixed up some details in the profile and posting the changes

Regards Stuart

Post by **Crash** » Tue, 06 Mar 2012, 17:49

Hi Stuart,
How are you going to cover the timber forms to produce a finished plug?

regards
Wayne

Post by **Crash** » Tue, 06 Mar 2012, 17:53

The Challenge is on... River Raiders 2012 build is at http://evchallenge.tumblr.com/

Post by **stuartri** » Wed, 07 Mar 2012, 00:54

Wayne great to hear from you.

The driver for me has been to minimise the cost of the buck creation as I dont have access to machinery.

The most practical way for me to go about it was

1. 3D model the Buck using longitudinal and lateral sections
2. CNC profile cut the forms you see in the pic.
3. Use glued high density polystyrene to create the form
3. Sand and prime surface
4. Male buck will be ready for female plug to be created.

I found this web link useful on youtube

http://www.youtube.com/watch?v=TNZK8-z0ndk

Stuart

Post by **EV2Go** » Fri, 09 Mar 2012, 21:21

Your front section looks a lot like what I have in mind for the rear section of my trike, very different approaches to get a similar look. I drew inspiration from hot rods of the 30’s-60’s. Went to hot rod show and took a whole heap of rear photos to see if there was a particular swoop that appealed to me.

I will be making the body fit the frame, whereas you are making the frame to suit the body by the looks.

The 36 Ford caught my eye as a real nice shape for an EV

36 Ford Coupe

Post by **Crash** » Sat, 10 Mar 2012, 00:07

Our focus has been aerodynamics and keeping the structure simple so the body shape is dictated by the profile of the driver,aerodynamic principles and the max length rule.
Wayne

Post by **stuartri** » Sat, 10 Mar 2012, 02:24

Wayne had a look at your car and looks great.

Yes I am working on the form first after all it has to have some sex appeal. The buck forms the external shell to create a reproducible mold from. The internal space frame is being worked on presently with safety in mind.

The aero dynamic modelling will be done at a later time as I can use software for this with my 3D model. More than likely this will be done on the next revision of the car as it has taken me far to long to get it from my head to CAD and want to start focusing on the spaceframe, electronics , motor and controller design and driver management systems which is what I have been hanging out for.

Revision 2 which is what this blog is about will use off the shelf motor and controllers but the planned revision 3 I will relase my own motor controller and motor that is currently in planning.

Stuart

Post by **stuartri** » Tue, 20 Mar 2012, 00:50

As you can see from the model, there are some sections where the longitudinal and later sections meet which can have some panels removed. Also I have found that I will neet to create some horizontal panels to preserve detail which I will post next.

Stuart

Post by **stuartri** » Tue, 01 May 2012, 01:59

Work is beginning on the space frame for the vehicle. Have submitted my battery configuration and Data sheets for the evchallenge so am waiting on a reply. Much simpler design than when I raced back in 2007 and much lighter than my old pack.

Stuart

Post by **stuartri** » Tue, 15 May 2012, 02:08

I am also well progressed now on the battery pack. This time the assembly is well ahead of the modelling which I am happy to say.

See Below the top and bottom battery locator plates with bus bar connectors.

Here is the battery layout with the batteries mounted in the bottom locator plate.

Now just working on the Battery management system specification before sourcing the most suitable unit. I will write more on the post regarding the BMS system as I have been doing extensive research for my purposes.

Stuart

Post by **stuartri** » Tue, 15 May 2012, 02:38

Forgot to add a pic of the battery assembly with top and bottom locator plates.

Please see below

Stuart

Post by **Greg partridge** » Tue, 15 May 2012, 09:12

Stuart,
What type and brand are these batteries? Where did you buy them from?

Post by **Johny** » Tue, 15 May 2012, 17:15

They are Headways. From the size they look like 38140, 12AH. They might be the larger again 40152, 15AH - Stuart will confirm which ones.
You can get them from EV Power. Smaller ones (38120, 10AH) from EV Works - or you can bring them in yourself. At the good prices these Australian sellers have them, I would not bother with bringing them in though.

Post by **stuartri** » Tue, 15 May 2012, 18:41

Johny thanks for that you are correct. 38140, 12AH.
The actual manufacturer of the Headway batteries is in Fact TEnergy.
When I won the EVchallenge back in 2007 [This is the first time I will be coming back since then] I raced on TEnergy NiMH F Cells.

The problem with LiFePO4 by the very nature of their battery chemistry is that they are very hard to match to the exact WH rating of the EVChallenge so inevitably you end up running an under rated spec.

That being said TEnergy have great products.

In terms of sourcing items you will need to do extensive research and form relationships to get the best pricing.

Johny has a good point to make as a first off but I have been building relationships for a few years now with the distribution chain so I sourced mine direct from the Factory.

Stuart

Post by **stuartri** » Wed, 06 Jun 2012, 16:48

Just received my brushless DC motor today which is very exciting. Will need to do extensive testing before I commit this motor to the latest revision of the car.

All I am waiting on now is my BMS module and charger which are on their way.

Working a few tasks in parallel now.
1. Battery/Motor/BMS/Gear Train -> propulsion sub systems
2. Chassis -> Progressing well. Models almost complete for manufacture
3. Body form -> Ready for manufacture.

Stuart

Post by **stuartri** » Tue, 12 Jun 2012, 17:43

Work has begun on the steering assembly.

I have modelled the steering wheel which is ready for manufacture and will be moving onto the steering assembly and couplings.

Here is a pic of the steering wheel.

Stuart

Post by **Richo** » Tue, 12 Jun 2012, 20:33

Wouldn't that pack be too big for the eV challenge?

Post by **stuartri** » Tue, 12 Jun 2012, 21:14

Richo are you referring to the battery pack?? The battery pack I have meets both the weight and Watt Hour requirements for the EV Challenge.

Stuart

Post by **stuartri** » Wed, 13 Jun 2012, 00:10

The steering assembly has begun. Eventually I will have a paddle shifter incorporated but not with the initial revision as I will focus on the linkage assembly down to the pull rods on the wheel.

Here is the first model of the steering wheel, adaptor bracket and shaft. Would like to incorporate a quick release steering wheel so if any of you mechanically minded people have any ideas for me I am open to suggestions

Regards Stuart

Post by **Richo** » Wed, 13 Jun 2012, 20:50

Sorry I got confused I thought your pic has 12 x 12Ah 3.2V batteries which is 460.8Wh which is more than the 432Wh limit.

Post by **stuartri** » Wed, 13 Jun 2012, 22:37

Richo,
You are correct the picture shows 12 batteries which will only be for charging purposes however I will be racing with a pack of 11 cells which means I need to make some mods to my BMS system.

It will mean I am slightly under rated but that is the best I can do given the LiFePO4 battery chemistry does not match well to 432Wh rating

11 x 3.2 = 35.2 Volts (Maximum battery voltage 36v)
11 x 3.2 x 12 = 422.4 Wh (Maximum 432Wh)
11 x 386g = 4.246Kg (Maximum Weight for LiFePO4 4.8Kg)

Part of making up the for the under rated pack is to ensure the motor I use this year has a better efficiency rating at rated speed and other improvements to lighten the vehicle along with a smarter motor controller.

Regards Stuart

Post by **Crash** » Fri, 19 Oct 2012, 15:42

Hi Stuart,
Haven't heard from you for a while, how is the build going? Are you on track to be here for an East coast challenge on the West Coast's EV race? I think we could use it to help get some press coverage if you are?

Wayne

Post by **stuartri** » Tue, 23 Oct 2012, 15:17

Wayne,
Thanks for the post. Unfortunately I will miss the race this year but rest assured I will be there next year as I wanted to make sure there were no compromises on the car. I will be posting some more images of progress just been tied down with some design considerations.

I am really impressed how WA leads the way with this sort of thing. I am working to creat a similar challenge in Queensland as I moved from Victoria.

Will have some postings next week.

Stuart

Post by **Crash** » Wed, 24 Oct 2012, 04:42

Thats a pity, was looking forward to the east coast challenge. Even looked at taking our cars across for the Hunter EV Challenge, but unfortunately the rules were not even remotely close and their rules are completely unsuited to cars with 3 or 4 wheels.

Post by **stuartri** » Sat, 05 Jan 2013, 02:19

Its been ages since I have posted any pics here. Must say modelling the body work has been a great frustration to me but part of the learing curve. Have not been happy with all the elements of the body detail so I have been reworking it a little to make it easier for me to fabricate the buck with limited resources available to me.

What is coming out is an internal protective shell which I can then attach the other body work to. Will show the surface modelling when I am happy with the rework. Mainly for my visualisation at present.

Stuart