Workman Stretch Mover Electric Trike - power not speed

[jeff peterson]

Hey Bob, I'm probably wrong here, but the one meter seems to cost about $130 and the other [though $50] is placed inline using much smaller wires than I'm using now. Plus I don't want all that power making a 14 foot round trip to the handle bars and back to the wiring box. So I don't foresee a meter being connected at this time. Since my max draw of 60 amps is less than what the battery is rated for and 20.5 under voltage will protect the battery. I think I'm okay. So for now the meter is on the wish list.

I will take you advise and gear down in long hills mostly when I'm hauling the heavy loads. I've also noticed I've been using the brakes a bit more. Thus I'm driving the bike more like a car.... That must stop if I want to achieve my 20 mile + range I had before to second motor.

I looked into the Nuvinci hub. Not only because I love the idea, but because it would also allow me to pedal when traveling over 7mph. [At this time, I can only assist while in first gear, once the motor goes into second my knees can not keep up] Sadly, thought the Nuvinci hub itself will fit in the trike, the chain will hit the frame. Though there could be a workaround by cutting the frame, I'm simply not willing to do it. So, if the 3 spd hub were to fail, I'll simply buy a better unit with more gear selections. I understand that I could add a larger sprocket to the pedals, but that would force me to use the battery at slow speeds. [I prefer to pedal passengers through tight or crowded areas like parking lots]

 

[dumbass]

Yes I share your feelings on the meters. But on the Nuvinci I don't think we are on the same page. The Nuvinci is normally installed in place of a sprocket hum cluster. Does your tric have a standard type of sprocket cluster located on one of the wheels? Or is it mounted on the drive shaft? If it is on the drive shaft the Nuvinci could not be direct mounted. It would have to be mounted as a mid-drive (lots of work). This all being said it would still work the same way your current system works. Unless of course you were planning to use it exclusively for the peddle crank. In this case you could alter the ratio between the motor and your peddles. Bob

 

[jeff peterson]

I do not have the normal cluster, nor could it mount on the drive shaft. I have a mid drive on the rear of the frame that's behind and under the drive shaft. Staton has a 3 sprocket set-up. I can fish the chain from the Nuvinci to both the pedals and motor, but not the driveshaft do to it's larger diameter. I was looking into extending the trike another foot. But that idea would include a floating rear suspension, something I don't think I can afford. It would also make the trike too big to fit into the pickup truck.... Sometimes it's better to start over, than to keep re-designing someone else's design. Plus in the long run, when I stop hanging at the beach, I'll remove the rear seats and put in a lockable aluminum box.

On the bright side, I have wired up the new pieces. But I'm using the brake kill leads to turn off the motors. Does this cause a power drain?

Weather is nice today, I'm going to try to run the trike out of power just to test how far it can travel under just battery power and also find out how long it take to recharge.

 

[jeff peterson]

Thought I'd post the latest issues.
1 - Charging problem. I thought it was the charger. Ping thought it was the BMS and was kind enough to send a replacement card. Actually the problem was in the charging connector. The contacts failed within the connector, something you could not see. It's a $5 part, but costing a lot of emails and wasting other peoples time. Big Thanks to Li Ping, who stepped up and send new BMS without being paid or anything. I can not believe how fast he offered to help. This means a lot to me and I will not forget this kind of service.

2 - The 3 SPD [Shimano "Nexus" 3 speed trans -coaster brake] Failed. I think this was my error. It seems a part was missing that prevents the axle from turning. I assumed I needed to torque the mounting bolts tighter to hold the axle shaft in place. I believe the added torque on the blots caused the housing to fail and the ball bearing to come out of the house as if it exploded. when I disassembled the 3 spd trans, only one ball bearing was remaining and it was stuck in the housing itself. Oh and whatever held the bearings in place is now grit within the grease. Side note, the gear system still works, yes it's making a lot of noise, but it shows the quality of construction used. This also shows what a small brain and a long wrench can do.

So live and learn... I've ordered a new 5 spd trans with coaster brake [SRC5(w)]. That hurt me for $180 for the trike kit and will take the trike off the road for a week. Needless to say I'll make sure I install this trans correctly. Other than that everything is Ok. I have 1220 miles on the trike so far. I average 17 MPH, maxing at 19.6 MPH. I replaced the rear tires once due to them having no tread. Chains and brakes are still looking good. I replaced the keyed switch coming off the battery with a true 500 amp battery switch. There were no failures, but the old terminals looked as if they saw some resistance heat.

The good news - Since the trike is on blocks for a week. I'm pulling the cover off my old High School 73 conv Mustang. It's American made for an American Holiday. Me and my 8-tracks, BBQ and apple pie are heading for the beach! Have a great 4th of July everyone!

 

[dumbass]

Jeff,

So this "trans your tralking about...is it actually a trans or a set of external gears like a 3 speed external gear cluster with a freewheel? Bob

 

[jeff peterson]

Old trans was a Shimano Nexus 3 speed. [pictured install on trike]

New 5 speed is a Sturmey Archer S5C Hub with and added sprocket which is given a new model - SRC5(w)
[pictured with white back ground]

Input sprocket may need to be replaced do to the size of the output sprocket.
But I do not know the teeth numbers at this time. I'll just wait and see what comes it.

I do know the gear ratios
3 speed 5 speed
1= .733 .625
2= 1.0 .75
3= 1.36 1.0
4= n/a 1.33
5= n/a 1.6

 

[zap]

It's good to see that the trike, although temporarily sidelined for now, is still kickin'. Best of luck with the repairs.

1220 miles... not too shabby!

 

[jeff peterson]

Thanks for the kind words Zap! I'm back and working on installing the 5 speed. First problem is that it's wider than the old 3 spd thus I'll need to spread the forks. Sprockets are a different size thus the chains will need to change. It seems my trike is longer than normal because the gear control does not fix to the handle. The local bike shop said they can fix that. New speed chart for flat ground 1st- 9MGH, 2nd- 12MPH, 3rd- 15.5MPH, 4th- 19.6MPH, 5th- 24MPH.

New project for the winter, I bought a $15 dollar kick scooter with 12.5 wheels. I'm hoping to add a motor to it.

 

[JEB]

I did not want to run the large current wires up to the front of my trike, sometimes I draw to 100amps~, so I placed a shunt close to the motor- ended up cutting the shunt down, with 1/10 of the current going to the digital meter, so it's not as accurate moving the decimal point over one digit- but close enough.

 

[jeff peterson]

Quick up-date to a long story. 10 Amp Ping Charger failed for the 3rd time. It took a month to receive a new charger. 3 spd transmission failed due to a factory install error. Opted to buy a 5 spd transmission which has been nothing but problems from day one. Months have gone by, with no progress repairing the 5 spd, 2 weeks back I gave up on the 5 spd.

Moving forward... The new charger has brought the pack back to what seems to be full power! And thanks to this forum, I bought a Nuvinci developer kit from Fallbrook. The Nuvinci hub is installed and working well. I do not feel any slippage and it shifts under 900 watts of motor load. The only drawback I'm having is understanding how to program the shift points. It's a bit early to tell, but I believe this Nuvinci is the way to go as I've added an average of 4mph to my average speed even while hauling 2 passangers (totaling 500lbs).

New Project: I plan to buy a new aluminum Schwinn trike, another Nuvinci Developer kit, Currie 450 watt bike motor and 20 amp hour 24v pack from Ping. This will be a light weight trike for cruising by myself and light loads.

 

[amberwolf]

If you need help with the NV stuff, there's a thread where several of us are discussing that dev kit, including various builds with it:
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=30641
I don't have the answers, but others that are already using it might.

 

[dumbass]

As soon as I starting reading your update I was going to tell you to buy the Nuvinci kit. I really think in your situation you would be better off if you could have a manual shift switch. Your situation is so dependent of verying torque unless you are somehow reading those torque veriations I don't see how it will work eff for you just reading the wheel speed. Bob

 

[amberwolf]

I've got a proposed method of doing that using the Cycle Analyst and the NV devkit controller, over in that thread. Not tested yet, but it ought to work.

 

[jeff peterson]

Thanks for the link Dumbass! It will take some time to read all of it and get involved...

Amberwolf, I've been slowly making adjustment to the controller with a bit of success each time. This evening I did a 10 mile ride. At first, with just me on the trike, I felt the auto shifting was not working very well with my latest reprograming. Then I look at the speed, I had hit 18mph without feeling the unit shift. It continued up to the 23-25 range. faster than this work trike has ever gone in the past. I only put out 900watts but I can tell you it shifts fine under my motor load. Next I came up to a old bridge that climbs over RR tracks. The Nuvince hub down shifted keeping the motor in the higher rpm dropping the speed to 13 mph. As soon as the hill started to lessen, the hub started to up shift and the speed increased again while motor rpm remained the same. I was VERY impressed. On the back half of the trip I had to stop for beer. (9-30packs and some chips & dogs) After straping the load down, I took off. The Nuvinci's shift pattern changed. I thought it woulds run weak and not shift due to the load. I was wrong, it really grabbed by up shifting strong. Putting a lot of load on the motor. again it shifted under load and again brought the trike up to the 23/25mph speed. So far this hub is the sweetest thing ever. A few other things. You can run 2 different shift patterns with just a toggle switch. you can manually/electronicly shift if you wish. They also offer a controller, price at $250, but it could be worth it in some cases.

 

[dumbass]

Very coll Jeff and thanks for all the great info. So if I understand correctly this would likely be the same situation in say a mid-throttle position as well. Of course the speed would be effected but the automation being the same. Correct? Load compensation is the one thing I was worried about..that and the manual shifting ability. So is there a switch selector (auto/manual) included or is that something they only advise can be added?

Bob

 

[jeff peterson]

Dumbass: So if I understand correctly this would likely be the same situation in say a mid-throttle position as well. Of course the speed would be effected but the automation being the same. Correct?

I'm guessing no. Because the hub would notice the lower speed and shift down to try to being the motor speed up. Remember the hub in automatic it trying to maintain a constant RPM of the motor (or pedal cadence) by adjusting the "gearing" to the land speed. If the land speed drops, the hub thinks the motor is under too much load, thus the hub will down shift. If the land speed is too hi it up shifts.

Dumbass: So is there a switch selector (auto/manual) included or is that something they only advise can be added?

If you want to control EVERYTHING, they sell a top notch controller for $250. But if you don't mind cutting back a few features. You can simply add a toggle switch and switch back and forth from two shift maps. For example: shift map for normal cruising and a second shift map for hauling a load. You can add an analog input (0-5VDC) that would very the shifting manually. All this info and more is in their manual posted on their site.

I believe the best way to think about this hub in automatic mode is that it's a smart hub. Except for control during very low speeds, your throttle is useless. Why? Because once you start moving the hub controls everything and it full throttle from then on. So, let the hub do all the work. How do you do this? Figure the sweet spot (RPM) for your motor, guessing 80-85% of free wheel speed of the motor. If you go under the 80%, the hub down shifts. If you go over 85%, it up shifts. Finding the sweet spot is up to you to figure out, but once you do, it's a dream.

You can also program a stepping shift pattern. The hub would feel and act like and automatic car transmission. You come up to a certain programmed speed and the hub would shift and defined percentage. For a lot of folks I believe this is what they want because this is what they are use to. Personally, I believe this shift map takes away from the true design and reason for having a CVP. But some folks argue that the constant adjusting of the controller may use up more battery than it's worth. All these reasons make sense to me but I want torque for my heavy hauling. Time will tell.....

BTW - I ordered a second hub kit due in tomorrow. Yes, I like it that much!

 

[dumbass]

You really opened up a can of worms for me and now I have even more questions. I keep looking at getting 1 or more of these but I just have so many project right now...Where to spend the money? Please see my questions in Blue

Bob

Dumbass: So if I understand correctly this would likely be the same situation in say a mid-throttle position as well. Of course the speed would be effected but the automation being the same. Correct?

I'm guessing no. Because the hub would notice the lower speed and shift down to try to being the motor speed up. Remember the hub in automatic it trying to maintain a constant RPM of the motor (or pedal cadence) by adjusting the "gearing" to the land speed. If the land speed drops, the hub thinks the motor is under too much load, thus the hub will down shift. If the land speed is too hi it up shifts.

OK, so is the speed sensor on the input of the hub? What exactly is the program doing? I am assuming from what your saying is you basicly creat a preset input speed in the program for the hub to maintain. If this is correct then what do you do when you actually want a different speed? Lets assume that with your program you would achieve 25mph under ideal conditions. But at some point under this same ideal conditions you want to lower your speed. Based on your comments as you reduce the throttle the hub would adjust to maintain the input speed. Correct? The problem I see with this is if I wanted to main tain say 12mph based on what your saying the hub would run in a very low range forcing you to increase the throttle. I've had a manual Nuvinci for 3+ years and I've played with hub/motor speeds to maintain a given bike speed. Based on my testing I've found that the sweet spot is not always the most eff motor speed for the given situation and/or bike speed. Your thoughts....

Dumbass: So is there a switch selector (auto/manual) included or is that something they only advise can be added?

If you want to control EVERYTHING, they sell a top notch controller for $250. But if you don't mind cutting back a few features. You can simply add a toggle switch and switch back and forth from two shift maps. For example: shift map for normal cruising and a second shift map for hauling a load. You can add an analog input (0-5VDC) that would very the shifting manually. All this info and more is in their manual posted on their site.

I believe the best way to think about this hub in automatic mode is that it's a smart hub. Except for control during very low speeds, your throttle is useless. Why? Because once you start moving the hub controls everything and it full throttle from then on. So, let the hub do all the work. How do you do this? Figure the sweet spot (RPM) for your motor, guessing 80-85% of free wheel speed of the motor. If you go under the 80%, the hub down shifts. If you go over 85%, it up shifts. Finding the sweet spot is up to you to figure out, but once you do, it's a dream.

OK, so a switch to control the auto/manual would be needed plus a speed pot to actually give the hub a range comand. Correct?

You can also program a stepping shift pattern. The hub would feel and act like and automatic car transmission. You come up to a certain programmed speed and the hub would shift and defined percentage. For a lot of folks I believe this is what they want because this is what they are use to. Personally, I believe this shift map takes away from the true design and reason for having a CVP. But some folks argue that the constant adjusting of the controller may use up more battery than it's worth. All these reasons make sense to me but I want torque for my heavy hauling. Time will tell.....

BTW - I ordered a second hub kit due in tomorrow. Yes, I like it that much!

 

[jeff peterson]

Bob: is the speed sensor on the input of the hub?

No, There is a programable controller, both the speed sensor and hub controller are wired to it. The programable controller conects to a computer via a USB cable whis is included with the kit.

Bob: Based on your comments as you reduce the throttle the hub would adjust to maintain the input speed. Correct?

Yes and no, as your speed decreases, the hub will gear down. If you lessen the power to the motor you could maintain a lower speed. But the hub will search for the correct gearing per your land speed and the setting you keyed in. When I said the throttle useless, this is for my situation, since 25MPH is about the max on flat land I'm normally at full throttle. I'm thinking gearing is not the word, maybe ratio is better. but I think you understand what I'm trying to say.

Bob: OK, so a switch to control the auto/manual would be needed plus a speed pot to actually give the hub a range comand. Correct?

I'm not 100% sure. I know a switch can be used to change from one auto program to a second auto program. I believe you have to tell the program to turn off the auto mode via the computer/USB connection. Then you could connect the speed pot, but I have not tried this. According to what I'v read, their $250 controller can switch from auto to manual. Switch between 10 different shift maps. Shift up and down in equal step that you program. As well as show what the hub is doing VS what your telling it to do and gives a read out of volts and other stuff..... It does a lot, but is it worth $250???

New learnings: It seem sthe currie motor output is not spinning at the stated 550rpm. That why my calulations have not worked as expected. The actual RPM speed is 382. With this new number I reprogramed the controller. The hub is now more controllable and predictable. All good! I'm truly just fine tuning it now. I'll see what happens this weekend when I add the weight of a few ladies in the back.

 

[amberwolf]

This is part of why I'd thought of using the CA to do the controlling part, having it's throttle output control the analog manual input on the NV shift controller. Since the NVSC can't be switched from auto to manual on the fly, that's a disadvantage for my purposes especially for experimentation.

But the CA controlling the manual input *woudl* be easily switchable on the fly, simply by flipping a switch to cut the CA out and a pot or hall control in.

The CA's speed sensor could be left on the wheel, or used on the motor itself, and the CA's sensing of the motor controller's battery current can be used to control shifting based on motor loading, too (not sure if this can happen at the same time, though).

 

[jeff peterson]

Amberwolf: This is part of why I'd thought of using the CA to do the controlling part, having it's throttle output control the analog manual input on the NV shift controller. Since the NVSC can't be switched from auto to manual on the fly, that's a disadvantage for my purposes especially for experimentation.

Please remember I stated that I was not 100% sure if the NVSC can or can't be switched from auto to manual on the fly without using their $250 controler. I have not tried it. Plus I do not have a CA or the Nuvinci controller.

Amberwolf: But the CA controlling the manual input *woudl* be easily switchable on the fly, simply by flipping a switch to cut the CA out and a pot or hall control in.

Not sure if this is doable, if you turn off the hub controller, you would not be able to use a pot to control the hub.

Amberwolf: The CA's speed sensor could be left on the wheel, or used on the motor itself, and the CA's sensing of the motor controller's battery current can be used to control shifting based on motor loading, too (not sure if this can happen at the same time, though).

You lost me here. Personally I think folks are trying to over design their systems. Which is great and I give everyone kudo's for it, but it's just a electric bike. I'd simply buy an over sized battery and remove the power concerns all together. The reason I switched to the Nuvinci so that I didn't have to deal the issues of the 5 spd hub that kept failing. I personally feel the 3 and 5 speed hubs are more eff than the Nuvinci. That being said, if the Nuvinci is 5% or 10% less eff, yet offers no worries in the brake down department, I'll eat the eff loss. But that's just me.....

Question for the world. I'd like to find away to mount a brake disk or brake drum to a keyless 7'/8" drive shaft. I could also use a set of 20" very HD tires like they sell at Workmans Cycles. Kmart BMX tires are not holding up.

 

[dumbass]

New learnings: It seem sthe currie motor output is not spinning at the stated 550rpm. That why my calulations have not worked as expected. The actual RPM speed is 382. With this new number I reprogramed the controller. The hub is now more controllable and predictable. All good! I'm truly just fine tuning it now. I'll see what happens this weekend when I add the weight of a few ladies in the back.

Jeff, The Currie motors are not rated for 550rpm. They are rated for 450rpm. However, I have tached them as high as 510rpm no load. But I have yet to find 2 motors with the same speed. This have always been a problem with my twin setup. One motor is pulling a lot harder then the other. I thought it was because the 2 24v controllers might be the problem so I changed to a single 48v 50a controller and wired the motors in series. Same problem one motor still pulls much harder then the other. The stronger motor also get 15 to 25 degrees hotter when I work them hard.

Bob

 

[jeff peterson]

Have you tried to mate them shaft to shaft? Have one spin forward and one back? I'd like to also put a free wheel in the middle! Any thoughts?

 

[dumbass]

Have you tried to mate them shaft to shaft? Have one spin forward and one back? I'd like to also put a free wheel in the middle! Any thoughts?

No I've not tried the shaft to shaft method. Right now mine are mounted side by side (actually one is above the other) and each has it's own drive chain going to a jack-shaft which has an independent freewheel for each motor. The other side of the jack-shaft has a 3rd freewheel (totally redundent but was easier because I could swap sprocket quickly on the adaptor until I settled on a gear ratio I wanted). So I guess I am currently doing the "freewheel in the middle" idea you have. The 2 freewheels in the infeed of the jack-shaft were because I originally only ran 1 motor at a time. The second motor was only used in case of a motor.controller failure.

Bob

 

[jeff peterson]

Bob, according to ElectricScooterParts - the 450 watt 24v motor spins at 550 and that the 250 watt spins at 382. I made the assumption 550 was wrong due to the error I was getting with the Nuvinci hub programing. We have a strobe here at work, but I didn't feel the need to go that far once the hub started working correctly. I'd love to be able to add a free wheel to the motors so I can pedal without motor drag. At this time if I pedal I actually spin the motors, Of course if the motor is in operation I'm assisting it, which is not a bad thing. Oh, I also have a motor what works harder that the other. I looked into the Cyclone, but that a lot of money and amps compared to the twin Curies I use now.

As for the Nuvinci hub: The second Nuvinci developer kit arrived. I removed the controller from the box and program both controllers with 2 different shift maps. This should make it twice as fast to finalize my shift points. Though I have to say that the hub is working great at this time. I tested the hub this week by adding two ladies on the rear seat. This time with the latest programing the hub worked fine with no noticeable shifting or motor rpm change with or without the additional weight of the ladies.

 

[dumbass]

Jeff,

Somewhere I had a spec on the Currie motor and it indicated 450RPM. But no matter beause I used a new dig tech on the motors and one read around 500 and the other was much higher. I think 535. Because of what I had read I thought my motors were just running a little faster the the spec. The problem with these motors is there are several (4 different ones that I have already) manufactures. So does each one build to the same spec? I really don't think so.

I looked at making a freewheel adaptor to mount directly onto the motor a few times. The problem is freewheels are so heavy and wide it's a big overhange on that little shaft. The other problem was I only need maybe 2 or 3 of these adaptors. And to do it right I needed a keyway brotch for the shaft key. Because it's metric it's hard to find and expensive. I'm guessing it would cost $100 to $200 for the brotch and a small press to do the job. The good thing is I have a milling maching a lathe to do the rest of the work.

Because of these problems and because I wanted t oreduce my ratio anyway I decided to install a jackshaft. So my freewheels are on the jackshaft. I don't understand why you can't do the same thing. It works perfectly and gives you another place for gear deduction if you need it and it gives a perfect and easy way to mount freewheels. Yuo can even do it so you could run one of both motors if you like.

Bob