Shawn Pierce's Course Project
The Robot's Design
I have been calling my robot "The Manticore". It gets its name from the fearsome beast which has the body of a lion, the tail of a scorpion, and the wings of a bat (only much larger). While my robot does not have wings or a poisonous tail, it will have a stride that I imagine is much like that of the Manticore.
Here are some of the photos I have taken so far:
An Early View of the Frame
This shows the two motor setup I am using. One thing that I have already noticed, as I uploaded this image, is that I will need another gear to reverse the motion of the hind legs.
A Top-down View of the Body
Not too shabby...
A Diagonal View of the Body
Researching possible robot designs, building with LEGOS™, and taking pictures.
The current robot consists of a body which makes use of two motors that will power two legs each. I am using a locomotive type of motion to allow the legs to walk. Early on I realized that I will have to stagger the rate at which each leg touches the ground, so that it will be able to walk in stead of stand in place and gyrate its body.
I am working on powering the motors using an older Lego system that predates the Mindstorm kits, but still uses the same connectors.
This week I am hoping to finish up the robot by making a few adjustments on the body, and then by adding its legs.
I also hope to begin assembling a CAD model as soon as the physical assembly is complete.
So far I have tried out 3 CAD environments.
The first was Bently Microstation. I found this piece of software particularly hard to get used to as far as its user interface goes. I was not able to load the step files for the lego pieces in Microstation (not to say that it cannot be done, but after about an hour of messing around I decided I would try something else).
The next piece of software I sampled was UGS I-deas, this program seemed to be a step up from Microstation. It actually had a mechanism for moving, rotating, and translating objects. However, to move an object you have to go through red-tape-heaven. Left click on the object, right click on the object, select DONE then go to the move toolbox, then select which type of move you want to do, then do the move. Simple huh? Well it really breaks your train of thought quite thuroughly. And after all the hassle, you are not in some sort of "move mode". Nope, if you want to move a part a second time, you have to go right back to the beginning. This goes for each of the other operations that I tried. There may be a much easier way to do things in this program, but it is not made apparent.
Megan let me try modeling with her already imported lego setup. It was fairly easy to bring legos out of their "bin" and into the assembly area. There is, although, a catch. You take the lego you want out of the "bin" and put it on the viewable area of the screen. Now, to your surprize/dismay, it does not exist in the "bin". So, say you made a robot with more than one of the same piece, you now have to make copies of these parts. This is okay, but it is just confusing as to why the designers of this software would make so many choices that confound the same process that they're trying to facilitate.
Adams, I thought, would be the solution to all of my problems. It has a slightly more polished interface than that of I-deas. It was able to load STEP (.stp) models without too much trouble. You must first import the model, and then navigate a hierarchy of the model to select the specific "part" that you want. That can be tricky, but Mike outlines the process quite nicely here.
After loading a model into the Adams viewer, you can rotate, translate or zoom the view (using the 'r', 't', and 'z' keys and a mouse movement). I was unable to actually rotate, translate or scale the actual objects (scaling being of very little importance for our purposes). I was also unable to load multiple parts at the same time.