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.


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 ;-)