[galderdi]

Very nice mate. Its a work of art. What did your total weight end up being after the modifications? Let me know how you go with heat on the volt cells. So far I have never had any detectable heat at all on mine.

I was looking at some hill climb videos last night. Mostly at Mt Cotton. I was looking for the typical top speed of the faster cars. I was a little surprised to see its only around 100kmph. This is great news, because I am hoping with my recent progress my car should achieve that. So next year I will throw my hat in the hill climb ring. That will also mean I should be eligable for the interclub challenge.

 

[galderdi]

Nice work. It's an inspiration.

 

[galderdi]

Nice work Duncan. So glad you held it on the road. I am about to upgrade my contactor too. I will now be running dual 500 amp units.

Can you charge the pack in parts? For the past 6 months I have been charging mine 6 cells at a time using a hobby charger. It is slow but it works. But hopefully I am weeks aways from completing the controller / BMS upgrade which should allow me to use my big charger.

Keep up the great work.

 

[galderdi]

Nice work. I wish you were closer by so I could take a look in person.

 

[galderdi]

By the way, I made all my panels (aside from the floor and firewall) from PolyCarbonate (Lexane). It is only 0.4mm thick and is really tough from an impact point of view. But not so tough in a tearing/ripping point of view. But it sounds perfect for the panel you were talking about. I get mine from bunnings in 5m rolls, quite cheap.

 

[galderdi]

That looks like my sort of event. Shame it was on the wrong side of the ditch....or did I see you cross the ditch?

The launch wasn't as fast as I would expect, was it grip, power or a combination of the two that limited your launch....or was it just an illusion caused by the video (I know how that feels).

You should come over and drive mine in one of our local events.

 

[galderdi]

You took out a cone!!!! Hasn't anyone told you smoking weed before or during a motorsport event isn't a good idea.

Although I see they removed all the sheep before you started, safety first right?

 

[galderdi]

Ah damp grass. That explains why it was a handful if you strayed off the worn path.

It sounds/looks like you weren't far off the pace. A little more familiarity would make a massive difference.

There are a lot of factors in being competitive. I used to take great pleasure in beating expensive cars with my $400 Pulsar. It wasn't a super car (although it wasn't bad), I wasn't a super driver (although I hold my own) it was mostly competitive because I was willing to throw it around. I didn't have to hold back because of risk to the car.

It's my 25th wedding anniversary in Sept 2017. I should tell the wife:

"Hey let's go to NZ to celebrate.......oh look, who's that over there, oh gosh it's Duncan with his EV, oh and wow there is an event happenning. What a cooincidence. Let's hang here for a while"

 

[galderdi]

I made myself a - Corner weight device

It lifts the wheel using about a 10:1 lever and a fishing scale - up to 40Kg

Seems to work quite well

Now to using it
The Device is almost perfectly symmetrical right to left and nearly so from to back

But when I get in there is 100Kg very close to the RHS rear - this means that the RHS rear tire has more weight than the LHS
So that tire spins when I throttle -
I do have an LDS so the car still accelerates well

What I have done is to move the spring pan on the RHS front wheel so that that wheel drops lower

Now when the car is empty it sits RHS high - and when I sit in it it is almost level

The rear wheels with "me" in the car have almost exactly the same load
RHS is still about 15Kg heavy compared to the LHS

But now the front right is about 20Kg heavier than the LHS front

I will take it to the 1/8th mile drags like this - not sure about the Autocross

Comments?

Firstly congratulations on an excellent and simple solution to a common problem. The counter lever scales are brilliant. What are you charging for your IP?

I am not an expert in corner weights but what you have done certainly aligns with my understanding of the correct approach. I think you would be fine to run it like that at autocross.

 

[galderdi]

I think Arduino is your friend. They can be made to do almost anything and at a reasonable price.

My initial thoughts are an input into the arduino from either:
a GPS module
a speedo (assuming the speedo isn't run off the driven wheels)
a G force meter

and another input from the tacho

Have the arduino do a mathmatical comparison of the two inputs. Set some limits (if x revs is between y and z kmph then thottle =100% otherwise throttle at 90%)

I think it's doable

 

[galderdi]

I am a novice too but I have successfully programmed one to control my reversing contactor so my confidence is building.

My next task is to build a better timing system for our club. That is massive by comparison. But I plan to just take it one requirement at a time and then string them all together.

I would understand a recommendation not to place it within a couple of feet of the motor. But other than that I can't see why arduino electronics would be any different from all the other electronics we have in our EVs. Any any way, even if it were an issue, you could alway build a little faraday cage around it.

It is a good point though. I think I should program up some way to test the impacts. Any thoughts on a suitable test?
Maybe have 2, one in the EV and one away from the EV both with the same timer program both triggered from the same switch so they are syncronised at the start. then drive around for a while. If they remain in sync then I would assume there hasn't been any significant disruption.

 

[galderdi]

Hey, Nice work there Duncan. I hope to have some vids from my new car shortly after Feb 11th.

 

[galderdi]

Dang, Really sorry to hear that. I would also be interested to know the approximate revs when it went bang?

 

[galderdi]

Hey Duncan,

I am no expert but I wonder if one of the Comm bars may have raised at higher revs, chipped the brushes but then were pushed back down as the revs reduced. In other words I would be gently checking if any of the comm bars move at all.

But I am no expert

Also I wonder if you have overloaded a winding/conductor. Maybe check for resistance across your terminals.

But I am no expert

You can try "Find it parts" for brush springs

Did I mention I am no expert?

 

[galderdi]

Duncan, You have done us a great service. It's not everyday that we get the sort of data that you have given us. We now have a better idea of the limitations of a motor like yours. I am sorry it came at such a cost. I hope you can find a suitable / cost effective replacement soon.

Obviously we are pushing these motors past their designed purpose and sometimes past their physical limitations. It is very dificult to know where to draw the line. They don't give audible warnings like ICE motors do.....until it's too late.

Please keep us posted on your progress.

 

[galderdi]

Coat those windings! Or get the arm. and stator dipped and baked at a motor shop.http://what-when-how.com/electric-motors/dip-and-bake-systems-electric-motors/

Megaohming the parts before and during the clean-up and re-coating process(es) would also be a good idea, since you're using it at such a high voltage.

This sounds like good advice. I will keep this in mind if I ever choose to increase my voltage.

Duncan, Its great to hear you have some options up your sleeve. I can't wait to hear that you have it back up an running.

 

[galderdi]

OK
Only allowed to up load 10 files at a time

You should have a word with a site administrator about that

Is this the past or future motor?

 

[galderdi]

Great to hear it is back Duncan. Can't wait to hear how it goes when you compete next.

 

[galderdi]

What are the chances that you are seeing a reflection of the safety cone in the nice shiny brake disk? It seems a bit of a stretch, but maybe..?


Bill

I think you are on the money.


I don't know about the cone part but I am convinced it is reflection. There are a couple of reasons.
1. The colour is consistant with the reflection on the other components like the wheel rim.
2. Take a closer look at the bottom right of the disc, just where it goes behind the spoke of the wheel. there is a portion there that is not orange. If it were glowing hot it would be consistant across the whole disc.


I think Duncan is safe......well safe from melting discs anyway.

 

[galderdi]

Oh and I just noticed the top of the disc (through the gap in the wheel) is also not glowing. So again I can't see how it could be heat.