Safe's Electric Bike Project #002

[safe]

Framework For Front Fairing

The tolerances are just so tight on this part of the project that I'm looking to grow the front fairing out in a sort of organic process. These pieces provide a general framework on which the last parts will be added. The "hand cups" or whatever you call them need to cover just enough so that you get good aerodynamics and also allow for the handlebars to clear. It's a very tight fit.

Bicycle Specific Feature...

On a motorcycle road racer you never need to get up off your seat and pedal. As a result of this you can allow the front fairing to slope backwards over your hands. This means that if you try to stand up the fairing will be really close to touching your hands.

On a bicycle you need a little extra space because when you pedal you tend to wiggle around and tip the bike from side to side, so as a result of this I'm going to taper the part where the fairing goes above the hands a little earlier than normal. This will allow extra hand clearance and when I make a bike that is pedal powered (this one will have no pedals) the fairings will work well with them. The rear fairing might actually be a bit tight as far as the pedal clearance, but I can always take a slice out of the middle and narrow it if that's a problem. (the only way to know is to try it)

 

[v_tach]

2. Never sand with your bare hands because that just repeats the errors that already exist. Use a sanding block and that way you are only sanding off the high spots and not digging the low spots any deeper.

That line right there indicates your complete inexperience with such work.

Okay, I'm curious now...

Are you saying that block sanding does not tend to smooth out ripples easier than hand sanding? The problem with hand sanding is that since your fingers tend to produce uneven pressure the sandpaper tends to dive down into the low spots and take away material that you don't want to touch.

So are you saying that you have mastered some hand sanding technique that gets past this problem?

Its been a while since I've visited the forum and I commend you on your progress. Looks great so far.

My comment in regard to the block sanding was because I thought you had posted the info because you had just recently figured out the pitfalls of hand sanding.

I had gotten a little frustrated with some of your previous responses to my posts and responded inappropriately. I apologize.

 

[safe]

More Updates

Well it seems like the only time I ever want to work on the bike now is when the weather is perfect. I've been riding the #001 bike two to three times a day on the "good days" and in between rides when the bike is charging I do a little work on the fairings.

It's getting closer... the sides where the top part blends into the bottom part are still kind of unclear for me yet. The top I like... that general shape is about what I was looking for and it should give plenty of room while you pedal when I get to needing to worry about such things.

At some point I'm going to remove the forks and front wheel and seal off the entire underbelly. The actual mold that is made will NOT have a hole for the forks. The idea for that is with each bike things might need to be slightly different and it's not that hard to make the hole as the last thing you do. I can see using this with a regular bicycle fork and in that case you would only need a small hole to fit through the head tube.

Adaptability is good...

P.S: v_tach, thanks. I have found that there are some circumstances where hand sanding is the only option. When I'm in a concave (sunken in) area the block sanding doesn't work very well (like the inside of the front fairing, underneath) so I've had to learn to be able to hand sand. It seems that if you are more careful with your fingers and pay attention more that it does work pretty well.

 

[safe]

Side Area Figured Out

I think I've got the side area of the front fairing figured out. Basically there is a straight line that runs parallel with the frame if you look at it from the side, but from the top it bends outward. I haven't decided exactly how much of a lip there will be and it might come down to when I actually try getting it out of the mold later on. Ideally it would be nice to have a rounded edge rather than a sharp cutoff of the fiberglass.

This week looks to have three good weather days in it, so I'm hoping to progress really far on the front fairing...

 

[CGameProgrammer]

Is that front fork the real one you'll be using? There appears to be no clearance for the front wheel even without the suspension compressed.

 

[deecanio]

wow thats taking a beautiful shape safe.
I loved my road racer motorcycle and that had a cafe racer riding position with clip ons and a full fairing, ah those were the days!!!
this bike will be soooo cool, watch me start dribbling when it gets some paint on the body
loving watching this build, keep her pretty safe


cheers


D

 

[xyster]

It's beautiful Safe, even with that funny little motor hanging from the frame instead of built into the wheel.

I'm wondering about the front wheel clearance though too...

 

[safe]

I'm wondering about the front wheel clearance though too...

To answer everyone...

It's a strange camera angle and the front wheel is slightly turned to the right, so it looks tighter than it is. Don't forget that I radically modified everything about those forks and they will only have one inch of travel. When you actually get up close and have the right camera angle you would see a lot of clearance (almost too much) so more pictures will make it more clear that everything is "okay".

 

[safe]

Side View

This photo gives you a little better idea of the clearance for the front wheel. There's actually an indention in the fairing sort of like a big fender so the tire actually fits inside the fairing slightly. It still looks a lot closer than it really is. :?

This picture was before I started today... so I got some more progress on the sanding after the photo. It's really hard to get both sides just the same. Just when you think you have one side figured out the other presents some slight variation and you have to rethink what you really want it to look like. I'd really like smooth edges rather than just blunt fiberglass that is flat and then just "ends". In order to do edges though you need to get the dimensions just right because you can't just sand stuff down after the fairing is made to even things out.

If I was doing this for profit I'd have to either charge thousands of dollars for the bike or accept pennies for my labor. At least when it's done I'll have a mold that can be reused many times...

 

[xyster]

If I was doing this for profit I'd have to either charge thousands of dollars for the bike or accept pennies for my labor. At least when it's done I'll have a mold that can be reused many times...

The "hobby economy"...? Again, very nice work on your bike.

 

[Lowell]

Were you planning on having any sort of 'tank' fairing to stop you from sliding forwards under braking?

 

[safe]

Were you planning on having any sort of 'tank' fairing to stop you from sliding forwards under braking?

Real motorcycle Road Racers do three things:

1. Accelerate really fast.

2. Stop really fast.

3. Corner really fast.

...so since you spend most of your time doing one of those three things you need to build a motorcycle to make those tasks easier.

On an electric Road Racer that has a lower power-to-weight ratio than a compact car I'm never going to have to worry about powerful acceleration throwing my body against the back of my seat or long braking periods where I'm being thrown forward. They just won't happen that much! Cornering I WILL be able to do and the general idea is to set up an electric Road Racer so that it does best what it's designed to do. Also, you will likely spend long periods of time in a tuck so that should be optimized.

So this was the design theory:

Eliminate the tank and narrow the top tube area so much that you can clamp your legs tightly together. By making the top area extremely THIN I can squeeze my legs together and bring my elbows in tight on top of them. The frontal area is reduced to the bare minimum this way.

What about braking?

Well... you COULD clamp your legs together, but that means no "air brake" by having your legs apart to increase your wind resistance. So I decided to place a small rise in the front of the seat (about the same width as a typical bicycle seat) and allow you to run up into that. Obviously, since I'm a guy, I don't want to place anything there that's going to hurt, so there's a limit to what can be done.

The bottom line is that unlike a motorcycle the electric Road Racer doesn't usually brake very often (aren't going fast enough to need to since you can simply take most turns at full speed) and with good brakes those times that you do brake are so short that you can use your arms to hold yourself from sliding forward.

Another factor is the pedaling situation... in the future the #003 Project will have everything AND pedals. If you use the "simulated tank" approach you are encrouching on the room for pedaling when you stand up.

So this design is conscious.... and unique... it's a new type of electric vehicle... (new ideas at play here)

 

[safe]

So Many Angles!!!

It's surprising how complicated this is turning out to be. There are just so many ways that things can go wrong with such a complex shape. What I would do is start with my eyes parallel with the windshield portion of the fairing and then move my eyes forwards and rotate down to observe how the shape varied. It was all over the place with one side dipping in and the other out. They would even alternate. After many fills and sands I'm getting closer to where it needs to be. I still think this shape would be very hard to get right if you tried to build it off the bike somehow. The bondo allows me to get it wrong five times in a row and then finally get it right on the sixth... I like it when things go like that... (rather than getting just one shot at it)

It's kind of nice that this doesn't need to be ready until next spring because I'd hate to have to rush through it... doing three hours every couple of days is about all the dust I want to deal with. (I sometimes use the dust mask, but I'd rather not and instead time my breathing around dust clouds)

I'm pretty sure I took the springs out of the forks so that's why the tire is so close to the fairing... (I think I left a little spacer in there)

 

[safe]

Getting Close

It won't be long and I'll be taking the front fairing off the bike and doing the final inside curve where the forks have a big hole right now. Everything is slowly coming together and if I stare at it long enough I can figure out what needs more fill and which needs less.

Patience is a virtue...

 

[safe]

Making It Generic

By closing the hole in the middle of the fairing where the forks go it makes the front fairing much more generic. As you can see there are still little imperfections as well as imbalances from side to side that I'm going to need to still work on. Not that far from being done though...

Once completely done then the next step is to buy the fiberglass materials and make the final female mold. Once that female mold is layered over this original mold and then released I will then finally be able to make the first true product. Once you have that female mold you can make as many new "final product" fairings as you like and they pop right out and other than a little sanding to touch them up they are pretty much ready to be painted.

So it's a long process to get there, but once you are done you can crank out fairings like a production line...

 

[xyster]

Once completely done then the next step is to buy the fiberglass materials and make the final female mold. Once that female mold is layered over this original mold and then released I will then finally be able to make the first true product.

Here I thought you were just going to ride the bondo.
Thank you for taking us through this process. I could see doing something like this for a fairing.

 

[safe]

Thank you for taking us through this process. I could see doing something like this for a fairing.

It's not that expensive to do, but it's dirty (dusty) and very time consuming. I've been doing a lot of the work out in the driveway because doing it in the garage is really intense when you get all that dust floating around. Wearing the dust mask for hours on end is no fun either. Being outside on a nice day with a slight wind is the way to do it because the dust just floats off with the wind.

 

[newbie electric rider]

Excellent work Safe, looking very sleek and sexy!

 

[RLT]

Complete newbie here; Thanks for all the good ideas and information; This thread (and others) are really helping me with design and methods on MY project #2 .

I'll have a bunch of questions for you later, but I have a really strong recommendation for now.

Tab your batteries! And either tab weld or solder the strings together.

For the last couple of years I have been thinking about building a 'stealth' e-bike with a battery pack built into the frame, and while I'm a newbie to bike building, I have a good bit of experience working with NiMH and LiIon batteries. Won't call myself an expert, but I'm only a step or two below that;

My experience is in building really powerful LED flashlights, caving headlamps and bike headlights from 'scratch' or modifying existing ones. (have built / modified hundreds in the last 6 years). One thing I have noticed, with both NiMH and LiIons of over 17 mm diameter is that just spring loading them, even 2 or 3 in series is not a good solution for even a flashlight if it is going to endure any kind of rough use.

Most of My C & D cell size NiMH batteries have dented bases just from the pressure of the stock spring in a 3 or or more cell MagLight ; a few have even split the cases slightly, and a couple of those have started leaking. Annoying with NiMH... Potentially disastrous with LiIon.

And even then, the spring force is not enough to keep the cells in constant contact when there is any significant bump or shock in a vector that compresses the spring. Sure, it only lasts for a fraction of a second per impact, and in a flashlight, you may not even notice it

But if it will do that in a flashlight , imagine what the forces of shock and gravity can do to the flow of power to your controller & motor when you hit the slightest bump on your bike, with that long column of batteries, gravity and various other forces acting to separate their contacts. I don't know how well controllers react to sudden make/break contacts from their power supply, but I can't imagine they much like it.

Now imagine a washboard road or cattle guard (for example) causing the current to be interrupted like a machine gun blasting electrons into your controller and motor.

Maybe on a bike intended to set speed records on a perfectly smooth, flat track, it won't be a problem. But for any kind of normal road (or off road) use, I think it is asking for trouble.

And with the perforated frame, I think you are very likely to get dust and moisture between the contacts, adding resistance and robbing performance, with or without any bumps causing momentary 'opens'.

I'm all for cutting expenses wherever possible, but this isn't a place I'd cut corners. Most of the places I buy batteries from will tab them for 25 cents each in small quantities, and 15 cents each in the quantities that the Safe 002 will be using them.

(Plus I'm close to perfecting two different styles of battery tab welders that should be doable with mostly scrounged parts and materials; One 'free' at best. The other for about 75 bucks if you have to buy everything new. I'll share those plans when I they are past the merely experimental stage.)

And one more little teaser: I have a source for D cell sized Lithium Ion batteries at a not too outrageous price even at retail. Rated at 5AH (real world testing has shown they aren't far below that ~4300 - 4600mah at 1C. The only real negative is that they are rated for discharge at only 2C (10 amps) each, so you would want to parallel at least two strings for an average bike motor. (But who knows what next year will bring... The Chinese are really putting a lot of effort in developing this stuff and I know a few guys over there that try to make them available to hobbyists in small quantities.).

 

[Beagle123]

Hi RLT:

Great info. I'm exactly at the stage where I need to understand how to make battery contacts.

You might be interested in looking at my build page at the bottom of this post. I built a bike from scratch from aluminum with the batteries inside the frame. I built the whole thing in about 5 weeks with very few mistakes. Then I tried making my battery packs, and it kicked my butt.

I'd really be interested in talkig to you about the best way to configure my batteries. I have 91 emoli cells, you can see everything on my page.

I'm looking for someone to help me spot weld them together. I'd be glad to help you with anything in return.

Right now, I'm sitting on a bunch of cell that I'm afraid to solder together. And I don't know the best configuration with charging leads etc. I'm sure you're on top if it.

Let me know what you think.

Yours,
Eric

 

[fechter]

I agree with RLT. Welded or soldered is the way to go.

I'd be real interested in your welder plans. I've seen some that use a recycled microwave oven transformer with a rewound secondary. A solid state relay and timer control the duration. That kind of junk I have lying around.

What I don't know is what is a decent electrode setup for welding tabs. I guess you need to maintain pressure during the weld and have the electrode not self-destruct after a few welds. What are the options for tab material?

Caving lights? I used to do that many years ago. I could have used LED lights back then. My best setup was a surplus miner's lamp modified to use a smaller bulb and battery. Heck, I used to use a carbide lamp too. When the guy in front of you gets stuck in a tight spot, you come up on his rear and give him a "carbide assist". Beware of barking spiders when doing this.

 

[safe]

Most of My C & D cell size NiMH batteries have dented bases just from the pressure of the stock spring in a 3 or or more cell MagLight ; a few have even split the cases slightly, and a couple of those have started leaking. Annoying with NiMH... Potentially disastrous with LiIon.

That's not good. I hadn't considered that the batteries themselves would not be able to withstand the spring pressure since that is the way that 99% of all batteries are used. How do they get away with selling batteries that they KNOW will almost always be used with springs if using them causes damage?

:? Hmmmm...

Well, I can always try the spring loaded idea first (being careful not to overdo the springs) and then add the solder later on. When you use the series type of connection like I will be using the proper connection method would be direct soldering.... no tabs.

What kind of results did you get with the silver paste?

My first "in reserve" technique is to use silver paste (not glue or gel, but permanently flexible paste) which the solderless battery pack manufacturers claim actually produces better results than soldering since solder has about 10 times the resistance. (solder is not a very good conductor) A very small (less than a drop) amount of the silver paste should make the microscopic pits in the metals of the battery ends link together in a near perfect joint. (so it's more like a thin film)

http://www.modelelectronicscorp.com/browse_product.php?pid=29

A123 Kits
We now have available, SPT (Solderless Power Tube) kits for the A123 cells. The kits are 'Universal", and can make anything from 2 cell, up through 8 cell packs in size. These cells make very powerful packs, as they can follow 70A continuously, up to 140A in bursts.

Packs can be assembled in approximately 30 minutes, using a screw driver, wire cutter, scissors, and a hot air gun. Considering the high cost of individual a123 cells, it's nice to know that your pack can be easily repaired, if it should suffer damage in a crash.

Repair capability is not the only advantage offered by this system, Since the cells are placed 'end to end' (touch each other directly), resistance is lower than either soldered, or spot welded packs, resulting in more power reaching your motor, to do work!

Soon, we will have a 'Phantom Cell' available, that will enable the assembly of battery packs with an odd number of cells. This will give you more control over the pack voltage, to match the capacity of your motor speed control.

With its aluminum can, the A123 cells are lighter in weight, but difficult to assemble in a fashion that promotes power output. If you ËœSpot Weldâ„¢ steel tabs, you are forcing the cells to discharge their power through small ËœDotsâ„¢ of burned ËœSteelâ„¢, and ËœMelted Aluminumâ„¢. In addition to this, is the physical touching of theËœsteelâ„¢ strap to the battery case. Hmmm sounds familiar. Too bad steel is a lousy conductor electricity! Oh, and by the way, if you try to remove the steel tabs by peeling them off, you will leave holes in the battery case.

 

[dirty_d]

ËœSpot Weldâ„¢, ËœDotsâ„¢, ËœSteelâ„¢, ËœMelted Aluminumâ„¢

what the hell?

 

[RLT]

Eric:
I glanced at your project a couple of days ago, but I'll have to study it more closely and get back to you... Maybe sometime tonight or tomorrow night I might have an idea.

I'm not quite at the point of being able to offer battery pack build services myself... Maybe in a few weeks. I can point you in the direction of someone else if you are in a hurry.
-------------------------------------------------------------------
Fechter:
Yeah, one of my welder designs is based on the same thing... I'm not even sure the timer is necessary though. Copper rod is apparently the best electrode....

About 15 years ago I built myself a crude capacitative discharge welder for spot welding titanium and niobium jewelry and it used tungsten electrodes from a TIG welder, which only worked so-so.

As far as tab material, Nickel seems to work best. It isn't as conductive as copper or silver, but its other properties make up for that shortcoming; I just bought my first batch from :http://sunstoneengineering.com/site/pages/batteryWeldingMats The price seemed reasonable, but I haven't shopped around much. My other developing welder will be a more compact version of my old CD welder which weighed about 85 pounds.

Funny you should mention 'barking spiders'... I did a mining project in a mine in Arizona called the Barking Spider. I'd have sold my soul for LED lights back in those days. Some of our projects we would live underground for a week, 10 days at a time, and the logistics for having enough light were a hassle.
--------------------------------------------------
Safe:
I've never used silver paste, nor do I know of any of the other guys from the flashlight community that have used it with any satisfaction. But if the RC guys and other E-bike guys are using it and happy with the results, it must be better than I would expect.

Until I followed your link just now, I didn't realize the A123 batteries have an aluminum can... That certainly poses design problems, and spot welding gets a little tricky.

I'm still very skeptical about the paste, I'm not sure how much of that info is hype, but if people using it in the 'real world' are happy with it, I am obviously wrong. I haven't messed with any of the DeWalt batteries yet so I just don't know what to think... Although I'd be surprised if they are using steel tabs as the silver paste guys claim. I'd bet a week's pay (if I got paid at all ) that they are nickel tabs.

But I still say for steel canned batteries, tab weld is the way to go. Direct soldering , no matter how good you are at it is a sure path to disaster. When I first started doing it on Nixx batteries, I probably completely ruined 3 batteries out of every 10, reduced the capacity and life-span measurably of 2 more, and reduced the rest by a small amount. Now that I have gotten better at it, I only ruin 1 or 2 out of 10 With a NiCd or NiMH, you are just out some money and time if you mess them up. Soldering on LiIons... Well... disaster is a possible outcome, although I've been lucky so far myself in that respect.

But I'm tired of taking the chance, so, my sudden resurge of interest in building a spot welder (my old one is long gone).
----------------------------------------------------------------------
All:
I don't know how soon I'll be able to show any results on the spot welders (or anything else) I have to provide full time care to someone that is disabled physically, mentally and emotionally, so I don't get much time to work on my projects. Heck, it took me an hour and a half to type this due to the interruptions..... Then, just as I was getting ready to submit it, my broadband connection wend down :x

 

[safe]

So far the only serious negative that I can see with using spring pressure is that "in theory" a battery might be unable to handle the spring pressure. I'm just having a hard time imagining that. Do you have any scientific numbers to point to that suggests that battery manufacturers are producing batteries with substandard spring pressure durability numbers that are causing widespread failures?

If in my case I have 20 "D" cells held in place mostly by gravity (since the frame tilts up about 25 degrees from level) and on top of the gravity I have a spring for each tube keeping all of the cells under pressure and then on top of all that I use a trace amount of silver paste to increase the conductivity to above the level of solder then "in theory" it should work great. (fantastic actually)

Are there any links to sites talking about the regular occurance of battery cell breakage due to spring pressure? (after all this should be a bit of a scandal if that's what's really going on)

If one cell out of 80 total has a problem then I can just replace that one bad cell. Or are you in the spot welder business now and looking for a customer? :wink:

My internal "doubt meter" is currently registering a very high value...