Multnomah County Chopper - Radio Flyer Tiny Trike Power Mod

The stock Radio Flyer Tiny Trike has exactly 0 horsepower. We decided to fix that.

So with a broken old saw, a new power tool battery, some bungee cords and wires we've made this thing go.

Step 1 Choose your engine

We had an old Makita cordless circular saw. The battery died long ago and new batteries cost more than a new saw. It also happens to be geared nicely.

I sawed off (I recommend a second saw for this) the saw's handle and battery mount. I also removed the on/off trigger and mounted it on the handle bars.

To engage the power wheel, I used a hole cutter on a drill press to make a nice little disk with a center hole. I mounted this little wheel on the saw blade spindle.

Without damaging the trike, there are three good bungee cord mounts. The two plastic axle covers and the rear screw hole for the seat. The trick is to get the bungee cords to hold the motor securely and keep the friction wheel pressed to the tire.

Comments

[Shifrin]

Ha

[jongarrison]

I'm glad to see that the Instructables community is so safety conscious. Don't worry, we're being very careful with it and I will update the Instructable with a motor guard at some point.

[jmkeuning]

Haven't you all ever heard of once bitten, twice shy?

[Jezza Bear]

Hilarious, what a great idea. How fast does it go with the young fella on it?

[jongarrison]

Too fast, I'm thinking about making the little friction wheel smaller (or maybe adding a speed control of some sort). It's probably walking speed or so.

[chadvavra]

don't worry so much about the "pinch-point" till you take it off the coffee table. hahaha. (are you my dad? cause I'm having a deja vu moment here)

[Hovercraft]

It's creative, I'll give you that but I'm concerned about safety of a toddler that young. Older kids would know to be more careful but toddlers... well. Please find a way to box the motor and pinch roller. The battery contacts are exposed to be touched or worse, shorted, and as others have pointed out, the pinch roller is an injury waiting to happen. Good build though, I see a bit of thought and experimentation has been invested to this point to get the mechanics worked out. Now for the user-friendly interface.

[Nana K]

Watch out for those little fingers and toes!

[LasVegas]

I certainly hope you come up with a shield of some sort for that thing. Especially if the child is going to be anywhere near it!

[Andrew546]

You should put a cover over the pinch point between the wheel and friction drive. It looks like one slip of the little one's foot, and his pants, with or without his legs, get dragged in.

[qultiq]

Good idea. I'm going to have to see if I can find one of my old cordless drills to see if I can make that work. It probably would be a little slower in low gear.