Electric Go-Kart

[jwax]

I used off-the-shelf Sears Deep-Cycle, 100 AmpHr, about $55 apiece at the time. (Less than a dollar a pound!) The "0" wire will work, but pay someone to crimp high quality lugs on it for you. Soldering to that stuff is ugly, and not as low resistance. Crimps are best. Remember, every milliohm at 100 amps drops a tenth volt. (10 watts)
As far as a "simple" on-off switch- there are none. Copper knife switch will arc like crazy. Ever drop a wrench across a car battery terminals?
Need a controller.
As Steven pointed out, at zero RPM, power will be at max torque, and that beast will fly off your bench if not restrained just dropping 48 volts on it.
Most of my kart accessories came from Northern-
http://www.northerntool.com/webapp/wcs/ ... sclrp101ln
10, 12, or 15 teeth motor gears, chain, and 40, 54, or 60 teeth axle gears.
I used a live axle, with noticeable rear tire wear after a summer from lots of turns! Also, i had a 1/4" thick steel chain shround- just in case! Bear in mind 'safety' every step of the way Vincent!

[Vincent]

Ugh...I lost the auction. It ended while I was at work. <p>I was thinking about some kind of high current relay for the on/off, but I guess that will still not work with the high torque. I'll look for a speed control.<p>A live axle will have to work. Aren't a lot of go-karts set up that way, anyways? Tires aren't that expensive. A motor for each wheel will mean a lot of fabrication and I don't have a welder. <p>A shroud will definitely be used. I don't want to get hit by a chain in the back of the head. I have plenty of allen screw terminals for the 0 gauge that should provide a good connection. <p>Oh well...back to search for another motor.

[jwax]

Yes, live axles are standard on karts, and works well. At the end of my summer of karting, the darn thing was getting slower and slower. Finally diagnosed it to the rear axle bearings! They were almost seized! Apparently battery acid had its corrosive way of destroying them! Not a splash of acid either- there was none of that, just the proximity of all those H2SO4 fumes ate the bearings! Don't know how to prevent that. Keep a spare set. BTW- they were a bitch to remove! Outside storage of the kart (rather than a closed garage) would help. Charging should also be done with plenty of fresh air circulating.

[Externet]

Hi jwax.
I did not receive confirmation of reception of a direct email to your address shown in this forum.
Miguel

[jwax]

Sorry Miguel, I got busy researching your motors and discussing their application with a few other guys! Also looking for 500 amp controllers!

[Vincent]

http://www.batteryspace.com/index.asp?P ... ProdID=326<p>1/4 HP 12v for only $20. Heh. <p>AWD would get me 1hp.

[Vincent]

I found three of the above motors on Ebay for $27 new in box. I picked them up to play around and keep me busy until a good deal pops up on a motor.<p>http://www.robotcombat.com/marketplace_motors_npc.html<p>These are extremely cheap. The top one does 0.7hp for $70. The others do almost 4hp for $270. I noticed that it's rated as peak power rather than continuous like others. You can browse through the other motors they carry...they are very cheap for the power also.

[philba]

don't lose an auction because you are not on-line. Use a sniping service...

[jwax]

Those are certainly adequate Vincent, except for that "1/4 hp" motor. By math, it appears that 4 of them would give your kart a hp, but between the wiring, drive losses, and motor-fighting-motor losses, I'd avoid multiple motors. Two or more motors require RPM sensors, and positive feedback to efficiently control.
Anybody familiar with the "Lynch Motor"? Now, there's a motor! Check-http://www.lemcoltd.com/

[Vincent]

Finally found a ESC. Picked up a used Curtis 1204 out of a golf cart for $80. It's the 48 volt 225 amp version. <p>Should work nicely. Hopefully this one will work out fine. <p>I won a new one on Ebay a week ago and the guy cancelled the transaction. He had 10-15 on Ebay at the same time (brand new) and all of them went for $70-$100. I guess he decided he wasn't going to let them go for that.

[gasayers]

sorry to show my ignorance
could you describe a "live" axle?
Cheers
Glen

[jwax]

Certainly! Both rear wheels are attached to the axle, a toothed gear for the chain drive is attached to the axle, transmitting power to both rear wheels equally. The alternative is to drive just one rear wheel.
John

[connect21]

Northern Tools sells a nice differential for go-karts and just around $75.00, but if you install it, you need 4 bearings, 2 at the end of the shaft and 2 close to the casing. I bought one, didn't install it yet but they look solid, they have a 1 inch shaft.

[Vincent]

I found a speed controller cheap. It's a Curtis 48v/225amp. Hopefully it works...I won't have a way to check for sure until I get the batteries and motor. The guy had good feedback on Ebay, so I assume there shouldn't be a problem.<p>I should be picking up a go-kart this Tuesday. It's a two-seater, so it should be built a little more rigid and will have room for the batteries. <p>I'm not having much luck with a motor. <p>How will I have to recharge the batteries? I have no idea which kind of batteries to use or the kind of recharger. If I run a 36-48 volt setup using 3-4 12's in series, do I charge the batteries while they are in series off of a 36-48 volt charger?

[Vincent]

On my controller, there are only three large terminals.<p>B+, B-, and M-. There is a label on the controller for A2, but there is not a plug like on most 1204's I've seen. It's not like it's been hacked up...it looks like it came that way from the factory.<p>Does this mean that my controller is only for permanent magnet motors?<p>The face looks like the bottom picture...<p>http://www.curtisinst.com/index.cfm?fus ... y&catID=11