I think some power wheels motors would work well. I picked up a corvette for 10 bucks at a yard sale that needed a battery. If the motors can pull around a kid or two it should pull around your bot.

I am actually planning a similar bot but it will be more like 100lbs (I figure I need the weight/strength to open my fridge door) and I am using wheel chair motors and tires. I got them off ebay with a controller for $150. I have another set that is a little older and uses a larger tire that I only paid $50 for. My plan is to make this larger bot an imbedded system.

I thought I posted this reply already, but it isn't here. lower power, but probably about right for the weight range you are looking at would be windshield wiper motors. You can get new ones from http://monsterguts.com/index.php?act=viewProd&productId=4 for $15.99 each. At their highest setting they draw 2amps so a little high for the H-bridge DJ sells. Might be OK at the lower speed setting though.

Alan

Good idea Alan.

Thanks for the ideas guys. I'll look into them.

Cool...I want to do a similar type robot for my second project. I am starting smaller at the moment.

I am interested to see the Kitty Igloo!

I have a old Peg Perego 'powerwheels' Jeep in the garage that I am parting out. I did a little research and these motors and found out they are pretty beefy (170 watts). So at 12V that rates them at about 14Amps if I am doing the math correctly. I will probably need a 25A H bridge to handle them. I think the battery that goes with the Jeep will work fine if I want to do any other work like a robotic arm. Not sure what your budget is, but mine is pretty small....so building a strong arm on the cheap will be a great challenge and I will certainly be interested in your progress if you are looking to save some $$ as well with your project!

I am liking the retrieval of adult beverages from the fridge concept alot!

Kevin

I hear you kkeast. I'm going to use my omnibot as my testing ground for my big one. But being budget stressed it will take some time to gather the parts.

Seems there just isn't enough time in a day to do everything Iwant! Robojeep is still setting out in the garage waiting on a motor driver and one of servo City monster servos. It's starting to get a little chilly, and because of health matters I stay inside. I'll try to get a pic of the Kitty igloo tomorrow. It will be the "before" picture. Sounds like you have a plan Bret! Seems you're doing your homework.I'm looking forward to seeing your progress, When I told the wife about the plans for a household robot, she said her first priorty was abot that would do housework! With discretion............I opted not to tell her my priorty was the fetching of that cold adult b77everage! LOL With the holidays upon us I have to budget my roboting time. I hear you on the budget thing. Inexpensive is always better! I'm hoping ole Santa might bring me another EZ-B. However...............as the wife and I treated ourselves to a new 47 inch, HD, 3D TV, the prospects of getting one is somewhere around mighty slim, and prob not! BTW, Happy Holidays to everyone!

Here are a couple of pics of the "Kitty Igloo"; which is destined to become "IGOR"
faithful servant and companion! Me thinks his creation is realitively far in the future. Perhaps come spring. For now he is residing with RoBo Jeep out in the garage. The top lifts off of the base; making for easy access to all the goodies inside. The opening will have a panel that will stay connected to the base and (hopefully) will support the arm/gripper. I'm kinda hoping for a mild winter so I can work on him a bit.

cool

RobotZ12248: Here is something to check out. I am using these in a robot here at the musem. http://www.robotmarketplace.com/products/AME-218-1003.html They have both right and left hand versions in 12 and 24 V versions as well. I am using the 12V version and have them hooked up to a Basic Micro Robo Claw 2x30 Motor Controller, which is basically the same thing as the Sabretooth 2x25. Both are available through Robot marketplace.com

They work well together and I can drive it over Commercial Carpert with no problem, so running it over wood or tile floors would be a piece of cake.

The nice thing about using the gear motors is that they will operated at a slower speed and have more torque than the scooter motors have and you don't need to build some sort of speed reduction with sprockets, or pulleys.

You can also set the max speed you want to set the motor to run at in the movement control panel.

Dan S.

Wow, that sucker pulls 21 amps at a stall. I see it only pulls 1.4 amps with no load. I wonder what it actually pulls under real life load.