DIY Giant RC Spider.

HibLaGrande · #1 10-15-2005

OK, so here is my idea, I will need as much help as I can get for this one.

A Giant RC Spider!!!!
I have thought about this for years A big hairy spider that could chase people down the street or pop out of my neighbors hedge row all at the touch of a button. It was only when I started doing the actual research that I knew I was in over my head.

I have 2 12/DC motors from a powerwheels kids car that I would like to use. I would like these motors (one for each side) geared down to turn a cam for the legs and and to also run the drive wheels. I would like to run both of these motors off of a motorcycle battery/ies. And I would like it to be controled like a tank 2CH left side forward/reverse right side forward/reverse.

Has anyone found a way of mounting these motors??? they are really odd shaped, the drive shaft(tube?) is screwy too.

What kind of RC stuff should I be looking for. (I know zilch about the RC world ) other than I need a transmiter and reciver and motor controls of some sort.Also, I am cheap so any help in finding the stuff I need cheap wold be greatly appreciated.

maxcarnage · #2 10-16-2005

finally, somethin I can help with

you'r biggest enemy in the cost department is going to be the amperage you're going to be pulling. Most over the counter esc's (electronic speed controls) aren't going to be able to handle it without dying. This pretty much leaves you with 2 options....home build a mechanical sc, or buy a nice esc....one is obviously going to be alot cheaper than the other....if you decide to build your own you would just need the transmitter, reciever, 2 channel reciever that matches the transmitter, a couple of servos, and four leaf switches rated to the stall amperage the motor is going to have to pull, a couple of fuses would be a good idea too....as well as something to putt it all on. Another huge disadvantage would be trying to make it walk correctly....if it were me, I would just build it so it drove on specially made "wheels" so it would shuffle, then try and animate the spider so it appeared to be walking.....it'll be alot easier to build, as well as probably faster, and more reliable. As for the motor mounting and such, I would be more than happy to help you design something, but I would have to see a picture of the assembly, and possibly a couple of measurements .

I have tinkered with "robots" before, and still have a small library of literature on the subject, I would really like to see somebody make something like this, so if you need any help with anything, just shoot. I'll be glad to help any way I can.

DeathTouch · #3 10-16-2005

You are in luck. I have been thinking about this for while, and I know what you can do Instead of going with a RC car, how about getting a power wheels car and taking the motors and battery out of that thing to make your spider. Those cars are powerfully. Most of them can carry two kids. That means you can make a big spider and have him go around the yard. But, I would suggest making a track for him like train. Have him go around the grave yard. That might look cool.

HibLaGrande · #4 10-16-2005

I have 2 motors from powerwheels car,
And the legs are for effect not locomotion.and won't actually touch the ground. I was going to use Bicycle wheels for the drive wheels. I f I could make this thing sturdy enough to ride it would be cool. "Spider rides 1 dollar!"

maxcarnage · #5 10-16-2005

it should be easy enough to do then....you should have enough power there with two motors to easily haul around a bit of weight...just make sure the motors will have plenty of juice. another interesting thing is that you can double up the voltage you use on these motors....it'll double the rpm's, but most importantly, it nearly quadruples the power output. but doing that also creates more heat on the motor, so you'd want to use some kind of small fans for cooling. would it be able to haul around an adult?....yes. Would it b cool?.....doubtless. If you need any technical assistance, just give me a shout, and I'll be glad to help however I can.

HibLaGrande · #6 10-16-2005

Here are a few pics of the motors I was thinking about using.

Photobucket (Videos)

Photobucket (Videos)

they are about -5-6 inches wide and about 9-10 inches tall. When I find one of my tape measure I will have a little more info. Ill have a better photo shop picture soon with some measurements drawn on it. I was thinking of drilling out the factory screw mounts and running longer bolts through it, sandwiching the plastic assembly between sheet metal.

I need to mention that only the white part spins. the black inner hub does not.

HibLaGrande · #7 10-16-2005

A mechanical sevo controled motor control set up would be mostlikly cheaper and plausable for me to build. I only worry about it sticking and running over someone. This thing is only going to move at a slow walking pace.

Doubling the power might eat up the nylon gears inside the assembly. so i dont' know?

any good sources for used rc kits? Ive checked on ebay and really don't know what to be looking for. I would like a 2 ch dual joystick type radio A compatible reciever and matching servos. and does not need a very long range. I looked at some rc toys at the store for possible canibalisation but came up empty handed.these wont handle the juice,

maxcarnage · #8 10-16-2005

no problem...I've done enough hobby level rc to help you put a budget friendly radio/reciever/ and servo combo together...

you are going to have a range of right around a hundred feet given you don't run into alot of interference with am stuff....cheaper

with fm stuff you can increase the range, as well as less chance of interference....but at a cost, fm stuff isn't cheap.

you're also currect in the assumption that the extra power might very well strip out the nylon gears, it is a very real possibility, so you're probably not going to want to double the voltage there.

here's an example of en ebay item you'll want to look for for the giant rc spider project http://cgi.ebay.com/Futaba-ATTACK-2-...QQcmdZViewItem

DeathTouch · #9 10-16-2005

I have known people to get the power wheels things to work. Let me she show you how it was done. Check pictures down below.

http://cr.planetchristmas.com/defaul...d=12012&fid=93

maxcarnage · #10 10-17-2005

I found a site for ya, that explains with pictures and wiring diagrams, some of the various ways to build a mechanical speed controller....

http://www.rctankcombat.com/articles/speed-control/