Deacon's DIY Electric Bike Forum!

Status
Not open for further replies.
I have come up with what I hope is a good next plan. First of all back to friction where I can handle the chain run and other factors more easily.

I have a 22 tooth rear coaster wheel sprocket attached to a motor. This is purely a concept bike.

Th the drive axle I will have an eleven tooth sprocket, Which is about and inch and a half in diameter. The drive wheel is three plastic caster wheels attached to each other with jb weld. the bearing for the drive wheel axle is going to be two skateboard wheels attached to the frame. The drive axle will turn through them making use of their bearings.

Chain tension is managed through a two part motor mount. The motor is on a platform and the drive axle is on a different one. The are attached in a upside down V configuration. ALL the pressure and torque should be tightening the chain not loosening it.

I'm using my funky test bikes on it.

the plan is that the larger wheel on the motor will make up for the loss of energy in the chain drive. With a little luck it will deliver a similar number of rpms to the drive wheel as it would in a straight run.

Once the motor drive combination is working, I am thinking of getting a mountain bike to put it or one like it on. A mountain bikes gearing would allow me to help the motor at a higher speed threshold and hopefully make the experience easier.

Now why I am doing this over and over. My wife and I were talking about this last night. Other than I'm crazy obsessed not to be beater by a piece of metal, I have a plan.

I want to design a bike that a retired person who is reasonably fit could ride to the grocery store. Most of you know that there are retirement housing areas for seniors. Lots of them don't get enough exercise, and many have lost their mobility because a car no longer makes sense.

The weed whacker bike was my first foray into smaller bikes. I had a lot of fun with it but at the end I realized that for ME as well as anyone in a similar situation it would not be realistic. To many nic picky issues arrive with so complicated a bike. I'm not saying this is purely a humanitarian thing. I want that kind of bike for myself.

When I finish I will hopefully have a bike I can ride five miles with a minimum of effort and then be able to ride home again. Five miles will get me anywhere I need to go on a regular basis. Also it will get me some exercise since the motor will only be a helper motor not a drive engine.

I think I have the basic design down, Now it is just check the components.

And oh yes I do fail a lot on this silly projects, but I pass a lot of time I would otherwise be filling with fast women and slow horses. I know that is a fantasy these days.
 
When the skateboard wheels arrived they did not have any bearings in them. The adv was a little misleading and I guess I was a little naive. Anyway I got these four used skateboard wheels for about two bucks each which is about a 100% more than they are worth.

Nonetheless I moved on, yes I cursed and kicked but on I went. I went to the plumbing section of the home depot and bought two brass plumbing pipe reducers. half inch on one side 3/8 on the the other. Problem was the threads, don't work on regular nuts... Don't to this at home kids. lol

Of course by the time I found that out, I had already drilled one out. So what I did was... I drilled my frame for a half inch hole. then I threaded the brash bushing into it. then I drilled the threads out of a half inch steel nut and wedged it onto the inside of the bushing and jb welded it on.

What I am hoping is that the force will not be to pull it off but to keep it together..

So here is how it will go left to right. Nut/nut- bushing through the motor mount-steel nut epoxied over the bushing inside the mount-nut-lock washer-#25 sprocket-lock washer-nut------nut-lock washer- fenderwasher-skateboard wheel- fender washer-lock washer- nut-steel 1/2 nut drilled out over the inside of the busing/motor mount=bushing end- nut/nut--- thats is the make up of the drive wheel. I know I'll have to shoot you a pictures when I get it done.

It's a lot of hardware for an easy build but I need to see what it will do. Im useing a 5/16 threaded bar as the axle.

I hope all the pressure is to hold everything in place not to pull it apart but only time will tell.
 
Last edited:
As promised a picture of the engine and drive. I still need to do a couple of cleanup things but this is pretty much how it will look....
t6w9l2.jpg
 
Okay the bike is more or less finished i think. I test rode it and it did well till the chain came off but I know why it did and I can fix it with a tack weld Of one nut..

Centrifical force moves the sprocket jam nuts.

but here is what it looks like engine and shoes custom battery bag.
2eajuqb.jpg

1220nlw.jpg
 
I cant believe I just lost a huge post.... need to do something about the auto time out on long posts.

In less eloquent terms.... I am still working on the learning curve for ebikes.

I tested two last week a 500 watt and a 100 watt...

The results were interesting......

First of all I build friction drive. I can't make anything else work consistently.

On the flat its all about the rpms of the motor and the size of the drive wheel. You want to build speed that you can bleed off on the hills so a large drive wheel is best along with a high reeving motor.

The wattage of the motor is about how often and how long you have to pedal. Since this is a hybrid bike some pedaling is expected and in fact the purpose of it, in my case. I don't find the 100watt objectionable at all. It will also be the most fuel efficient Ie batter life.

I did toast it for the moment due to bad welding.

If I come up with a better system than direct drive i will let you know.

thanks for the interest.

I threw a chain during a test of the 500watt bike. I didnt have a tool kit of course, but I was able to kiddle ride (legs as outriggers) with just the engine pulling. I was amazed that it got me home like that but it did with no pushing. It was about 3/4 of a mile uphill.
 
Last edited:
deacon said:
I threw a chain during a test of the 500watt bike. I didnt have a tool kit of course, but I was able to kiddle ride (legs as outriggers) with just the engine pulling. I was amazed that it got me home like that but it did with no pushing. It was about 3/4 of a mile uphill.
Click to expand...
deacon, where is that tool pouch? lol

Sounds good that you have one that runs consistently! and will give you exercise!
.elec.
 
Tool Challenged...

I needed to build a perfectly square steel from to use as a base for my next electric motor project. I really needed a corner clamp but I don't have one. So I began racking my brain for something that would work.

First of all let me preface this by telling you why I need a corner clamp. I have built a couple of different versions of the mount I want to build next. None would work because I don't have the right tools and the tools would cost a small fortune. I'm retired and just cant justify the expense for a hobby.

Since I need holes which are drilled the same on all sides of the steel frame I decided to do with pre drilled L type shelf brackets. Not those thin metal things but the real quarter inch steel muthers. Well 1/8 " at least.

So just to make sure they are square I add a smaller third L to the corner and clamp it down to hold the joint for welding. I have it ready to weld when the rain stops.
 
Last edited:
Deacon in my shop i use clamps alot,i have found that a scrap of plywood works great.All you need to do is to lay your tubeing out on it and drive a nail on each side to hold it in place so you can tack it.Last week i needed to weld some 1x1 tube at 37 1/2 deg.it took only a few seconds to set up. Harleys Dad
 
excellent idea.... The factory corner would also be perfectly square.
 
Last edited:
Deacon think about it you may be building a hybred ,all you need is a gas motor,you have the electric starter.Harleys Dad
 
Im hoping it will be the people/elec hybred....
The direct drive ones I have built work just fine but the engine hangs off the side of the bike. Can be a balance nightmare.

What i want is an engine sitting over the drive wheel, so that I can mount it directly over the bike wheel. That way the thing will be balanced to the center line of the bike. Hossin' around that much weight on a lightweight frame is tough.

I have the battery rack centered over the rear wheel like a luggage carried. I just need to get the chain drive to friction wheel to work

My previous attempts have been plagued by the fact that im not nearly detail oriented enough. This one I'm trying to pay attention to strength and keeping things square and in line. The chain I plan to keep short to prevent as much movement as possible. With the motor sitting on top of the drive wheel, I think it will help with alignment.
link wont work so go here to see what I mean ImageShack - Image Hosting :: diagramvi4.jpg
 
Last edited:
Hey could I use a skateboard wheel like you for a drive wheel for my weedwacker bike??
or should i keep with a bmx peg??
 
If you can figure out a way to attach it sure. Im sure you can weld two nuts together one to attach to the WW and one to attach to a bolt you run through the wheel. There you got instant drive wheel
 
I got a square engine mount built and drilled out for the axle. I'm waiting for the skateboard bearings which I plan to use on the axle ends. Won't know if I can until they arrive.

In the meantime I rode the 500 watt direct drive bike this morning, It was cold so I didn't enjoy it. I am riding for exercise so Im not supposed to. The bike pulls enough to crawl up the hills on it's own so, I could stop pedaling all together if it gets to be too much.

The thing is I get to ride along at a few miles per hour enjoy the ride even speak to people along the way, not that there were many this morning. and when I come to a long nasty hill that I could never pull on my own, the bike helps me out. If nothing else works this bike will do the trick for me.

I do have the tension too tight. The too tight tension makes coasting downhill very slow. I need to ease off it a bit to save on the batteries. It will decrease the torque but I think It's a fair trade. The other thing I can do is build a lift to ease off on it. I have a complete lockup for the bike trail, when I build up to it again. But a cable lift to just cut the tension might be better than reducing the tension on the spring. Or maybe a combination of both.

If it doesn't rain I will give it a try this afternoon. There is a lesson there for the WW friction builders as well. The tension needs to be just right. I know I never thought that was true till today. I have had too little tension and the bike had almost no umph. Now I think I have too much so that the motor drags when it goes downhill. When trying to maximize the energy use that is probably not such a good thing for any bike. It would have to cut down on your mileage I would think.
 
Last edited:
well I screwed up the direct drive scooter motor. No sense going into details. I have two more attempts planned for the scooter motors because they are easy to find an not too expensive if you shop around on ebay.

I have a test drive sitting on the kitchen table with jbweld and bearings setting at the moment. I am waiting for an engine to test it. The engine should be here today or tomorrow I hope.

More later.
 
21dlt0o.jpg


Yes its the latest version of my drive/motor project.

I won't be able to test it on the bike till tomorrow but I have bench tested it and it works fine or at least seems to.

The requirement was that it be simple to build and require little to no maintenance. I hope that I have achieved it.

The frame is two 6" L brackets laid out to over lap giving me a 5x6 rectangle. Before welding I clamped them together back to back and upside down, then I drilled a hole through both at the same time. It was the only way I knew to get them pretty much in the same place.

The motor was attached to a one inch square tube on each end. It needed the height to clear the drive wheel. The motor was the last thing to be installed on the frame.

I Jb welded a skateboard wheel bearing to each side of the frame inside the frame actually.

The I pushed a 5/16 all thread rod through from the outside.
I added a nut & lock washer then a sprocket bought from a scooter store. (I chose one the same size as the one on the motor. It gives me a one to one rev on the axle. In my case 2500rpms.)

The sprocket was followed by another lock washer and nut but I did NOT tighten them,

I screwed more rod though to add a skateboard wheel with appropriate washers to hold it in place. The I added one more nut and worked the axle through the second skateboard bearing and the frame. I double nutted the ends in place,

then I went back and tightened everything and bench tested the motor. It hummed and sounded pretty strong. I moved everything around so that I could jb weld under the nuts to lock them into place. I didn't have any locktite at the time and I wanted to finish it.

It is going to need to sit over night to secure the nuts in place but that's okay.

I added a half strap hinge to use in attaching to the bike. It will have a lock up connected to the top of the hinge and a cable lift as well. I found both helpful during my tests of the engine.

The cable lift works well when coasting and the lock up would be for the bike trail.

Remember this is a human/electric hybred bike. Meant to be powered on the hill climbs but mostly to be ridden like a bike.

I'll make some better images when I have it on the bike and tested. No sense wasting space on a failed project.


A couple of things I am finding out.

1. build stronger than you think you need to. Flex is the deadly enemy of chain drive.

2. Plan well test well and be prepared to start all over. It is easier to start over usually then to try to patch up a bad idea.
 
Last edited:
Deacon good to see you at it still. I see you have moved over to a new form of power. LOL, you could use a small generator for your electricity that would still give you the sent of petrol in your nostrils. I have a Mighty Might generator small but not much power. Have fun, Dave
 
Well I test rode it and found that the sprocket slipped since I hadn't welded it. So I took moved it around in an attempt to secure it and go the darn skateboard wheel on crooked and I welded it down that way. I'm going to give it some thought then change the axle I think.

I might just cut a slot in the frame mount up the axle then slip it into the holes. The free bearings will be an issue but nothing I can figure out. The axle material is cheap. I know the 25 chain will work if I get it tight and the frame rigid that was my problem all along. The build frames were too light even for the ww builds.
 
Status
Not open for further replies.
Back
Top