Tabwelder Setup

Tabwedler setup

Ok so we finally got the tab welder to do some constant OK welds. I am not 100% satisfied with the quality, but I give them a 80%... so it's not so bad. Either we stick with this quality or buy a new tab welder. To date this tab welder is far from being the best! We don't have much experience with tab welding, but we seem to have so much problems with it. We can't weld copper, we can't use tungsten rods, it's very hard to do constant welds on thin materials! We have a good setup and we will keep it.

I think the best solution is to do more welds per battery and we will be fine.

Next, I will be reviewing the nickel tab design to include a fuse in between each cell. It's a simple design solution and doesn't cost anything more. The guys that are converting a another Porsche from MIT documented this process. Pretty cool project they have! I also need to check how to machine does tabs... Laser or waterjet??? hmmm.

Quick note on our setup: We made up a rack to hold the welder higher off the ground, like this the battery packs can go underneath the welder. It is easier than making long and complicated extensions from the electrodes holders.

Transmission measured, Thanks to WME and SPGdata3D

FARO ARM_Transmission

A couple of weeks ago I started to work on the motor mount and coupling and found that ElectroAuto was making custom adpator plates with a very nice design! After confirming that they could do the custom work for me. It was time to either send the transmission or take the measures myself. However, do to critical alignment of the motor with the transmission, I couldn't get enough accurate measures with a simple caliper.
So I looked and CMM shops and found SPGdata3d and WME near Montreal that could probably help me!
They were so helpful and quick to respond. By Sunday night everything was done! They used a FARO arm to take accurate measures of each mounting holes and the transmission shaft. Take a look at the pictures to see the setup!

Thanks a lot to both Dan Popovici and Jim for the great help, I'll be sure to contact you once the car is done!

Next step! Finalize my design to mount the rear battery rack on the adaptor plate!

Battery Pack Update!

Battery_Pack_update

Quick update on the battery pack!

We received 55 meters of nickel from our Chinese supplier! Very fast delivery! Its 101mm wide and .254mm thick(.010")

We received 300 A123 Batteries and the RIM1000 IR tester to test the internal resistance to make sure they are OK! To date all are good but I only tested 20.

We simulated the packs with some pressed wood to see how well they would fit in the car. It still needs some fine tuning, but it looks for now! It was long to find a good setup to fit those 3420 cells. The pack is devided in 14 sub pack each have 30 cells in parallel and 8 in series to make 24V packs. 10 packs will go in the back and 4 in the front!

I will post more info on the battery pack as we go along.
The next step is to validate that the batteries are all good to go as they are not new. But should be within 98% of there initial capacity. Only time will tell!

Cool Artistic photos!

Artistic Photos by Linda Ross

Last weekend while we were working on the car, my very friendly neighbor Linda passed by to take some pictures! Take a look at the result! It's amazing how she made great photos with the mess there was. She has the eye of an artist!!!

Tab Welding tests

Tab welding tests

Not So easy to Tab weld batteries!!!

After two days of tests with different batteries, electrodes and welding materials. Here are our results.
Batteries tested : K2 Energy (Steel), A123 (Aluminum)
Tab Material tested: Copper (5mils,10mils,12mils), Nickel ( 5mils, 10mils, 12 mils)
Electrodes: Copper, Tungsten

We first tested copper tabs (with Copper Electrodes) because we preferred to go with the most conductive material and the cheapest. However we were never able to make any welds. The electrodes would stick to the copper, but not to the batteries. We tested all thicknesses, different power outputs, sloted copper, even stepped tab welding (one electrode on the tab, the other directly on the battery). Also, one electrode would blast through the copper most of the times (pic2).

Then we tested tungsten Electrodes to see if we could tab weld cooper. Nothing worked, the electrodes welded to the copper but not to the batteries(Pic4). We don't want to make any conclusions with the tungsten electrodes because are setup was far from ideal(Pic6), because of the diameter of the electrode the contact might not be big enough to pass all the current. We will modify the electrodes to do more tests.

The next tests were with Nickel tabs and copper electrodes. This is where we achieved the best results.. With a little adjustments we got great tab welds (bizarrely I don't have a pic of them). 5mils thick Nickel tabs are too thin, 10mils achieved the best result for our setup.

P.S: I want to specify that none of us are Tab welder experts and that we may be doing something totally wrong, but we don't know what!

Motor has arrived!

Motor has arrived

We received the motor almost 2 months ago, I just haven't had time to post and work a lot on the project since! I recently started working with my brother on a start-up and it's taking a lot of time and energy. We are making domestic Wind Turbine! Hmm clean Energy for the Porsche! Well Hydro is pretty clean.

Anyways, back to the motor.
The motor looks GREAT! just the packaging is amazing. The controller was packed in foamed urethane (expended directly in the box to fill all the gaps and avoid any vibrations or shocks).
All the connectors are military type application. Also great!
The quality of the motor looks flawless for now, I cannot say much more without testing it. Looking at the size of this motor for the power in can deliver is just amazing. It is sooooooooooooo small. Can't wait to make it fit.

I should be posting pretty soon again with some battery tests we did a couple weeks ago!

UQM 125EX Is Ordered

Today is a big day, the motor is ordered!!! there is no going back now. The 125 EX should really be a great fit with the car. Since we will be keeping the clutch and the transmission, it was best to choose a motor that is similar to the actual 911's. With it's torque of 400N.M Peak, 170KW for 10sec, and 8000rpm. It is a very close match.
Except for the top speed that should be limited at around 170km/h continuous and 200km/h peak, this motor should bring the car to 100km/h in under 6sec just like the original.
Still a lot of choices to be made but it's the first big step in this project. Lead time is approx 6 weeks.

Gas tank is out!

Not much to say, but what a great feeling to remove the gas tank out of the car.
It's a symbolic item to remove even more than the engine.

But it didn't come out without a fight!!! We thought it would take an hour to take down, instead it took 6! The shape of the tank is so complicated that you need to take the entire front frame, coolant hoses and suspensions to take it down.

Back from Colorado (Visited UQM and Elithion)

UQM Visit

So i'm back in Montreal after visiting UQM and Elithion. Both meetings were great and both give a lot of confidence working with them.
UQM is a great company with one thing in mind Quality, each part is made directly at the factory, from the machining of the blocks of aluminum for the motor to all the assembly of the inverters. Each motor is tested before being shipped.
After a good technical discussions with Andrew and Dana, we found out that another option might be available for us the PowerPhase 125 EX. Just an inch longer than the regular 125, but with 140KW peak(possibly to 170KW for 10sec) and a continuous rating of 70KW. I'm really looking forward to get the full spec of this one.

Next stop Elithion. What a friendly guy this Davide and so much experience to share. We sat down for two hours looking into details of how to setup the pack and I got a very good explanation of how CAN works and communicates to each other. I'll share on another post what we came up with for the battery pack.

Overall, it was a great visit to Colorado and i'm looking forward to working with both of them.

ICE MOTOR IS OUT!!!!

Engine removal

After a little break for christmas, we worked hard this weekend to remove the Porsche's motor. With the great help from Alex and Laurent, everything was done professionaly with no great difficulties. The scissor lift was very handy to lift the car while the motor was supported on a wood case.

It's fun to see the engine out, but it is very compact and does not leave us with a lot of room for the battery pack in the rear. I will try to analyse the space available for the batteries both in the front and back. But the key is to have lots of weight in the back like the original car.