Milestone: We've got motion !!

Hallelujah! After installing the motor, transmission and the torque bar, after fiddling with stuck brakes on the rear wheels, after sitting around for hours and hours thinking where and how to place the batteries in the engine compartment, I thought "What the heck, let's not wait any longer until all the batteries are installed and until all the cables and switches are ready, let's install the inverter with the mains rectifier and spin up some wheels!". A bit doubtful because of my last experience with the transmission, I hooked up everything, connected the mains and the laptop, let the motor spin in neutral first and then punched in 3rd gear. No explosions, no grinding, no blown mains fuse - only wheels spinning happily. It was so quiet that at first I thought "heck, why did the motor stop now?". :) But everything was all right. Only the wheels were spinning backwards. But that's not a problem with an AC induction motor anyway. Let it run "backwards" and the wheels were spinning like they should. Shifting from 1st to 2nd and to 3rd went pretty well with the wheels in the air. The other gears needed a bit more juice on the shift knob - too much for my taste - but I think that's only because the wheels slowed down significantly while shifting. Under real driving conditions, the wheels will still be spinning through the inertia of the car. So also 5th and 6th should be possible without a clutch. (yes, I'm going clutch-less).

Still, I need some Nord-Lock washers for the batteries: Why? There's a lot of vibration in a car and I don't want the battery connections to become loose.

Unfortunately the wood shed I used as my garage caught the dry rot - that's a really nasty mildew. The entire area where it becomes visible, plus at least 1 meter of the wood has to be removed and everything else desinfected. It grows 1-4 cm per day (!) and destroys the wood so it gets soft like carton within days. All the wood and also the wall visible on this picture had to be removed in a very costly purification procedure. So half of the floor in the shed is gone now. It was renewed 1.5 years ago for 6k so it could carry the load of the car and the lift.
Bummer!

Crankshaft and CAM signal faking

I'm trying to fake the crankshaft and CAM signal with an arduino based system (www.gevcu.org) according to Volvo's specification. The output of my signal generator (https://github.com/neuweiler/EngineSignalSimulator) is looking a lot like the one in Volvo's spec. But somehow the ECU is not happy with it yet. I get DTCs about alorhythm problems. On the right side you see the spec sheet and the output on the oscilloscope. In the spec the crankshaft signal is supposed to be a sinewave with voltage range from 0.1V to 100V according to the motor speed (the rpm sensor it's a magnetic inductor). But on other pages, it's said to be a sinewave from 0.1 to 5V. So I'm not sure if my timing is out of spec or if it's just the voltage which does not conform to the speed of the signal or if the ECU is not happy because it's a square wave and not a sine wave.
I think I need a reference signal..

Construction Time, Part II

With the transmission fixed, my spirits rose again and I spent more time in the shop, finishing the battery bay. No rocket science but an important step. Also the brackets mentioned in the video, which will mount the rear part of the bay to the car, are already done and ready to be mounted. After checking the distances of the batteries again, I found out that it should work within the tunnel and on the left side. But the ones on the right side of the car, exactly where I'm working on in the video, are most likely a bit too close and I have to re-do them - sacrifying a bit of the safety space towards the rear strut. With some insulating rubber or silicone it should still be allright though.
To prevent the batteries from moving up in the construction, I first thought of velcro straps. But I think I'll be placing a plastic sheet on top of the batteries and then fill the space above with expanding construction foam. This should sufficiently hold the batteries in place vertically. The major forces will be picked up by the aluminum construction.

Transmission Repair

Finally, I've cut my video on the transmission repair. It came out quite lenghty and is totally not EV related. But it might be interesting for some folks dealing with transmission problems. Without spoiling the story, I think I got very lucky and am thankful that it didn't get as expensive as I first expected. One of the next videos will be a report about mounting the motor and transmission and probably we get some wheels spinning :) Mwha ha ha !

Construction Time

The construction of the "underbelly battery support structure" is progressing well now. In the video below you'll get a look at how I attack the topic which might give you an idea for your conversion. In the meantime I also messed up with my transmission. When I got the adaptor plate, the transmission shaft and the motor back, of course I had to put everything together and spin up the thing. It was exhilarating to also see the output of the differential spin when selecting a gear. I knew from Volvo's service manual that I'd have to take care so the differential doesn't start to move the wrong direction. So I only selected a gear with 500rpm. All went well the first time. The second time during a demonstration to some friends, I was distracted and forgot to switch back to neutral. At 2500rpm: klong - krrrrrrrrrrrrrrrchchchch.. I immediately pushed the emergency stop button but due to inertia and no regen applied, it took about 10-15 very long seconds until everything came to a standstill. To say I was downhearted was an understatement. Looking inside the differential you could see loose gear wheels and a rod I didn't remember was there before. Comments from other car aficionados didn't lift my spirit either: "Looks like everything fell apart..", "This looks wasted..", etc.
So I went to the Volvo dealer/shop of my choice to ask if they could help with repairing the tranny. Apparently OEM's no longer fix transmissions. They just replace it with a new one. When the supportive mechanic looked up the price in the computer - keep in mind that Volvo's service part are not really cheap - his puzzled face and a "whoops!" didn't help my mood much either: 4200.- USD. !! :( That's not an option for my already strained budget. Then there's a transmission shop close to Lucerne: Automaten-Meyer. Their initial estimate: 1200.- USD for the work only, no parts included. That's better but still, there has to be another way. The used trannies from wrecked Volvo's were also in the range of 1500.- USD - with 200'000km on them, that's just to much. In Germany I found a dealer which sells new tranmissions for 1700.- Euro. This after-market transmission would be my fall-back. I found some details about the inner life of such a manual transmission on the net: here and and here. But what really gave me the right kick, was the detailed report of a diff replacement in an M56 transmission. Mine is a M66 but it was close enough, the M56 is its predecessor and told to be quite simmilar. Thanks to this post, I thought: Well, I have nothing to loose, let's open the darn thing and see what's wrong with it, maybe with a huge bunch of luck, I'll be able to fix it. Bear in mind that if anybody told me that I'd have to open and try to repair the transmission during this conversion, I'd have never started it at all. Opening transmissions was a big taboo for me - for someone with no machanical education, a software developer. Yet, I opened it.. found out what happened.. and ? The conclusion will follow in the next video.
Now that I've got all major parts, there's only one but very important thing missing: Nordlock washers. Based on experience and reports from evtv.me, they are certainly a part I have to include in my conversion to secure the bolts in the batteries. As I have 120 cells with 2 poles and some other connection terminals, I will require about 260 pieces for M8 bolts. I will not do it otherwise. To my impression, these Nordlock washers are the only thing which ensure tight and reliable connection to the terminals. Non-secure power connections are cause of heat, increasing resistance, more heat and potentially fire. So no trade-off there. I just haven't got around to get my hands on them.

High Voltage

I'm mainly building a mounting rail below the car for the batteries at the moment. I must admit, it's the task which taxes me most in this conversion. I like designing, doing electronics and software - but metal construction is a bit foreign to me and I find it tedious. Yet, I'm a bit proud of my construction. In the pictures on the side you see the T-shape rails in the exhaust tunnel and the almost finished construction. The third picture shows how I used a hollow aluminum tube (square) as a spacer to attach a rail. Inside is a threaded rod which attaches the construction very firmly to the former gas tank mounting. The rails will be bolted together in the lower right side of the picture. In the fourth and fifth picture you see an example how the batteries will be placed in the construction. The L-shaped rails from left to right will be bolted down to the T-shaped rails on the side with gibs. The L-shaped rails are close to the poles of the batteries but I think it is still safe this way. The batteries will be strapped down with velcro bands. Klaus AG is also helping me to create a mounting structure for the motor to the original motor mount. More on these things later (incl. a video for evtv).

Aside from that, I'm prepping up my HV stuff. Buying some missing things like another contactor for the heating system (Gigavac GV200), a maintenance switch (Gigavac HBD41a), some high voltage - low current fuses from EV West, a Polycarbonate case for an HV distribution box (Hoffman Q403013PCICC). As I require 4 bus bars with 5 connections each, I decided to create them myself and save 400 CHF. In the metal shop of my choice, where I got all the rails, I also found an offcut copper bar which suited my needs: 2.5cm x 1cm, cut down into 4 pieces of 12cm length - all for 35.- CHF. I'm going to drill 8mm holes, insert screws with a copper washer and cast it into polyurethane resin - two blocks colored red and two colored black. They will be put into th HV distribution box together with 3 contactors, 1 pre-charge relay and some fuses (see overhauled wiring-diagram).

I'm itchy on getting my motor back with the adapter plate - I need to to get some wheels spinning to boost my motivation.. I'm getting closer, I know, but after one year, I must admit, I'm looking forward to put an end to crawling around under the car. I want to sit in it for once... :)

Shaft & Batteries

The shaft to connect the motor with the transmission is ready and looking very nice! I'm looking forward to get the setup spinning. But right now the motor and transmission are still at Klaus AG because the motor still needs to be mounted to the original mounting bracket. We have to find a good approach to replace the huge prototype made of wood with a construction made of aluminum. This is currently my biggest worry.
The battery construction is making great progress and I'm confident to get a working approach. I started to replace parts of the wooden construction with T-shaped aluminum struts and now I'm able to determine where and how many batteries can be placed. In the exhaust pipe tunnel 17 cells find their place, in the gas tank area at least 45, in the area of the spare tire 22-24. This leaves only about 36 cells which have to placed in the engine compartment. The huge trunk will remain untouched - and this with 120 cells of CALB CA 100Ah. Most of the cells are placed at the lowest possible point in the car - resulting in a low center of gravity. I will create a movie to illustrate how I did it.
Also the wiring diagram is 90% complete. My version of the GEVCU will support 1 relay to connect the pre-charge resistor with HV+, 1 contactor to connect HV-, one contactor for HV+ and only relay to switch the enable signal for the controller. The sequence is like listed before: first the pre-charge relay closes, no current is running yet and no sparks are created in the relay. Then the HV- contactor closes and the capacitors are pre-charged. The contactor is hermetically sealed and thus less prone to sparks. When the pre-charge cycle is completed, the HV+ contactor closes and then the pre-charge relay opens. The HV part is ready to operate and thus the "enable" relay is closed to signal the controller and DC-DC converter to start their operation.
Next steps: Finish battery construction and boxes and the motor mounting. Then I'll be able to connect the cables and get it moving. Timeline? Hopefully within the next 1-2 months.




Oh yeah, almost forgot: I made another small video about the day of electromobility here in Zurich and about the EFORCE - a conversion of a truck: