Hello! Need some help with a project.

[Joker_Of_Hearts]

Hello everyone,

This is my first post here which I would first like to say hello to everyone at this forum. I know you get a lot of similar questions which leads to alot of (╯>.<）╯︵ ┻━┻

So here I am a college student working on a project of my own to ask some similar stupid, table throwing induced questions for you guys.

*A bit of backstory so if you don't care to read just skip on to questions.*

My friend and I work in a lab together at our school and he came up with a great fun idea of creating out own electric scooters/motorcycles. I believe he is going for a small motorcycle while my approach is a mini electric bike.

Me being a WW2 nut with some friends back home, I remembered the british making a minibike which unfolds out of a parachute canister. This bike is known as a Welbike. Compact, light weight, and it folds up to something small.

Now I already am working on the frame, (I got some welding work to do but I need to get parts to finish it completely), and its a touch bigger... the frame is 12 inches tall, and 43 inches long which will results into a little bit bigger frame than the welbike. (Welbike uses 10 inch tires instead of 12 and its 51 inches total.)

Anyways.... rambling on... sorry about that.

*Backstory complete so continue on for the questions

So the point of this bike is to get me around my campus from point A to point B. My plans are not to go fast as I am not sure about putting an actual brake on this thing!

So I weight 220 lbs, and the cart with all the batteries and motor and tires will probably weigh... something like 50 to 60 pounds??? (Not quite sure.) So to play it safe lets say everything will weight about 300 lbs.

As to speed, again im not looking to go more than 5 - 10 miles per hour. Im not drag racing in this little thing. Its just supposed to be a ridiculous miniature sized toy for a giant guy.

So the question remains is what motor to get. Now I have been looking into projects online such as trains made with 24 V and 500 Watt motors which pulls 2 adults, there are other people who have done go carts with 24V and 500 Watt with 36V's of battery (the guy said he only weights 170 lbs though).

Frankly, I don't know if 500 Watts is good enough, or not enough, or over kill. This is my biggest conundrum. Should I invest in 24 V 500 Watt motor and use 2 batteries to keep it light? Is 500 Watts even enough?

Since im super tall and weight 220, would i need to bump up to 750 Watts?

Any help would be greatly appreciated. And this isn't a one time post, I am planning on putting pictures up to show you my progress on this bike....

Im going to continuously work on the frame and order the wheels tonight, but I would like to order the motor this weekend and maybe have it come next week. I get a week off of research that i am working so I plan on finishing this next week or two.

So cheers,

Thanks for reading my long post, and help would be much appreciated.

-Joker

 

[Chuechco]

Hi Joker,
I don't know you but I don't think 5-10mph will make you happy. Maybe for the first 5 minutes. Then you will be bored. Take at least the 1000W motor on a 36v or 48v system. Then you need to think about how long you want to ride. Less than 20 minutes is probably not what you want. Calculating how much current your motor will take is difficult (depends on gearing, weight, driving style...). but a 20Ah 48v battery-system sounds good. Next thing you need is a controller. 100A maximum current might be good for your purpose. Maybe the rest of the community can share some more information. Keep the work up and post some pictures of your progress

 

[Joker_Of_Hearts]

Thanks for the reply Chuechco!

But remember I want this thing to be light weight, so I can carry it in and out of classes and such, (prop it up into the corner, then ride off when class is done.)

Also not having a brake maybe rough if im going more than that.

Is 1000 Watt overkill a bit with 48 V of batteries?


Again, I don't know much of anything and my research isn't really helping that much. Most people don't put weight in their posts and if they have, they talk about their kids which is usually 90 lbs or so. I haven't found much luck nearing 250 lbs in the same talk....

And yeah I would like this think to last for a few hours. I'm using this thing to ride around campus, not really go on long treks anywhere... though roaming DC on this thing could be alot of fun...

-Joker

 

[Chuechco]

So the point of this bike is to get me around my campus from point A to point B.

Are you too lazy to walk? There are these electric wheelchairs that could help you out. Seriously, think again about what you want to build it for. How old are you?

 

[devino246]

Are you too lazy to walk? There are these electric wheelchairs that could help you out. Seriously, think again about what you want to build it for. How old are you?

Judging by the fact that he wants to ride it around campus, Id say hes college age, 18-22.

Have you seen some college campuses? Good luck running a mile with a backpack full of books and 5 minutes till class starts.

 

[Joker_Of_Hearts]

Hello everyone!

Well, its a tid bit of lazyness, a little of being late to class, and a little bit of wanting a joy ride around campus while pedestrians are everywhere. I just fear going 25-30 MPH when there are tons and tons of people out and about is a bit.... dangerous??? Maybe??? Idk.

I think I will end up going 36V 800 Watt motor so i am taking your word on going higher, but I still think 1000 Watts is overkill.

Currently I have parts of the mainframe done, which again is a little bit bigger than an actual welbike, but its pretty close. Since the shop is closing down I can't work on it this weekend, but I got next week to work on things. Hopefully my wheels come in as that will dictate me finishing the frame by next week.

Here are some updated pictures of the frame that I got built.

These are the frame pieces:



Uploaded with ImageShack.us

And this is what the frame will somewhat resemble.



Uploaded with ImageShack.us

If anyone is to lazy to look up what a welbike looks like or what the frame looks like its something like this:

So you guys can be the judge whether its similar or not. I sort of already made the frame so there isn't any turning back now.

Cheers guys, and thanks for some feedback.

-Joker

 

[Chuechco]

800W will definitely be enough to drive along. Your welding stuff looks good to me. Did you weld something together before? You mentioned a friend building a motorcycle. Does he use an electric motor? Keep posting your progress

 

[Joker_Of_Hearts]

Hey Chuechco,

Yeah my friend and I have worked on a school project called Mini Baja (I don't really know who actually knows about this competition) which is a like an off-road dune buggy which is made to do various tasks. Plus for another school project I created a mansized Big Wheels which fit me (and I'm 6'5). So I have worked on some welding in the past. Thanks!

My friend is working on his small motorcycle which he also intends to make electric so maybe ill post up his progress if he wants me to. He is working on his frame at the moment like I am, but his is going to be bigger than mine, and a little more complex. I don't really know whether to classify it as a small motorcycle or a minibike. But its looking pretty cool.

And Yeah, I definitely will keep posting details, but it will have to wait till next week... I wish I could just work on this all weekend...

-Joker

 

[Chuechco]

HI,
I got something for your friend (and you perhaps): http://www.bastelrobi.de/2kw-runner.html
I know it's german. The motor might be an example for you friend how to go 50km/h (~30mph). He used an traction motor of a forklift. It weights 20kg(44lbs) which is a lot. Their nominal voltage is 24v. But in a lightweight vehicle like go karts, bikes you easily overvolt them to 48v without problem. They can generate a huge amount of torque and are very reliable. I got one for 40€(57$), painted it and now it looks just new.
But of course this is not an option for you. Scooter motors are more lightweight.

 

[Joker_Of_Hearts]

Hey guys,

Thanks Chuechco, Ill def shoot him that link though I think he may be doing the same thing as me. We may just get two motors and save on some shipping costs. Thanks for the link!


Now you mentioned a 48 V battery system?

I was reading about over charging your motors and I'd rather just get the required voltage of batteries to not only save weight but money. (I am definitely one of those broke college kids.)

So looking at batteries, I looked into the 20 AH 12 Volt Lead-Acid batteries and I came upon these at Amazon.

http://www.amazon.com/20AH-SEALED-LEAD-BATTERY-Replacement/dp/B004WEOFMO/ref=lh_ni_t

These seem decently priced. But i feel like there is a catch. Are these good to use??? They are the cheapest I can find.

Also, assuming these are a good find are they rechargable? (Maybe all batteries are? Not sure but I assume so.)

Wow I feel like I should know this...

Cheers,

-Joker

 

[Chuechco]

Look for sealed AGM batteries, whose acid does not flow out. Also make sure they are deep cycle ones. Normal car start batteries are not made for discharging deeply. This type will survive dozens of charging-discharging-cycles without losing capacity. How much is the 20Ah battery you've chosen?

 

[NateIngram1]

You should just buy a small 2hp engine wont go very fast but you said you dont want it to. And also you wouldnt have to worry about charging but gas for a 2hp engine wouldnt cost more than 4$ to fill a 1 gallon tank. it would get you pretty far.

 

[j.concepcion54321]

im not sure if his college friends would like that..... (the dean) lol

 

[Joker_Of_Hearts]

Hello,

Sorry everyone, the link didn't save last night and I didn't realize it.

http://www.amazon.com/20AH-SEALED-LEAD-BATTERY-Replacement/dp/B004WEOFMO/ref=lh_ni_t

Lets see if this work this time. Any thoughts?

and NateIngram1, I am looking to go electric. I've had some experience with gas engines, and also the gas station near my area is absurdly priced at $5.00 a gallon. Going out of my way to find cheaper is just a hassle. So I am trying to stick with electric.

Cheers,

-Joker

 

[Chuechco]

They don't seem to be the deep cycle ones. Make sure you buy batteries for this purpose. Deep cycle batteries are more expensive, but will survive more charging-cycles. You probably will ride the bike nearly each day, don't you?

 

[Joker_Of_Hearts]

Hello everyone!

And thanks Chuechco! I got some new battery news.
But first im happy that I got in the machine shop again today to work on my little bike. This thing is somewhat coming along nicely. I got the seat part figured out, and i believe i have the parts for the handle bars.... (If I can only find some more of this thicker bar I got now I would be golden... but again im broke and using up extra material in the shop.)

So here again is another picture of the layout which i got currently. The seat is about 26 inches off the ground, and the handle bars will reach about 22 inches from my seat (which is good with my height)



If you look at the layout, there is a line below the frame in the tiles. That line symbolizes the ground. So I know i got little clearance (only 4") but its gonna be the design. Just another perspective for you to look at.

So I was looking at batteries again... this time on ebay. Any thoughts on these?

http://cgi.ebay.com/POWER-KINGDOM-12VOLT-18AH-SEALED-LEAD-ACID-BATTERY-/300575179250?pt=PCA_UPS&hash=item45fbad41f2#ht_500wt_969

Thanks for checking in guys!

Cheers!

-Joker

 

[Chuechco]

http://en.wikipedia.org/wiki/Deep_cycle_battery
The batteries you chose are once again not made for electric vehicles. They will wear out quickly in daily use.

 

[Joker_Of_Hearts]

Hey Chuechco,

Haha, I was hoping low discharge rate was the same as deep cycle.

Thanks for getting my back.

So I found some more on ebay, which has some decently priced batteries. And so I found these which is a pack of 4.

http://cgi.ebay.com/FOUR-UB12180-12V-18Ah-Sealed-Lead-Acid-SLA-AGM-Battery-/110569815960?pt=US_Batteries&hash=item19be797f98#ht_12942wt_952

And I also looked up online the actual model number of the battery. So on the ebay site it doens't say deep cycle but on this website it does.

http://www.impactbattery.com/ups-battery-backup/12-volt-18-amp-ups-batteries/12-volt-18-amp-ups-backup-battery-ub12180.html

Same thing hopefully???

Cheers Chuechco, and thanks for all the help.

-Joker

 

[kendelrk]

if i was you id go with a gas predator engine, put a big straight pipe on it, and when you accelerate, everyone would know you were coming

 

[jrmints1415]