# Electric Gocart



## sayno2vtec (Oct 8, 2008)

Here is a link that looks like it has everything. What do you guys think?
http://www.electricvehiclesusa.com/category_s/43.htm


----------



## brywisco (Aug 18, 2008)

This should be a fun project. You should first start by defining some of your major parameters such as estimated vehicle weight/size, useage (on or offroad) etc. This will gve the folks here much better data to work from. You can then select the power required to muster the performance you desire.
I would consider looking into buying the basic frame and suspension/steering components then adding the electric drive. This would save alot of headaches down the road and keep the main focus on the electrics.
There are lots of places online to buy the gocart components.


----------



## sayno2vtec (Oct 8, 2008)

Yeah I was considering buying an assembled used frame and modifying it to hold the batteries and motor and such. I'll be finding out all of that info today.


----------



## kixGas (May 2, 2008)

I built one for my son but because he is 6 yr old it is a little milder than what you are looking to do. His does maybe 18 mph. Here are some pics and I have lots more if you are interested. pics
It is 36v with a 1hp Chinese motor and controller. I built my frame myself and the whole thing weighs around 150 lbs. I could have made it lighter. I used 1/8" wall steel tubing and then later switched to .09" I probably could have done the whole thing out of .06" and saved more weight and be still quite strong. One thing I would suggest is to keep it low to the ground and keep the stance wide. I have considered making a faster one for me to play with and thought about using a Perm motor or a Advanced DC Motor #A00-4009 but we will see....


----------



## sayno2vtec (Oct 8, 2008)

Kixgas. Thanks for chiming in, I cant see the pictures b/c these campus computers dont have the codecs. I'm still looking for more info on the competive Karts to see what kind of rpm's there turning and how much power they have to get an idea of where I want mine to be. I'm going to a track this weekend to poke around and see how long these races are to get an idea of how long I want mine to run for. But, I will def. be contacting you w/ questions once i figure out where I need to be. How much would you say you spent in parts(if you dont mind me asking). I have to start putting together numbers for my proposal.


----------



## sayno2vtec (Oct 8, 2008)

Ok so Im looking for the equivalent of about 8-10hp the motors they use turn about 12K rpm's max but the power drops off at 4K rpms and falls exponentialy after that so I doubt they turn em more than 6.5-7K rpms. I'll find out more when I check at the track. Also its looking like I might build my frame. The price of a good used frame isnt to high but I'm sure making one will be cheaper......and well I just love welding.


----------



## kixGas (May 2, 2008)

sayno2vtec said:


> Kixgas. Thanks for chiming in, I cant see the pictures b/c these campus computers dont have the codecs. I'm still looking for more info on the competive Karts to see what kind of rpm's there turning and how much power they have to get an idea of where I want mine to be. I'm going to a track this weekend to poke around and see how long these races are to get an idea of how long I want mine to run for. But, I will def. be contacting you w/ questions once i figure out where I need to be. How much would you say you spent in parts(if you dont mind me asking). I have to start putting together numbers for my proposal.


I have about $600 all in. The motor, controller, and batteries I got from a guy on ebay for $250. Wheels and tires were around $150, brakes were about $50, seat belts were $50 and the rest is in the frame, steering, seat etc.
To do something like you want to do I would figure close to $2000.


----------



## sayno2vtec (Oct 8, 2008)

Finally got a look at the pix. Nice setup. Did you get the plans offline or are they your own design?


----------



## kixGas (May 2, 2008)

My own design


----------



## TX_Dj (Jul 25, 2008)

kixGas,

Thanks for sharing your kart pix. Man, that brings back some memories of when Pop started teaching me to drive and race. 

This one especially brought a smile to my face. How could someone say "no" to making a kid this happy.


----------



## gmijackso (Sep 30, 2008)

The only thing I'd add, is that if you're going to strap somebody into a 5 point, you need to put a hoop/halo over them. If that cart gets upside down for any reason and the person is properly strapped into the 5 point, they're going to break their neck. 

There's no way for them to move out of the way when properly strapped in, and since their head is above the back of the seat, it's now the highest point of the car.


----------



## kixGas (May 2, 2008)

that is a good point. I didn't do a hoop because none of the race karts have them and with this wide stance, low CoG, and relatively low speed it is near impossible to flip it. however I didn't consider what if something else hits it or what if he slides sideways into a curb. I guess you can't be safe enough. As of right now he can't drive it until he gets a full face helmet and I upgrade the brakes to hydraulic. I wonder if you can get a HANs device for kids. LOL


----------



## sayno2vtec (Oct 8, 2008)

LOL Hey is that a clutch like device on the other side of the gear in that pix?


----------



## kixGas (May 2, 2008)

sayno2vtec said:


> LOL Hey is that a clutch like device on the other side of the gear in that pix?


that was brakes version 1. It was a band brake which is similar to a drum brake except it is on the outside of the drum instead of the inside.
Version 2 was a cable actuated disc brake (it may be in some other pictures) but it wasn't much of an improvement and unfortunately the way a 6 year old mind works he pushes the brake *where* he wants to stop not fully understanding the principles of momentum (ask my old neighbor's fence LOL). To overcome this I laid a rope in the middle of the parking lot and had him go as fast as he could and then stop and not cross the rope. After about 10 times he stopped crossing the rope and then I had him do it another 20 times before I let him loose in the parking lot.
Version 3 will be hydraulic disc brakes- I just hope they are an improvement because version 4 would be disc brakes on the front wheels which is mucho $$.


----------



## sayno2vtec (Oct 8, 2008)

Ok I have a friend who seems to think a high torque starter motor gutted and modified would be good. I cant see it......he's talking about some neo magnets and ceramic. Any input on this? I dont know much about DC motors on this scale.


----------



## TX_Dj (Jul 25, 2008)

It could be done.

Alternatively, you could find an old VW generator (not alternator)... many folks have used the old VW generators as motors on 24-36v with no problems.


----------



## sayno2vtec (Oct 8, 2008)

I'll look into that. Is there a certain year or range of years I should be looking at?


----------



## order99 (Sep 8, 2008)

TX_Dj said:


> Alternatively, you could find an old VW generator (not alternator)... many folks have used the old VW generators as motors on 24-36v with no problems.


 Not to derail this thread-but i've never understood how you rate Generators as EV engines. What I mean to say is,I know you can use them-but how does one look at (for example)a 1970 WV Generator, 12v 50Amps...and translate that into an estimate of Horsepower, Max RPM and useful Voltage range? Is there a handy formula, does one need several expensive measureing devices, is it a Guesstimate?

Reason i'm asking(besides the sheer curiousity)-I happen to have a spare VW Generator lying around...while I don't have the time, tools, workspace or funds for commuter EV, I wouldn't mind digging a salvaged Recumbent Trike out of some Flea Market/Estate Sale and playing around with designs for a few weekends. Good experience for the real thing-but i'd like a few more Benchmarks and less trial-an-error, that latter one can get PRICEY!

BTW, surfed up to Ebay last week in case I wanted more generators (considering Windmill power-alas, i'm in a low wind valley  ). Going price is only about $40-50 for a "working fine until I pulled it out" model.


----------



## TX_Dj (Jul 25, 2008)

order99 - if it's a 12v 50A generator, you should be able to put 12v 50A into it as a motor, at the least. That's 600w right there, or almost 1 HP. As we all know, the motors we use for traction applications in our EVs are typically rated at less voltage than we actually use, but as long as we don't overspeed them, we can more or less feed more volts so long as we don't exceed the amps. That would imply that if you pushed the VW generator up to 36v 50A, you may see as much as 1800w, which is more than 2HP.

I played with the concept some 10 years ago, because at the time I had a surplus of VW parts... but I never got around to building anything with them. *shrug* Others have, though.


----------



## gmijackso (Sep 30, 2008)

order99 said:


> What I mean to say is,I know you can use them-but how does one look at (for example)a 1970 WV Generator, 12v 50Amps...and translate that into an estimate of Horsepower, Max RPM and useful Voltage range?


To add to what TX_DJ said above...

Lets say you have this 1970 VW Generator. Lets say it's rated to turn at up to 6000 RPM and creates 12V, 50A when you do so. You can then generally assume that if you apply 12V and 50A, you'll get something approaching your 6000 RPM.

Now, as TX said, you can generally over power them some to get better performance, and the relationship from generator to motor and vice versa aren't quite equal, it's not exactly the same voltage current RPM relationship, but it's close.


----------



## order99 (Sep 8, 2008)

So...24V to a VW generator yields roughly 1.5 HP and virtually no chance of damaging the motor, with 36V leading into over 2HP and still not too much stress? A 12V-36V motor rated at 1.5HP casual output is certainly nothing to sneeze at for $40-50 on Ebay, is it?

I could see a Recumbent Reverse Trike (Some of which support up to 500+ lbs) as a base design. We install a single 12V Gel on each side of the frame, place the VW Generator onto the frame just behind the front axle and run short chain to the existing drive, remove pedals(ruining it as a bike of course, but simplifying the design greatly). The controller, DC/DC converter and charger could go in the back...use the bike's existing gearings for now I suppose. So far i'd be looking at maybe $400 or less with decent scavenging...

Of course if the Trike got up to a decent speed i'd have to get it licensed as a Motorcycle, so I could use that empty front piece to mount a salvaged headlight(what the heck, mount a Speedometer/Voltmeter too), add some LED turn signals and brakelights-and a seatbelt just because i'd want one-then, (using my patented Cardboard-and-Fiberglass method) I could create some weatherproof covers for the motor, the Electronics Suite in the rear and the Battery tops. Later on I could replace the Bike wheels if something sturdier passes my way, and I could have fun with designing a body shell after-

GAAAAHHH!!! I'm supposed to be studying for my Network Exams and a job interview this week, and now I want to tackle this project so badly my hands itch! Who started this thread? It's all YOUR FAULT!



Excuse me, i've got grab a pen and some paper...hmm, 100lbs for the Trike, 90 lbs for Batts, motor, Electronics......


----------



## sayno2vtec (Oct 8, 2008)

lol. That would be me. Sounds like you got a plan as well.


----------



## sayno2vtec (Oct 8, 2008)

Aight. Hit another snag guys. When I presented this to my advisor he didnt go for it. After research it wouldnt have taken me long to do this at all, I knew that but he did too. He says he wants me to do something more challenging. He wants me to design something. So I got to thinking. What if I designed the Speed controller for it. I found a few sites that designed them for lower voltage applications but what if I did it for my gocart. Do you guys think this would be feasible using a microcontroller?


----------



## TX_Dj (Jul 25, 2008)

Absolutely. Check in the tech section, there are several DIY controller threads chock full of good info.


----------



## order99 (Sep 8, 2008)

I've seen webpages for DIY controllers, DC/DC converters, DC/AC Inverters (the guy used it to run his power tools from a DC utility cart) chargers, etc etc. A bit above my Tech knowledge currently, but you might find some inspiration there...

Hey, isn't somebody on this Forum building a Motor from scratch? Let me check...oh yeah, Beshires1 in the Technical Discussion Sub-forum has a real monster over there! Unless your adviser is a real hardcase he couldn't possibly say no to building your own EV from Raw Components, right? Draw the line at smelting the steel though!

Now if you'll excuse me i'm off to Criagslist to find a local Trike with enough battle damage to make it really cheap-with any luck i'll be done with my studies before a good deal pops up. If not i'll just chain myself to a desk or something...

(and it's still your fault)


----------



## sayno2vtec (Oct 8, 2008)

Thanks for the replies guys. I'll look more into it tomorrow Im gonna be up late working on this power point about Electric Vehicles. This is a really cool place......Order99 Im glad I inspire you.lol You should race me to see who finishes first.lol


----------



## order99 (Sep 8, 2008)

I'm currently trying to finish A+, Technician, Networking, and fall into Cisco and MSCE by the end of next summer...so I hope this is one race I lose!

Doing the research and shopping for cheap parts online make for refreshing study breaks though!


----------



## sayno2vtec (Oct 8, 2008)

Sounds like a plan. I wish I had the discipline to do that during study breaks. I'll stop to look and get carried away and before I know it I've spent 2 hours looking for parts.lol


----------

