Since Evelyn never knew about Go Karts as a kid, we decided to make her one as an adult. This is our initial version. It’s also a great way for Evelyn to get to know all of the shop power tools. Everything you see in this series will be cut by her. I’m just the mean boss (a role I’m good at).

We started working on the design of the adult-sized Go Kart (non-motorized) yesterday. We’d purchased the wheels a couple of weeks ago, but just got the rods for the axles recently.

We were going back and forth with the design. Use full length axles? Use Pillow Block bearings? In the end we went with full length axles fitting into a dado (slot) cut into 2×4 supports. The primary reason is that lumber is cheaper than bearings.

Here are some of the pieces on the bench:

In the back you see one of the 10″ pneumatic wheels. Got these at Harbor Freight for about $8 each. They take a 5/8″ axle, which we got at Lowe’s. (The axles are probably one of the most expensive parts — $10 for each 3′ piece.)

The rods are 36″ long, and each wheel assembly requires about 3″ of clearance, leaving 30″ of space in between.

For the rear axle we cut two pieces of 2×4 30″ long. In one piece we used a router to cut a dado (slot) along the entire length. I used a 3/4″ straight bit (didn’t have a 5/8″ on hand) and gradually made it to a depth of 5/8″. Do NOT try and cut this slot in one pass! We put the lumber through a couple of times, each time adjusting the bit to cut about 1/4″ more. You’re less likely to bog down to router that way.

The result is the piece second from the front. You can see the 30″ span with the 36″ rod slipped in.

For the front, we need clearance for the center pivot point (for steering — the whole length will tilt — this is unlike the way a car works). In this case, we cut two 13″ pieces of 2×4 and slotted them. This means 26″ for those two blocks + 4″ clear in the center for the pivot + 3″ left tire + 3″ right tire = 36″.

A 1×4 cut to length (30″ for rear, two 13″ for front) will be placed over the axle and screwed into place. This will encapsulate the axle rod. The whole thing will then be screwed into another 30″ 2×4 (for front and back) making the complete assembly. (We don’t have the 1x4s yet — they aren’t in the photo.)

We’re making a 2×4 sandwich: 2×4, 2×4 with slot, axle placed in slot, 1×4 to keep axle from coming out. The 2x4s are on the top. The 1×4 provides no structural support — it’s only there to keep the axle in the slot. I’ll take a photo when it’s put together, it will make more sense then.