Semi-enclosed Electric Feet Forward Project

nestofdragons

nestofdragons

100 mW
Joined
Jul 7, 2010
Messages
39
Location
Belgium, near Antwerp
Hallo,

using a glassfibre body of a velomobile (aerodynamic bicycle) I plan to create my personal EV which will also protect me again cold and rain (typical problems in Belgium as motorbiker). 8)

I plan to order my parts pretty soon, but ...as I am totally zero in electronics I hope the forum can correct me from making silly mistakes.

My goal: trying to get somthing similar like the Feet Forward EV of Cedric Lynch.
http://www.bikeweb.com/image/tid/57
It is really impressive! Has a larger range than my Suzuki Intruder 1500cc chopper! Cedrics EV's cruise speed is 80 km/h.

Motor: AGNI 95 or 95-R (what is the difference anyway ???)
Controller: BRUSA MD95
Contactor: double pole changeover (to reserve and brake regenerating)
Batteries: 18x Thunder Sky 100 Ah (2,8 - 4,0V) model no: TS-LFP100AHA
Mini-BMS: http://www.thunder-sky.com/products_en.asp?fid=&fid2=&page=10
Some grip throttle
Some charger

Could somebody please confirm that I am not making some idiot mistake.

Once I got this right I am going to buy the wheels and start tinkering inside the glassfibre body.

Thanks in advance,

Koen Van de Kerckhove (Koen is pronounced as "soon" but with K)
 

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That's a beautiful shell you have done in glass. How much does it weigh?

It sounds like you have a good plan. The thing I worry about with the fully enclosed velos is the their susceptibility to strong effects from crosswinds. I think that's a main reason none of the motorcycle manufacturers have come out with one. I believe that's also the reason for pretty strict limits on the forward area of farings for the EV's used in electrathons.

I plan to try something similar at some point, but I'd go with hub motors in both wheels for quiet operation. As I understand any noise is greatly amplified inside a velo. That route would be far cheaper and still capable of plenty of speed and acceleration. eg My e-bike with a single hub motor is capable of over 90kph and uses 55wh/mi (34wh/km) at that speed pushing a total load of 365lb (166kg). A fairing would increase that dramatically. A second motor would affect efficiency very little, and would improve performance up hills, as I'm currently restricted to about 8% grades without pedal assist. If you're interested in looking at hub motor solutions as a possibility, don't order your batteries yet, because you'll probably want to go to a higher voltage if you want traffic capable speeds.

Major questions to determine your drive train are:
1. How fast do you want to go.
2. What kind of hills are involved, and if there are hills then what kind of weight are you looking at.
3. What is the nature of your riding, stop and go or mostly cruising?

Definitely put the faring you have to good use. Ideas you might consider for the 2nd phase are things like enlarging it to make room for substantial cargo or a passenger to make your EV even more useful than as transport for just you. Another is that those velos must be terrible in good weather, so think about a removable 2 piece top that fits securely and out of the way inside the vehicle when not in use.

I look forward to seeing your progress and results, so please share along the way. You definitely came to the right place for help with the electrical side.

John
 
nestofdragons said:
I plan to order my parts pretty soon, but ...as I am totally zero in electronics I hope the forum can correct me from making silly mistakes.
Click to expand...

Well, you need to know what the approximate vehicle weight will be, and the expected typical speeds, and what kind of terrain it will be on (hills, or all flat, etc), as well as will it be start/stop in traffic or all highway use. Knowing that, you can use some of the many online EV and/or power calculators, and figure out approximately what your power usage will be.

Knowing the power usage, and then figuring the range you need to get out of it assuming only say 70% DoD (depth of discharge, or using only 70% of the total power in your batteries at absolute max, to prolong their life), you can figure out how much total Wh you need from your pack.

Then figure approximately how much current your motor/controller will pull from your batteries at maximum, and at average, and try to size your batteries so that they will never have to supply more than their max C-rate at maximum, and whenever possible, no more than half that for the average current draw. The lower you can keep the current draw from the batteries vs their capabilities, the longer they last, and the less waste heat you generate within them.


Motor: AGNI 95 or 95-R (what is the difference anyway ???)
Click to expand...
Don't know the difference on that one, but it's possible that one of them has advanced brush timing for better operation at higher voltages, and one of them has neutral timing to allow use in reverse or as a regenerative braking motor. If you use a brushed motor with advanced timing in reverse or with regen braking, you can cause damage, so make sure you use a neutrally-timed one.

I dont' know anything about that controller/etc either; but the TS batteries are generally ok, as long as you don't exceed 1C-2C (100A to 200A in this case, since the ones you're listing are 100Ah) current draw from them.

Do you already have a rolling chassis, just missing the motorization stuff and the shell? If so, you can weigh that and yourself, and estimate weights for the other stuff. If not, you'll have to estimate weights for everything based on the materials you intend to use, and their lengths/sizes/etc, plus fasteners/etc.
 
Many thanks for the comments and the encouragements.

I contacted the UK firm of Cedric Lynch's motors and I was advised to not use the BRUSA. It was used in Cedric's EV as there were no alternatives at that time. Today there are. I was proposed to use Sigma. It has regenerating braking and reverse in it already.

My goal:
cruise speed= 80 km/h
range= 120-150 miles
empty weight= about 100 kg (batteries are already 60 kg!, the frame will be in alu, wheels will probably be of Honda 125 cc Innova to have them as light as possible)
type of surface: flat (no hills)
type of traffic: stop and go and cruising (house-work-house and cruising with (EV)friends) 8) 8) 8) 8)

My shell weight at this moment 10,4 kg (both halves). But it has three layers of glassfibre. I know that on velomobiles many places have just a single layer. But they tend to vibrate at higher speeds. Just heard that vibrating sides reduces the top-speed. It kind of takes away energy.
Making half-tubes (single layer over half-tube foam (boilertube-isolation cut in half)) in glassfibre along those surfaces will stop those vibrations. Reinforcements (multi-layer) at entry hole and foot-bombbay-doors will be needed. The final version will be made in carbon or Kevlar. I have no idea at this moment what the weight will be of the shell in that version.

http://www.youtube.com/watch?v=zD8PA0lRRFY en http://www.youtube.com/watch?v=91OgYizuqGQ&feature=related show how you can get in a enclosed EV with top entry hole. I used a Quest velomobile on a extra height to have a more realistic height of the top of the EV. Closing the Quest (closing the hole to just under your head) was done with something flexible that you could put inside on hot days. The WAW had a removable top with visor. But it tend to fly away at high bikers-speeds (40-60 km/h). :roll:

Yes ...inside noise might be a problem. I recall one guy who had a WAW (= model of velomobile), which we nicknamed "thunderstorm". :twisted: He was like inside a drum.

I had one summer a WAW, which is totally enclosed. I never had trouble with the heat inside. I could open the visor to let air hit me in the face. But I guess my EV-visor will be fixed. I will install some kind of air-intake to be able to refresh the inside air and to blow on the inside of the visor to prevent damp on the visor during the winter. I might install a PC-desktop-ventilator to have some forced air blown on the inside of the visor.

I choose not to use hub-motors as I read they are not very powerful at lower speeds. The rpm are low at that moment. In a motor-gears-wheel configuration the engine can turn at a higher rpm and have more power/efficiency. It might have been the most quickly made version of my EV. Pity.

Greetz,

Koen
 
Oh yes ...sidewinds. Yep ...can be a handfull to handle :shock: , but ... if the vehicle corrects itself it has not to be a problem. And ...that is possible. :eek:

If the forward side-area is larger than the rearward, the wind will push more onto the front of the vehicle. Ok, it will try to fall over :( , but ...there is also another force working here. :shock:
The front of the EV will move left when having righthand wind. This makes the steering-axle of the fork also go to the left. But ...the tyre-surface that touches the ground is located behind the touching point of the forks steering-axle. So ... the front of the tyre gets to point to the left. :roll: Still following?

Ok, here comes the tricky part. If you have your front wheel pointing to the left, you incline towards ... right. Don't believe me. Go try on your bike. Be super sure you stay perfectly upright on your bike and ride straight and now pull the left side of the handlebars. Now believe it? Good! :p

Ok, if you now know that this force is higher than the force pushing the EV sideway by the wind. You will see that the EV will self-correct. The Ecomobile has a smaller negative effect by sidewind than conventional motorbikes. It was tested on a special test-track for sidewinds. Somewhere on the internet the test-pics are placed.

Greetz,

Koen
 
Koen,

I understand that the side wind won't knock you over and the resulting countersteering self correcting part, but won't it push such a light vehicle to the side just like it does on my long wheelbase bike? If not, then I need to dive in to get a better understanding when side force is applied well in front of the front wheel. What you're saying is very interesting, though I think where I live is too windy when the weather is nice. I'm tempted to attach a piece of plywood to my bike that extends out in front of the front wheel to fully understand this concept.

Since you live where it's flat, weight will have little effect other than as it relates to the power to weight ratio for acceleration. Personally I think the Agni is overkill unless you're looking for motorcycle type performance. Noise and price would be the only drawbacks for me.

Regarding hub motors, there is a wide variety and with easy mods and higher voltage than normally used on ebikes, meeting or exceeding the Agni's performance with a dual hub motor rig is possible, and you can get 2 motors and the controllers for the price of the Agni alone. My bike already has performance on par with scooters and small motorcycles, and if I had flat terrain I could go much more aggressive with my controller settings without worry. Once I do a build with dual motors the acceleration should be exhilarating. I don't know your acceleration goals, but I wanted let you know that you may be missing something by dismissing hub motors as poor performers

With the Agni, your all up light weight, and gearing for only 80-90kph, your e-velo is going to be amusement park ride fun. :mrgreen: The Agni will also get you net you a bit better efficiency.

Another option to consider is a brushless RC type motor. There's an economical water cooled one almost finished with the prototyping stage that will be a 12kw motor and far smaller and lighter than the Agni, and far cheaper and similar efficiency. Since it will be water cooled, you could completely isolate it from your compartment to suppress the sound. If your goal is minimum weight, then the RC motor route can't be overlooked. Check out this thread http://endless-sphere.com/forums/viewtopic.php?f=30&t=16728&start=0. You should also look at some of the higher performance stuff in the non-hubmotor drive section of the forum. One of our guys has 18kw on a downhill type bike.

Regarding the 2nd generation model, I'd suggest a carbon/kevlar weave cloth. Then you get the toughness and strength in one material.

I can't wait to see how your build progresses, especially how you design for entry and exit, as well as the bombay doors for putting your feet down. On the latter I haven't been able to visualize a way to do that without my feet catching on the edges when I pull them back in. Do you plan to spring load them in a way that they will pop further open when you push them a little, and stay open until you pull a lever to snap closed? All those little details are the tricky parts of the build.

John
 
John, I use the Agni because range is my top-priority. I read that hub-motors have less efficiency. I want something that has similar range as the choppers of the motorbike-club I attend to. :mrgreen: Or to be able to visit the coast on a single charge. Maybe even to return with that same charge. Home-coast is 100 km (about 60 miles).

Entry will be done like shown in the videos I mentioned earlier. I am used to this kind of entry. For me ... no problem. The roof will hinge in some way (still not sure which). For emergencies I consider to place a easy dismountable "sun-roof" (transparent of not). 8)

Bombbaydoors ... well, that part is indeed tricky. I get advises about how to hinge hard plates, but ...i still feel like that fabric might be the solution. I fear complex systems and getting caught on the edges with my boots. Tuscano (http://www.tucanourbano.it/main/termoscud.aspx)(manufacturer of winter-protection for drivers of scooters and motorbikes) has a system where they reinforce the fabric by placing a air-tube in it to avoid flapping at higher speeds. I think of something similar. Maybe i contact them to make a prototype-project. But at first I will drive it with open sides. Once i am sure the hole has the right shape, I will search for a way to close it properly.

Ok, this project of me might become costy. Might be that the second prototype might be totally different. This first prototype is for personal use. A second ...hmmm...low cost and ability to make more quickly at a reasonable price might be the goal (carbon or Kevlar out then not possible, but ...I already have another solution in mind). Hub-motors might be the solution then. Watercooled new motors will not be considered. I don't want to end up with something that still has teething problems. If there is interest in the first prototype I might consider to make more of them. Ah ...no dreaming allowed ...only building first. ;)

Greetz,

Koen
 
Koen,

With your great aerodynamics and flat terrain I have no doubt that you will be able to easily double the distance per watt-hour that I'm getting at cruise. With in town riding, lots of stop and go, sure you may go as high as 40wh/km, but away from town with few stops, I believe you'll do much better than 20wh/km at 80kph. That's 1600 watts continuous, and I think you'll be well below that, but power consumption is something you can prove first using some small cheap lead batteries, before investing in the expensive pack.

For being able to put feet down, other than just leaving it open, the things I was thinking of are:

1. Using an elastic material that stretches and is pushed to the ground by the rider's feet.

2. Similar to #1 but not elastic. Instead a more rigid material or plastic that is held on a spring roller, so it's self retracting.

3. my favorite...One longish hinged door for each foot with the hinge at the front. Instead of putting feet on the ground, your feet push the rear edge of the doors to the ground. 2 independent are needed to easily stay vertical on uneven pavement. Make them narrow at the back so less edge needs protection. Springs of course would close them tightly with edges overlapping the holes they cover.

A bit of creativity and a travel limit past vertical and they can also function as a 2 point kickstand. Strategic placement might even allow you to put your first foot entering the vehicle on the ground instead of balancing your full weight on the vehicle, eliminating some issues of entry. You could also sit down, and then just take off with the doors snapping closed automatically. If you made the point of contact with ground out of the steel, and had good strength in the assembly, then on hard pavement you could also use that as a pivot point to easily turn the bike around within its own length to point it in the right direction for takeoff.

Now you just need wings and a propeller.

John
 
John in CR said:
3. my favorite...One longish hinged door for each foot with the hinge at the front. Instead of putting feet on the ground, your feet push the rear edge of the doors to the ground. 2 are needed to easily stay vertical on uneven pavement. Make them narrow at the back so less edge needs protection. Springs of course would close them tightly with edges overlapping the holes they cover.
Click to expand...
That's exactly how some folks made simple brakes for soapbox racers in the thirties: a u-shaped outline cutout in the floor, the top of the u facing the pilot, the bottom of the u hinged with a spring... so the pilot would push down on the ends of the u to drag them on the pavement.
 
TylerDurden said:
John in CR said:
3. my favorite...One longish hinged door for each foot with the hinge at the front. Instead of putting feet on the ground, your feet push the rear edge of the doors to the ground. 2 are needed to easily stay vertical on uneven pavement. Make them narrow at the back so less edge needs protection. Springs of course would close them tightly with edges overlapping the holes they cover.
Click to expand...
That's exactly how some folks made simple brakes for soapbox racers in the thirties: a u-shaped outline cutout in the floor, the top of the u facing the pilot, the bottom of the u hinged with a spring... so the pilot would push down on the ends of the u to drag them on the pavement.
Click to expand...

Good one...emergency brakes too!
 
John in CR wrote:
That's 1600 watts continuous, and I think you'll be well below that, but power consumption is something you can prove first using some small cheap lead batteries, before investing in the expensive pack.
Click to expand...
Yes, I know I did choose for a expensive way of testing my ideas. But ...it is now possible. Let me think 6 more months and I find another way to spend the money that has less benefits to the EV-community. ;)

On my test-mule (some primitive vehicle using the intended wheels on the intended wheelbase with a seat of rails and a steer that is displaceble to test the ideal sitting position for a vehicle of the intended weight) I might test this idea of pushed down side-supports too. If it proofs to be useful and not easily to be forgotten (not like many beginners do in the Ecomobile) I might adapt my plan to this idea. My favorite solution is still the fabric that has some rigidity due to air-tubes or something else. But ...if possible I like to keep the airflow as clean as possible.

Anyway ...still waiting for the reply of my email of L.M.C. (Lynch Motor Company) to be able to order the right parts.

Also i am curious about the way the motor behaves when full of mud and ...can it be cleaned by a high-pressure hose?

Greetz,

Koen
 
This is an interesting project,
I read through & didn't see any referance to some of craig vetters current work regarding practical streamlining for an every day comuter type vehicle. here is a linc if you haven't seen it before.
http://www.craigvetter.com/pages/470MPG/Freedom-Machine-intro.html
please keep us posted on your progress.
 
Koen,

On these kind of vehicles is there a rule of thumb geometry for the rake and trail? Everything happens so much faster with such a low center of gravity, that I'm sure the bike wouldn't be as forgiving as my long wheelbase bike with a 26" high seat. Does wheelbase affect what is needed for the steering geometry?

Do you have any construction pics for the glass shell? I'd love to see how you did it. You mentioned 3 layers, but what weight glass cloth. Which method did you use to make it?
 
John in CR said:
Koen,

On these kind of vehicles is there a rule of thumb geometry for the rake and trail? Everything happens so much faster with such a low center of gravity, that I'm sure the bike wouldn't be as forgiving as my long wheelbase bike with a 26" high seat. Does wheelbase affect what is needed for the steering geometry?
Click to expand...

John, good you mentioned it. yes, low CG vehicles reacts quicker. In my first thoughts i was planning to combine the stability of long wheelbase and low CG to still have a forgiving motorbike. But I now have a shell that only allows the same wheelbase as a normal scooter or chopper. I now realize I need to alter the design of rake and trail. Altering the suspension already seemed like a challenge.

My glassfibre shell was made in real amateur-style. :shock: No vacuuming the over-added residue. We only respected the special mask and gloves rules. Weight of glass cloth i cannot recall. If i ever make the carbon version I will get the help of a guy i know in the Netherlands, who is a expert in this type of work. Making new molds will be done there too. At this moment I simply amuse myself with the glassfibre. 8)

Greetz,

Koen
 
Koen,

So you did a female mold first? The overall shape is superb. With a nice firm mold good squeegie work isn't too far from vacuum, and once you add a motor to the equation a bit of extra weight only matters for hills and drag racing.

No steering geometry hints or places to look for rules of thumb? I'll probably have to go out to a 1.8-2m wheelbase, for what I want to do. Think fully fared bak fiet that is perfectly functional with or without a canopy, Monotracer-ish but pilot slightly elevated and at the rear, so the overall shape is more like yours just bigger.

Crosswind worries has really been the only thing holding me back.

Regarding your interest in minimizing weight, better batteries could save 1/3 or more. Lipo has really improved over the past 2 years, and considering the reduced shipping cost, the price rivals your Thundersky's, but 10x the power density.

John
 
How did you make that shell? I didn't see a reference to the process. Did I miss it?

Katou
 
John in CR wrote:

Regarding your interest in minimizing weight, better batteries could save 1/3 or more. Lipo has really improved over the past 2 years, and considering the reduced shipping cost, the price rivals your Thundersky's, but 10x the power density.
Click to expand...

John, I based my selection of batteries on a video that is about 2 years old. Could you please inform me more about this better choice in batteries. At this moment my selected batteries (18 batteries of 100 Ah) have a total weight of about 60 kg. Seeing it reduced will make my goal of total weight (empty) of 100-110 kg better achievable.

Thanks in advance,

Koen
 
katou said:
How did you make that shell? I didn't see a reference to the process. Did I miss it?
Click to expand...

The shell was made from a female mold we got our hands on. It was made by a guy who made a 2wheeled race-bike with it called Aeroproject. I will attach the only picture I found of it.

At this moment I am the owner of the mold. The shell was made using the mold in preparation of a velomobile-project. But the group that was doing this project lost too many members to still work on this project. So now I do something solo (with the help of a befriended alu-welder and ...this forums advise).

I plan to keep both halves apart as long as possible. I can put a few inches between them if it is needed. The work needed to get the wheels running in separate sections will be done first with foam, then getting glassfibre over them and later I dissolve the foam. Seat will be a existing alu recumbent seat from another project. Foaming that seat will be thicker than the first intended foam thickness for the bike-project.

Greetz,

Koen
 
You are one lucky fellow to have come across that female mold - and to have space to store it!!

I wonder what it would cost to have a shell like that made for me.........

Looks good so far.

Is it necessary to custom make the bike to fit the shell?

Katou
 
nestofdragons said:
John in CR wrote:

Regarding your interest in minimizing weight, better batteries could save 1/3 or more. Lipo has really improved over the past 2 years, and considering the reduced shipping cost, the price rivals your Thundersky's, but 10x the power density.
Click to expand...

John, I based my selection of batteries on a video that is about 2 years old. Could you please inform me more about this better choice in batteries. At this moment my selected batteries (18 batteries of 100 Ah) have a total weight of about 60 kg. Seeing it reduced will make my goal of total weight (empty) of 100-110 kg better achievable.

Thanks in advance,

Koen
Click to expand...

I just checked and 18 of the Tsky 100ah batteries would weigh 63kg. As an example, 54 of these Lipo packs for the same total battery capacity (actually the Turnigy lipo's run higher than rated capacity, because rated is at max continuous discharge) would weigh 44kg, and you can make use of cabling and connectors already there. http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=10480. You'll need to educate yourself about Lipo, eg NEVER overcharge or overdischarge, which just prematurely kills the Lifepo 4, AND Lipo requires balance charging.

Prices are roughly comparable, and Lipo prices are still declining. Also, they have such a higher power density, so you could test it out with just a 5 or 10kg pack with your bike in the test phase and determine what kind of capacity pack you really want. I believe you'll need a lot less than you think, though extra capacity is always good for longer life. Then you can expand your pack however you like with better and likely cheaper batteries down the road. Plus the smaller sub-packs give you much more flexibility in placement. The disadvantage is more tedious and time consuming wiring, and there is more safety risk though they can be safe with due care. eg I believe Tesla is still using Lipo in their packs.

Spend some significant time in ES's Battery Technology section of the forum, and you'll probably get some new drivetrain ideas in the Non-Hubmotor section as well. 2 years is old news in EV's and I'd say that ES is the best source for cutting edge developments that are freely shared.

John
 
katou said:
You are one lucky fellow to have come across that female mold - and to have space to store it!!

I wonder what it would cost to have a shell like that made for me.........

Looks good so far.

Is it necessary to custom make the bike to fit the shell?

Katou
Click to expand...

Katou, at this moment I don't feel like a expert in glassfibre. So ...I cannot offer you that product. Let me gain more and more experience in glassfibre and carbon/Kevlar and I might do it.

Yes ...the internal frame will be a total new frame. I even think to redesign the forks.
 
John in CR said:
54 of these Lipo packs for the same total battery capacity would weigh 44kg, and you can make use of cabling and connectors already there.
Click to expand...

Waaaw ....that is about 20 kg less. Sounds really really interesting. Hihi ...I "knew" I had to ask this question here. I will read the topic you mentioned.

Just one question: I will be sitting nearly on top of them. Are they as safe as the proposed batteries by Cedric? Can some devise keep them under control?

Greetz,

Koen
 
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