I don't normally introduce anything to this blog that isn't related to electric cars but sometimes there are exceptions. My daughter, Tammy, is in Geneva at the moment doing a unit at the Murdoch University on International Refugee law. This post is a must read for Australians - in my opinion.
http://tammyingeneva.blogspot.com.au/2013/06/refugee-rants-and-eating-badly.html
A link to her whole blog:
http://tammyingeneva.blogspot.com.au/
I'm still awaiting my tailshaft's return.
Saturday, June 29, 2013
Wednesday, June 26, 2013
Tailshaft and Coupler at the Balancer
The tailshaft (driveshaft) and motor coupler are out of the car again and at the balancers.
They are going to thoroughly check out the mating between the two and balance them as a set.
They are going to thoroughly check out the mating between the two and balance them as a set.
Tuesday, June 25, 2013
More Heater Woes
I have good news and bad news.
Good news #1 is that I know that I can drive for at least 25 minutes withOUT the DC-DCs running into my 9AH 12V battery. In the daytime anyway.
Good new #2 is that I now also know that the NS syle BS88 16A offset blade industrial fuses that feed +300V and -300V into the Heater and DC-DC, simultaneuously blow and safely disconnect the 600VDC from both the afore-mentioned. When replaced with 20A (that's all I had) they safely blew again. (I crushed one in a vise after it blew and the sand had nicely fused to break the Arc).
The bad news.
My heater stopped again rather dramatically. It had worked for about 3 days then one morning last week - no heat. After about 12 minutes of driving I decided that the 12V turn indicators were a fraction slow and pulled over to check the 12V battery - 12.0 volts - not good. There was no power to the DC-DCs. Neither +300V or -300V - which surprised me.
So I went back home because I wasn't carrying spares or even a screwdriver.
I disconnected the heater (funny that), replaced the fuses and DC-DC was back again. 13.6V on 12V battery.
While live (car on) I reconnected the heater -300V all OK, then +300V SPLAT - BUUMPH! Both 20A fuses blew at once.
So I have the heater controller out again. The IGBT AND the Fast recovery diode across the Ceramic element have shorted. It also blew a bit of track off my PCB.
Is PWM controlling a ceramic heater element that hard?
The bottom of my control board. I have circled the missing bit of track. The missing track used to connect the fast recovery diode across the heater element.
After a heap of discussion on the AEVA forums we have finally concluded that ceramic heater elements have very high capacitance. That's why they are not suited to PWM control. The power IGBT is switching into something close to a short circuit at normal switching rates.
In other news, somewhere last week the Vogue passed 1100kM as an electric vehicle.
I'm not driving it this week (or late last week) due to 1 degree C temperatures on Melbourne mornings.
Good news #1 is that I know that I can drive for at least 25 minutes withOUT the DC-DCs running into my 9AH 12V battery. In the daytime anyway.
Good new #2 is that I now also know that the NS syle BS88 16A offset blade industrial fuses that feed +300V and -300V into the Heater and DC-DC, simultaneuously blow and safely disconnect the 600VDC from both the afore-mentioned. When replaced with 20A (that's all I had) they safely blew again. (I crushed one in a vise after it blew and the sand had nicely fused to break the Arc).
The bad news.
My heater stopped again rather dramatically. It had worked for about 3 days then one morning last week - no heat. After about 12 minutes of driving I decided that the 12V turn indicators were a fraction slow and pulled over to check the 12V battery - 12.0 volts - not good. There was no power to the DC-DCs. Neither +300V or -300V - which surprised me.
So I went back home because I wasn't carrying spares or even a screwdriver.
I disconnected the heater (funny that), replaced the fuses and DC-DC was back again. 13.6V on 12V battery.
While live (car on) I reconnected the heater -300V all OK, then +300V SPLAT - BUUMPH! Both 20A fuses blew at once.
So I have the heater controller out again. The IGBT AND the Fast recovery diode across the Ceramic element have shorted. It also blew a bit of track off my PCB.
Is PWM controlling a ceramic heater element that hard?
The bottom of my control board. I have circled the missing bit of track. The missing track used to connect the fast recovery diode across the heater element.
In other news, somewhere last week the Vogue passed 1100kM as an electric vehicle.
I'm not driving it this week (or late last week) due to 1 degree C temperatures on Melbourne mornings.
Friday, June 7, 2013
Checking it's been Charged
I have a 15A timer on the wall of the carport to set my charge time and I don't use any kind of watt/hour meter to measure charge - and the car itself can't measure charge. So my primary method of checking if the Vogue charged during th night is the Energy Easy website which links to our electricity Smartmeter.
Here is what I see when I log in each morning.
The Vogue starts charging at 2AM currently and is generally finished by about 4:30AM. The peak at 6:30AM is our bathroom towel rail turning on. The website is very useful as one morning a few weeks ago I logged on to find no peak at 2AM. The previous night I had checked all chargers by switching the timer to On, then pressed the button again to switch to Auto On and instead switched it to Off. Now I know to press it twice and also check the display.
Here is what I see when I log in each morning.
No Problem Charging in the Rain
The Vogue was the last of three cars into our single lane driveway last night. I took the opportunity to measure up the shortest reasonable length of extension cord that would make it from the mains timer in the carport to the car and cut down my 25 meter Bunnings cord to 12 meters. I haven't blogged it yet, but the socket end now has a custom "shroud" on it that covers the Vogue fuel inlet nicely. Water is directed via a lttle moat through a tube to underneath the car. That's the original system. Anyway, it charged with no problem and this morning when I unplugged the cord from the car the pug was dry. The hinged fuel cover was another matter but a quick dry with a towel helped before closing it - I'll make up a plastic "sock" of some sort for that - no biggy.
As I left it last night.
I added this next photo to this post on the 29th July. The white part of the socket is a $2.50 plumbing fitting cut to size and glued on so that is extends about 3mm past the end of the extension cord's socket. Since the Vogue's plug is elevated above the "moat" by the same amount, it forms a splashproof connection. You can see the drain hole which goes via a plastic hose in the boot (the original) down through to under the car. I have now charged several time in pouring rain with no water at all getting under the socket.
That's not my 150K Ohm resistor - it's in the original sealed socket! The socket has a pathetic little red LED that is barely visible when the power is on.
As I left it last night.
I added this next photo to this post on the 29th July. The white part of the socket is a $2.50 plumbing fitting cut to size and glued on so that is extends about 3mm past the end of the extension cord's socket. Since the Vogue's plug is elevated above the "moat" by the same amount, it forms a splashproof connection. You can see the drain hole which goes via a plastic hose in the boot (the original) down through to under the car. I have now charged several time in pouring rain with no water at all getting under the socket.
That's not my 150K Ohm resistor - it's in the original sealed socket! The socket has a pathetic little red LED that is barely visible when the power is on.
Thursday, June 6, 2013
A Tail of Two Flanges - The Tailshaft saga
Reading back over the blog when I first installed the tail shaft I kind of skipped over some of the messing around I had to do to get it fitted.
One of the reasons I didn't blog all of it was that it seemed like a criticism of the guys that made the coupler and tailshaft and the problems were sorted out pretty quickly - but maybe they weren't after all.
Here is the whole story.
The first ever time I installed the tailshaft, it took me a longer time than I would have thought possible to realise that the four bolts that hold the front tailshaft flange to the motor coupler didn't actually line up. The holes in the motor coupler, while being the correct Pitch Circle Diameter (PCD), were arranged equidistantly around the circle. The universal joint flange on the front of the tailshaft was arranged as a rectangle. This is pretty standard for universal joint (UJ) flanges - at least with cars that I have played with.
This picture isn't of mine but shows what I mean. The two holes on the right are closer than the two holes across the top.
That being the case, the first drive of the Vogue had the front of the tailshaft being held to the coupler with two M8 bolts 180 degrees from each other as all four bolts could not be fitted.
Obviously I wasn't going to leave it that way, so before the second drive I removed the coupler and tailshaft and took them back to the guys that made them and they added some holes and tapped them out to M10. (The original M8 tapped holes were left alone).
When I got it all back and managed to find some fine thread M10 bolts of the correct length, I took another huge period of time under the car before I decoded that there was no way I could get these standard hex bolts in past the universal joint ears (the bits jutting out that hold the cups). So a day or two later I bought some M10 Allen head machine screws.
Again I messed around for an hour or so trying to get these in with no success. They fitted through the tailshaft (UJ) front flange OK but would not all thread into the motor coupler when I offered it up. At some point I realised that the tailshaft flange holes were imperial 3/8 inch - that's 9.525mm.
So I pulled the tailshaft out completely, held the tailshaft as best I could in my workmate, and hand drilled the holes out to 10mm - the biggest drill I had. I cleaned up the facing side of the flange with a 1/2 inch drill bit and ensured there were no burrs.
Once the holes were drilled out, I could almost get all the bolts in by hand. Importantly I could now place the tailshaft flange on the coupler flange, mate the spigots up (the 60mm diameter sections used to correctly locate the flanges) and insert and tighten the bolts up. There was always one or two bolts that I had to pull in with the Allen key the last 6mm or so but it all looked correct.
I explained this to the guys that made ther tailshaft and coupler but they weren't too concerned and have had the tailshaft back twice since then.
So now we are up to this week.
When I picked up the tailshaft on Monday night, it was explained that the balance was fine and they hadn't changed much. It fitted it Tuesday night and it behaved pretty much the same way as before. However, this time I had arranged a system were I could control the motor speed while lying under the car so could have a "play" without having to ask someone else for help controlling the speed. What I found was, even though earlier tests showed the front of the tailshaft rotating without excessive runout, that was not the case on the slip yoke. The UJ flange rotated true but the inner part of the slip yoke did not.
I whittled a chunk of wood and tried moving the UJ centers in their housings (in the direction that would remove the runout) - no give at all (they were properly installed and very good).
For some reason I decided to remove the four M10 bolts and track down the two M8 bolts and washers that I had used on the first drive.
Once I had the tailshaft bolted to the coupler with only two M8 bolts, there was an immediate and substantial improvement. I made a further slight improvement by loosening the bolts and using the tiny bit of play in the spigot to move the mating flanges in a direction that would help.
That's how I drove it today - a lot better. Not perfect yet, but better.
It appears that there is a concentricity problem in the front slip-yoke and UJ combination at the front.
If the tailshaft is being held by the front flange during balancing I would think it would be balanced out.
So we know what it is, the front end of the tailshaft involving the slip-yolk and universal joint - now to fix it completely.
A note here. I measured runout months ago and concluded that the tailshaft was fine. The closest I can normally get to the front of the tailshaft is about 300mm from the front, and it's a lot better at that point. I've got a lot braver with rotating machinery (while still being careful) over the time. A whole lot of factors have conspired to create this problem and make it hard to track down. My inexperience hasn't helped.
Edit: Some changes made for clarity thanks to comments from AEVA forum member weber.
One of the reasons I didn't blog all of it was that it seemed like a criticism of the guys that made the coupler and tailshaft and the problems were sorted out pretty quickly - but maybe they weren't after all.
Here is the whole story.
The first ever time I installed the tailshaft, it took me a longer time than I would have thought possible to realise that the four bolts that hold the front tailshaft flange to the motor coupler didn't actually line up. The holes in the motor coupler, while being the correct Pitch Circle Diameter (PCD), were arranged equidistantly around the circle. The universal joint flange on the front of the tailshaft was arranged as a rectangle. This is pretty standard for universal joint (UJ) flanges - at least with cars that I have played with.
This picture isn't of mine but shows what I mean. The two holes on the right are closer than the two holes across the top.
That being the case, the first drive of the Vogue had the front of the tailshaft being held to the coupler with two M8 bolts 180 degrees from each other as all four bolts could not be fitted.
Obviously I wasn't going to leave it that way, so before the second drive I removed the coupler and tailshaft and took them back to the guys that made them and they added some holes and tapped them out to M10. (The original M8 tapped holes were left alone).
When I got it all back and managed to find some fine thread M10 bolts of the correct length, I took another huge period of time under the car before I decoded that there was no way I could get these standard hex bolts in past the universal joint ears (the bits jutting out that hold the cups). So a day or two later I bought some M10 Allen head machine screws.
Again I messed around for an hour or so trying to get these in with no success. They fitted through the tailshaft (UJ) front flange OK but would not all thread into the motor coupler when I offered it up. At some point I realised that the tailshaft flange holes were imperial 3/8 inch - that's 9.525mm.
So I pulled the tailshaft out completely, held the tailshaft as best I could in my workmate, and hand drilled the holes out to 10mm - the biggest drill I had. I cleaned up the facing side of the flange with a 1/2 inch drill bit and ensured there were no burrs.
Once the holes were drilled out, I could almost get all the bolts in by hand. Importantly I could now place the tailshaft flange on the coupler flange, mate the spigots up (the 60mm diameter sections used to correctly locate the flanges) and insert and tighten the bolts up. There was always one or two bolts that I had to pull in with the Allen key the last 6mm or so but it all looked correct.
I explained this to the guys that made ther tailshaft and coupler but they weren't too concerned and have had the tailshaft back twice since then.
So now we are up to this week.
When I picked up the tailshaft on Monday night, it was explained that the balance was fine and they hadn't changed much. It fitted it Tuesday night and it behaved pretty much the same way as before. However, this time I had arranged a system were I could control the motor speed while lying under the car so could have a "play" without having to ask someone else for help controlling the speed. What I found was, even though earlier tests showed the front of the tailshaft rotating without excessive runout, that was not the case on the slip yoke. The UJ flange rotated true but the inner part of the slip yoke did not.
I whittled a chunk of wood and tried moving the UJ centers in their housings (in the direction that would remove the runout) - no give at all (they were properly installed and very good).
For some reason I decided to remove the four M10 bolts and track down the two M8 bolts and washers that I had used on the first drive.
Once I had the tailshaft bolted to the coupler with only two M8 bolts, there was an immediate and substantial improvement. I made a further slight improvement by loosening the bolts and using the tiny bit of play in the spigot to move the mating flanges in a direction that would help.
That's how I drove it today - a lot better. Not perfect yet, but better.
It appears that there is a concentricity problem in the front slip-yoke and UJ combination at the front.
If the tailshaft is being held by the front flange during balancing I would think it would be balanced out.
So we know what it is, the front end of the tailshaft involving the slip-yolk and universal joint - now to fix it completely.
A note here. I measured runout months ago and concluded that the tailshaft was fine. The closest I can normally get to the front of the tailshaft is about 300mm from the front, and it's a lot better at that point. I've got a lot braver with rotating machinery (while still being careful) over the time. A whole lot of factors have conspired to create this problem and make it hard to track down. My inexperience hasn't helped.
Edit: Some changes made for clarity thanks to comments from AEVA forum member weber.
Tuesday, June 4, 2013
The Tailshaft returns
It's back. I'll try to get it on tonight. I need the car mobile for Thursday.
I picked it up yesterday afternoon but there was no great hurry to re-fit it as Jeff from Precision Balancing indicated that there was no significant change (I also cooked dinner last night amongst other things so time ran short). We may have come up with a way to do an on-site balance of the whole drive train while the car is on stands. I'll post when I have more info.
I picked it up yesterday afternoon but there was no great hurry to re-fit it as Jeff from Precision Balancing indicated that there was no significant change (I also cooked dinner last night amongst other things so time ran short). We may have come up with a way to do an on-site balance of the whole drive train while the car is on stands. I'll post when I have more info.
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