Friday, 13 March 2015

Battery testing continues now that spring is finally here :-)

So I have recently gotten back out to my workshop to try and pick up on the battery testing again, there has been a big break from this due to the shitty English weather over winter and other time pressures, but with only 6 months to go before I need the RX8 (which is barely started) I need to get a move on.
I have done a few cell tests recently but have not as yet gotten back into the swing proper, just prepping the rig so that I can easily swap out cells and test 2 every 30 minutes or so has taken some time, plus the blow up of my decent Antec PSU hampered the charging situation somewhat, I have now completed charging all of the cells ready for testing (other than a few failures that need retesting, failed due to random setup failures that are not necessarily problems with the cells) 

“Honey I blew the Gearbox”

Ok so speaking of failures in my last few posts here comes another!
Yes I can now confirm that my adolescent driving style over the last year and a half has finally taken its toll on the tiny little Honda Beat gearbox :-(

After driving over the mother in laws the other night I hear the dreaded “pop” and grinding of teeth once again (barley a month after this happened before) except this time I was literally and coincidentally driving past my mechanics workshop so it was a simple matter to roll it round the corner and park it up for Brent to look at ASAP.
He got around to it a couple of days later, however this time the news was not good, I had stripped the splines from the old clutch plate that we had used to make a coupling plate from and it has also worn the splines on the gearbox as well, so a new gearbox and clutch plate are in order.


You can just see from this blurry photo that there is a distinct lack of splines in that there hole :-(

We have source a replacement gearbox and clutch plate and should hear on this Monday coming from the guy who is selling them.

For now I am back car sharing the deep fat fryer :-(

Meltdown on the Powerlab!

Here comes another failure! I was picking up on the testing rig the other day and after starting a test smelled the bad smell of burning plastic, I began checking over all the battery connections with my nose looking for the source and then the charger quit with “Banana plugs disconnected” during the test. Checked the plugs and sure enough the negative terminal on the Powerlab 8 had melted! Bugger.
Luckily I had a stack of these sort of banana sockets (albeit for old school jacks) that just so happen to be a perfect fit, and after investigating an exact replacement I discovered that they were originally of a distinctly poorer quality than the ones I had in stock, Also luckily my partner had a kids birthday party to attend with our kids so I managed to find a couple of hours to affect a repair (and a pretty nice one at that) Confident that the issue was resolved I went straight back to testing, Successfully now the melted plug has been replaced, I replaced both the –ve and +ve connectors just for ascetics reasons and made a much better mechanical connection that the poor soldered connection that were present originally.
I think the reason for the meltdown was due to the fact that my battery testing rig has a set of buss bars that are connected via banana plugs to the Powerlab 8 which means that I am not plugging and unplugging the banana jacks after each test (as you would normally if you were just testing a single cell pack) so any degradation of the banana jacks was not being noticed until it caused a problem (i.e. melted) So in order to prevent the same happening again I replaced the faulty banana jack plug with a shiny new one (stripped from a dead cell pack) and cleaned the banana jacks pin with wet and dry paper. I will just have to check the jacks more often between cell tests.
I can honestly say that if there is one thing I have learnt (the hard way) it is that the most common cause of problems with HV EV tech is bad electrical connections.

Wednesday, 25 February 2015

Second EMW charger build begins (Very slowly)

So I finally got around to clearing up my den where I have my own PC and do soldering and the like indoors and pulled out the PCB set for the next Non PFC charger build, straight away I noticed that the control board is of a different version V12 and that it has had some “Modifications” to the PCB, some of the ground plane has been drilled out in around 8 places on the board to rectify a ground plane copper flood issue that they must have had with these PCB’s, So I spent a very long time (several hours) catching up on the charger thread on the diyeletriccar forum and much to my dismay the V12 board looks like it might be a bitch to get working, we will see, I have yet to source all the components for the charger build and so I will spend a while collecting resources and parts before doing any major assembly.

Charger fans packed up!

This blog is starting to look like a long list of failures, but then I guess if you take into account that I drive and charge this baby every single working day of the week (5 days a week) and some weekends to boot then the CPU fans I used have probably not done to badly for 18 months of use charging every day throughout the miserable cold & wet winters we get here in the UK, and the last couple have been especially wet, positively monsoon like!
Went to charge night before last and when I powered up the charger the usual fan noise was not present and immediately obvious as such, I left it a while and monitored the temp but it was soon obvious that no fans would mean imminent charger death, So I powered down took the following day off and replaced the 4 small CPU fans I had used in the initial build for a larger single CPU fan and despite its now precarious securing method (zip fasteners) it is jammed quite snugly in the hole cut in the ex-engine bay and secured by a single zip fastener to stop it coming adrift, this is very definitely a temporary bodge and will need addressing properly with 2 new correctly sized fans that are double the depth and preferably a little more robust than the puny CPU fans I have been using up till now, I wonder if you can get IP rated fans I guess so, more research needed.

Also on a side note the small LCD display on the charger is starting to show signs of imminent death, it has developed a couple of line faults in both the horizontal and vertical planes, very annoying as the display is small anyway and any sort of loss of info makes it very difficult to read, also the test after the fan failed appears to have killed the temp sensor, this will also need addressing soon, now reads -68 which I seem to remember is a not present reading (obviously it has become disconnected maybe the excess heat has melted something or more likely my removal of the lid has inadvertently disconnected the temp sensor plug.

RX8 Motor Coupling

Brent called the other day to discuss the motor coupling as it turned out the Kostov K11 that came out of Steve’s MX5 had a splined coupling collar of some sort but Brent had to drill down the length of it and split it open to get the motor detached from the MX5’s gearbox, destroying the splined collar in the process, so much to my partners dismay I will have to purchase further bits to get this sorted.
After discovering that Kostov were going to charge me £235 for the coupling plate (which they incorrectly call a torque convertor for some odd reason) I found a universal coupling plate on eBay that is a perfect fit, ordered this immediately as despite the US duties I will have to pay, It is less than half the price of Kostov’s offering. In fact Kostov seem to charge well over the odds for their parts, I bought brushes for both the motors I own and bearings for the K9 and these also seemed overpriced, I will source all spares I can from elsewhere in future, in fact if I ever get more motors they will probably not be Kostov’s due mainly to the price.
Brent also needs the plastic bush coupler that goes between the K11 coupling pate and the RX8’s diff’s coupling plate.

***Update***

So the parts I mentioned above arrived in good time but unfortunately the motor coupling plate looks more than a little weak to say the least it is split in several places to allow for the easy fitting I guess but this also means that there is only around a 3mm ring of metal that is going to take the full motor torque, Shit that will not do so it is back to the drawing board for this part and to top it off my mechanic gave me the RX8’s coupling plate and this will also need modifying to allow the plastic bush coupler to fit both the RX8 and Motor side.
Still I have a friend who is hopefully going to help me machine up something that will be strong enough to do the job, watch this space ;-)

Monday, 5 January 2015

RX8 Collected by mechanics “The build begins”

Sweet, So after all the fuss the Honda is fine and the mechanics have literally just collected the RX8 for the initial strip down and motor fitting, Once the mechanics have the RX8 in place and stripped I will visit Brent and discuss the build proper.
But at last at least I can actually say that the RX8 build has begun :-) Better get back to the battery testing then!