Super Size RC Car Build

[MadManAndrew]

I've been into hobby grade radio controlled cars since I was little, mainly because my dad had been into them long before I was born. For those of you that don't know what a "hobby grade" RC car is, they're just like toy RC cars except they cost about 10-20x as much up front, and every part is replaceable, so no throwing them away when you go off a ramp too big, or run into a tree, etc. I sold the last of my RC's when my son was on the way; y'all know how that goes. Now funds are a little less scarce, and I've developed a pretty big metal fabrication hobby, so I've decided my next RC and my next project will be an RC go kart.

I threw together some basic plans in Solidworks to get an idea of what I wanted and how much material I would be looking at; that's attached below. Other than those basic frame plans, I'm planning to just iron out the details as I go. I've got a pretty good knack for building from my vision and things turning out pretty nice, so hopefully this will go as smoothly as all my previous projects.

The plans so far include:
Approx. 44" wide at the tires
Approx. 60" long
Approx. 32" tall
1x1x1/16” steel tubing
Lifan 6.5HP/212cc motor
Solid mounted 1x36" rear axle
Floating .75x4.5" front spindles
16" tires
Wiper motor steering servo

I would like to use a Torq A Verter, but the budget as I get closer to completion will determine that.

My axle, spindles, and hardware show "Delivered" today, but the receiving department at work says otherwise. Hmm. UPS pulled that stupid crap where they handed off my package to USPS, and USPS has a reputation for not bothering to deliver our packages, so they probably are sitting at the post office waiting for me right now. What BS.

Anyway... What do you guys think?

[Gates72ss]

I've been building Hobby grade rc cars for years now , nitro brushless etc...I say go for it...Going to need some strong servo's for that puppy but they are around, how is that wiper motor going to work?I thought they are basically just power on then they run their course?Can you use like a electronic speed control to control the amount of turn?Learning something new here...Good luck man, show lots of pics..

[MadManAndrew]

Thanks for the encouraging comments. I started off with a Traxxas Stampede, then E-Maxx, then moved to nitro with the HPI Savage X, and then on to gas with an HPI Baja 5T. The Baja was definitely my favorite. As for the wiper motor, I plan to attach a potentiometer to the shaft of the motor, and then use an Arduino to interpret the desired position from the throttle channel on my receiver, and move the motor to the equivalent position based upon the potentiometer readings.

[Big Kev-O]

Nice, getting all you suspension and steering geometry correct is going to be a task. Can't wait to see it.

I have a T-Maxx on steroids and I love it, Wish my real truck was a nice as my RC.

[MadManAndrew]

Just a short update: I've gotten all of my axle parts in and they look good. I've been having trouble getting a local metal supplier to respond to me so i think I'm just gonna order my frame material from home depot. Hopefully I will be able to get started on it this weekend.

[Oldtruckfanatic]

You need to google 1/4 scale gravedigger on youtube. He used a mini conelly V8 but the truck is close to that size. His servo setup works but I forget what he used. I didnt think wiper motors would reverse but then again I never tried it.

[MadManAndrew]

I've seen that truck before, pretty awesome. Mine will not be near as "scale", or like the real thing, as his is. The reason wiper motors are popular for conversion to large servos is that it's just a plain motor/gearbox combo, nothing special about it, and it's a really good gear ratio for use as a servo. Right amount of torque and speed.

[MadManAndrew]

Today's update sucks. I lost the rear main on my truck today so I will be broke for at least the next month. Kill me.