A vendor has asked why the design uses one larger junction box, the BJB, instead of two smaller boxes.
Two smaller boxes would allow splitting the 12V signals like ignition ACC, Ignition RUN, Ignition START, Brake switch, accelerator switch, accelerator position, brake position, gas gauge, from the larger power signals connected to the charger, the batteries, and the motor.
The simple answer is because no one thought of it. It makes sense to separate the 12V signals from the higher voltage and higher current signals for many reasons. To name just one, NPFA 70E suggests voltages above 50V have finger-safe guards installed.
So the next iteration of the Big Junction Box will need new names. So far, Power Junction Box, PJB, and Signal Junction Box or SJB. That does not appear to conflict with anything else and will keep the labels separated.
I have gotten to a point. Time to document some of the process.
Splitting the Big Junction Box into a High voltage and a Low voltage box was an EXCELLENT idea. It has cleaned up the issues with large diameter conductors crowded beside small gauge conductors, small terminal blocks always getting in the way, breaking off the backplate when the larger cables are not tethered well ... many issues, one solution.
I have been working on an AC drive for the sprint. It is as simple as I can think of right now. The power is not battery, but an extension cord. 120V from the cord through a 2000 va transformer to get 220V. This voltage fed into the drive. Drive sends 3 phase to the motor. Speed potentiometer gives a voltage reference 0 - 5 V for 0 - 60 Hz. Enable to the drive is a simple switch.
I'm VERY behind in posting updates. Updates were posted to the WIKISPEED team group, so I will use them to 'backfill' posts. When I'm caught up, I'll try to post details in this build log that are too detailed for the WIKISPEED group.
The High Voltage Junction Box (the Power Junction Box did not stick as a name) and Low Voltage Junction Box (again, Signal Junction Box did not stick as a name) are not split into two boxes as yet. They are in different sections, but they still share a single backplate. That's the first picture
There is a sketch of the wiring diagram and schematic of the combined electric Junction Box. This is the second picture
The first revision (untested - written after testing) set of instructions for interfacing to the electric Junction Box is attached. There are 'future' portions of the HVJB and LVJB described.
The DC option of the Electric Motor Module, as many have already suggested, is simply less money to develop. That's where the effort is focused for now.
Made some updates to the next version of the HVJB - or the backplate, anyway. Picture attached. Not complete, but close.
Wire up the first separate version of the LVJB - again, just a backplate. Picture attached. Not complete, but close.
Update sketches for wiring diagram and schematic. Pictures attached.
Order 3 gigavac contactors
On the todo list, but not yet done:
The DC motor that I'm using has a separately excited field. That gives some control of the available starting torque of the motor, but it involves a more complex controller than I have. There is a requirement to turn off the armature current if there is a problem with the field current, so that the motor does not speed up dramatically and exceed it's safe operating speed. I have a circuit that should work ..
- need to verify the operation of 'loss of field current' circuit
But just in case ... safety first!:
- install scatter shield (metal plate) between DC motor and cabin
This week I received the Gigavac contactors that I ordered. Pretty fast for something shipped from the US to Canada.
Before ordering lugs for the battery cables, I verified that the surplus cable I have is really 2/0 or #00. The local automotive store wanted to make sure, since the minimum order is 25 lugs
#00 cable - I have about 30 feet of surplus cable - is rated for 185A continuous. But that's a bit less than the 4/0 or #0000 (my original, if somewhat paranoid, cable size) that is rated for 235A continuous. The #00 cable, besides the fact that I have some surplus cable, is also a better choice for use in the car. I'm told that 2 runs of #00 is easier to bend than 1 run of #0000. I guess I'll find out.
There are separate part numbers for 1/4, 5/16, 3/8 holes in the lugs for #00 cable. They are also different widths so that there is enough contact area between the lug and the terminal post on the battery.
And then there are two different 'grades' of lugs - light duty or 'battery' lugs and heavy duty lugs used for 'continuous' duty. The fork truck cables that I have seen use the 'continuous' duty. The 3 cables that I have (salvaged from a VFD cabinet) that have lugs crimped on are also 'continuous' duty rated.
For comparison purposes, #00 light duty cable lugs are about $2.50 each and are stocked locally by one supplier. The heavy duty lugs are twice as much, at just under $5.00 per lug. Premade battery cables are $22 - $35 for 6 - 12 inch long cables with two ends, heat shrink on each end, etc.
No one local stocks any battery cables of #00 size (3 cables total from 5 suppliers). #4 cable is the largest commonly stocked.
And I went through the instructions for building HVJB and LVJB. There was a bit of an update but nothing worth attaching.
Update from Feb 14 - Heat shrink, battery cables and wiring
I got the Gigavac contactor ( received a while ago) installed in the bus bar holes that I made a few weeks ago, in the High Voltage Junction Box (HVJB). It's the second one, that connects the main battery power to the controller. That's the top part of the first picture that's attached. The contactor is/will be controlled by the key switch on the car.
I crimped connectors onto smaller wires to get the Low Voltage Junction Box (LVJB) done. The terminals that I wanted to use were difficult to mount on the backplate and required small labels to keep things straight. These small bolts work better. Its a bit of work to crimp on ring connectors, but it's secure and easy to follow, like a larger version of the schematic.
I have updated the HVJB/ LVJB summary. It's up to Rev 2 but still does not contain build instructions. I think I repeated some stuff. It will require more work. It`s too big to attach as a .doc or as a .pdf ... so I guess I won`t post it?
Battery cables from the chev sprint. I had 8 battery cables (sized #2) of 30 inch length from another project. These can be used between HVJB to controller, HVJB to battery pack, and between the battery packs. Then I have 2 cables with lugs (badly corroded, but salvageable) 72 inch #00 as well. So I'm down to several 6 - 8 inch cables that must be cut and assembled to connect the batteries in one pack to each other through fuses.
I have an experiment to try. High quality electrically insulated tools have multiple layers that are different colors. So if you cut through the outter Red or Orange jacket, you see a bright Yellow beneath and know that the insulation was damaged. It needs repair or replacement. I have not been able to locate multi-layer heat-shrink ... but I have an idea. The base layer would be yellow electrical tape. Then I can use the Black heatshrink that I have a large roll of. And lastly, bright orange electrical tape.
So I started with the wrench that fits the bolts on my fuses. I actually used two layers of yellow, then the heat shrink, then two layers of orange. It bulks the wrench up. And I need to figure out where it should end so that the wrench still works as a wrench ... I covered the whole thing and cut out the insulation that was in the way. That's not the right way to do it!
I used a meter probe connected through a 6 ohm power resistor to a variac on the tape and an alligator clip on the other side to connect to the metal on the wrench. It passes! I boosted the variac as high as it would go, just over 140 VAC. All OK. Then I used all of the UPS batteries that I have from a previous project, in series to et 360 VDC nominal (about 375 actual). And it still passes!
So I continued and added one small socket wrench, a small crescent wrench, two screwdriver shanks and two more wrenches. I didn't bother testing the insulation on each. The electrical tape wrapper states that one wrap is good for 1000 VDC. So I guess 4 layers is severe over-kill. I'm OK with that.
The battery cable crimper and #00 lugs took a bit of experimenting to find out which dies would give me a good solid crimp. Everything on the dies is in square mm and the lugs are in cable gauge. The large Heat shrink fits well over the cable and lugs, it shrinks down OK. And works well as electrical insulation to 140 VAC (I didn't test to 360 VDC because I forgot).
The already hard-to-bend battery cable is even less flexible with the heat shrink shrunk. That's not good news. Maybe I can shrink some if it in place in the car AFTER the cable is routed and bent? We'll see.
The existing/recycled battery cables are not #00. They vary from #6 to #4. There were a few lugs on these cables that did not appear to be on very solidly. Another couple were crimped with a hammer crimper (it puts a big dent in the lug and the cable beneath). They were on solidly, but I used the crimper on them anyway. The largest heat shrink that I have fit over most of the lugs and was shrunk down to cover the bared copper (recycled cables) and the lugs up to the `flat part`that makes electrical contact with the battery terminals. It took some experimenting, but there were no big surprises.
One things that I ought to mention - I understand why the crimp dies list sqaure mm instead of wire gauge! I had to use different sized dies on the light duty lugs and the heavy duty lugs for the same cables size. That made sense when I thought about it. Light and heavy are different in the thickness of the copper. BUT .. different heavy duty lugs (maybe different manufacturers?) ALSO required different dies. That one is a bit harder to swallow.
The smaller heat shrink that I bought a bunch of seems to work OK over the crimped cable ends on the small gauge (#12 and #14) wire ... even when you forget to put the short tube of heat shrink on BEFORE you crimp the connector on. The heat shrink drops from about 3/8 diameter to be snug around a #14 un-stripped wire (insulation still on).
Now if only I had found different colors of heat shrink for cheap ...
The target for the week is to get all of the pieces arranged on my garage floor, get things wired together, and to make sure everything works.
The High Voltage Junction Box (HVJB) should have finger-safe guards on it to prevent accidental contact with the 72 VDC. It's just a chunk of plywood, sort of like a backplate, so I don't have a junction box to mount it into, either.
The Low Voltage Junction box (LVJB) does not really need to be finger-safe, but there should be some sort of cover to prevent a dropped wrench from shorting things out. Again, it's just a chunk of wood.
I have some clear and some tinted plexiglass of various sizes, most are large enough to soften and bend into U shapes to cover the bus bar. But that's a LOT of work and I don't think that this is the last time that I'll need to re-arrange parts to make additions. I`ll do that for the final design so that it looks neat and professional ... but I`m not there yet.
As is my custom when I`m looking for inspiration when solving a problem, I went for a walk around the yard (OK, not quite the whole yard - the path through the snow that goes to each shed and the garage). I found some tempered glass, but that would be even MORE work to use. A few clear plastic jugs that could be forced into service if required ... but nothing that shouts - THAT`S IT... Then I tried the basement. My wife bought some clear plastic Rubbermaid containers that stack together. If I can make the HVJB and LVJB backplates fit into the bottom of a clear container, then I can use one cover and the whole thing is finger-safe! THAT`S IT! Minimum work is always nice.
So I did a trial fit of the backplates, to stack it all together. A bit of a problem - the HVJB is long and narrow where the container is shorter and wider ... I guess there is SOME work required ...
So I re-arranged the HVJB from battery pack + on the far left and B+ to the controller on the far right to more of an L shape. The B+ terminal to the controller comes out nearest you (bottom?). It still doesn't quite fit into the bottom of the container, but it will clear the top portion and allow the next container to stack inside - good enough.
The LVJB was on a larger backplate but only required a 'trim' to have it fit into a clear container.
The wiring between the HVJB, the LVJB and the controller will be quite short when it is installed in the Motor Module. I don't have a 40 inch wide plate to mount everything on. So I stacked the LVJB on the bottom, the controller in the 'middle' of the stack, and the HVJB on 'top' since it has a manual disconnect switch that I need access to.
I set up the batteries in 3 sets of 2. A longer cable between - on one pair and + on the next pair. The connection between the batteries in each pair was + on battery 1 to a 6 inch cable to a fuse or a switch, then another 6 inch cable to the - on battery 2. A short *ALMOST* anywhere should blow a fuse .. or as close as I can get, anyway.
Connecting up the high voltage cables was an issue - the clear container does not allow for the cables to enter and exit and sit correctly while still stacking ... and when I get the cables to fit onto the IN and OUT terminals, the cables won`t exit at all. SIGH! I guess the next iteration I'll change it around again. Maybe I can get all of the larger cables out one side and that will allow clearance? Or maybe I should find an easier solution?
The LVJB cables can exit correctly, but the cable that I had lying around ended up being about 6 feet long, so I did not need to stack it beneath the HVJB. So I spread things out. I used 5 foot long cables to connect to the controller so everything is well spaced and easy to see. I can still use the clear containers to be finger guards when this all gets installed inside my test car.
I'll post some pictures and a video of the setup working on the floor when I get the pictures trimmed down far enough to upload. The video will have to be a link to Youtube.
The target for last week was to get all of the pieces arranged on my garage floor, get things wired together, and to make sure everything works. I got to that target this week.
The existing/recycled battery cables that I am using have corrosion on them. Some of them have a LOT of corrosion. The corrosion is a pretty good insulator, increasing the resistance in the cable connections. Increased resistance means increased heat as well as less power being delivered to the motor. So, I dug out of my painting supplies an emery cloth block. It looks like a sanding block, but the abrasive particles do not fall off when you are using it, so there is no residue of sand in the threads of your battery connections, or between the contacts of your cable lug and the battery post.
Removing the corrosion is not difficult. Even the very corroded cables took only a few minutes to knock off the corrosion. I took video of it. It's pretty boring, even for me. I'll get sections identified that illustrate each type of connection and get it put together and posted ... but it's not a big priority for me. I knocked the corrosion off EVERY cable ... or every POWER cable I guess ... even the 'new' cables have corrosion. It's just not as easy to see. Alunimum, copper, tin, they ALL corrode almost immediately in air. Most of the time it is a thin coating, and that coating is a barrier to more air, so the corrosion stops. So EVERY time that you put in new cables, or when you take apart your cables to remove a battery or add another, change controllers, etc you SHOULD knock the corrosion off before putting the connections back on. This is only necessary for the high current connections like the batteries, controller and motor. This same effect happens to all of the rest of the cables used for signals and low power ... but the increased resistance does not lead to drastic issues with heat unless there is a lot of current going through the increased resistance.
The emery cloth would not take off the corrosion inside the holes of the cable lugs - because it won't fit into the holes. There should not be current passing through that part of the lug, and then through the bolted connection, to the battery or controller or motor. But I put the cables on my bench and used a battery cleaner wire brush to scrape them out a bit. I don't think I'll do it every time. I think that the little wire pieces that break off the brush would do damage by being dropped into the rest of the electrical connections and batteries, or get into the bolt threads.
The cables are important, but so are the connections on the controller, the motor, the HVJB and the batteries. The corrosion was knocked off ALL of these. The corrosion on the bus bars, terminal posts and fuses in the HVJB were knocked off during the assembly process some time ago, so the only parts that were re-cleaned were the terminals into and out of the HVJB.
With everything arranged on the garage floor and the cables newly cleaned, I began connecting things together. I started at the load and worked backward. Motor terminals first, connected to the HVJB. Then the Controller connections to the HVJB. Make sure that the HVJB maintenance switch is open. Connect Pack+ and Pack - to the HVJB.
From there, I switched to the LVJB. The cabling from the HVJB to the LVJB was done. Then from the throttle (potentiometer) and pedal switch (mini breaker) to the LVJB. Then the LVJB to the Controller. The final connection to the 12V battery was left undone. The ignition switch (mini breaker) is turned off.
Wiring the pack together, I connected the longer cables between battery packs first. The packs are set up as three pairs. So HVJB pack - to pair 1 -, pair 1 + to pair 2 -, pair 2 + to pair 3 -, pair 3 + to HVJB pack +
Then I added the connections between batteries with each pair. Pair 1 battery 1 + to a 6 inch cable to a fuse to a 6 inch cable to Pair 1 battery 2 -. Pair 2 battery 1 + to an 8 inch cable to a maintenance switch (turned off) to a 6 inch cable to Pair 2 battery 2 -. Pair 3 battery 1 + to a 6 inch cable to a fuse to a 6 inch cable to Pair 3 battery 2 -.
Check voltages on the batteries. Each is 12.5 - 12.6V. Check resistance of connections and cables between batteries. Each shows 0.0 ohms, or less than my meter will read - this is a GOOD check, but not accurate. To get an accurate measurement I'd need to use a high current measurement device like a ductor. A ductor uses 5 or 10 amps of current through the probes so that the voltage drops can be measured more accurately, and the resistance calculated. They measure milli-ohms (thousandths of an ohm) and micro-ohms (millionths of an ohm). They are a bit expensive for a hobbyist. I'll sign a ductor out of the tool crib at work and take video of checking the connections when I get everything set up in the test car.
I set up the video camera ( my phone), got my green laser pointer, and started taking video of each piece of the setup. Besides tripping on the tripod legs a couple of times (no damage to me or the phone) it went pretty well. After looking at the video, I think I'll set up some extra lighting next time.
Now for the moment of truth - turn it on. I started by plugging in the 12V battery for the 'car'. Again, video camera set up and I went through 'turning on the ignition', verified the correct contactor in the HVJB closed, saw the controller turn on and give me some blink codes for low voltage and accelerator active. So I turned down the accelerator to 0. Then I turned on the maintenance switches for the pack and the HVJB, measured the pack voltage at the HVJB, then pressed the 'pedal' to close the contactor across the precharge resistor. The controller is OK to go, so I turned the 'throttle' and the motor started!
There were a couple of problems - blink codes on the controller that I needed to look up before I continued, a bad crimp on the 12V 'car battery' so the controller would not turn on ... as well as a couple of checks that I did since things were powered up - measure the resistance of each contactor and each switch in the ON state ... those ARE on video somewhere but I did not go through the effort of taking parts of several videos and splicing them together. Most of the video that I have posted is from one file, with the silences and muttering to myself parts removed.
I added a piece of tape so that the video would show the motor turning. I stepped on the motor the first time I started it since I don't have it on a mount and if it started with a lot of torque, it could 'roll away'. I think I did that in later videos as well, just to be paranoid.
After some run-up testing with the smaller motor, making sure that everything was working as it should, I connected the Netgain motor. The first time it turned, I was surprised at how much throttle it took to start. There were SPARKS coming from the brushes ... and the motor did not sound as it should. I repeated the run-up, but not to a very high speed in case there was something wrong in the motor - I did not want to damage it, but I wanted to see if the sparking and the noise would go away with a bit of runtime. As it turned out, the sparking lessened but it was still visible. The noise did not get any better at all.
So - what can be wrong?
1. The brushes may be new even though it is a used motor. If the brushes are new, they are not worn into the shape required to make good contact with the armature, so they spark a bit until they are worn in. There is a noise that the motor will make when this is happening, but the video that I have seen and listened to does not quite sound like this.
2. The brushes may be in backward. If someone worked on the motor that was not familiar with DC motors, the brushes DO fit backward and only a very small part of the brush would be contacting the armature. The angles would be wrong, so the leading edge of the brushes would wear quickly and make some noise.
3. It could be turning backward. If the brushes were worn in going clockwise and it is now going counterclockwise, or if the brush position is advance for clockwise and the motor is turning counterclockwise .. I'll have to check. This may explain the sparking but the motor should not sound like that.
4. The bearings could be making that noise and making it hard to spin the motor. That would explain the noise but not the sparking.
5. The armature (part that turns) could be damaged and could be rubbing on the stator (outside part that does not move). That would be bad, and hard to fix. I won't talk about that one any more.
6. Something else that I have not thought of could be wrong. I'll need to take it apart and inspect it to see. Perhaps a cleaning will help?
In any case, that's it for today.
I stopped the video and took pictures of each piece and the overall connections for documentation. If I can get the pictures compressed enough to post, I'll add them to this update.
I'll be away from home for the next couple weeks, so there will be no progress on the motor inspection but I'll try to get some items off my todo list, like editing the video.
The target for this week was editing some video. That video was taken last week and filmed last week but edited this week. It is attached to last week's update.
This week I found out that there is a potential customer for the still-in-development Electric Motor Module! This is exciting and scary at the same time. Exciting because someone out there, besides me, thinks that this is a good idea. Scary because there is now a deadline for something to work.
Getting everything working on my garage floor last week was a very big step, but much work remains. On the electrical side:
- Do we stay with a DC motor and controller or move to an AC system?
- What kind of batteries should we use, and how many?
- How do we mount the batteries to the Motor Module Frame?
Then there are some issues that are a bit more mechanical in nature:
- Which transmission should we use?
- What type of transmission, automatic or standard?
- How do we source the motor to transmission adapter and mounting plate?
- How do we adapt the output drive shafts of the selected transmission to the 2006+ Honda Civic wheels that WIKISPEED uses?
I entered these decision tasks, some follow-on tasks, and some miscellaneous tasks into a package that WIKISPEED is using called KERIKA. (www.kerika.com if you are interested)
Kerika is an interesting software product. It is like a Kanban board, where you have a bunch of tasks posted on the left of the board in the approximate order of priority. From that list each member of the team selects the highest priority item that they know how to do, or that they WANT to know how to do, and assigns it to themself. Normally the people who WANT to know how to do something seem to be the ones that assign the task to themselves and then go about talking to the rest of the group to find out who is there that KNOWS how to do the task. At that point they pair up and do the task TOGETHER. It's progress, but it's training, and it's a 2 person team so there are different perspectives.
When the task is done to the satisfaction of both team members, they take a short video of it working, or of them describing how it works and post it to the WIKISPEED youtube channel. The task is moved to Pending Review. At that point, the person in the shop who knows the most about that task reviews it with the team and determines if it is done or if there is all or part of it that needs some more work. If it passes review, it is moved to the DONE column and a bell is sounded to let everyone know that another task was completed.
The Kerika software does not have a bell, and not all participants are logged in at the same time. But I'm told that the effect is similar by those who participate in both methods.
For next week, some research is required. A few phone calls or emails to determine if the list of options can be narrowed. A discussion with the potential client to see what their expectations are, and how best to fulfill them.
I have made some tentative design decisions to move forward on the Electric Motor module, outlined below. Please point out any issues you find. I don't believe that this will be the final design ... in fact, I think that there will be more than one final design ... but I believe this design is a good start.
Executive Summary, since this post is so long ... that I need a SUMMARY!
The design will use a DC motor driven by an open source DC motor controller. The DC motor will be coupled to a Honda Civic manual transmission 1984 - 2005. The power will be supplied by a number of lead-acid deep-discharge batteries. The charger is plugged into an ordinary 120V receptacle. All of these parts interface only to the High Voltage junction Box and the Low Voltage Junction Box, not directly to each other. The interface to the rest of the car is not detailed quite yet.
Details
Looking for `more sets of eyes` to see comment on whether these decisions make sense and will be sustainable. Each section has a title, a list of options, a Plus and Minus list, and a summary with the decision that I think is best.
Motor
There are, in my opinion, 2 obvious choices for the Electric Motor Module. I am not considering purchase of another motor at this time since it would add cost and delay for delivery:
1. my aircraft generator
2. my Netgain 9 inch motor
1. my surplus aircraft generator, separately excited
Plus list
+ it has a mounting plate and a coupler already fabricated for the chev sprint transmission
+ I have it
+ no machining is required if there is a joy coupler on the transmission
+ it is light (under 100 lbs)
Minus list
- the generator is separately excited, so more controls are required, another pair of batteries, field current monitoring, etc
- it is less safe to use, since the field current must be established before applying the armature current
- there is a challenge to mount a cooling fan to the motor. The motor drive end has no holes to allow air flow in
- there are no specs available for this generator. I've read ratings from 15 HP to 21 HP but I have no backup for those numbers. Any information may need to be tested and measured.
2. the Netgain Transwarp 9 inch series wound motor
Plus List
+ the controller handles all of the speed control. No external circuitry is required
+ there are holes in the shroud to allow for an external cooling fan
+ it has a coupler for the motor side, and I have a joy coupler that can be used to drive the chev sprint transmission
+ it is a popular EV motor
+ it is available new from several distributors for 'mass production' of the Electric Motor Modules if that ever is required
Minus List
- a mounting plate will need to be fabricated for either transmission
- a coupler, or half a coupler, needs to be machined for the honda transmission
- it is heavier at just over 200 lbs
Summary
I think that the Netgain motor is the obvious choice. It is a standard motor, it is easily controlled by a commercial DC motor controller. The aircraft generator is more dangerous to control, requires external circuitry or another controller to effectively control torque and speed. The Netgain is more powerful and more likely to be a standard offering for the Electric Motor Module in the future. Applying the Keep It Simple principal - Netgain motor.
Controller
I have two different available DC controllers. Again, I am not considering purchase of a different controller due to cost and delivery issues:
1. Kelly controller - KDHD
2. Pauls & Sabrina's 'ReVolt' Open Source 500A DC Motor Controller
1. Kelly Controller
Plus List
+ it is powered up and operating
+ the rated continuous current is 300A, maximum current (1 minute) is 600A, which is likely more than the batteries can source
+ it is a very simple electrical interface
Minus List
- there are no optional connections
- it is not very powerful
- since it has no optional features, it does not indicate the internal temperature although the manual states that it will cut back current in order to prevent the internal temperatures from failing the components
2. Paul & Sabrina's 'ReVolt' Open Source DC motor controller, Open Source project
Plus List
+ it is more powerful than the Kelly, 500A continuous but no information on maximum current for short periods of acceleration
+ we have drawings for the controller, a Bill of Material, and the files required to produce more boards
+ we have an interface that will communicate the internal temperatures
+ it has self-protection circuits to shut itself down on over-current and prevent damage
Minus List
- mine has not been tested as yet
- it will take some work and some time to test
Summary
The interface for each of these controllers is very similar. My intent is to use the Open Source controller. If there is some issue that cannot be quickly resolved, the Kelly can be used instead. There will not be a large difference either way. Decision to use Open Source. The Kelly will be held as a spare.
Transmission
There appears, to me, to be 3 ready options for the transmission. This section considers purchase, since I have only one transmission and it is not, in my opinion, an ideal candidate for the car:
1 - 5 speed manual from my 1990 chev sprint
2 - 5 speed manual from a 2006-2011 honda civic
3 - auto trans from a 2006-2011 honda civic
4 - added - 5 speed manual from a different year of honda civic
1 - chev sprint
Plus List
+ I have it in a car, available immediately
+ I can measure things on it
+ The transmission runs
+ It has a splined shaft, but the splined shaft also has a joy coupler mated to it, made by the machinist who sold me the car
+ The output shafts of the transmission are available for machining if required
+ It is a very common EV conversion
+ it may not be available new, but you can pick one up used at any wrecker in North America
Minus List
- It may not handle the output torque of the Netgain Transwarp 9 inch motor (it may break)
- The output shafts from the transmission require an adapter to mate with Honda wheels and suspension
- the transmission mounting to the motor module must be fabricated from measurements. Testing is less than ideal
2 - 5 speed manual from a 2006+ Honda Civic
Plus List
+ the transmission is stronger and should handle the output torque of the Netgain Transwarp 9 inch motor
+ Randy at Canev tells me that the DC motor can be reversed with a contactor, and that running at low speed in reverse will not damage the brushes. They do this in their industrial trucks and have not had wear issues.
+ the existing selector for the linear actuator in the car is P, R, D (not sure if there is a neutral?). The standard transmission can be locked in second gear, R will activate a reversing contactor to turn the motor in reverse, D will de-activate the contactor and turn the motor forward.
+ still available new, but can also be picked up from any wrecker in North America
Minus List
- the transmission must be procured and delivered
- it will cost time and money to find it and buy it
- an adapter plate and coupler need to be fabricated since this model of civic is not a popular EV conversion
3 - auto transmission from a Honda Civic
Plus List
+ the output shafts do not require an adapter to mate with the Honda wheels and suspension
+ the transmission is stronger and should handle the output torque of the Netgain Transwarp 9 inch motor
+ the transmission is the same as the gas Motor Module engine
+ The existing linkage available from the WIKISPEED car is Park, Reverse, Neutral, Forward which ALREADY works with this transmission
+ The WIKISPEED shop can measure anything required to fabricate the required motor-to-transmission coupler
+ the transmission mounting to the motor module can be fabricated at the Lynnewood shop using existing designs
+ the transmission is available new from Honda via the existing WIKISPEED agreement
Minus List
- the transmission may or may not shift from 1st to 2nd to 3rd to 4rth gear. This will be a bit of an experiment.
- the motor to transmission 'slips' before lockup so some efficiency is lost when part of the power is lost to slippage. This is not really a big deal at this stage.
- Randy at CanEV has advised against using an automatic
4 - 5 speed manual from a 1984 - 2005 Honda Civic
Plus List
+ the transmission is stronger and should handle the output torque of the Netgain Transwarp 9 inch motor
+ the motor coupler and the transmission adapter plate are available from Canev pre-made
+ Randy at Canev tells me that the DC motor can be reversed with a contactor, and that running at low speed in reverse will not damage the brushes. They do this in their industrial trucks and have not had wear issues.
+ the existing selector for the linear actuator in the car is P, R, D (not sure if there is a neutral?). The standard transmission can be locked in second gear, R will activate a reversing contactor to turn the motor in reverse, D will de-activate the contactor and turn the motor forward.
+ still available new, but can also be picked up from any wrecker in North America
Minus List
- the transmission must be procured and delivered
- it will cost time and money to find it and buy it
- an adapter needs to be fabricated to mate the output shafts of this older style transmission to the 2006+ wheels used by WIKISPEED
- the transmission coupler and adapter plate need to be procured and delivered
Summary
It appeared to me about a week ago that the automatic transmission has many positives and almost NO negatives. After a quick discussion with Randy at CanEV (an EV conversion shop), that has changed. He advises me that there are many problems driving an automatic transmission with an electric motor and advises on the Standard transmission. He did not go into details on the attempts that they have made with their heavy-duty vehicles, but I am inclined to take his advice.
So the added option, number 4, is the tentative path forward. It appears that all the transmissions of this era, 1984 - 2005, have the same mounting to the gas engine so the adapter plate and coupler works. A transmission needs to be sourced so that measurements can be made and the adapter to the wheels can be machined.
The High Voltage Junction Box and Low Voltage Junction Box are part of the design. It may be a challenge to fit everything into the motor module frame.
Last edited by thingstodo; 03-29-2013 at 03:44 PM..
Reason: missed one line
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