Going to build my kids a kart, but new to this!

[vorkerman]

Hey everyone, thanks in advance for any help/advice!

I'm planning on building my kids (ages 5 and 3) a two seater kart. Planning on going electric but that's not my issue at the moment! I've been reading quite a bit, and plan on still reading, but basically, looking on how to get started! I'm assuming a plan and frame design?

I was originally thinking of doing a wood kart, I saw a cool looking one on another site, and given my lack of experience would be totally easier to build, but I also understand it would make it way heavier, and likely not as durable. I'm hoping that my father in law can help me with some welding or at least let me borrow his. Would a metal frame be the way to go if it is all possible?

My end goal is more of a buggy, because I told my son I'd try to make it sort of look like a police car. I've seen some kids karts/buggies that I like, but I also want to keep the frame to a minimum difficulty if I do go metal.

So for starters other than the above wood/metal question... I'm thinkng what size? My kids are pretty short/small for their age, but I'd like them to be able to use it for a while, but also don't want it to be huge so I have trouble storing it! I was thinking somewhere in the 28-36" width range, and like a 50"ish length? Does this sound reasonable?

Should I consider available axle lenghts/etc when considering the width? Any considerations on how to plan the length?

Thanks and this forum is pretty sweet and packed with info!

Charlie

 

[XMG50]

Hi, Steel is the way to go without a doubt. If your father in law will help, have him or borrow the welder.

On the Home page you'll see kart plans. Also check out kartfab for other plans.

DIYGOKARTS PLANS

Kart Plans Kart Fab

Have fun and start a build thread when you start.

 

[vorkerman]

Thanks XMG50. I've seen the kartfab one before, and I like it with it's simplicity... though as mentioned, I'd be curious how to modify it to more of a buggy, though I could likely figure that out. Do people always use steel as the floor pan? Doesn't that get hot in the summer sun?

Maybe I'll start with the kartfab one and sort of modify it.

What I'm thinking is something along the lines of the trailmaster mini, but not as elaborate.... I also don't need it to be super tall either as mentioned my kids are pretty short.

Thanks again.

 

[XMG50]

You're welcome.

Yes, the drawing board is up to you. You can make what ever you want with just a few tools.

I started with a cheap $50 frame off craigslist and made it a two seater for my son. We had fun and learned a lot. That might be an idea as well.

 

[vorkerman]

I've looked around on our craigslist equivalent here in Canada (kijiji) but haven't found any frames locally... just working karts. Maybe I'll expand my search area.

Appreciate the help/direction.

 

[OzFab]

For the length/width issue, we suggest at least a 4:3 wheelbase:track ratio; the frame can, of course, go beyond those boundaries...

To calculate size, lay a large piece of cardboard on a flat surface, have your kids sit on it & mark the seating position & feet positions with legs outstretched; that will give you a gauge of what length it needs to be now...

Just a few ideas to allow for growth but, still enjoy it now:
-adjustable seat
-pedal extenders
-adjustable height steering column...

As they grow, move the seat back then, once the seat is right back, remove the pedal extenders & move the seat forward again...

Feel free to continue asking questions, we have most of the answers...

 

[vorkerman]

Awesome Fabroman, thanks and appreciate the tips! Adjustable seat sounds a great idea, as do the others.

I did start with a piece of wood and had them sit on it, but I'm unsure how much room is needed from their feet to the front (to account for steering/bumper, etc), and then how much room to leave behind the seat for batteries/motor/controller, etc.

Also, it appears the wheel base is the critical dimension, not so much the overall length of the kart? I kind of want to put a bit of a front bumper of sorts since kids are pretty young... but the back wheels pretty much go at the back is standard design?

---------- Post added at 09:58 AM ---------- Previous post was at 09:52 AM ----------

One other question...wheel size? That kart fab kart, seems to have ~ 12 inch wheels ish, which was the range I was thinking (10 -13)... what's a good size in peoples opinions for that age range of kids 4 and up for a few years. I probably won't let the 3 year old drive right away

Common sizes in a good price range I've seen are the 4.10, 140/70-6 and just general 13 inch tires (by the way, all the different size units are driving me nuts!). I thinking primarily on grass/dirt with some sidewalk type of driving.

 

[OzFab]

With 140/70-6:
140 is the width of the tread in millimetres
70 is the profile, the height of the sidewall as a percentage to the tread width; ie: the height of the side wall is 70% of 140mm
6 indicated the rim size

Note that the above is for that particular tyre, others are different:
4.10x3.5/4 means the tyre is 4.1" wide, sidewall is 3.5" high & fits a 4" rim... &
18x9/8 has an overall height of 18", a total width of 9" & fits an 8" rim...

You're in the right size range for the type of kart though...

The overall dimensions of the kart is totally up to you; in most cases, the pedals attach around the front axle & a small (4-6") bumper extends beyond the axle; same with the rear, the rear of the frame usually extends around the same distance from the rear of the rear tyres...

Have a look around the forum or even the internet in general for ideas of what I mean; start with my kart...

 

[vorkerman]

Thank you very much Fabroman!

I'm hoping to get started soon, I confirmed my father in law has a welder (though not what type of welder yet...) so hopefully with some free weekends coming up I can get something welded up and get some feedback.

For axle lengths... should I go width of kart + width of tire + buffer?
Also, even though this is for kids, should I go with 1" axle diameter? Solid shaft instead of hollow tube?

 

[OzFab]

Definitely 1" solid axle...

Although you can buy custom length axles, I would try to find something on the "standard" field; if you build the frame correctly, the rear section holding the engine & axle can be narrower than the main body of the kart so, you have a basic frame like in the pic below...

My suggestion is start with the axle & work from there...

 

[vorkerman]

So, for what to construct the frame out of. I was thinking of the 1" steel square tubing I can get at home depot to weld up. Will it be of adequate strength? It's not very thick, I think only ~1/16th it looks like? But I've read on here (I think), that larger dimension, less thickness is stronger than smaller dimension more thickness? Also, weight considerations.

Here is what I was looking at:

http://www.homedepot.ca/product/papc1x100x48-square-tubing/955466

Keep in mind this is for smaller kids.

Thanks,

 

[landuse]

That will be fine. I would definitely not buy it at Home Depot though. Any type of hardware store is going to charge you a lot of money for the steel. You must see if there is a steel merchant close to you where you can go buy the steel. It can sometimes be half the price of what you will pay at hardware stores

 

[vorkerman]

Wow ok, thanks Landuse. I'll look around then! That would also be helpful if I could get some other types. I'm planning on using pillow blocks bearings for a live rear axle, and I've read it's not a great idea to bolt them through the frame (weakening and all that), and it's best to weld on a piece on the side of the frame to mount them. I wasn't sure what was best to use, just some angle iron, or some sort of square plate or something.

 

[jandj]

As to pillow blocks, my unasked for two cents worth:
Yes, if you use them you want to weld on something to bolt them to instead of drilling holes in your frame, but....
As long as you have to weld, get a pair of weld on bearing hangers, a couple bearings and 2 sets of mounting flanges.
Now if a bearing goes bad you only need to buy a bearing instead of a pillow block.