Friday, August 29, 2008

Transmission Dowel Pins and Alternate Vacuum Pump

In the process of removing the engine from the transmission and selling it off, I lost one of the critical alignment dowels that mates the adapter plate to the transmission housing.

Apparently, you can see if local Honda dealers have these parts in stock by browsing the catalog at My local dealer had three of of the alignment dowels. Part number is 94301-14200 and the dimensions are 14mm dia by 20mm long.

I also received an e-mail from Paul Pancella who is converting a '92 Civic Hatchback. He's using Ni-MH batteries to save space and also found a 12V vacuum pump that's smaller than the Gast pump used in many EVs. His blog entry regarding the pump is here. It's great to see progress on other Civic EVs.

As many of you have noticed, things have been quiet for a few weeks. It's the end of summer and I'm trying to cram in all the weekend activities I wanted to do while the weather is still good. Expect progress to be slow for awhile. At least I have all the critical parts I need and it's up to me to keep things going. I've received many offers for help from people who have seen this blog on Slashdot. I feel very fortunate to have the support of the online community.

Off to pick up my alignment dowels...

Sunday, August 17, 2008

Rotating the Brushes on the Warp9 Motor

Many people don't realize that the Honda crankshaft going into the transmission actually turns clockwise for the forward direction, as opposed to counter-clockwise for the vast majority of cars. As such, most EV motors have advanced timing on the brushes to optimize counter-clockwise rotation. Since we have a Honda Civic, we're going to rotate the brushes on the Netgain Warp9 motor so that they have optimal advanced timing for the clockwise direction.

The first step in the process is to remove the protective grating from the rear end of the motor.

The next step is to remove the four allen-head bolts that hold the rear motor housing on.

Note that the allen-head bolt hole lines up with the "CCW" (counter-clockwise) mark on the red motor housing. I drew a line here at the CCW mark so we know how far to turn the motor.

We then use a 2x4 and small hammer to rotate the rear-end housing so that the black pen line (formerly on the "CCW" mark) is now on the "CW" (clockwise) mark. Here we have tapped the end housing almost to the "neutral" or no-timing advance position.

Now the black line is aligned with the "CW" mark. Note that the "CCW" and "N" marks have bolt holes aligned with them for the other two possible brush positions.

On a side note, there are two quick-disconnect terminals the black connector just to the right of the main electrical connection bolt in the picture above. These two terminals are tied to the end of the brushes to auto-detect when they are getting low. I don't know the best way to measure this, but I'm sure I'll figure it out.

With the brushes rotated to the proper "CW" (clockwise) position for the Honda Civic, we use blue loctite and insert the allen-head bolts back into the motor. I didn't know how many foot-lbs we should have tightened these to. Update: Netgain motors has mentioned (see comments below) that these should be torqued to 35 ft-lbs.

And finally, we re-attach the protective grille to keep large rocks out of the motor brushes.

This whole setup was suspended from an engine hoist and supported on a stand; however, I'm guessing most people would just sit this on a furniture dolly or crate and work with it. Interestingly enough, the ADC 9" motors come in a crate and the Warp9 motors come all bundled up in a large cardboard box on top of a pallet.

Visiting EV-Supply in Bellevue

Yesterday, I took a road-trip to Bellevue (near Seattle) to pick up the rest of my major EV parts from Carlo at EV-Supply. Most of the EV garages that I've been to have been a hodge podge of parts and people scurrying around like bees to get things done. This garage was no exception.

Here's a crate full of Netgain Warp9 motors. Mine was originally scheduled to be shipped back on July 2nd, but Netgain has been swamped with orders for motors, so their production backlogged. I guess that's not a bad problem to have given that I want to see more EVs out there.

This Chevy S-10 project is almost done. You can see the ADC 9" motor bolted to the transmission in the center of the vehicle. I wish I had an automotive lift in my single car garage...

Carlo is working on several adapter plate and hub designs for the ADC and Netgain motors. This is one of his test-fixtures.

One of the most popular vacuum pumps used for braking assist in the EV industry is the Gast pump. Here is the Gast vacuum storage tank with the pressure switch protruding down the the lower left of the picture. I wanted to capture this since I purchased a Gast pump from Carlo and I need to figure out the hose connections.

Next up: rotating the brushes on the Warp9 motor for the Honda Civic drivetrain

Belktronix Controller is Here

Last Thursday I received a FedEx package from Belktronix. It looks like the controller, contactor, potbox and integrator unit all showed up.

Here's the pile of parts that I received. I'm not entirely sure what the roll of black padded foam is just to the right of the main motor driver. The contactor is in the upper center with the potbox to the lower right and the integrator unit to the upper right. A small bag of mounting hardware (bottom center) also came with the system. Belktronix said that the charger/DC-DC unit and battery monitors for the AGM 12V batteries will arrive in another 3-4 weeks.

Here's a closeup view of the integrator circuit board. It looks like there's a comparator on the left, a bunch of transistors and several opto-couplers. A big red power resistor with measurement thermocouple under it exists on the right edge of the board. The four black blocks at the bottom of the picture are relays.

Here's another picture of the Belktronix integrator module (the "brains" of the controller).

The contactor has a 48V coil and looks smaller than the typical SW-200 contactor used in many DC EVs today.

Here's an inside view of the potbox. In order to prevent wear on any potentiometer, the Belktronix system uses an optical detector to detect pedal position. The optical transmit/receive sensor is the black box on the far right of the board. A chip in the center drives a PWM (pulse-width modulated) signal back to the integrator. Both the integrator and potbox have a resistor mounted in a socket, perhaps for easy replacement if it tends to blow.

Here's the underside of the potbox cover. The plunger on top is actuated by the accelerator pedal and a piece of white reflective tape on the bottom provides a surface for detection by the optical sensor. I really like this design because you can put it directly under the accelerator pedal and not worry about special cabling. It's optical-based design also prevents any mechanical potentiometer from wearing out.

I'm still a beta-test candidate for the Synkromotive controller, so hopefully I can test both out and see which is better.

Picking an Accessory Battery

Given the limited space and mounting locations in the engine compartment, I tried to pick a 12V accessory battery that would be the most optimal. The original 12V battery from the Civic was just too big to fit anywhere useful. I ended up deciding on the YIX30L battery from Yuasa. This is a standard size motorcycle battery that has similar amp-hours to the original Civic battery. It also has a width of 6.5 inches, just like the group 31 batteries, so it mounts nicely in the front grille battery rack next to the other two main traction batteries.

Here's the battery. I had trouble finding this at a local store, but it was available on the internet and shippable due to its sealed nature. I found the best price at

On a more interesting note, I found out last week that this blog was listed in a slashdot article
I've been somewhat bombarded with offers for help and requests for further information.

Saturday, August 16, 2008

Back in the Saddle...

Well, as many of you have noticed, there haven't been many blog entries lately. The weather has been good, so I've been out hiking on the weekends. I also had to put my cat down on Friday due to kidney failure and I took the weekend to bury him and recover.

On the much brighter side, I received the Belktronix controller last Thursday via FedEx (pictures soon). I also took a road-trip up to EV-Supply in Bellevue to pick up the Warp9 motor, battery lugs/covers and Gast vacuum pump for the brake system. I'm also getting my engine hoist back tomorrow morning from a friend who borrowed it for his truck.

The weather is hot these days (close to 100 degrees F) so I'm moving slowly, but now that I have all the major parts, I can continue engineering work. There's still the open issue of which batteries to use, but that shouldn't hold me up from going forward.

Time to break inertia and get this project moving again.


Rest in Peace, Tigger