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.
If you are interested in these wheels, please contact Rotacaster.com.au
As you may be aware I have been building a Robot called Wheeler out of old parts (old grey and RCX 9V motors etc). I was hoping to have it finished over the Christmas break but had hit a small issue with driving the wheels with the new weight of the body. Anyway what I managed to get up and running is the top half of Wheeer and the controller which is a Android phone (Dell Streak).
Mindsensors RCX Multiplexer
I was utterly impressed with the Mindsensors.com RCX Multiplexer and using Xanders driver suite (check BotBench) how fast I was up and running. I wish there was a way to run the RCX Multiplexer off the NXT power supply but thats a small thing compared to how useful it is. I wish I had 3 more of them so that I could control 16 RCX motors!
Android NXT Remote Control
So to try and work out how to control the NXT via Android, I stumbled across the NXT Remote Control project which is free to download. This uses Lego’s Direct Commands to control the 3 motor ports on the NXT. This means it bypasses your own code and you have no control over it. However, what I managed to do is reduce it down to a very simple program that sends messages to the NXT which you can deal with in your own program. In RobotC, it sends messages that are compatible with the MessageParam command and so you can send a message ID and 2 params to the NXT and deal with them in RobotC anyway you want to.
Code will be available soon once I have tidied it up
Today I had a little bit of spare time while looking after my son and watching some films, so I decided to try and build a studless (I always build studded) robotic arm using NXT motors (I mostly use PF).
Here is the result.
I have to be honest and admit that I loved building using studless Lego. It does involve building in a different type of way, you could say in a more structured / planned way. However until I have enough of it to build giant robots, I will be sticking with studded Lego which I have tons of!
I still need to spend some more time with the NXT motors as they still feel very alien to use due to their random fitment and shape but I am sure I will master them soon.
Merry Christmas everyone and have a great New Years!
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.
