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Discussion Starter · #1 · (Edited)
Hello.

I'm a raw neophyte trying to learn as much as I can from everyone before I jump in and start screwing things up trying to build something.

I'd like to thank everyone for sharing all this great information. I've been reading over everyone's shoulder for a couple of months now.

There are too many good posters to mention them all, but I'll hit a few of the highlights:

1. I've read all of Jim Hustead's (HiTorqueElectric) posts. Heck... I not only searched the archives and read all of his posts, but I read every entire thread that he has ever posted in. I also have drilled through his entire website. I learned a great deal. Thank You Jim.

2. I've been digging through every build thread I can find. (Sorry your cars got smashed Brian, just when I was getting through your build thread your car was gone. Felt like I got kicked in the groin. What a let down. I'm sure you felt a lot worse than me. I was just living vicariously through your posts, but still. That su#$%ed! It was a nice car while it lasted, and I still learned a lot.)

3. I've watched about every YouTube vid that I can find. Yes, I've seen all of Gavin's, Ben's, Forkenswift, n2confusion, and a bunch of others. Thanks guys.

4. I've been digging through various blogs too. Too many for me to remember them all.

5. I've read the entire Wiki. Good Stuff.

Here are the most important points that I think I've learned so far:

1. If I want to save some money, I need to learn to weld. My Grandfather had a welder and I sputtered with it when I was younger. Didn't have a clue what I was doing, but I manged to stick a few things together. Time for me to get serious and get the proper equipment and safety gear. I'll need to invest the time and energy to practice and get it right. There's no doubt in my mind it will pay off in the long run. (I've got more things I'd like to do than just mess with EV's and welding would sure help me do them (is that sacrilige to say on this message board?).

2. I want to start with a small screwup before I begin my bigger more expensive screwups. I'm thinking about building a bicycle trailer that has and electric assist capacity. Yes, I'll need brakes on it too, but it seems like a fun starter project. At least it should be fun until I have my first crash. Who knows? Maybe I'll invest in a good camera in get the whole thing on YouTube and you guys can laugh at the old guy tumbling off his bicycle. Why do I envision the trailer rolling on down the road without me to mock me? Eh... I'll get over it... I hope. Maybe I better double check to see if my health insurance is all paid up? Once I fix all of my mistakes on that small bike trailer project, then maybe I'll move up to a conversion of some kind. Then I get to make more expensive mistakes.

3. It's all about the details. The basic concepts make everything seem so simple (in some ways, that's probably correct), but getting all those details just right are what makes a project safe, reliable, efficient, and... well... USEFUL. Making an expensive toy is one thing, making something you and your family can depend upon every day is something completely different.


I've learned a lot more and probably forgotten 3/4th's of it already, but I keep plugging away.

My brain hurts. It's crammed full, and I know there's a lot more to learn. Everything I read from now on is probably going to cost me as it forces old knowedge out my ears. My daughter says I don't even know how to dress myself already. Will I now lose eye-hand coordination and verbal skills as I learn more?

AM I DOOMED?

 

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Discussion Starter · #3 ·
Thanks Pete.

Right now my expectations are probably already too high.

1. I expect to have fun.
2. I expect to build a little trailer that doesn't kill me.

I don't really have any big performance goals. It's more of an excuse to build something small. I'm not much of a motorcycle type, so this seemed a reasonable compromise. If I can build something safe, controllable, and using the basic princples I've learn that apply to car conversions, I'll be very happy.

I'm thinking a tiny pump motor and a cheap lower voltage system. Cheap small lead batteries. Not looking for extravagant performance, just functional proof of concept. More trying to prove to myself that I can build something than trying to prove the motor can push me.

I'm well aware of reasonable expectations on an eventual car conversion. No problem there. 20 miles in round town non-highway range is reasonable. 40 miles is possible. More than that gets really expensive. I'm comfortable with those numbers. Actual performance will vary a lot depending upon what I finally decide to do. Those decisions will wait until I've cut my teeth, or broken them falling off a bike.
 
G

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High expectations are normal but reality really sets in when you get further into the conversion.

1. Fun : A result of doing.
2. Small: Good start.

Ever think of doing a remote controlled electric vehicle to get an idea? That was my actual first EV. Brushed DC motor with an over powered battery pack. NiCad's Suck. The buggy was very fast as I purchased a big power DC brushed series motor. Now they have the Perm Magnet style motors that have 3 wires. More like AC. My boy has these in his. Loves them. Now to build a full sized one. Or maybe a bicycle. I am going to try to build a bicycle using an old VW 12 volt generator advanced enough to take 36 or 48 volts. I think it will work. I can install an alternator cooling fan to one side for cooling. They do fit. : )

I decided to go with a car first because I don't have real safe roads to drive a bicycle on. Our roads are hwy and a fast driven side street. 55 mph on the side street and 55 to 85 mph are on the hwy and it is only two way traffic. Very unsafe for bicycles. I will only try the VW generator for learning purposes and maybe to sell later. Just wanting to find out how much power I can safely extract from the VW generator for a drive motor. Might be interesting to see how much power you get as a generator.

Pete : )


Thanks Pete.

Right now my expectations are probably already too high.

1. I expect to have fun.
2. I expect to build a little trailer that doesn't kill me.

I don't really have any big performance goals. It's more of an excuse to build something small. I'm not much of a motorcycle type, so this seemed a reasonable compromise. If I can build something safe, controllable, and using the basic princples I've learn that apply to car conversions, I'll be very happy.

I'm thinking a tiny pump motor and a cheap lower voltage system. Cheap small lead batteries. Not looking for extravagant performance, just functional proof of concept. More trying to prove to myself that I can build something than trying to prove the motor can push me.

I'm well aware of reasonable expectations on an eventual car conversion. No problem there. 20 miles in round town non-highway range is reasonable. 40 miles is possible. More than that gets really expensive. I'm comfortable with those numbers. Actual performance will vary a lot depending upon what I finally decide to do. Those decisions will wait until I've cut my teeth, or broken them falling off a bike.
 

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I'm no EV expert yet-my brain is far from full-but I suspect that a bike with a Pusher trailer might be inherently unstable, especially in turns and particularly if your trailer uses the popular swivel hitch. The bike and Pusher could easily end up going in separate directions! :(

Have you considered mounting the motor on the bike (chain drive, friction wheel, whatever) and then mounting the Batteries and Controller in the trailer? Without the trailer you'd have a normal bike with an extra few pounds(motor and throttle control) and then you plug in to the trailer and have your power-and you'd be properly balanced and not worrying about the trailer pushing you into a ditch on a sharp turn...
 
G

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I agree that if you go with a bike you should have a trailer with your batteries and only the motor and throttle attached. It will allow you to carry a large load of batteries for a long drive and if you want later you can just have a bike to ride with only a bit extra weight. If you build the trailer properly you will have room to haul groceries home too. You can have a few 12 volt orbitals and have a very long commute. With tires that hold high pressure you can have a low resistance trailer and it will not be overly difficult to tow under person power if needed. Make sure you have a good mountain bike to convert.

Pete : )
 

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Discussion Starter · #7 ·
I'm no EV expert yet-my brain is far from full-but I suspect that a bike with a Pusher trailer might be inherently unstable, especially in turns and particularly if your trailer uses the popular swivel hitch. The bike and Pusher could easily end up going in separate directions! :(

Have you considered mounting the motor on the bike ...

You've hit upon the one area that has my highest concern.

Part of my logic is that this will be a bit of an experiment. Control will be everything. Trailer brakes will be critical, but there will be more to it than that.

I'm convinced that the trailer hitch will need to mount as low on the bicycle as practical. (that probably means somewhere near the real axle.) The higher the hitch is located the more the trailer might want to push me over in a turn.

Yes, I've considered mounting the motor on the bicycle. It is a tried and proven method. If I were to go down that path, I wouldn't want to do it to one of my nice bicycles that I already ride. I would want to go find one at a garage sale or something. That is certainly a possibility.

Part of my desire to lean toward a pusher trailer would be that it could be interchanged on any bike I chose (more or less.)

Keep in mind that my expectations are pretty low as far as performance goes. I'm not looking for rapid starts, or fantastic speeds. My hope would be to only have a pusher trailer that would essentially push itself and whatever payload I have on it with a tiny little extra. I expect that I'll still be doing a significant amount of effort with good old fashioned pedals. In fact, it seems to me that lower gear ratios for the moter may not be desirable at all. Human power for 1st gear and startups seems fine. The trailer would be pushing for uphill and long sustained straighaways once I'm riding in a stable manner already. I don't anticipate using it in a busy urban environment. I don't like biking those environements much at my age anyway. I'm no teenage daredevil.

I agree that powering through corners would probably be very unstable, especially going downhill. Hence, I expect that the trailer will be coasting through any turn that is very sharp. I've actually considered this while riding my bike, and it's extremely rare that I'm applying pedal force through any sharp turns. I can't imagine wanting to gun the accelerator on a trailer when I'm not willing to pedal.
 

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If you want a electric bike setup that isn't a permanent mount, then it seems to me like the simple, safer answer would be a trailer with the batts, and a motor that hooks over the axle of the rear wheels and on the seat. If you don't want to use the axles, then some sort of hook arrangement that slips over the frame tube to the axle would be needed. You'd hook, roll the motor forward, hook the seat tube, then tighten. The motor would then drive the tire with a friction drive. You'd need some sort of slide adjustment on the axle arms to allow the use on different tire diameters, but that will complicate it and make it heavier. Be better to design it to one tire diameter, and a single slide on the part that goes to the seat to adjust the motor to the tire. What you would wind up with is a motor pod that hangs behind the seat. Then you'd just need a throttle cable with a reusable nylon tie arrangement and a removable squeeze lever throttle to one of the handles on the handlebar.

The trailer could be very simple, just an aluminum shelf with bicycle wheels attached. If brakes on the trailer are a requirement, then an electric brake setup that has a lever attached on the opposite handle would be the way to go. That wouldn't need much juice, so the battery could supply that power even if it was too drained to run the motor. Worse comes to worse on that, you could attach a bike generator to the trailer that would be able to provide braking power, or a separate, dedicated lawn mower battery for the brakes. I don't know if they make electric bike brakes, if not you'd just need a servo that can pull a cable, then use regular bike brakes. You'd need a way to control the servo according to how strong you pull the brake pedal though, would do no good to have brakes that are either 100 percent on or 100 percent off.

Here's a rough sketch of what I'm suggesting. With this arrangement you could have an electric power system that could be moved from bike to bike in less than 5 minutes, without worrying about a setup that would cause an accident.

 

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http://www.rqriley.com/b-pusher.htm

I doubt you'll need the plans-but if you run into a problem they're available.

If I ever get the spare cash together (living on beans and rice at this point,alas) I plan on using an old VW Generator and a one-speed Touring bike for a modest 24V EV. The pack will be mounted on the chassis.

I'm 15 miles from the nearest town though, so i'm planning on using a trailer myself-rather than a Pusher though, I plan on mounting two 24V strings in Parallel,which plugs into the circuit as an add-on. Given three Parallel strings of 24V the Bike+Trailer will carry over 60 Ahr total. With any luck this should net me well over 40 miles at roughly 20 MPH to roughly 65-70%discharge-this assumes i'm not pedaling(though I will be). The batteries will be secured on the sides, leaving plenty of room in the inner well for cargo...

This assumes that New Horizons gets off its collective posterior and lines up some job interviews soon(i've got my certificates so it's time for NH to keep up its end!). The good news is i'm using a dirt simple system-with the low voltage and robust components i'm just using a switch and a resistor for Off/12/24V states-so a single decent week's check should net me all my components. The Economy being what it is though, i'm hoping you finish yours first. And that it doesn't push you places you don't want to go, of course. :D
 

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My brain hurts. It's crammed full, and I know there's a lot more to learn. Everything I read from now on is probably going to cost me as it forces old knowedge out my ears. My daughter says I don't even know how to dress myself already. Will I now lose eye-hand coordination and verbal skills as I learn more?

AM I DOOMED?
Most definitely, like most of us you're now doomed to talk EV's, dream EV's and think EV's until your spouse, your collegues and friends are quite fed up with your rambling. And yes, there's lots of more to learn if you want to, for example the intimate details of a controllers daily life. There has definitely been times when I've had to stop trying to grasp all the concepts and just let it be for a day or two so the poor brain had time to sift through all the information.

This forum's great for learning though, I can't imagine trying to collect all this knowledge without diyelectriccar or Internet in general.
 

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slurryguy,
what you need is a Bob-trailer. check the link - http://www.rei.com/product/722504
If you put a sprocket on the trailer wheel, you could have a complete, self-contained power trailer that would fit on any of your existing bikes. Then you just need a good throttle control on your bike, and good brakes. Should be fairly simple. with this design your CG is very low, and it wont' push you over since the trailer leans into the corners too, and it pushes on the rear axle of the bike, not on the seat post.

Mike
 

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Discussion Starter · #12 ·
Thanks to everyone for your input.

One thing I may not have made clear is that one of the primary goals for the bike trailer is my own personal education. It's intended to be a small project to give me some experience in some areas where my skills are lacking.

Welding is a skill I lack that I definitely want to learn. While I hardly think that welding up a bike trailer will make me an expert welder, it's as good of an excuse as any to get me started. I figure if I can weld up a bike trailer that hauls around payload, motor, batteries, and absorb the pounding on the pavement, then battery racks in a car conversion shouldn't be a lot more difficult.

The "Bob Trailer" design is interesting. I hadn't considered that type of a design before. Clearly I won't be purchasing one, but I might try to weld up something similar. Bending curved tubes or other metal to form the curved front without getting kinks might be tricky without a fancy pipe bender, but maybe I can rig something up.

I suppose I could build a more boxey prow. I'd lose some aerodynamics, but it would be a lot more simple to build.

The downside to the BOB design is that half the weight on the trailer is added to the rear bicycle wheel. Ideally the trailer would hold most of it's own weight. Of course this depends upon whether the trailer is loaded with most of the weight toward the rear or toward the front.

I need to figure out what kind of max gross weight I expect to have on the trailer and make sure I don't exceed what one bicycle wheel can safely handle.

Up until now, I had figured on building a rather generic trailer something like this one:
 

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You could always try a single wheel in the middle!

~---O---

The downside is that you lose some of your Cargo space-the upside is that you could(assuming the components were at least roughly balanced) have a Pusher that leans with your bike but doesn't put a great deal of weight on the axle.
 

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Slurryguy,
half of what weight? A couple batteries and a motor for a bike? Not much weight there. one thought would be to use the Bob design but bring the wheel inboard enough that you could have your batteries on each side of the wheel so the wheel is carrying their weight. Then the bike just shares the weight of the motor and contoller, etc. If you use a small motorcycle rear tire and rim, you have a sturdy axle and the sprocket is already attached.

You could even add a removable rack to fit over the whole trailer to give you cargo room so you wouldn't need to load up your bike.
 
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