Progress

Well, here we go.  My little brother, with the help of friends, built most of the standard LEGO "wall" that sat on top of the DUPLO bricks.  Then, I implemented the coin-manipulating device.  However.....now I'm going to have to find a way to cover the device (but leave the bottom two-thirds of the machine open so the products can be seen).  We're running low on standard LEGO bricks here.  Perhaps I should take out some of the standard LEGO bricks and put in those other DUPLO bricks to compensate for the loss of height.

 I added a side door so that the coin holding device can easily slide out (and hopefully take the coins with it)

Additionally, I hinged a section of the top of the machine to allow for access to the bucket-rotating motor and this NXT Intelligent Brick's motor port and USB port. 

Sorting

A few days ago, I sorted the DUPLO bricks that I wanted to use for the vending machine's frame from the ones that I did not want to use.  I then put them together in a frame to give me an idea of how big the machine could be just with the DUPLO bricks.  Answer:  Either I was going to have to have few products, or make it bigger using standard LEGO bricks.


I have spent a lot of time sorting standard LEGO bricks from our huge collection for their use in the machine's frame.  Yesterday, with the assistance of my younger brother and sister, we managed to sort a sizable amount of bricks into divided containers by color.

While my boat pieces dried in the background from their second test!  (I wanted to see if the wheel were more buoyant on their sides than straight up and down.  I should have remembered that if they are completely submerged, they will displace the same amount of water anyway.  Despite this, the wheels on their sides provided more buoyancy than the straight ones because they were more submerged.  For the sake of personal challenge and NXTLog competition appeal, I'm going to have them on their sides....and....)

By the Way...

This is a test for an entry into The Explorerbot Challenge
 Inspired by this project

Pictures!

Finally, pictures.  The first one you see here is the version that my friend and I worked on.  Shortly afterward, I decided that the prototype was good enough, and as aforementioned, I disassembled it and began to rebuild the modules in a more compact fashion.  And as I said, I did stack the two modules on top of each other to make it much more compact.  Then, what's new?

• Cross-braces added to strengthen robot
• Change chute updated - now it feeds to the left and then to the front.  Light sensor is more reliable.
• NXT is mounted vertically - might change its position later, but it will likely still remain vertical.
• Touch sensor that helps in coin type detecting now has a changed wire position - touch sensor attachment is entering the coin "bucket" much more consistently

Remember this old list of things to fix in the final version?  Well, let's see what's done.

• The attachment on the touch sensor that contacts the coin tends to get stuck on the "holding tank" if it is not in the perfect position.  Possibly, I could fix this using a troubleshooting part of the program?  Must make the entire money manipulating mechanism easy to access.  This might be fixed by changing how the touch sensor's wire is positioned (not over the little bar seen on the upper left in the above picture)
• The connecting ramp between the coin detecting and coin dispensing modules is not steep enough.  No ramp in this version!
• The place where the coins come out is very hard to get to.  Must make ramp that connects to front of machine.  Fixed - no ramp needed
• There is no ramp for the coin return.  Partially completed
• The "walls" that hold the coins in their stacks jump over the wheel that dispenses the coin.  (I don't think that it is harming it, however)  I don't know if it is harming the wheel, but I think I'll just leave it.
• No bill feeder or bill reader  Not done.
• Coin dispensing motor is not electrically run It can be run, but I have to switch between the touch sensor moving motor and the coin dispensing motor with only one NXT Intelligent brick.  When I add a second (and some programming) this should be solved.

What next?  More programming and the rest of the machine....