Motorbike Conversion - 1985 Nighthawk 750S - From Junk

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 01 2018 2:23pm

Aha. It's actually an "EZ-Go" 25864G09 golf cart controller, which is a Curtis 1206-4301 (which is not written anywhere on it, you just have to know that).

And for future people who may come across this thread: http://products.jacobsen.com/img/manuals/28646.pdf <-- Manual for the golf cart, which has some controllery bits in it on page E-17, but not enough for me to figure the pinout.

...

Revisiting a couple rejected options I didn't discuss before...

I also have a controller from the forklift yard's junk bin that was marked: "Needs repair, low output". It's a Curtis PMC model: 1-187-067. 24-36v, 275 amps.

Again nothing comes up on google, and I couldn't get into it, it's potted shut. Drilling out the potting to find 6 screws underneath and some hammering later, it says on the board it's a "1204x-42". Hard finding that exact model, but at least it's a model that exists and I can find pinouts for.

So that's promising. You know, most of the time, in any place, when stuff is marked as damaged there's nothing wrong with anything but the technician, so, let me just see why the output might have been may be marked "low"...

Image

Err... oh. Not the technician.

Looks like everything that's steel (mounting hardware) is rusted, everything lead (all the solder joints) are crumbly white powder.

I can't get inside the thing because the side boards are all soldered together. It's at least dozens of solder joints just to examine it further. FETS are I+R9207, (+- symbol?), can't find a datasheet on them.

I do like a challenge, and I do like repurposing junk, but:

1 - I don't know if it's in working condition.
2 - I have to make dozens of desoldering connections just to access the FETs and clean them.
3 - It's hundreds of soldering joints that are corroded, any one wrong and it probably won't work.
4 - Is the circuit board corroded internally?

Sounds to me like the 1204 is a shelf-it project, maybe turn it into a charger later.

I also pulled a GE Clark EV-T5 controller out of the junk bin last year which is 3x the size of the Curtis 1204 (as big as a double-slice toaster), but, it's only 24v and 75 amp (250amp at 50% duty cycle). The current is probably okay, but the 24v is just hot wet garbage (and I don't know if it's working).

Image

So, I guess a bit more sleuthing on the 1206 as that's my best bet at something that might hit highway speed.

Normally I'd be happy with trial and error. Pain in the ass is, once I arrange the 18650s into their plastic holders, (head or tail in the correct directions)the entire pack has to be disassembled to get them apart again, let alone all the soldering. And soldering the batteries damages them a little bit each time I'm sure. A lot of my projects get abandoned when I hit a point where I have to backtrack because of how discouraging that is, so, trying to prevent that this time.

So, I'm kinda stalling out at this stage to see if I can get a higher voltage controller that I'm more sure will work before I double-down.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by amberwolf » May 01 2018 11:04pm

MattsAwesomeStuff wrote:
May 01 2018 2:23pm
controllery bits in it on page E-17, but not enough for me to figure the pinout.
I might be able to help with that.

Since I dont know how much you know about them, Ive attached the cart schematic and notes on what I know or can surmise, wiht the controller itself inside the red box. Everyting outside that box is part of the cart, not the controller.

This is a controller for a sepex motor AFAICS, since it has a separate field coil connection from the brushes. I cant remember if sepex controllers can be used for series motors or not; its been too long since I read up on that. I think that you can simply leave teh F1/F2 busbars unconnected for series motors....

If you did have a sepex instead of a series motor, however, then one contact for brushes on the motor connect to the A1 busbar on the controller, and the other to the B+ busbar (which also connects to your battery positive. In the schematic they use a solenoid/contactor for precharging the caps in the controller and for a cutoff controlled by a keyswitch, between battery positive and B+).

If not using a precharge or contactor, leave J1 pins 6 and 7 unconnected, otherwise they drive the contactor coil.

The field coils go to F1 and F2.

B- goes to battery negative.

If youre using a keyswitch it connects to J1 from pins 8 to 9, otherwise you just jumper those together.

J1 pin 10 is unconnected since you dont use reverse.

J1 pin 1 gets jumpered to pin 3, and pin 2 is left unconnected, because you dont use reverse.

J1 pin 4 can be left tied to battery positive if you dont need to disable the controller during charging. Otherwise you can setup something at the charger port (like a magnet on the charger cord to open a reed switch) to disable the controller during charge so you cant ride off with it plugged in. ;) (its possible that Im misreading the schematic and it actually needs pin 4 left unconnected to enable teh controller, but its easy to test).

J1 pin 5 connects to battery positive.

J4 is the throttle, and uses the switch between pins 1 and 2 to show whether throttle is engaged (so that any input on 3 and 4 are ignored if 1 and 2 arent shorted). Pins 3 and 4 probably go to a 5-10k potentiometer, between the wiper (center pin) and one of the sides. The other side of the pot would be left unconnected.

J3 appears to smply be another set of enable switches, jumpering from pin 1 to 2, and from 3 to 4.

J5 is probably a hall sensor used for speed monitoring; it will probably work without it but it may be usable to prevent an overspeed condition (I dont know what RPM it might be set ot limit at).

J2 looks basically like a jumper-programming block, though which pins enable or disable what options I dont know, so you might have to simply use it jumpered like it shows (or experiment). It might also be an option connector for another piece of electronics; I dont know (didnt read any of the service manual, just going by what I know of other curtis and similar brushed controllers).
1206 diagram.png
1206 diagram.png (125.23 KiB) Viewed 533 times

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 02 2018 11:22am

amberwolf wrote:
May 01 2018 11:04pm
This is a controller for a sepex motor AFAICS, since it has a separate field coil connection from the brushes. I cant remember if sepex controllers can be used for series motors or not; its been too long since I read up on that. I think that you can simply leave teh F1/F2 busbars unconnected for series motors....
I bet you have a 1206mx. X is for SepEx. It has a PDS ("Precision Drive System" aka "speed control and sensors"), mine doesn't. (Oh, duh, says there right on your diagram, "1206mx controller"). I linked the manual in my previous post, after it gives my diagram it gives the PDS diagram where your image came from.

Series motors technically have no speed control, only power control that might suggest what speed it might go which depends entirely on the load :p.

My Curtis 1206 only has 3 of the giant terminals, B+, B-, and M-. Then there's a row of 6 other numbered pins (Pin #5 is absent-at-factor, presumably for polarity idiotproofing).

I went through your pinouts and the diagram though, I agree with all of it.

I kept digging, found this: http://ev.evdl.narkive.com/0masMVv9/ezg ... on-diagram

"On the 5 pin style 1206 Curtis controller pin one and two are your 0 to 5 k/ohm throttle input. Pin three is half speed reverse and pin four is your key switch input to power the brains. The fifth pin is not used."

Sounds pretty straightforward. 1-2 pot. 3 ignore. 4 short to... positive when on (? that's where KSI goes on the 1204, which I do have a manual for). 5 ignore.

Well, after going through the much more complicated 1206mx... the 1206 dumbo system is easy, and I only just discovered the pins on the terminals are actually numbered.

Image

Not sure why I was having trouble reading this before, pretty clear. Pin 3 had me confused but, just ignoring it I'm okay again.

So... I try hooking it up on a power supply...

Confusion.

1 - If the power supply is on B+ and B-, B+ and M- have the same voltage on my multimeter. Is that because there's no load, or, does that mean blown-short mosfets and back to square 1?

2 - I have 3 "E-bike throttles", of different styles. None of wires on them do what a potentiometer should do. Nothing changes when I twist, resistance doesn't is either infinite or isn't variable. I (foolishly?) presumed all throttles were just pots, is there something else going on in them?

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 03 2018 1:48am

Doing a little more research, I discover most e-bike throttles are not, in fact, potentiometers. They are instead, hall effect sensors based on a magnet, and some amplifier. So they output 0.8-3.8v or so.

I'm not sure if this is compatible with my controller.

The controller expects a 0-5,000 ohm potentiometer, but, it uses that to lower the voltage on some pin probably, so, by coincidence, 0.8v-3.8v might be what the controller ended up sensing and might be a plausible imitation, but, probably not.

So...

1 - By coincidence it will work anyway.
2 - I have to find some kind of pot that will work inside the mechanism.
3 - I have to order a different throttle entirely.
4 - I have to convert my signal to the right voltage using a microcontroller or something, which I've never used before.

This was the one part of the build where I was like "Well this is such an engineered solution, I'll just buy one, problem solved." Problem is not solved. Hrmph.

This is the first actual outright mistake I've made on the bike.

http://www.evwest.com/catalog/product_i ... cts_id=294 <-- I could spend $58 to remedy this. That's 3x what I paid for the bike, so, no.

I could half-ass a variety of solutions, epoxy a pot into the handlebar and have the end of the throttle twist it (presents a hazard if the bike falls over), etc. Don't really want to half ass it.

Not exactly sure what to do next. It's a minor problem, I currently have the original cable throttle hooked up to a pot box, but it's the size of baby's skull, cumbersome and annoying. It's solvable but not in an elegant and cheap way.

... More pressing is the fact that the controller itself appears blown.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by amberwolf » May 03 2018 2:41am

MattsAwesomeStuff wrote:
May 02 2018 11:22am


I bet you have a 1206mx. X is for SepEx. It has a PDS ("Precision Drive System" aka "speed control and sensors"), mine doesn't. (Oh, duh, says there right on your diagram, "1206mx controller"). I linked the manual in my previous post, after it gives my diagram it gives the PDS diagram where your image came from.
I dont actually have one of these; I was just going by the diagram from your link--I didnt see a different one, only that one, but osme of the pages in the link come up completley or partially blank when I view the PDF. I guess the one with the correct controller diagram must be one of those blank pages. (its probably just my computer--wierd stuff happens sometimes).

I do have an old 1204, I think it is, that I used on CrazyBike2 with its powerchair motors; that was a long time ago. :)


"On the 5 pin style 1206 Curtis controller pin one and two are your 0 to 5 k/ohm throttle input. Pin three is half speed reverse and pin four is your key switch input to power the brains. The fifth pin is not used."

Sounds pretty straightforward. 1-2 pot. 3 ignore. 4 short to... positive when on (? that's where KSI goes on the 1204, which I do have a manual for). 5 ignore.
That sounds right, if its like the 1204.

I dont remember which + wire youd use for teh KSI, it might be the + out of the pot, or it might be B+. Its probably the same as the 1204.

1 - If the power supply is on B+ and B-, B+ and M- have the same voltage on my multimeter. Is that because there's no load, or, does that mean blown-short mosfets and back to square 1?
I dont know--it could be that its simply starting out with the bridge switched in a way that floats the voltages like that, until you apply trhottle and/or theres a motor on it.

You can use a multimeter on ohms or continuity to test for a short. Itll start out appearing shorted because of the caps, but as they cahrge up it should increase to tens of thousands of ohms and higher.

2 - I have 3 "E-bike throttles", of different styles. None of wires on them do what a potentiometer should do. Nothing changes when I twist, resistance doesn't is either infinite or isn't variable. I (foolishly?) presumed all throttles were just pots, is there something else going on in them?

Almost all ebike throttles use hall sensors, which do not start at zero volts, and dont go up to 5v. Typically their output range is around 1v to 4v, varying up to half a volt at either end. Because of that, they generally dont work with controllers like yours, even if that controller uses a voltage input rather than a resistive reader circuit (current).


A number of these brushed controllers like the curtis (and other non-ebike EV controllers) use safety systems on the throttle that require a pot because it uses the current flow thru the pot to determine if its connected or not, or if it has a problem, at power up / etc. If theres no current flow the controller may remain disabled until its power cycled wiht a pot of the correct resistance range connected and with the pot at its throttle-off position.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 16 2018 2:38pm

Controller Success!!

Image

I basically sat with my thumb up my butt for 3 weeks, figuring the controller was broken because it showed full voltage on the motor output without the keyswitch or the throttle even connected, indicating blown mosfets. And then I was bummed about my throttles all being the wrong type and not being able to use them to test either.

So today I decided to actually just hook a motor up to it and a pot (had a 50,000 ohm rather than a 5,000 ohm, but, no matter).

Well lookie that that. As soon as there's really any load at all on the output, there's no voltage there, so, must have some high impedance path through the controller.

I used an 1800w treadmill motor (easier to carry onto my office desk), threw on the pot, shorted pin 4 to positive, and... nadda.

About to give up and then I tested the pot and even after checking it thrice, discovered I'd wired it backwards (so I was adjusting between 45k and 50k, rather than 0k-5k, and just never bothered to twist it all the way around to the far side).

And the damned thing spins. And it changes how fast it spins when I twist the pot.

A few interesting tidbits:

1 - The max supply voltage is 46.6v. Above that it shuts down. Since it was designed for a 36v kart, and 36v batteries are at absolute most 45v when boiling their electrodes, that's sensible. But it means if I want to use a higher voltage than that I'll have to reverse engineer it to find how it determines that.

2 - The min supply voltage is 28.4v. Below that it shuts down. Again since it was designed for a 36v kart, when your lead acids are less than 9.5 volts on a 12v battery they're plenty dead (heck they're dead by the time they actually get to 12v). Shouldn't be a problem for me, an 11series lithium pack is well dead below 33v (3v/cell) anyway. 28.4v is 2.58v per cell. That's already into damaging territory, but my low voltage cutoff is human-decision-based anyway, so I'm fine making the choice whether I want to stop or continue driving. I don't need it idiotproofed except perhaps to actual idiot level (I leave the lights on, ideally it won't murder my batteries).

3 - High resistance is low speed. The documentation didn't actually say which, controller might be built either way.

4 - Below some resistance, the motor cuts out. So it goes faster, faster, faster, dead, if you bring the resistance too low. I'll need to have my stop switch sometime before this, as, you'd come to a complete stop while at wide open throttle, ease off a bit and then backflip as it slams max power again.

....

Decision Time:

Do I design the pack for 46.2v and start soldering cells, or, wait for a better controller?

It will be a huge pain in the ass to change my mind later, it involves desoldering every single cell, and likely rebuilding the entire battery compartment since it has to be built around the frame.

On one hand, this isn't the voltage I want to run at. It might not even hit highway speeds and there's no way to find out until I try. That would be a huge disappointment.

On the other hand, I'm getting pretty tired of seeing other riders on the road enjoying their summer, while I have a pile of parts. And I don't have another controller to use anyway.

Maybe I'll split my battery pack into two full sets of 11series so I can rewire them for double-voltage later. If I upgrade the controller down the road, I can design it for whatever voltage and, 46x2=92v is an okay target.

Controller claims 275 amps, 46v = 12,650 watts = 17hp when completely topped up. Should be enough for highway speed if the motor will be spinning fast enough with that load. No way to tell. Not sure if the controller has overcurrent protection either, so maybe I can manually demand 500 amps and as long as it doesn't overheat it'll be fine.

Next up, start making cardboard battery boxes and seeing how/where I can stuff them into the bike.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by amberwolf » May 16 2018 2:53pm

MattsAwesomeStuff wrote:
May 16 2018 2:38pm


mb u ing the controller was broken because it showed full voltage on the motor output without the keyswitch or the throttle even connected, indicating blown mosfets.
is normal; thes eground th eoutptu to spin motor otherwise open, cnt remember for sure.

1 - The max suppl
y voltage is 46.6v. Above that it shuts down. Since it was designed for a 36v kart, and 36v batteries are at absolute most 45v when boiling their electrodes, that's sensible. But it means if I want to use a higher voltage than that I'll have to reverse engineer it to find how it determines that.
probly is board on side panel usin g cpmparator chip like 339 etc.



4 -
Below some resistance, the motor cuts out. So it goes faster, faster, faster, dead, if you bring the resistance too low. I'll need to have my stop switch sometime before this, as, you'd come to a complete stop while at wide open throttle, ease off a bit and then backflip as it slams max power ag
ain.

si protection agisnt shorted throttle wires.







Con
troller claims 275 amps, 46v = 12,650 watts = 17hp when completely topped up. Should be enough for highway speed if the motor will be spinning fast enough with that load. No way to tell. Not sure if the controller has overcurrent protection either, so maybe I can manually demand 500 amps and as long as it doesn't overheat it'll be fine
.

probly need big heatisnk adn maybe fasn to susiastn makx power. see diy elecrotric car forum for pics of peeoples curtis stuff fo rideas.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 17 2018 11:31am

Dafuq happened to your reply? Looks like it went down the garbage disposal and then the software tried to reassemble it back into a ham. :P

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by MattsAwesomeStuff » May 18 2018 4:07am

Battery Bulk:

My big goal was to get 60 miles (100km) worth of range at highway speeds. I need ~140-200 watt-hours to travel a mile at those speeds.

I have these 4x5 battery holders, an 18650's average voltage through it's discharge curve is ~3.7, maybe 3.75v, cells are roughly 2000mah each (good ones are 2600, I'll stuff in as many of those as possible), so each 4x5 brick of 20 cells is roughly 150 watt-hours and weighs 2 lbs.


Battery Weight:

At a brick a mile, I need to find room to fit 60 of the bricks in the frame (9000 watt-hours). Since I'm doing strings of 11, might as well round it up or down to 55 or 66 bricks. It'll weigh about 120 lbs to do that.

Motor is 92lbs, so motor+battery is 212 lbs, plus the weight of wiring and the battery enclosure.

The original engine according to spec was 181 lbs dry. Plus fluids. Plus exhaust. Plus fuel.

I should weigh the bike now and compare it to the 467lbs it was originally.

In any case, I'm in the right ballpark I'd say.


Battery Sizing Layout:

My first big happy surprise. I had more room in the frame than I thought.

66 bricks is roughly 2 milk crates worth, bulk-wise.

Just looking at the bike, I figured there was no way I'd find room to fit them. I've been putting it off forever, but tonight I dummied up a bunch of empty battery trays and started seeing where they could go.

Image


1 - Below radiator, in front of frame: 4x4 bricks, +4 if I remove radiator. 16-20 total.
2 - Below/between frame, below motor (as in pic): 3x4 bricks. If I double-stack (each stack is 2.5" tall), double that. Brake disc is 6" above ground, so I figure I'm okay with that clearance for city riding? 12 or 24 total.
3 - Beside motor: Sloppily, sticking out of frame, 5 first tier, 8 on second tier, 8 more on third tier. 21.
4 - Above Motor Right: 5x2 bricks. Three tiers. The mounting for the motor sticks out 2" so I have to separate right from left. 30 total.
5 - Above Motor Left: 4x2 bricks. Three tiers, but it's getting ugly to not narrow at the top of the frame. 24 total.
6 - Under Tank: 2x2. Not much space, hard to fit, but room for 4 total.
7 - Above Swingarm Triange: 3x2. 3 tiers. Nice and narrowly tucked, won't interfere with my thighs. 18 total.

Grand total: 125-141 bricks.

Jeez, I only needed room for 66.

Heck, I only have enough weight available for 66 (not 250-280 lbs).

I don't even have 141x20 = 2820 cells = 21kwh of cells. That's almost as much as a Nissan Leaf.


This isn't the layout I'll be using, or even the orientation, it was just the easiest way to slab up cell holders and ballpark the spacing available. If I'm over what I need by at least double... I can afford to make some choices based on cosmetics, not "What used to look like a motorbike now with a bunch of bricks".

I can skip the whole row in front of the frame. The 2nd tier below the frame. I can slim a whole row of bricks off of the left and right sides each. Still have room for 66. Easy.

Expecting my hubris to bite me later, but, for now I have some breathing room.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by parabellum » May 18 2018 8:48am

It is better to use protected areas for the cells to have some margin of robustness for unforeseen events, like roll-over, slide, little crash or curb jump. So you can get the bike up and eventually drive home. You may also consider leaving front open, for direct airflow to the motor, for cooling.

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by larsb » Nov 11 2018 1:12am

Like it! Subd

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Re: Motorbike Conversion - 1985 Nighthawk 750S - From Junk

Post by Voltron » Nov 11 2018 1:19pm

It's harder on the cells mounting them vertically... It makes the central mandrel inside the can bounce up and down, compared to having them mounted on their sides. Not sure how much real world difference it makes depending on how fast you cycle thru a pack...

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