If you’re looking to get some of the coolest wheels available on the market today, then go check out the Rotacaster Omniwheels. They’re currently having a sale on their website with a 15% discount. You can find their shop site here: [LINK]. Use the discount code: RoboticsXmas to get the 15% off. The sale ends December 19, so don’t delay too long.
These are the wheels that I used to create the LEGO Wheelchair and the LEGO ATV. They rock!
So here is a prototype of my latest project, the LEGO Wheelchair which is capable of moving a 90KG person around a room using just LEGO Mindstorms, LEGO Technic and Rotacaster multi-directional wheels. This is still a prototype and under constant development however I really wanted to let people see what I have been up to.
My wife giving version 0.8 a test drive.
Me having an initial go on version 0.5.
The lastest version uses 6 LEGO Mindstorms NXT’s for moving and 1 NXT(master) for controling the direction. Each of the driving NXT’s has 2 NXT motors attached to it and 2 touch sensors used to control direction. The master NXT has 4 touch sensors connected (forward, back, left and right) and 2 motors to switch on the drive touch sensors. It is programmed in RobotC.
One of the next things on the list is to add remote control to the wheelchair using an Android device. The chair is controlled via 1 NXT, this will be very straight forward to control via bluettooth.
I have managed to get hold of some very cool Rotacaster.com.au 125mm omni-directional wheels to try out. I managed to use up most of my yellow technic beams building this massive platform which will eventually house a large robot. I plan to mix it up a bit with some of the new metal parts I have been sent including some very large beautiful linear actuators.
The video below shows the platform easily moving over 12.5kg of weight using 4 XL power function motors. The wheels are a little on the heavy side compared to a normal Lego wheel however they are massively stronger and can hold over 100kg per wheel. They are 6 studs wide.
I was lucky enough to win a set of 3 48mm Rotacaster multi-directional wheels from a competition held on BotBench. These wheels are built to be compatible with Lego axels.
I have great plans for these wheels but first I thought I would put them through a simple weight test. Now according to the website the wheels can take up to 35KG per wheel however I don’t think the plastic Lego axels can!
I spent around 15 minutes building a rather simple platform to test out the wheels on. 2 of the wheels were directly connected to 2 PF XL motors (1 per wheel). The main point of this test was to see is how much weight a simple layout could move and more importantly turn.
Once I get a rough idea of the basics then I can scale it up for my bigger models using more gearing, more motors or even more wheels. As stated in my previous post, moving heavy weight is my biggest issue when building my robots.
In my opinion, 2 non geared xl motors moving and turning 12.5 kg of weight is pretty impressive! Maybe I should use them to move my son around the house:)
For more information on these wheels, please visit Rotacaster.