Planet-9 Porsche Forum banner

1 - 20 of 88 Posts

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #1
It's winter, my Boxster is sleeping in the garage, and i'm bored. And my daughter almost grew out of Spyder I build two years ago:

https://picasaweb.google.com/105243537975717937980/SpyderKidsCar?authuser=0&authkey=Gv1sRgCMHwqJ-Tw6jOiQE&feat=directlink

So time for a new project. The Spyder was pretty heavy (117lbs), not size adjustable, and too big to bring it anywhere, like real race track. My new project is ultralight, super adjustable, compact tri-go-kart with real race car handling and grip.



The frame is a composite floor with aluminum rails that most of the components will be mounted to. Wheels are 3 racing go-kart wheels. Disc brakes and belt drive from 350w motor. It should be able to reach 30-40mph and take turns without slowing down. But since it's for 5 y.o and 3 y.o. kids - I'll limit the speed to 15mph.



I'm aiming at 50lbs for the whole go-kart. And size of 41" which is exactly the size that will fit into my FX35 SUV.

 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #2
Got the wheels. First mockup. Ground clearance is 2"



Aluminum T-slots and composite bushings from ebay. 8lbs all toghether



Got the seat. Cool looking and 2.6 lbs!


Total so far for t-slots, tires, seat and bearings - 17.2 lbs. Not bad.

Anybody can spare 1/2" titanium bolts?
 

·
PCA Nat'l DE Instructor
Joined
·
1,668 Posts
Looks like it'll be a lot of fun -- for the kids, too! ;) Your kids are lucky to have a creative dad (or mom?) Please keep posting your build progress.
 

·
Premium Member
Joined
·
285 Posts
very cool, lucky kid!
 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #6

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #8

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #9 (Edited)
This thread is so un-loved... Thought I'd post some updates.

I'm slowly but surely. But slowly. But surely... Moving ahead.

Here is rear axle assembly (minus brake disk and sprocket). Aluminum axle (not trimmed yet), plastic bearing housing. All very light.


Aluminum rim and hub:


And the last big milestone - the structural floor/chassis. Carbon fiber sandwich with 0.5" balsa core. Weight - 5lbs even!


Bottom view:


I'm pretty much on target with sub-60 lbs weight. Hopefully sub-55lbs. Depends on the lightest batteries I can find. That's 55 lbs with real go-kart handling. Not sure about the motor yet. But even with 250w it'll be better than usual electric rental go-karts.

Need to cut/trim aluminum parts, and waiting on some bolts and nuts to bolt together (somewhat) rolling chassis. Love the wings. Hope I can put batteries under the seat, so wings will stay uncluttered.
 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #11
oil cups are for the housing of self-aligning bearings. Totally unnecessary since it's slick plastic anyway. It's gonna be live axle of course. And since it's only one wheel I won't have to deal with traction-in-turns problems.
 

·
Premium Member
Joined
·
2,574 Posts
Outstanding. Love the live axle......can't remember if I mentioned it previously but I raced Sprint Karts in my teens. It was my first introduction to the live axle (aka poor man's LSD). 180s were challenging but 4 wheel drifts off of high speed turns with both wheels driving was outstanding. I was racing long before I had a drivers license and it was funny when I started driving a car and had to learn that on the street you didn't use your left foot to brake. Love your kart.......good stuff.
 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #13
I don't think this thing will drift. It has pretty wide tires for the weight. We'll see.

Yeah, reteaching my kids to break with right foot - after 12 years of driving go-karts (they started at 3) will be a problem that I'll have to deal with later :)

Outstanding. Love the live axle......can't remember if I mentioned it previously but I raced Sprint Karts in my teens. It was my first introduction to the live axle (aka poor man's LSD). 180s were challenging but 4 wheel drifts off of high speed turns with both wheels driving was outstanding. I was racing long before I had a drivers license and it was funny when I started driving a car and had to learn that on the street you didn't use your left foot to brake. Love your kart.......good stuff.
 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #14 (Edited)


Chassis are done (minus front wheels mount/steering). 15.8 lbs


With rear wheel mounted. The ground clearance is between 1" and 1.5". The box on the right wing - is very approximate size of one of the two batteries I'm considering
 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #15
The first motor test. Glad I went with belt transmission. Belt and acetal pulley are so light and quiet. And it looks so clean.

 

·
Vendor
Joined
·
6,488 Posts
Discussion Starter #16 (Edited)
It's been a while.Finally find time to get back to this fun project. The kart is 95% ready. Just need to finish wiring everything, and design/add brakes

That green battery is 24v 10AmpH LIFEPO battery. Weight 5 lbs.


Super complex dashboard. Voltmeter and master switch. There also will be bike's speedometer/trip computer on the steering wheel



Gas and brake pedals. Pure carbon fiber. Gas will have magnets for Hall sensor attached. Brake will just use cable. I though about hydraulic system for the fun sake, but it weights too much.





 

·
Registered
Joined
·
83 Posts
Really impressive, Carbon fiber on a go-kart is COOL:drivingskid:.
don't you think that the wheel base is a bit short? like very short?
 

·
Registered
Joined
·
556 Posts
I think it would corner better with an Ackerman style steering instead of the single arm. You are going to have competing wheel arcs on corners. Plus I would groove those slicks with a groover for off road adventures. Looks like a lot of fun...nice job! Ha ha I still have a bubble balancer for Go Kart wheels.
 

·
Registered
Joined
·
258 Posts
My kids are grown, but the grandkids are just about right. You are giving me an answer for when my wife asks "What are you going to do in retirement?"
 
1 - 20 of 88 Posts
Top