My project for Uni

[bigdavevw]

Hi guys, I,m studying electrical engineering and i,m planning to convert a go kart to electric for my end of year project.

So, i got this go kart about 4 years ago, planning to take it round the local track just for a bit of fun, i started to restore it, but due to other hobbies, it got put on the back burner.


Now that i`m studying again i thought i would convert it to electric, maybe using super capacitors.

So i will be posting all my progress pics in here, and i will be asking lots of newbie questions.

I would like about 8kW-10kW if possible, and id like super capacitors too, as i find them a lot more interesting than batteries if i,m honest.

I am a student, so funds are tight, i would like to get all electrical parts for around £600 ($900ish).


Oh yea, the front wheels came with the kart, my mate used to use it in a field just to mess about on. I intend to do the same for now, i do have the original wheels too.







Dave

 

[bigdavevw]

Hi guys, i,ve been looking at DC motors on Ebay.

Would this be a suitable set up?

http://www.ebay.co.uk/itm/281761922699?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

Would the controller handle 36v ok?

Dave

 

[landuse]

Welcome. It looks like you have an offset kart for oval racing

 

[DirtyDamage]

Sorry landuse but I disagree, it looks to be a normal frame, probably a cadet size, if you imagine it without a seat it's no longer offset, I think it's just the way the seat is cockeyed...a oval racing chassis has the entire chassis bulges on the driver side, to add more weight to the left for turning...this is just a strait shot...may look a little off center because the engine goes to the right of the driver so the seat is pushed more to the left just a tad...

As for electronics personally, I would check to see if anyone around has golf cart you can snag cheap....can get the ESC, and all the connections needed. But that would only really be beneficial if you get a good deal on them....

I could be wrong, but that's my reasoning...

 

[landuse]

Sorry landuse but I disagree, it looks to be a normal frame, probably a cadet size, if you imagine it without a seat it's no longer offset, I think it's just the way the seat is cockeyed...a oval racing chassis has the entire chassis bulges on the driver side, to add more weight to the left for turning...this is just a strait shot...may look a little off center because the engine goes to the right of the driver so the seat is pushed more to the left just a tad...

As for electronics personally, I would check to see if anyone around has golf cart you can snag cheap....can get the ESC, and all the connections needed. But that would only really be beneficial if you get a good deal on them....

I could be wrong, but that's my reasoning...

Hey, no problem. I think you are right. The seat is what was throwing me off

 

[bigdavevw]

Yea we just put the seat in roughly to see how it would look. I'll maybe re-drill it if it doesn't feel right.

As for the motor situation, I don't know anyone who is into golf, never mind has a spare motor kicking about!

I'm guessing this motor would be ideal tho?

Dave

 

[DirtyDamage]

I don't know anything about electric, I just saw you using a racing frame. Lol

 

[itsid]

Hi guys, i,ve been looking at DC motors on Ebay.

Would this be a suitable set up?

http://www.ebay.co.uk/itm/281761922699?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true

Yes, 10kW will be a blast...
unfortunately the controller doesn't amtch the motor;
but still a good start!

Would the controller handle 36v ok?

the controller is good up to 60 Volts (but that would require active cooling I guess)
The motor though will NOT!
(but it'll fry that controller anyways!)

Forgive me, but you talk about a University project, correct?
you should be much too smart for risking deep fryed electronics/motor for no reason.

why overvolt (and if you say 'more power' I'm going to click the "buy now" button! )

That set is nice,
but the controller will not handle that motor well.. it's just too small (you'd need close to 500Amps)
but it'll handle a smaller motor really nicely (say a 4kW version)

'sid

 

[bigdavevw]

Hi Sid! Thanks for the informative reply!

I emailed the seller on sunday night, he said the motor and controller came off the same golf buggy.

I,ve emailed him to find out if he would sell the motor on its own, i dont think the twist throttle will be of much use on a kart!

I,ve read your "sticky" and i,m slowly starting to understand it. I haven,t covered much on motors at college yet (mainly capacitors and transformers).

Dave

 

[itsid]

Hi Sid! Thanks for the informative reply!

I emailed the seller on sunday night, he said the motor and controller came off the same golf buggy.

I,ve emailed him to find out if he would sell the motor on its own, i dont think the twist throttle will be of much use on a kart!

I,ve read your "sticky" and i,m slowly starting to understand it. I haven,t covered much on motors at college yet (mainly capacitors and transformers).

Dave

he did?
well then he's lying about the specs of either the motor or the controller or both.

Ask him for a photo of the motor label and the controller label.
or at the very least the make and model of the golf cart.

He clearly states that motor is a constant 6kW (let's assume that's electrical power)
And that means at 24V it draws 250 Amps constantly

A controller that's only allowing for 200 Amps @24V is not going to handle that well.


Still if you can get it for less than 100 you should be going for it.
even if it's a 4kW motor you'll be getting; it'll be a blast on your kart.

'sid

 

[bigdavevw]

Hey guys, not much progress with the kart im afraid.

I,m trying to sort the wheels and brakes first, but i,ve been busy with other stuff.


Ok, so i,m considering batteries now, just doing my research, seeing whats out there.

My budget for batteries is £200. I,d like no less than 36Ah (24v). I was thinking about Lucas 12v AGM motorbike batteries, they`re cheap and plentiful, but its still old technology. I started reading into using Lithium batteries. The obvious choice at first was a lithium golf buggy motor. But then some more research revealed that building my own batteries from 18650 cells would actually work out cheaper ( going by a 2800mAh cell for £1.60).

So now for some questions;

Has anyone done this before?
Any particular brands i should be looking out for?
Protected or non-protected cells?
Has anyone bought from Alibaba?


I`ve been weighing up certain values such as Ah/cost, Ah/weight, and Lithium doesn`t seem too dear when compared to the performance of AGM batteries.

Any help would be a great help!

Dave

 

[bigdavevw]

Hi guys,

small update, I,ve decided to make my project go kart a hybrid instead of fully electric. I like the idea of fully electric, but i dont like the idea of charge times, and i dont have the money to build spare batteries.

So I had an idea, keep the existing GX200, and run a motor as well on the other side of the seat.

With this set up I,m thinking i could run the kart on the engine, motor, or both. Due to the high starting torque of electric motors I would like to run the motor first up to about 15-20mph, then somehow switch to the engine or a combination of both.

Has anyone done this before?

The main thing confusing me is the transition of the motor to the engine under acceleration. Is there any way that the engines centrifugal clutch could be used?


As for the engine, i found out it has 12.4Nm of torque as standard @ 2500rpm. The engine is a 6.5HP, but will have the following mods; govenor removed, ported GX160 head, 18lb valve springs, solid flywheel, and a home made exhaust. The motor is going to be about 3kW-4kW.

Any help would be great, most information seems to be on electric or gas karts but not much on hybrids!

Dave

 

[ezcome-ezgo]

Coincidentally, many golf carts have this exact power-train. I had one for use in a parking lot that had a robin engine and electric motor. Step on the accelerator pedal and the electric motor would get you moving and start the engine, then the engine would take over. Stick a paper clip in the right throttle/governor spring and hold on to your hat.

 

[bigdavevw]

I didn,t know that! I,ll see what I can find on the googles