Adventure EV

Motor Bracket

Motor Installation Complete!

by on Dec.09, 2009, under EV Land Rover, Motor Adapter, Motor Bracket, Tachometer Sender

Last we left the motor mount situation, I had welded new brackets to the frame of the Rover.

While the motor was out, and the bracket paint drying, I took the time to bore a 12mm hole in the side of the clutch bellhousing to house a proximity sensor used to generate a tachometer signal.  The motor controller can use this signal to discover how fast the motor is spinning in order to limit motor rpm for safety and longevity.  A tachometer also comes in handy when datalogging and giving user feedback.  I can use the tachometer to determine which gear to be in to optimize efficiency (there are other tools for this, as well, but motors like to spin faster rather than slower, within limits.)

Proximity Sensor

I also had to remove the flywheel to grind two notches, set 180 degrees apart, into the side.  The proximity sensor detects the presence of metal within 2mm of its face.  When placed 1.5mm from the flywheel edge, it will detect the presence of the flywheel.  When a 2mm deep notch rolls by the sensor doesn’t see metal anymore, breaks the connection, and that creates a pulse.  The circuitry in the motor controller and tachometer count the pulses, divide by two, and output motor revolutions per minute.

Proximity Sensor Installed

I used an AM1-AN-1A proximity sensor from Automation Direct for about $20.  It has three-wires and is shielded with a sensing range of 2mm.  They sell others that sense up to 6mm if necessary.  Of the three wires, one connects to a power source (10-30VDC, in this case 12VDC), the other to ground, and the third outputs the pulse signal.  Some proximity sensors require a pull-up resistor to provide a clean signal, though the tech at Automation Direct assures me that this particular model does not need one.  In order to easily set the distance, (when attached to a power source) the sensor is equipped with a yellow LED that will light up if the sensor is sensing something.  Very handy.

With the flywheel installed again, along with the clutch and clutch pressure plate, I maneuvered the motor into place in front of the transmission input shaft, and after much cursing and back tweaking, the two were  successfully connected.

I know, I know… it seems everyone’s EV blog has some video of the time the motor was first installed and run off a 12V battery to see if everything was working.  Yeah, my Dad and I did that, but it was late and really freakin’ cold, so I’ll save that tidbit for another day.  But the wheels did spin!

The only problem was that a leaking clutch slave cylinder (I should have know if the master was leaking the slave wouldn’t be far behind) meant disengaging the clutch was a no-go.  By the way, this was all done with the rear wheels off the ground… not toodling across the snow covered mesa.  A new clutch slave arrives tomorrow evening.  Hopefully the lack of full clutch control really is just the slave cylinder and an adjustment, rather than a miscalculation, by me, on the motor adapter side.

Now that the motor was fully mounted to the transmission, I could concentrate on attaching the motor to the new motor mount brackets on the chassis.  Glance into the way-back machine and you’ll find a photo of a round bracket assembly in two halves that I posted earlier.  Here it is again:

11" Motor Bracket

11" Motor Bracket

It wasn’t possible to attach the chassis brackets to a position in-line with where the round motor bracket would go.  So I came up with this bit of metal-jiggery:

Motor Bracket Modification

The round motor bracket halves cradle the motor, and 2″ x 3″ square tube was welded to the top half of the round bracket.  The square tube transfers the weight onto the chassis brackets via rubber-filled motor mounts, the same mounts used when the ICE was in place.  I realize that this puts quite a bit of stress on the union between the square tubing and the round brackets.  Again, hopefully the welds will hold up, as well as the metal stock.  Everything looks and feels beefy enough, though.

Motor Bracket Detail
Underside of top motor bracket
Motor Bracket Closeup
Bracket in place on rubber mounts prior to paint

Below is the final result fully painted and bolted together.  It can’t be seen, but there’s a 5/16″ Grade 8 bolt that connects through the upper part of the motor band to the lifting eye socket in the motor.  This should help prevent the motor from rotating under load.  Amazingly, everything aligned properly and the motor sits correctly!  I mean, I meant for it to be like that…

Final Motor Install

With the motor fully in place, I can now concentrate on the fabrication of the front battery box and the bracketry for the electronics that live under the bonnet.  Next time on… Adventure-EV…

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Back To Our Regularly Scheduled Programming

by on Dec.01, 2009, under EV Land Rover, Fabrication, Motor Bracket

I hope everyone had a great Thanksgiving!  I know I did.  No snow this year, but it’s getting cold around here nonetheless.  It makes working outside less than enjoyable.  We’re projected for a high of 28F on Thursday… so yay.  Well, I better get a lot done on Wednesday.

Starting the post out with a picture

It seems like it has been awhile since I last updated this blog with actual project material, but rest assured I’ve been toiling away.

One of the tricky bits has always been the connecting of the motor to the Land Rover’s transmission.  In some cases electric motors can be strong enough, have enough torque, to power the EV through a direct-drive link to the differential.  With my project, I decided I wanted to retain the transmission for a few reasons.

For one, I wanted to retain the full capabilities of the Land Rover.  That meant retaining the four-wheel drive system.  Sure, it’s not the most efficient way to go, but keeping the Rover’s full off-road capability was one of my design mandates, and the easiest way to accomplish this was to utilize the existing transmission.

Secondly, the transmission allows me to change gear ratios in order to improve performance and efficiency.  The Land Rover isn’t the lightest conversion, so being able to downshift to climb a steep hill could help.  My projections indicate that I’ll be able to do most, if not all, of my driving in third gear up to 60mph.  Past 60mph I’ll need to grab fourth.  We’ll see if I have enough torque to start off comfortably in third.

Electric motors like to spin, they’re not happy poking around, so while I may have enough torque and power to single gear most of my driving, it may not be the most efficient at slower speeds and higher loads.  Again, the gearbox gives me flexibility.

Thirdly, the transmission’s clutch becomes a safety device.  In the event of a motor or controller failure which might result in the equivalent of a full-throttle situation I can easily disconnect the drive through the clutch.  Let’s hope this doesn’t happen.

Lastly, it’s just easier.  Connecting to an existing transmission is a common conversion technique, so many components already exist to facilitate this… like my adapter plate.

Motor with adapter plate.  Flywheel and clutch mounted.

I once considered going with a direct drive AC system designed to haul electric buses around, but in the end I didn’t like the performance specs, and while that system (Azure Dynamics’ AC-55) was designed to connect directly to a rear differential via a driveshaft and yolk, I would have needed to engineer a way of connecting it to my transfer case if I wanted to retain four-wheel drive.

You may have heard that a good conversion means lightweight and no four-wheel drive, two rules I’m somewhat breaking.  Maybe more like bending.  The Land Rover, as we’ve discovered isn’t terribly heavy for what it is.  I’ll keep telling myself that.  And the four-wheel drive system is unlike most modern setups.

The Rover’s four-wheel drive system is actually very basic.  It’s a manually selectable, part time four-wheel drive system.  That means most of the time I’m only in rear-wheel drive, with the front driveshafts disconnected by freewheeling hubs.  While there are still an additional set of gears to run through in the transfer case, it also means that there are no frictional losses running the front driveshafts and wheels when I’m in two-wheel drive mode, as you would find in most modern drivetrains.  Not so bad.  During the occasions I would need four-wheel drive, I shove down a lever and I’m in locked four-wheel drive.  True, I still have to lug around the weight of the additional four-wheel drive components, but that’s the way it is…  otherwise I would have converted something like a Civic.

Anyway, back on target.  While waiting for some additional components needed to mount the motor to the transmission, I test fitted the motor temporarily.  I needed to solve how I was going to mount the motor to the chassis.  The motor and transmission, when coupled together, act as one big unit, but the transmission’s mounts really only serve the rear of the unit.  The motor needs to have a front mount.

Here’s what I saw with the unit bolted together:

Conundrum_v01

The yellow circles are the two existing motor mounts.  The red arrow is pointing out the only position I can wrap my motor mount bracket around.  Big difference in location.  That flat black plate is the bottom of the motor mount bracket.

Mounting the very back of the motor would have been perfect, but that’s not a very structural part, and it’s where all the motor cooling happens with a fan back there.  Further forward and I run into a band of metal that covers the internal brushes, that’s a no go.  Further still and I hit the electrical connection block, that’s out.  So just in front of the block it is, then.

I have two options here, try and build some kind of bracketry to connect everything up, but I don’t like the idea of being levered out that far away from the chassis mounts… or build new mounting points into the chassis.  The latter idea isn’t attractive as it would mean designing new brackets and welding them to the chassis, but it’s the idea that won out in the end.

First I built a template out of cardboard and determined where on the frame I wanted the new mounts to go.  I soon discovered that I wouldn’t be able to put the new brackets directly under the mounting band because of front driveshaft clearance, so the mounts go a few inches to the side.

Template

The brackets are made from 2″x3″ – 1/8″ rectangular steel stock.  Initially, I wondered if the 1/8″ wall material would be strong enough, but the existing chassis used 1/8″ material that supported 490 lbs of engine and accessories instead of the motor’s 200 lbs.  Weight won’t be the issue, hopefully the increased torque from the electric motor won’t be, either.

After tracing the arc designed to allow driveshaft clearance on the steel stock, I used an angle-grinder and cut-off wheel to transfer the shape.  Came out kind of nice,  a relief after shattering a half dozen cut-off wheels with previous tasks.  Cut-off wheels are tricky, a slight grab or cut to deeply at the wrong angle, and they just blow apart.

Cutout

A smaller bracket was fabricated for the other side.  Both brackets have open bottoms to prevent them from collecting and holding debris.  Once welded to the frame, they should be very strong.

I decided to keep the existing mounts, in case.  In case of what?  I don’t know… returning the vehicle back to stock?  Doesn’t seem likely, but the stock mounts aren’t in the way, so for now they stay.

Here’s the longer bracket next to the stock bracket… you can see the driveshaft below it.  While nowhere near the bracket now, when the front axle is under articulation off-road, the driveshaft would have hit the new bracket if it had no arch.

Detail

Here are the two brackets welded into place, and you can see the arch in the original mount, as well.

New Mounts In Place

I’ve painted the brackets with POR-15, which works brilliantly for this stuff.  I coated the frame with POR-15 awhile back and the paint is tenacious!  You can’t scrape it off with a screwdriver.  Only an angle-grinder has succeeded in removing POR-15 from the well prepped chassis.

Hopefully, by the end of tomorrow you should see the painted result with the motor in place and mounted!


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More goods arrive…

by on Nov.07, 2009, under EV Land Rover, Motor Adapter, Motor Bracket

All these great EV goods sitting on the shelf!  It shouldn’t be long until I can start ripping the old ICE gear out now that the clutch problem is being taken care of.

In the meantime, UPS dropped off some more goodies from across the border…  Canada, that is.  Pictured are the motor adapter plate and flywheel adapter.

Motor Adapter Plate and Flywheel Adapter

Motor Adapter Plate and Flywheel Adapter

The former is a plate that bolts to the motor which then bolts to the existing transmission.  Each adapter plate is custom made for a particular application, and Canadian Electric Vehicles, LTD have a decent library of adapter plates available for EV conversion.  If you can’t find one commercially, you have to make one yourself with the help of a machine shop.  Luckily Can-EV stock a Land Rover adapter.  Whether it works with my Kostov motor is another matter.  Technically, the adapter is designed for a Netgain 9″ motor, but all reports point to the Kostov 11″ having the same bolt pattern and face.  I’ll know for sure in a couple of days.

The flywheel adapter keys into the electric motor’s output shaft.  I’ll bolt my existing flywheel to the adapter which will then make contact with the transmission via the clutch.

The big motor bracket is just that.  It bolts into the existing motor mounts on my frame, cradles the motor, and ensures that it can’t spin in place.

11" Motor Bracket

11" Motor Bracket

This is one part I’ll have to modify since the piece is generic.  I’ll have to figure out a way of mating it with my existing engine mounts.

Many thanks to Randy at Can-EV for helping me out with these bits!

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