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AwesomeMatt
Posted: July 04, 2017 08:01 am
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I've wanted to build an electric motorbike for a while, and have been half-shopping for old bikes with good bones but blown motors for a few years. Nothing really came up. Some guys that have been looking for me point out that a bike with only a blown motor is still worth $500, and anything less and it'll need $500 in parts. So, conclusion was that I'm not getting one for less one way or the other.

$500 is way too much of an investment for my nearly-zero completion rate for projects.

However, on impulse I picked this up:

user posted image

The original superbike. 1985 Nighthawk 750S.

An old retired guy with 3 expensive bikes bought it to work on and he wrecked the heads and crack some the engine when he was taking it apart. It sat for a long time and he wanted to just part it out to get space back in his garage and his lift for other bikes. He had it half disassembled. I asked him how much for it. He asked what pieces I wanted. I said all of them. He emphasized that the motor was blown. I said that's fine, I've been looking for an old bike with a blown motor to convert to an electric motorbike.

He was hoping for $1 per part. I told him I don't even know things were separate parts, so, just tell me how much for all of it.

$20. Total.

You can't buy an indicator for that. Only needs a new front brake line that he'd thrown out. He sold some exhaust bits that I don't need but I got the rest.

I don't now how to ride a motorbike, and know less about engines.

Originally was 80hp on a 696cc (tariffs for engines over 700).

Hard to find out exact info on it because I can't tell bikes apart. It's a shaft-driven model, not chain. I don't think they sold in the US, just Canada and overseas.

He said the motor and tranny are a combined unit, so I can't just chuck the motor and keep the tranny. Not sure if they have common oil for them or if I can just sawzall the engine parts away and couple to the tranny input.

Shaft-drive makes it a bit harder to mount a motor if I'm throwing out the tranny. Might mean I need a gearbox too since I can't even cheat on my geardown with different sprockets.

Some models of these had some semi-auto transmission where you click through gears. I don't know how to tell if this one is one of those or if those are the US models.

And if it's a complete failure... I spent $20 on beef jerky today, I can waste $20 on a whole motorbike.

I'm thinking of getting a junk forklift and ripping the drive motor out for a future electric car build, and then using the lift motor for the Nighthawk. It should be roughly the right size.

...

I bought it because it was $20. It could have been anything. I looked it up after I brought it home, it appears to be a decent beginner's bike. A bit heavy, but steering is easy and it's quite maneuverable. I dunno, 99% of what I know about motorbikes I've learned tonight after I bought it, so, I don't even know the right questions to ask yet.

But it's a motorbike. For $20. Don't ask me why, I haven't even figured out how yet.
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Sch3mat1c
Posted: July 04, 2017 08:50 am
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Score! w00t.gif

Tim


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gremlinsa
Posted: July 04, 2017 05:42 pm
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Real Score..

I'm a HONDA fanatic, and what you got there is close to a limited edition..

I owned:
1972 Honda CB550 SS
1975 Honda CB750 K
Co-owner in
1982 Honda CB900 F
1983 Honda CB1100 F..

So:::

Engine and tranny are single unit shared Oil.. Tranny is a 1 Up 4 down rotary selector (neutral is between 1st and 2nd) and the gears are Dog Box (No syncro's).Clutch basket (yup Multiple plates for the cutch) on the right side front bottom.

I looked into doing a similar type of mod to one of them some time ago.. And worked out quite a lot in regards to how..

Take the head and Sleeves off, in the middle (between cylinder 2 & 3) is the timing chain for the Duel overhead cams.. However the chain is not quite strong enough, but you could use it for proof of concept: Make a cover that allows the chain to come up and out (covers for oil splash). You will have to turn out the Loooooong studs that hold the sleeves and head down, and make allowment for the oil ports next to some of the studs (high Pressure up to the head and cams) mount the electric motor(s) and run the power down via the cam chains..

Idea was to have a new straight crank shaft (without lobes for pistons) and fit a stronger gear, for a bigger (wider) chain machined once it was proven to work...

However i never found a suitable Donor bike, cause the motors in these are extremely difficult to break.. Even when rings and bearings are shot you can ride them on redline with out killing the motor..

And if the motor no longer wants to run, it normally just a few cheepish parts and your up and running again..

I rebuilt the 550's motor for the equivalent of $250 parts, and could ride with a group of Ninja 900's without problem, holding 220kmh (135mph) easily..

For $20 .. that is one hell of a score...


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MacFromOK
Posted: July 04, 2017 08:28 pm
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Nice score indeed. thumbsup.gif

You also might consider a wrecked/damaged golf-cart for the motor. Easier to handle than a forklift once the motor is out.

Also bear in mind that you don't need the same hp rated electric motor to get similar take-off power as a gas engine.

There may also be issues shifting a tranny with an electric motor, dunno. I might go with an auto variable speed belt drive. Those are pretty cool.

Just a couple thoughts. beer.gif


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AwesomeMatt
Posted: July 04, 2017 08:33 pm
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QUOTE
I'm a HONDA fanatic, and what you got there is close to a limited edition..


So, I hate to be the guy who turns steak into hamburger, whittles a tree branch out of a coffee table kind of thing.

Is it too nice to junk up and convert to electric?

I mean, it's the only bike I have, gotta piss with the cock ya got, though I suppose I could trade it.

Let me reframe how little I know about engines and bikes. I just last night, several hours after purchasing, realized that bike model numbers aren't just model numbers, they generally denote cc's of displacement. By looking at them I couldn't have told a Honda CB250 from a 750S, they just look like bikes.

I didn't really care, I just needed something bike-shaped I could put a motor on, hopefully with tires and brakes and something to sit on.

Engine is half disassembled and missing all the little fiddley bits inside, I left them in his junk box. Bike is mostly apart already.

These units have some kind of fancy chain tensioner that is a frequent source of issues. I have most of those parts, maybe. Again, I know nothing of engines, I can barely identify which and how many cylinders. A rebuild is utterly out of my knowledge.

I'll take some pics of it after work tonight.

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dmg
Posted: July 04, 2017 10:14 pm
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i for one.. think that bike is an important part in the history of motorbikes,
and would not really consider at all chopping for conversion, i would do my best to fix it.
but that is just me...

anyhow. you could keep the transmission as it is, along witht he clutch and stuff.
at least i would. you can chop off the cylinders , and replace the enigne main shaft with one that is made to fit but simple straight shaft with a sporcket for a chain drive on it.
then you can bolt basicly an electro motor mounting instead of the cylinders, and use a chain to drive the transmission and clutch from there.

now electronics wise mimicing the behaviour of a petrol engine might get a big challanging, however with the transimission in place you can get away with a small motor.

but honestly if i was you i would be hearthbroken to do this..
its an iconic bike, it is the all capitals widowmaker of its time.
conversion to electric would be simular to castrating mike tyson and dressing him up as a transsexual.
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AwesomeMatt
Posted: July 05, 2017 12:45 am
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Mac:
QUOTE
You also might consider a wrecked/damaged golf-cart for the motor. Easier to handle than a forklift once the motor is out.


Oh, I'd already forgotten about that because I was stuck thinking "drive motor for car, lift motor for bike". I almost picked up a forklift for a couple hundred, and then didn't have anywhere to put it, (no garage or driveway), or any way to move it. I hadn't considered... even small forklifts weigh as much as 3-5 cars.

There's service places in town that guy industrial gear. Friend of a friend of a friend might know somewhere I can grab one for scrap. If not, golf cart is a great idea.

QUOTE
Also bear in mind that you don't need the same hp rated electric motor to get similar take-off power as a gas engine.


Yeah, for electric car conversions, most people just leave it in 3rd gear all the time. Start in 3rd, highway on 3rd, no problem. Torque for days. It's so powerful in 1st and 2nd it's dangerous to the car.


DMG:
QUOTE
for one.. think that bike is an important part in the history of motorbikes,
and would not really consider at all chopping for conversion, i would do my best to fix it.


Hrm.

I completely lack the ability to fix it. Maybe a brainless engine swap, but, to do that I'm just cannibalizing another 750.

My barometer on this stuff is generally... the market. If this was a rare piece of history that warrants restoring, it would be valuable.

You can't buy a cheap '69 Corvette for example, regardless of condition.

Now, I got this one for a song so that's not a fair comparison, but, there's others available on the continent in moderate condition for $750-1000 so, doesn't seem to be too valued.

I doubt it's hot. I saw the old bill of sale and his behavior didn't fit. The old man called me back to let me know it doesn't have the front brake cable, he just didn't want me to think it would be rideable right away.

I guess, you can look at any piece of history and say that it's a shame to gut it. Is *this* model in particular something that's treasured?

Counterpoint... I've already rescued it from being parted out. Intake and exhaust are already gone. I pulled other bits out of his garbage. I left dozens of little... motor internal parts I can't recognize on the lift. And, I didn't get a full explanation of what's wrong with it so I don't even know where to start.

I'm moderately in over my head on an electric conversion, but I'd be dead on impact trying to restore it. Which means I'd have to give it away to someone else.

I mean... I get it. Which is why I asked if I'm turning steak into hamburger. But at the same time, if it's not valuable to anyone else, I just want a cheap bike to play with. I don't plan on modifying it excessively, ideally if I eventually get a replacement motor I can just swap it right back in down the road.

QUOTE
you can chop off the cylinders , and replace the enigne main shaft with one that is made to fit but simple straight shaft with a sporcket for a chain drive on it.
then you can bolt basicly an electro motor mounting instead of the cylinders, and use a chain to drive the transmission and clutch from there.


So, it's shaft driven, which should be way quieter than chain. It'd be a shame to add a chain back into the mix since that's one of the few perks of being electric. But I'll take whatever works. I'd rather that than build a custom gearbox.

Also, if I can avoid the tranny I would, I could add in a heck of a lot more range with the equivalent space and weight if I don't need it. I'll have to measure what speed the shaft needs to turn at and if I can get it into the ballpark without the tranny. The engine originally redlined at 11,000 RPM, which is absurdly fast for electric.

QUOTE
its an iconic bike, it is the all capitals widowmaker of its time.
conversion to electric would be simular to castrating mike tyson and dressing him up as a transsexual.


Hey man I don't tell you how to spend YOUR Wednesday evenings. tongue.gif

I had no idea it was famous. Well, I'll snap some photos and go from there.
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gremlinsa
Posted: July 05, 2017 08:28 pm
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MAKE NOTE: I said Close to Limited... It's NOT a Limited Edition.. (Nighthawk denotes the shaft drive) 6 speed box would make it a limited and worth allot more (which AFAIK the 750's never got)..

QUOTE (AwesomeMatt @ July 04, 2017 09:33 pm)
Is it too nice to junk up and convert to electric?
Not if you do it properly.. Please do not hackup the frame, that is sacrilege.

QUOTE (AwesomeMatt @ July 04, 2017 09:33 pm)
These units have some kind of fancy chain tensioner that is a frequent source of issues. I have most of those parts, maybe.
Might as well chuck them... If there was an issue with the motor, they needed replacing anyways....

QUOTE (AwesomeMatt @ July 05, 2017 01:45 am)
My barometer on this stuff is generally... the market. If this was a rare piece of history that warrants restoring, it would be valuable.

I guess, you can look at any piece of history and say that it's a shame to gut it. Is *this* model in particular something that's treasured?
All Pre 90's Honda's are something to be treasured.. IF ITS Complete, Here I say previous owner(s) killed it.. Time to give it a new life... Your Way...

QUOTE (AwesomeMatt @ July 05, 2017 01:45 am)
QUOTE
its an iconic bike, it is the all capitals widowmaker of its time.
conversion to electric would be simular to castrating mike tyson and dressing him up as a transsexual.


Hey man I don't tell you how to spend YOUR Wednesday evenings. tongue.gif
thumbsup.gif You tell him !!! thumbsup.gif

QUOTE (AwesomeMatt @ July 05, 2017 01:45 am)
I had no idea it was famous. Well, I'll snap some photos and go from there.
All Pre 90's Honda's are famous...... But again, this ones near the end of life, Give it new life...

Looking forward to following this project...


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gremlinsa
Posted: July 05, 2017 08:42 pm
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BTW...

Pics of two of the Honda's Posted previously on here..


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dmg
Posted: July 05, 2017 09:16 pm
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o come on.. its just an old bike with a lot of history.
i only told that i for one would absolutely find something else to scrap.

but anyways, i em absolutely excited to see how things turn out.
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AwesomeMatt
Posted: July 06, 2017 05:40 am
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QUOTE
6 speed box would make it a limited


Does 5 + Overdrive count as 6, or do you just call that 5 still?

http://paulsnighthawkpages.blogspot.ca/p/nh-700s.html

QUOTE
Please do not hackup the frame, that is sacrilege.


If I'm stuffing lithiums in there, they can be shaped for the bike. If I'm stuffing cheap lead acids in... ... it might need to change shape.

Also, I dunno what the hell I'll do with the gas tank. That's a lot of wasted space.

...

Pics and parts I kind of recognize maybe.

user posted image

user posted image

user posted image

user posted image

user posted image

user posted image

user posted image

user posted image


So, in terms of eating an elephant...

Any suggestions on what's next for me? Just start unbolting everything that looks like engine/transmission stopping at the driveshaft?

Or is this the kind of thing that I don't touch until I know a lot more later?

Any idea what speeds the tranny output should be, so I can start shopping for motors and ballparking voltages? I can't see anything I can easily crank to force the rear tire to move so I can count, which is why my plan was to just remove all gasoline parts and just spin the shaft manually.
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MacFromOK
Posted: July 06, 2017 06:29 am
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QUOTE (AwesomeMatt @ July 05, 2017 11:40 pm)
If I'm stuffing cheap lead acids in... ... it might need to change shape.

Saddle bags... wink.gif


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gremlinsa
Posted: July 07, 2017 06:45 pm
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QUOTE (AwesomeMatt @ July 06, 2017 06:40 am)
QUOTE
6 speed box would make it a limited


Does 5 + Overdrive count as 6, or do you just call that 5 still?

http://paulsnighthawkpages.blogspot.ca/p/nh-700s.html

QUOTE
Please do not hackup the frame, that is sacrilege.


If I'm stuffing lithiums in there, they can be shaped for the bike. If I'm stuffing cheap lead acids in... ... it might need to change shape.

Also, I dunno what the hell I'll do with the gas tank. That's a lot of wasted space.


5 + overdrive = 6 thumbsup.gif

As I said (AFAIK) the 750's never got the Overdrive, that link is describing the 700 Nighthawk with a 6 speed box...

I see the shaft drive motor assembly is slightly different to the Chain drive.. but what you marked is mostly correct..

On the handelbars, you got the Brake and Clutch switched... (Cable Clutch, Hydraulic brake)..
The radiator is an oil cooler..
Rear Something + Rear fender = The rear wheel mud guards.. so that you don't spray water over the motor/ Electrics/ Air intakes/ YOU in wet weather
A2 = Gear shifter. (You will need this if you keeping the box)
AB4 = Main harness Connector mount.. (not needed anymore)
3, 5, 6 & 7 = Mostly random mounts, and not needed for your conversion..

The gas tank while it looks like wasted space, straddles the main top support bar and mostly overlaps sideways, the bottom of it is almost flush with the support bar, and there's normally a lot of space between it and the motor...

Next step.. Lift of the sleves, and fish out the cam chain..

You can turn the crank with the nut on the pickups (left front of motor, below and forward of alternator) with a spanner.. Just don't use an impact on it or you may sheer it off, and it's a bitch to sort out again..


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AwesomeMatt
Posted: July 13, 2017 06:47 am
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QUOTE
Next step.. Lift of the sleves, and fish out the cam chain..


Next step was actually... take out the whole engine/tranny! tongue.gif

user posted image

It was way heavier than I expected it to be. Like, 150 lbs.

This is the tranny output. Just loose coupled straight into a u-joint.

user posted image

The U-joint/driveshaft.

user posted image

Taking a closer look at the tires, they have some cracks. I don't know if these are horrible dangerous cracks or just "sooner or later replace your tires" cracks.

user posted image

user posted image


So here's my thoughts on the tranny and not using it...

There's 3 reasons I kinda need a transmission:

1 - If my motor speeds don't match the correct range to spin the driveshaft for the speeds I want to go.
2 - If my motor isn't powerful enough to accelerate reasonably.
3 - If my motor needs more power than it can handle at low speed hill climbing.

Breaking those down..

1 -

It's a 16" tire, so, 16x3.14 = 50" tire circumference or 4.2 feet. So every tire rotation moves the bike forward 4.2 feet. 5280 feet in a mile, so, 1257 tire rotations before it covers one mile. 60 minutes in an hour, so 1257/60 = 21 RPM for each mile per hour I want to go.

So if I want to go 60mph, I need to spin the back wheel at ~1260 RPM. The rear gear seams to be 3:1 with the shaft, which means 3750 RPM on the shaft goes highway speed. Which is in the right range for a direct drive motor.

The bike engine originally redlined at 11,000 RPM, but then it also had a top speed of 125 mph which was often around only 9,000 RPM. 9,000/125 = 72 driveshaft revolutions per MPH. Which does not match the tire RPM (21) so, something somewhere is still gearing down by 3.5:1.

Most transmissions only exist to slow the engine speed, where top gear is just straight linked with no reduction. The diagrams for the shaft-to-tire 90-degree gear as having a lot more teeth on the wheel than the shaft, it looked like 3:1 but could easily be 4:1 and in any case, is within the right ballpark.

No tranny needed to hit the right RPM, motor depending.

2 -

Engines have to spin up to high RPM before they have any power, electric motors have all their torque immediately. That's probably enough in itself, the issue is if I have a weak motor and I'd be annoying to traffic behind me because I accelerate too slowly.

Kinetic energy = Mass * Speed * Speed / 2

It's the first, oh, 20 miles per hour that are going to piss people off in traffic, what would be the low gears. Above that the effects of wind resistance start to climb anyway and you start having to consider that you only have the left over power not being used just to maintain speed. So, 20mph is 9 meters per second.

E = 350kg * 9 * 9 /2*
= 14175 joules.

Joules are useless to think about, 3600 watt-hours in a joule, so about 4 watt-hours. About as much as a cell phone battery holds, to bring a 350kg bike + rider up to 20mph, ignoring wind resistance.

So, in a frictionless environment, a 4 watt little toy motor would take a whole hour to bring a 350kg bike up to 20mph.

Of course, I don't want to take an hour, so I need a motor a lot bigger than 4 watts. 750 watts in a horsepower, a treadmill motor is about 2 horsepower, so, that's 1500 watts. Or, about 375 times faster than a little 4 watt toy motor. My 0-20 time would be.. 10 seconds. Seems really slow but the bike is pretty heavy.

Anything above 0.3g of acceleration is considered aggressive, anything above 0.5g is considered dangerous. 0.3g would be 3 seconds to reach 20mph. That's a good target, and is about 3x as fast as a treadmill motor could do it, so, a 6hp motor should be good enough for acceleration. (I counted when driving calmly, about 5 seconds is decent too).

The problem is that even though you get full torque off the motor at the start, that doesn't mean the motor can handle it.

Power = volts * amps

I have the max power (2hp or 6hp or whatever) only when the motor is spinning at max speed. The voltage determines how fast it spins, and the wire thickness determines how many max amps can flow. The speed controller increases the voltage, but the wire thickness can't change.

So if the motor is designed for 100 volts volts and 15 amps, 100*15 = 1500 watts. But the motor (and bike) isn't up to speed, the motor will only be given, say, 10 volts right away, and ramp up. The wire thickness can't change so I'm still limited to 15 amps. 10*15 = 150 watts. So it will be massively underpowered. The motor can do it, but if you give it 10 volts and try to move the bike with it, it'll try to pull 150 amps rather than 15... and it will. But it's 10x as much as the wiring is rated for and it'll get smoking hot in seconds.

Obviously the solution is a transmission, where I could give it 100 volts, pull 15 amps, and just mechanically gear it down to 1/10th the speed.

Unlike with a gas engine, once it's up to speed it's fine. You never need to gear down to handle a lower speed, only to get acceleration improvements. If I want to just travel at 5 miles an hour, and it takes 10 volts on the motor and draws 15 amps... that's fine.

The limit isn't electrical, it's thermal, and most motors have a big surge on startup way over spec anyway. Not really sure how to figure this out any better than just, plug it in and try it and see if it gets too hot.


3 -

Climbing hills is the same problem as low speed, but it doesn't go away in a few seconds as you come up to speed.

It takes more power to go up a hill. Which is fine if it's at a fast speed or within my motor's power ratings. If it takes 2hp to maintain a given speed and a given incline, I'm fine. But if it can't handle it, I'm in trouble because slowing down no longer helps. Slowing down means it takes less power to climb the hill, but it also means the motor is spinning slower and less power is available. Which means it's fighting even harder all over again. Gearing is the only thing that helps this.

However, there aren't many long hills I'll be climbing. The bike's only going to have a 20 mile range, if that, so, I'm not worried.

I'll leave the little radiator on there and plumb some cooling lines along the motor to give it a fighting chance.

...


As to mechanically attaching the motor to the transmission, I anticipated it not being an issue because there's a U-joint. Easy? Nope.

The driveshaft isn't anchored to anything alignment-wise, which makes complete guesswork out of what is straight and what is the right position for it and the motor.

Next up I just wanted to see the damned thing spin. And also rotate.

I figured out that a toilet plunger is the same width as the U-joint on my bike's driveshaft, so I set it inside and then hammered it down to force it to create matching splines with the U-joint. Attaching the shaft of wood to the motor was harder, had to hollow some out and sleeve it with a PVC coupler.

user posted image

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Just a test rig to figure out 4 things:

A - Count the gear reduction to the rear tire (3:1)

B - Test how sensitive the alignment is (very, very, even with a U-joint, the shaft is loose all the way back to the rear and depends on the transmission to be perfectly straight and rigid, which a plywood test platform is not), and

C - See how well a 2 hp motor handles the bike (never took it off its stand, but it held up okay with no load). It's a 90volt motor and I never spun it up past about 25v, which means the rear tire was going 15 mph.

D - How weird it feels having the motor way off to the left of the bike (not bad, plenty of width and the right side can hold batteries still.

http://imgur.com/pkQeuA3 <-- Short video.

By calculation, 2hp is enough to bring it up to 55km/h. I need 3.5hp to go 70 km/h which if I register it as a moped instead of a motorbike (half the insurance and no special license) is the fastest I'm allowed to go. The little test motor might actually be fine overdriven that much, in an airstream or with cooling lines from the radiator on it.

I thought the tough part would be the coupler, but, I think I can pull the same trick with a bar of aluminum and a hammer it into place same way I did the wood. Should be plenty strong enough.

The hardest part is alignment. Any ideas?

I think I have to re-mount the transmission and make templates for where the shaft goes. I couldn't even find the sweet spot by carrying the motor and trying different angles. The u-joint is clunking against the shaft housing no matter where I try to hold it.

I could saw the old shaft off the tranny, weld or couple it to the final motor shaft.

If I need to, I can use the 90-degree gearbox at the ass end of the tranny and then have the motor running sideways like the engine was, but I don't think I will.

Heard back from a forklift repair place. Guy is swamped but said he has time for me to climb through his boneyards next week. Also, for completely unrelated reasons, ended up at a golf course buying decorations off craiglist from one of the service guys (he happened to want me to meet him at work, which happened to be a golf course). He said there's a good chance they could give me a motor from one of the golf cart clunkers.
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dmg
Posted: July 13, 2017 06:35 pm
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maybe it would worth having the original transmission.
that can keep the u-joint the way it should be,
and can give you that extra accelration needed for smooth traffic moves.

not sure how sensitive is the controller, maybe the clutch could help in getting the thing to go, on a bike if say.. blimp the throttle in a turn that has interesting effects.
usually a slow entry and a constant but not harsh acceleration after the apex stabilise the bikes.
the reason behind is that most of them are front heavy. if you accelerate weight transfer will supposedly lessen the load on the front tires and loads the rear a bit more, so your front wheel does not slip away. witch is catastrophic.
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AwesomeMatt
Posted: July 13, 2017 10:08 pm
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QUOTE
maybe it would worth having the original transmission.
that can keep the u-joint the way it should be,


If I add up all the modification and work to re-use the tranny, including somehow separating it from the engine, plugging the common oil ports, jigging the timing chain, etc... I imagine that would be a lot more work than whatever I have to do to align the motor. And, always the limiting factor to me... how much I can figure out on my own versus how much I have to ask other people. I'm sure I can blunder through alignment issues, might just take some time.

In addition to that, the tranny is probably 75lbs, which is probably 2000kw worth of battery I can't have in its place. Which is probably 12 miles of range.

So I'm not ruling anything out, I still have the engine, but I'll keep that as a backup plan if my other efforts fail.

QUOTE
not sure how sensitive is the controller, maybe the clutch could help in getting the thing to go


I don't have a controller yet. I might just a big resistor or several and chill them with the radiator. But I suspect any motor I buy I can also purchase a controller for.
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dmg
Posted: July 13, 2017 10:27 pm
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question is if you have a small hill, you get a red light, will the electric motor start tourqe get you running or not.
with the tranny in place you can supposedly draw less amps and use more volts for the same power.
i never built an electric thingy, but have hydraulic driven stuff.
basicly the current would be pressure and flow would be volts.
currently most usefull designs do not incorporate direct drive, unless we are talking about say.. excavators, when they just have to get enough to the tracks to make em move somehow.
other things, like a forestry forwarder uses usually an automatic gearbox after the hidraulic motor to ensure enough starting torque is available at any time.
otherwise they would need a silly big hidromotor to cover the range of 25 k / hr road speed to the slow creeping.
surely if it is only for creeping around then direct drive works well.
older designs have a manual 2 or 3 speed tranny.

thing is, when it comes to IC engines usually the torque rises as rpms fall.
that means on an uphill scenario you got grunt to back you up.
however, an electric or hidraulic drive has a constant torque,
if by any reason you suddenly need mre than that, you stall.
you run out of current or you run out of pressure.
with an IC engine the revs fall slightly, but you get grunt in exchange to overcome the thing.

in your case you could shift back. bike transmissions are usually geared close to eatch other, gotta keep that engine revving high as hell to get the most of it on a track.
witch i think makes it verry suitable for the electric motor, you want to -i think- pull small amps on high volts to be efficient and have "grunt" in it.

but thats just my 2 cents.
i would just remove the cylinders and machine a straight shaft instead of the original mainshaft. check the top speed you want, put the bike in top gear and see how many spinns you need. gear the motor to the tranny with that ratio.
yess it is a challange on its own, but i suspect it would pay off well.
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MacFromOK
Posted: July 13, 2017 11:36 pm
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Bear in mind you must allow for wheel suspension movement if you intend to use the driveshaft.

Just a thought. beer.gif


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Nothing40
Posted: July 14, 2017 04:11 am
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The tires are probably okay for initial mock-up/testing,but I would replace them before actually taking it to the road at any considerable speed. Blow-outs suck,and I'd imagine they'd suck even more on a bike.

Sort of related..
I had bought a set of used tires for the Chevelle several years ago. At the time,they were cheap,in reasonably good shape,and still had plenty of tread on them.
More recently,when I got back to driving it,they had become pretty weather checked,cracked,and hard,so I ordered some new ones. When I got to the tire shop,the guy came out to look at the old ones,saw the date on the first tire (1983! I didn't realize they were that old!) backed away,and refused to even stand near my car to look at the other 3 tires any further.He was afraid they were going to explode and take out his kneecaps,with the car just sitting there parked. He gave me a bit of a stern lecture for driving on them,almost refused the job,but realized just why I was there,and sold me the new ones.


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AwesomeMatt
Posted: July 14, 2017 07:52 am
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QUOTE
i would just remove the cylinders and machine a straight shaft instead of the original mainshaft. check the top speed you want, put the bike in top gear and see how many spinns you need. gear the motor to the tranny with that ratio.
yess it is a challange on its own, but i suspect it would pay off well.


That's my backup plan. It looks like I'll have a plenty powerful enough motor (the treadmill was barely powerful enough, but I had it already and nothing else to tinker with), so, tranny should be unneeded.

For long distances I'll put some kind of genny or maybe scooter motor in a push-trailer. Maybe. I dunno, one thing at a time.


QUOTE
Bear in mind you must allow for wheel suspension movement if you intend to use the driveshaft.


Not sure if you've looked at pictures.

The driveshaft ends in a U-joint, right where the pivot point of the rear suspension is. So, hopefully hitting any bumps has nearly zero impact on the geometry and there's already a hinge there due to the U-joint.

Then the tranny normally plugs into the other end of the U-joint, then makes a 90 degree turn in the gearbox.

I'm getting rid of the 90 degree turn, but, the rest shouldn't change and I should be okay. Or am I missing something?

QUOTE
saw the date on the first tire (1983!


Tires have dates on them eh? I'll check what mine are tomorrow. The odometer says 51,000 so I can't imagine they're original, and the back one looks like he knew the bike was being retired when he last drove it.
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dmg
Posted: July 14, 2017 04:01 pm
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if the tires where original, then they are selected at the tire factory.
means those got the high grade ingredients and made well.
usually OEM tires have paint strips on them to make sure its clear they are for OEM market.

anything else you get is 90% had been defective at manufacturing and had been repaired before sold.
i seen this in real life while i worked for hankook. and the whole michlein group does the same.
mold fill errors and sutch are repaired and those are the usual tires you can get.

i kid you not, if you want some good tires head down to a car dealer, find you car, if they have it in stock then do what you can to get the OEM tires.
they are model selected, vibration tested, balanced at cunstruction state.
when the tire is built ones for generic market are just made out of rolls of stuff (carcas, inner liner, beads, thread) but for OEM its done in a dustfree area. makes a difference, as th layers will stick better. allso they pay attention to have the "green tire" balanced.
and allso molds used for the curing are cleaned after every OEM tire, while for regulars only when errors in mold fill get really bad.
allso OEM recepies have more natural and sythetic rubber and less filler materials.
allso the fillers are finer. (instead of carbon black particle size 220 and 270 they use lamp black 120 or 140, and do not use clay as filler at all. instead, silicates are used. and allso cobalt content is higher. that makes a tire wear resistant. more rubber makes it sticky and strong. and cords used are not simple nylon, but rayon. its stronger, adheres to rubber better, but is sensitive to moisture and therefore the whole manufacturing is a lot more expensive. then they simply make a low quality copy for the general aftermarket.
hence sometimes you get XY tire and it can last really long, witch is a re-sold but faulty OEM one , and you purchase the same kind of tire again and it will not last half of that. that was the generic aftermarket version. about 8% of tires made are good enough for OEM. )

so if the car salesman is willing to let you purchase the OEM tires, go for it. i would say 2x market price is verry acceptible deal.
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AwesomeMatt
Posted: July 19, 2017 08:07 am
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Went to the forklift place today for a couple hours.

They had a 1969 (?) little York that was garbage to them, and a powerjack I didn't have time to get to yet.

user posted image

Big motor is under the water bottle, or, either of the two smaller pump (?) motors above it. Big motor looks pretty beat up and filled with grime, but I'll take it anyway.

user posted image

Cabling and relays. 2/0 cable. Grabbed it all. 30 lbs or so of relays and cable.

user posted image

Found an intact schematic, score.

user posted image

GE module on the opposite side of the giant relays. Might be an SCR board?

user posted image

I was fighting daylight, so, I'll go back for motors tomorrow morning and evening if I can.
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Sch3mat1c
Posted: July 19, 2017 01:27 pm
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Hmm, SCRs, wonder if that's commutated with another SCR.

Tim


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MacFromOK
Posted: July 19, 2017 09:58 pm
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QUOTE (AwesomeMatt @ July 14, 2017 01:52 am)
QUOTE (Mac)
Bear in mind you must allow for wheel suspension movement if you intend to use the driveshaft.

Not sure if you've looked at pictures.

The driveshaft ends in a U-joint, right where the pivot point of the rear suspension is. So, hopefully hitting any bumps has nearly zero impact on the geometry and there's already a hinge there due to the U-joint.

Then the tranny normally plugs into the other end of the U-joint, then makes a 90 degree turn in the gearbox.

I'm getting rid of the 90 degree turn, but, the rest shouldn't change and I should be okay. Or am I missing something?

Indeed I did not look at all of the pics, it's just really slow on dialup. Sorry.

Your description explains the drive/pivot setup quite well, and there should be no issues with the suspension if you maintain the current drive-shaft angle (the one from the 90 gearbox to the suspension pivot).

Carry on. beer.gif


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AwesomeMatt
Posted: July 22, 2017 02:14 am
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QUOTE
Indeed I did not look at all of the pics, it's just really slow on dialup. Sorry.


Yeah no worries. Figured you hadn't.

...

I think the motor is likely a Series Wound DC.

You'd think this would be an easy thing to find out how to do, but, everything I find is either stupidly simple, or stupidly complex.

I just want to hook the damned thing up and make it spin, and rudimentarily control speed what for tinkering and timing. How do I do that?

I don't really get what I do with the field winding. Does the main power flow through the field, or through the armature? Is there a small control voltage or is it huge?
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