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thingstodo 09-23-2014 12:32 AM

Mazda MX-6 build thread (EV conversion)
 
I've finally started to build a daily driver. I'm using my first car - a 1992 Mazda MX-6. A demo purchased off the lot in 1992 with 1500 km.

It starts the EV build at 376,709 km.

I have a few projects posted on this site that were not completed, or are on hold pending some side issues. So I delayed posting on this one.

I have a few updates to post, so I have SOME confidence that it will continue.

thingstodo 09-23-2014 01:04 AM

Day 1 of Build
 
Video on youtube if anyone is interested

Mazda MX6 Day 001 June 30 2014 - YouTube

https://www.youtube.com/watch?v=8IGHkhO8jjM

I am not mechanically inclined, but I am learning. I find that most 'electrical' projects (I'm an electrical engineer at a mine. I have 25 years of experience on 'electrical projects') actually take MUCH more time and money to get the mechanical changed/removed/working. Then the electrical part and the instrumentation are done right at the end, after the project is already out of money and the schedule has slipped far enough that we're already late when we begin.

Hopefully this is not the 'typical' electrical project:D

The car is operational as is, but it needs some maintenance work:
- the windshield needs to be replaced
- there are rust spots on the corners of the doors and several other places
- the car needs new paint
- the tires need to be replaced, likely with low rolling resistance tires
- the driver's rear wheel does not spin freely
- the parking brake may be dragging a little bit
- the clutch is original, so it should be replaced
- the inner and outer CV boots were regularly replaced during the life of the car so they likely need to be replaced again

I'm not putting any cash into the mechanical issues on this car until I can get it rolling electric. No point fixing a car that will never move again.

When the car rolls electric, the issues will be addressed based on priority.

If something is exceptional, perhaps some repairs will be done as I go. We'll see!

Astro 09-23-2014 09:43 AM

Day one of the build. It all goes very quickly as you strip out all the internal combustion stuff.
Progress is very visible and very satisfying. I really enjoyed pulling all the rubbish out of my car.
Hope you have as much fun as i did. :)

I hear what you are saying about fixing minor issues nearer the end of the conversion rather than at the start.
I spent quite a bit of time fixing things in the beginning and then found out that i couldn't use the car due to some air bag regulations. So after pulling out all the ICE stuff and fixing all the faults on the car i had to start over with a different car. Really wish i hadn't wasted all that time fixing the faults on a car that never got used.

So you are off to a wiser start then me. :o

MetroMPG 09-23-2014 04:16 PM

Subscribed & following with interest.

I do miss rolling around town in my quiet EV.

thingstodo 09-23-2014 11:05 PM

Day 2 of Build video 002
 
Remove more gasoline parts from the car

YouTube

Not too exciting, but it's progress

Astro 09-24-2014 02:46 AM

I am converting a entirely different car but similar era, mines a 94 Holden Barina.
I found that pretty much all of the fuel injection and engine management wiring just went directly back to the computer and was very easy to remove.
Very early fuel injection setups were just slapped on on top an existing models wiring. So when you remove it you may just have some very basic wiring to deal with. That's what happened with mine.
After removing the computer and engine loom pretty much all that was left was oil pressure, temperature sensor and starter motor energise. The only connection between the computer and the other non engine systems was a single connection from the air conditioning relays which i believe was a signal for the computer to increase the rpm of the engine to compensate for when the a/c compressor clutch engaged.
Newer models went on to integrate the computer into more and more systems making it more difficult to remove.

The first car i stripped i removed everything off of the motor leaving just the block, pistons and crankshaft. Even though it was a tiny 4 cylinder motor it was enormously heavy to lift manually. Probably around 60 kilos.:eek: Very difficult to lift that sort of weight out of the engine bay and doing a dignified drop out through the bottom seemed like it would have been just as difficult.
This time i am going to use an engine crane, i am just waiting for it to become available. i am borrowing it from a friend. It will also save me time as i don't have to strip as much off of the engine this time.

When you get to removing the air conditioning from the motor i would try and keep it intact. I just unmounted it from the motor and cable tied it to the front cross member. So now i have the option of adapting it to run off of a pulley on the rear shaft of the drive motor or replacing it with an electric compressor from a scrapped hybrid.

Another suggestion is that while the ICE motor is still in place get some reference measurements for the gearboxes current position so that you can get it in the same spot with the electric drive motor. That way all the alignments of the drive shafts will be the same.
Some cars don't have much clearance and if the gearbox ends up much higher up or lower down in the engine bay then you may have clearance issues when the suspension is at full travel.

When i removed the fuel tank i just disconnected the fuel lines in the engine bay and stuck the ends into a fuel can.and then energised the electric fuel pump and allowed it to pump out 99% of the fuel. Makes the job much easier. There will still be some fuel in the fuel lines so don't be under them when you disconnect them at the tank.:o

Let me know if you want any more suggestions. I am only a little bit further along in the build process than yourself so all the mistakes are fresh in my mind. :D

thingstodo 09-24-2014 07:28 PM

Quote:

Originally Posted by Astro (Post 447048)
Let me know if you want any more suggestions. I am only a little bit further along in the build process than yourself so all the mistakes are fresh in my mind. :D

Please list any and all suggestions - communication is what the forums are all about! I may not be able to use all of the suggestions, but many lurkers read the forums and learn a lot from the comments of others

I'd be MOST interested in the suggestions that save me time, or money, or both!:D

thingstodo 09-25-2014 12:13 AM

Mazda MX6 Day 004 video 003 July 3, 2014
 
Another video posted

Mazda MX6 Day 004 Video 003 July 3 2014 - YouTube

Today more parts were removed, including the top of the engine block.

It feels like progress!! I did not expect the dis-assembly to take so much time.

The labelling of each wire and bolt is tedious but I know it will pay off in a big way when I try to put things back together.

freebeard 09-25-2014 04:01 PM

All right.

My car's up on jackstands. As soon as I have a picture of the MGR in position I wiil start a thread. But I won't be posting a Youtube video every day.

Quote:

I find that most 'electrical' projects (I'm an electrical engineer at a mine. I have 25 years of experience on 'electrical projects') actually take MUCH more time and money to get the mechanical changed/removed/working. Then the electrical part and the instrumentation are done right at the end, after the project is already out of money and the schedule has slipped far enough that we're already late when we begin.
That's my plan. :)

thingstodo 09-25-2014 09:12 PM

Quote:

Originally Posted by freebeard (Post 447327)
.. But I won't be posting a Youtube video every day.

I hope that everyone noticed that I started these videos in .. JUNE .. and am finally confident enough that I will finish the project that I began to post them.

thingstodo 09-25-2014 11:11 PM

Mazda MX6 Day 007 video 004 July 6, 2014
 
Exhaust finally removed. The bolts were all rusted so I got some THERAPY smacking things apart with a sledge hammer (2 lb) and a wrecking bar!

Remove engine from car. I got it out without removing the transmission, but I had to rotate it in place first.

Do some measurements (kind of rough) to check pin locations for canev adapter and compare to drawing emailed from canev

Mazda MX6 Day 007 Video 004 July 6 2014 - YouTube

I'm concerned that the transmission adapter from CanEV.com is not going to fit. The drawing does not match ... or does not appear to match. So I take more measurements. The Mazda is not a popular conversion anymore, so Randy will not be fabricating more of these adapters. This last one is a 'final sale' .. so I want to make sure it will work before I dish out $895 plus shipping and taxes ...

freebeard 09-26-2014 01:25 AM

,,,ohh, a cliff hanger. Stay tuned. I'd noticed the date, but wasn't going to draw attention to it.

Are you weighing the stuff as you remove it? Would it be a spoiler to estimate the weight lost and gained?

Astro 09-26-2014 02:57 AM

Quote:

Originally Posted by thingstodo (Post 447414)
...
Remove engine from car. I got it out without removing the transmission, but I had to rotate it in place first...

Ouch, i will never again be able to complain about difficulties getting an engine out.
Yours looked like quite a struggle. I had heaps of room at the timing belt end to move the engine clear of the transmission and i didn't have a mid drive shaft support to deal with.
How good does it feel though knowing that you never have to put that horrible oily engine back in again.:)
http://i1310.photobucket.com/albums/...psacf34958.jpg

The only thing that made the engine removal difficult was having no access to an engine crane. :(

But after a lot of crazy lifting attempts it was out.
http://i1310.photobucket.com/albums/...psd3379c06.jpg

You can see how much of the wiring loom was able to be removed. All the loom from the left side of the photo is now gone.
Hopefully your loom can be simplified just as easily.

I liked the shots near the end of your video of the engine lying on it's side, defeated and soiling itself all over the floor. :thumbup:

mechman600 09-26-2014 09:39 AM

Looks like a fun project!

I'm not gonna thread jack with a link or anything, but if you need some EV parts, PM me.
What's the plan - clutch? No clutch?
Do you have a motor already? Controller?

Good luck with the build!

thingstodo 09-26-2014 08:53 PM

Quote:

Originally Posted by freebeard (Post 447430)
Are you weighing the stuff as you remove it? Would it be a spoiler to estimate the weight lost and gained?

It would not be a spoiler. I just have to figure out which video it's it and write down the numbers.

I'll try to do that tonight.

thingstodo 09-26-2014 08:58 PM

Quote:

Originally Posted by Astro (Post 447434)
How good does it feel though knowing that you never have to put that horrible oily engine back in again.:)

*VERY* good.

By the way - I did not measure the clearances when I had the dino-burner in place. I'll have to go from the pictures and estimate the ride height.

thingstodo 09-26-2014 09:10 PM

** SPOILER ALERT **

Not that anyone is in suspense or anything, but info below makes the info in the videos even LESS interesting ... if that's possible ...

Quote:

Originally Posted by mechman600 (Post 447480)
Looks like a fun project!

Fun, but in a scary sort of way. I'm an electrical guy and this is a pretty steep learning curve for me.

Quote:

I'm not gonna thread jack with a link or anything
A lot of the fun of forums are the tangents we take. Post away!

Quote:

if you need some EV parts, PM me.
Sure. I will PM. Right now I'm having issues with the accelerator. The Netgain Industrial controller wants 2 hall effect signals related by some formula. I can use their pot-box replacement .. but no one in Canada appears to sell it. Or their normal accelerator pedal. There is a setting for a Prius pedal ... do you have one of those?

Quote:

What's the plan - clutch? No clutch?
I'm leaving the clutch in but since I removed the transmission I am told I need to 'bleed' the hydraulic lines to have it work again. Not sure if I will be successful on that one. But my old clutch plate with 370K on it will be my mechanical 'fuse' and tell me when I have turned up the controller TOO FAR ... I am told I should smell clutch when that happens.

Quote:

Do you have a motor already? Controller?
Yes. Netgain warp 11 series wound DC with a Netgain Industrial controller.

Quote:

Good luck with the build!
Thanks

thingstodo 09-26-2014 09:24 PM

Mazda MX6 Day 008 video 005 July 7, 2014
 
More measurements for motor adapter plate.

The 'read'em and weep' comment is because the measurements that I was looking for were:
- 130 mm from hole to hole on the top edge
- 220 mm from the right top hole to the right pin
- 346 mm from the right pin to the left pin

When I discussed these with Randy at CanEV.com, he said that they matched his adapter perfectly. So I ordered it (but I am still worried)

Mazda MX6 Day 008 Video 005 July 7 2014 - YouTube

mechman600 09-27-2014 01:45 AM

I do have a pot box, but it's a cheapo and kind of toast. A 0-5000K one. After sitting for a while the contact isn't the greatest and the throttle response is a bit jerky unless you give a few depresses of the throttle before turning the key on. I sprayed some electrical lube into it a couple times which cured it for a few months. I strongly suggest buying a genuine Curtis unit, as they have better internals. I would give mine away for $10. Probably less...ha ha.

Here's my parts for sale thread:
http://ecomodder.com/forum/showthrea...ger-29943.html

Not sure what's of use for you there.

I would strongly suggest keeping the clutch, which I guess you are anyway. Adds a margin of safety in case of possible [heaven forbid] "welded controller & contactor EV runaway" and makes shifting much easier. Not that EV clutchless shifting is that hard, but I guess quicker is the better word. Clutchless shifting takes more time.

freebeard 09-27-2014 03:04 AM

Quote:

I'm leaving the clutch in but since I removed the transmission I am told I need to 'bleed' the hydraulic lines to have it work again.
Hydraulic clutch? If you remove the engine and transmission, what does the clutch attach to? Or should I be watching the videos?

mechman600 -- Is there a second reason for retaining the clutch? Because I watched a Youtube video of a Porsche EV conversion, and as he was driving he'd say, "Oops, there goes the clutch...there goes the clutch."

Won't a switch like they put on the outside of race cars substitute?

mechman600 09-27-2014 09:22 AM

Quote:

Originally Posted by freebeard (Post 447586)
Hydraulic clutch? If you remove the engine and transmission, what does the clutch attach to?

You don't remove the transmission. You make an adapter plate to mount the electric motor to the transmission, and the flywheel to the output shaft of the motor. DC motors have a relatively narrow efficient operating RPM, so we keep the transmission and use maybe three gears to get the best acceleration in every situation.
Quote:

mechman600 -- Is there a second reason for retaining the clutch? Because I watched a Youtube video of a Porsche EV conversion, and as he was driving he'd say, "Oops, there goes the clutch...there goes the clutch."

Won't a switch like they put on the outside of race cars substitute?
Not sure why he said that. He likely was using the old original clutch which couldn't handle the increased torque of a ginormous DC motor.

You always need redundant safeties build in, like a contactor or two. Rule of thumb: engineer it so that if ANY two devices fail, you will be able to stop the car.
For example, a failed closed controller & failed closed contactor - without a clutch you are screwed, flying down the road in a runaway condition, which is why it is recommended to use TWO contactors in a clutchless DC powered EV.

thingstodo 09-27-2014 01:21 PM

Quote:

Originally Posted by freebeard (Post 447430)
Are you weighing the stuff as you remove it? Would it be a spoiler to estimate the weight lost and gained?

I have 296 lbs removed from the front so far, 50 lbs from the back.

I can't find the weight for the gas tank, so the rear weight will rise a bit.

Netgain Warp 11 is 229 lbs. The adapter plate and coupler from CanEV were 12 lbs from the shipping carton - I can't find video where I weighed it so maybe 10 without packing. Netgain industrial controller 23 lbs from the web site.

As I put stuff in I'll be weighing it.

The motor weight may be a problem as it weighs more than the original ICE!

The left/right weight balance will likely be off. I was planning to mount the controller above the motor, but maybe it should be above the transmission to try to balance things out a bit more?

The rear spring and shocks may need an upgrade. I intend the battery pack to go beneath the back seat, where the gas tank was, plus a smaller pack right behind the back seat taking up part of the trunk. The batteries are just over 400 lbs, plus frame, plus insulation, plus battery heating, plus supports. So the car may drive like I have 2 sumo wrestlers sitting in the back seat!

Contactors, wiring, inertia switch won't be much - 30 lbs

Liquid cooling will be significant - maybe 50 lbs for coolant and pump

DC/Dc converter and small 12V battery will be another 20 lbs up front

Charger is another 50 lbs in the back

Did I miss anything?

freebeard 09-27-2014 01:50 PM

So the transmission is going back in; makes sense. Has anyone posted a comparison of shifting and just leaving it in top gear? I was thinking that torque gets you off the line and horsepower limits the top speed.

I think you're right about the 'old, original clutch'.

The reason I ask is I'm following http://ecomodder.com/forum/showthrea...mgr-29878.html and wonder about the downside of a single-speed, clutchless, electric reverse drivetrain.
______

I need to educate myself about contactors. I noticed in Paul Holmes VW conversion he had a lanyard to pull on a shorted plug. But thread like http://ecomodder.com/forum/showthrea...ack-29765.html have it in the trunk. Better to have it accessible from the driver's position?
_____

thingstodo -- For whatever reason your post doesn't have a Thanks button. Thanks.

Astro 09-27-2014 07:10 PM

Quote:

Originally Posted by freebeard (Post 447650)
I think you're right about the 'old, original clutch'.

Could also be caused by the increased torque due to most EV drivers choosing a single gear for most driveing. 2nd or 3rd. Taking off from a stand still in 3rd gear, even though the electric motor has the required torque it may exceed the clutches torque handling abilities. An worn clutch would be even worse.

Quote:

Originally Posted by freebeard (Post 447650)
The reason I ask is I'm following http://ecomodder.com/forum/showthrea...mgr-29878.html and wonder about the downside of a single-speed, clutchless, electric reverse drivetrain.

I believe the MGR is an AC motor which is much less likely to fail full on. The controller needs to continue to do all its very complex math and timing to keep the motor turning. Maybe if the accelerator pot failed full on it may cause the motor to full on. Luckily Paul thought of that and in Paul's controller (maybe other controllers too) he checks for 100% pot output and detects it as a fault and shuts down the motor. I think full throttle is designed to be reached at 95% (or something around that) so that 100% throttle can be set as a fault condition.

Quote:

Originally Posted by freebeard (Post 447650)
I need to educate myself about contactors. I noticed in Paul Holmes VW conversion he had a lanyard to pull on a shorted plug. But thread like http://ecomodder.com/forum/showthrea...ack-29765.html have it in the trunk. Better to have it accessible from the driver's position?

I was toying with the idea of getting the park brake mechanism from an overseas version of my vehicle. Driver on the opposite side, so park brake on the opposite side of the tunnel. Paint it red and mount it on the passenger side of the tunnel. As my battery pack will be at the back under the rear passenger seat (where the petrol tank was) the cable end will be right near the batteries and should be able to join to a shorted Anderson connector. Anderson connectors come in 350amp types and have nice screw holes for attaching one to the end of the cable and the other to the body.
So in an emergency, not just a runaway motor but also a fire or after a collision. Simply pulling the red park brake will cause a physical disconnection of the battery from the rest of the vehicle.
This would be in addition to the emergency stop buttons in the cabin and engine bay. Which are wired in series along with an inertia switch, to the main contactor energise circuit.

thingstodo 09-27-2014 11:42 PM

Quote:

Originally Posted by freebeard (Post 447650)
Has anyone posted a comparison of shifting and just leaving it in top gear? I was thinking that torque gets you off the line and horsepower limits the top speed.

I have not seen one. I would be interested as well.

Talking it through, I would expect the acceleration to be a bit less unless your motor and controller are over-sized .. and your transmission/axles/etc can handle the boosted torque.

The siemens motor on the single-speed borg-warner transmission for the Ford Etransit is rated over 100 kw. The motor used by the Coda is(I guess WAS) also over 100 kw, using a different gear ratio on the same borg-warner gearbox.

The original beetle was no speed demon, but it got by with under 60 hp (45 kw or so)

Quote:

The reason I ask is I'm following http://ecomodder.com/forum/showthrea...mgr-29878.html and wonder about the downside of a single-speed, clutchless, electric reverse drivetrain.
I am no expert. My opinion is that the downside is a bigger controller and a bigger motor to get good performance. My standard transmission weighs under 75 lbs. I hope that the MGR gives decent acceleration. I hope to use it in a WIKISPEED car. I hope it gets GREAT performance on a 1400 lb car

Since Toyota designed the motor, gearbox and axles I would expect them to be well matched, with decent safety factors. My clutch is a mechanical fuse for my system. I can turn up the torque until I smell clutch. The MGR should not need anything so crude.

Quote:

I need to educate myself about contactors. I noticed in Paul Holmes VW conversion he had a lanyard to pull on a shorted plug. But thread like http://ecomodder.com/forum/showthrea...ack-29765.html have it in the trunk. Better to have it accessible from the driver's position?
The contactor opens when 12V is no longer applied. It can be wherever you like. If you have a pull switch or cable, you have fewer options on where it can go since the cable must be routed.

I have two contactors, one for the precharge and one for the main enable. That gives me minimal redundancy. I need to figure out a visual indication that both contactors open each time.

In the case that the contactors BOTH fail AND the controller fails ON to full throttle, there will also be a cable connected to a DC breaker under the hood. Similar in function to the shorted plug you discuss. Pull the cable (I hope it looks like an old style choke) and the breaker (like the breaker in your house panel, but BIGGER and it can open on 500A of DC) the controller loses power. That should be paranoid enough for most people.

And lastly, if all else fails, I press the clutch and let the motor overspeed until it tears itself apart .. but it stops and I don't die. Perhaps I am hurt by the motor shrapnel, likely not. The warp11 is big and sturdy.

Watch out:eek: .. reading posts by paranoid people may be hazardous to your health:confused: .. paranoia is catching!:mad:

oldtamiyaphile 09-28-2014 01:14 AM

Quote:

Originally Posted by freebeard (Post 447650)
So the transmission is going back in; makes sense. Has anyone posted a comparison of shifting and just leaving it in top gear? I was thinking that torque gets you off the line and horsepower limits the top speed.

Accelerating in top gear will pump a lot more amps. You can get away with a smaller controller if you use the gears. Easier on the motor and gearbox (input shaft etc) too. Electric motors have the very real capability of breaking gearboxes as often they're torque rating isn't much above what the OE ICE produces.

mechman600 09-28-2014 09:06 AM

Yes, AC systems are much safer because it is impossible for them to fail full-on, unless of course it is a potbox failure, but allegedly Toyotas were known to fail that way a few years back too.

DC motors have a limited RPM range because as their speed increases, so does back EMF, which is self-induced voltage in the opposite direction that it is spinning. Therefore, voltage necessary to maintain a given amperage (amperage is proportional to torque) is proportional to RPM. At zero RPM it takes almost no voltage to reach max controller amps, and at, say, 5000 RPM it may take full pack voltage to achieve the same amperage/torque. On my 72V Electric Booger, the crossover where full pack voltage was put to the motor to maintain max amperage was at 3500 RPM. Above 3500, while pack voltage remained at the motor, amperage began to fall as the motor speed increased above that. Thank-you back EMF!

AC motors do not have back EMF to deal with, which is why you see a single speed Tesla S with a motor that delivers 300 ft/lbs of torque and revs to 14,000 RPM.

As for the above question about starting off in higher gears, here is a video I posted a long time ago about first gear vs second gear starts in the Electric Booger. As you can see, having no clutch really slows the upshift down, which is why I will do a clutch next time. This was more or less a test to show that. A third gear start with the car would have been PAINFULLY slow, so I didn't even bother to show that.
https://www.youtube.com/watch?v=OpbHJPgcVIY

Astro 09-28-2014 11:00 AM

Quote:

Originally Posted by thingstodo (Post 447716)
...
Watch out:eek: .. reading posts by paranoid people may be hazardous to your health:confused: .. paranoia is catching!:mad:

Too true.:thumbup:
I doubt i will use the second park brake idea, it was more appropriate when i originally thought i would only be able to afford a DC system.
But now i have the AC motor the emergency cut out button and inertia switch in the main contactor seems like it will be enough.

Somebody mentioned the pre-charge contactor circuit. I think i will put the emergency cut outs in the earth return that will be used by both the pre-charge and main contactor coils.
I don't think the pre-charge resistor would last long at full current and so wouldn't be a huge issue in a contactor fail on scenario. The pre-charge resistor would act like a fuse at full amps.
But best that both circuits are cut with the emergency cut outs in case of an electric shock scenario.:eek:

freebeard 09-28-2014 11:17 AM

Thanks all. If you are curious, visit the MGR thread; but they are "multi-phase DC" for reduced back EMF and the gearset is single speed (6.xx to 1 reduction). I'm more concerned about off-road creeping than 60 foot times.

I'm going to let this thread go back to the assigned topic.

Astro 09-28-2014 11:53 AM

Quote:

Originally Posted by thingstodo (Post 447644)
...
Contactors, wiring, inertia switch won't be much - 30 lbs
Liquid cooling will be significant - maybe 50 lbs for coolant and pump
DC/Dc converter and small 12V battery will be another 20 lbs up front
Charger is another 50 lbs in the back
Did I miss anything?

Vacuum pump if needed for brake assist.
Electric power steering pump unless you use the original pump driven off the rear shaft of the drive motor or have a manual steering rack.

Probably not very heavy items but it all adds up.

Just like you I weighed each item as i took it off and then did the same for the items i planned to put on, either weighing them if i had them or using weights from spec sheets or just by estimating.
I was shocked to find the car would be one third of a kilo lighter than factory original.
That made me feel really pleased until i bought my AC motor. Which was about 20 kilos heavier due to buying a cheaper rewound AC industrial motor rather than a purpose built car AC motor. :(
But then i GPS logged my commute and found that i would need much less battery capacity than i originally guesstimated. 20 kilos less, so i am back to factory weight again. :)
My commute is not a long distance but lots of waiting at traffic lights.

You listed 50lbs for liquid cooling.
Is this for cooling the controller?
This seems like a lot to me. Of course i have no idea what would be involved in cooling a controller but i would have thought a few of litres of coolant at the most with a nice fan assisted aluminium radiator to cool it down. Like the after market ones they sell to cool transmission fluid.

I just finished pulling the heater core out of the cabin in my car as it is to be replaced with a ceramic heater element. Maybe the heater core could be reused as a cooling radiator? That would make it zero cost. :thumbup: Maybe strap a couple of 12v fans from a computer on it to increase the air flow.

thingstodo 09-28-2014 11:58 AM

Quote:

Originally Posted by Astro (Post 447756)
Somebody mentioned the pre-charge contactor circuit. I think i will put the emergency cut outs in the earth return that will be used by both the pre-charge and main contactor coils.
I don't think the pre-charge resistor would last long at full current and so wouldn't be a huge issue in a contactor fail on scenario. The pre-charge resistor would act like a fuse at full amps.

The pre-charge resistor limits current into the controller, so it won't be a fuse. The controller gets just enough power to run the electronics, but not to turn the motor.

My precharge gets quite warm if I forget to pull in the main contactor while I'm testing on the bench. I haven't cooked one yet!

thingstodo 09-28-2014 12:19 PM

Quote:

Originally Posted by Astro (Post 447767)
Vacuum pump if needed for brake assist.
Electric power steering pump unless you use the original pump driven off the rear shaft of the drive motor or have a manual steering rack.

Yes - I did miss those. I have the power steering pump and was thinking about using a separate 12V motor to run it. But it ends up being QUITE heavy. I'll find out how badly I need the vacuum pump when I get it rolling in my driveway. If my wife cannot get the brakes to function, I will add the vacuum pump.

Quote:

You listed 50lbs for liquid cooling.
Is this for cooling the controller?
This seems like a lot to me. Of course i have no idea what would be involved in cooling a controller but i would have thought a few of litres of coolant at the most with a nice fan assisted aluminium radiator to cool it down. Like the after market ones they sell to cool transmission fluid.
Yes, the controller is liquid cooled. I kept the original rad with the original fan. There's a few liters of fluid, the pump, and some piping. The controller is happy up to about 55C so I was considering using the coolant to feed the original heater core. I'd still need a ceramic element to keep the windows clear until the controller warmed up ... and I'm not sure how the plumbing would work. I may need to add a shutter on the rad for cooler weather.

I should be high on the 50 lbs. I forgot, until I started typing this message, that the rad and fan and fill bottle were not weighed coming out of the car.

IGBT controllers, which is most controllers that allow voltages above 200V, have a voltage drop across the transistor. I've seen specs as low as 0.6V but they seem to be around 0.8 - 1.0 normally. When you get above 1/3 to 1/2 of the rated amps (which should be into your design factor or just for acceleration) the voltage drop increases - 1.0V - 1.8V. Since Power = Volts * Amps, a 1000 amp start at 1.8V drop is 1800W. Getting 1800W away from your controller is difficult. So the heat sink is designed to absorb much of that for a few seconds of acceleration and then the liquid cooling takes it away while you are coasting/cruising to the next light.

MOSFETS have a much lower voltage drop, but they can't pass as much current. So the MOSFET controllers have a bunch of MOSFETs in parallel to allow 1000 amps or 500 amps. But if you have 1000A at 0.2V, that's 200W and an air-cooled heat sink can do it (you still need to fan cool, and the heat sink has to be big, but you can do it)

I'm planning to use a mineral-oil coolant, like they use in large industrial transformers. It is not conductive, so if it leaks my controller won't be damaged. The coolant WILL BURN, but if the temperature is that high, my cables and all of the plastic under the hood is ALREADY on fire.

thingstodo 09-28-2014 12:30 PM

Quote:

Originally Posted by Astro (Post 447767)
But then i GPS logged my commute and found that i would need much less battery capacity than i originally guesstimated. 20 kilos less, so i am back to factory weight again. :)
My commute is not a long distance but lots of waiting at traffic lights.

Wow - you seem to have a strong handle on what everything weighs and what battery capacity you need.

What does you car weigh and what are you projecting for w-h/km or w-h/mile? Does that include some 'fun' driving?:D

I'm expecting the Mazda will be around 350 w-h/mile at first. When the tires need to be replaced, low rolling resistance tires should drop that a bit. I think one rear wheel bearing need to be replaced, which should help as well. The emergency brakes are dragging a bit, so fixing that will help as well. After that is closing off the radiator space up front (if the cooling system can handle it), adding to the hood to streamline the wipers, perhaps eventually a belly pan.

At 350 w-h/mile, I just make my commute with no safety factor. I will charge a bit at work, just 110V, and keep the batteries warm so that they perform well. But it's not much of a safety factor.

If I can get her down to 250 watt-hours/mile, my 22 kw-h pack will get me about 90 miles in a pinch, 75 miles comfortable, and I need 60 miles for my daily commute. I don't expect to have the air conditioning running ever again, but I left it in place in case I change my mind (I know I can save some weight here, but it's easier for non-mechanical people like me to leave it where it is then to keep all of the parts together and install it again)

thingstodo 09-28-2014 03:01 PM

Mazda MX6 Day 010 video 006 July 9, 2014
 
The motor adapter and motor coupler and an emergency disconnect (mounted in an electrical box) were ordered from Canev

Battery pack measurements 24 wide x 13.5 deep x 9.5 high for 16 renault/leaf cells plus the supports on each end. I have 3 of these assemblies, rated 8 kw-h each but they measure out closer to 7.3 kw-h

There is 49 inches across the back seat, seat is 8 inches off the floor plus 3 - 6 inches of foam in the seat, 6 inches in the front sloping down to 3 inches at the back.


Mazda MX6 Day 010 Video 006 July 9 2014 - YouTube

Astro 09-28-2014 09:27 PM

Quote:

Originally Posted by thingstodo (Post 447775)
Wow - you seem to have a strong handle on what everything weighs and what battery capacity you need.

What does you car weigh and what are you projecting for w-h/km or w-h/mile? Does that include some 'fun' driving?:D

Fun driving has been one of the main requirements from the beginning.

I have a spreadsheet i used to calculate everything right at the beginning of the project. It uses logged GPS data to calculate power usage taking into account such things as the rolling resistance, wind resistance, conversion efficiency, weight, terrain etc.
When i went to get some figures for you i noticed they all seemed a bit off.
I dug down into the formulas and found a fudge figure.:(
Looks like this figure is used to tune the result to match real world. But that makes it not very accurate as a prediction tool prior to the build.
I didn't notice this in the beginning as i didn't know enough to feel that the figures were not quite right.
So i will have to rewrite the formulas to reduce the need for the fudge figure.
My battery requirements may need some revision.:o

thingstodo 09-29-2014 11:40 AM

Quote:

Originally Posted by Astro (Post 447848)
I have a spreadsheet i used to calculate everything right at the beginning of the project. It uses logged GPS data to calculate power usage taking into account such things as the rolling resistance, wind resistance, conversion efficiency, weight, terrain etc.

That sounds like a complicated spreadsheet. Perhaps a predictive model would be a better description?

Quote:

My battery requirements may need some revision.:o
So are you willing to share? Predicted weight of the car, required battery, depth of discharge, watt-hours required per km or mile?

I'm sure that it's not just me who - others would be fascinated as well!

I'm not asking for the spreadsheet, just some juicy details:D

thingstodo 09-29-2014 11:48 AM

Mazda MX6 Day 014 video 007 July 13, 2014
 
Put a 12V battery into the car and determine if I removed too much of the wiring harness.

Review of what still works inside the car - dash, windows and locks, heating and cooling, signals, etc

Mazda MX6 Day 014 Video 007 July 13 2014 - YouTube

Astro 09-29-2014 07:56 PM

Quote:

Originally Posted by thingstodo (Post 447960)
That sounds like a complicated spreadsheet. Perhaps a predictive model would be a better description?

So are you willing to share? Predicted weight of the car, required battery, depth of discharge, watt-hours required per km or mile?

I'm sure that it's not just me who - others would be fascinated as well!

I'm not asking for the spreadsheet, just some juicy details:D

I wouldn't want to post the figures it gave for my car as they were not accurate and may miss inform later readers.

The spreadsheet came with the details for a Mazda MX3 in it.
The accuracy of that existing data is apparently spot on.
The spreadsheet was sent to me by another Ecomodder.
I did a Google search and found it at https://mazdamx3ev.files.wordpress.c...energy-mx3.xls
Much of it is in Slovenian. (Google translate is your friend here)
There is an introduction page in English.
The spreadsheet is fairly straight forward, it's the formulas that are tricky.

It is when i put my data in that the accuracy dropped due to me not knowing in advance what value to use for the fudgefactor variable.

This spreadsheet is crying out to be converted to a web application that would allow people to upload their commute GPS logs and car details and get all the power usage details. (Including regeneration) Maybe even allowing people to share GPS logs so you could see how your vehicle would go in different terrains. (whilst being privacy aware)
Maybe even create some theoretical terrains, like 100klm of perfectly level road to get the theoretical best case figures for your car.

More time, more time, too many projects, not enough time. :)

thingstodo 10-01-2014 11:39 PM

Mazda MX6 Day 018 video 008 July 17, 2014
 
Driving the transmission with a cordless drill

Mazda MX6 Day 018 Video 008 July 17 2014 - YouTube

- measure the transmission splines
- measure the distance across the engine bay
- assemble a linkage to drive the splined shaft with a drill
- the assembly did not work out - failure on this one

thingstodo 10-02-2014 08:00 AM

Mazda MX6 Day 021 video 009 July 20, 2014
 
Weighing the parts removed from the car

Mazda MX6 Day 021 Video 009 July 20 2014 - YouTube

293 lbs from the front
102 - 122 lbs from the rear
395 - 415 lbs total


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