Train update

by John Clemens
in trains

So the STAMP has a bad pin on it but I managed to solder it back together, so that works.  After building another serial cable from scratch I was able to get the STAMP to work under Linux using the BStamp project.  Using the STAMP and a RadioShack IR emitter/detector pair, I was able build a simple circuit that detected the presence of a train and lights an LED.  Good to know I can still build simple circuits.

This past weekend, I borrowed my friends truck and we bought the wood needed to build the train platform.  I knew roughly what I wanted to do, which was build a 4’x8’ platform with removable legs and a hinge in the middle so it would fold up for easy storage.  So we grabbed the following from the local Home Depot:

    1. 4’ x 8’ sheet of particle board
    1. 8’ long 2x4’s
    1. door hinges
    1. 5/16” 5” long bolts
    1. 5/16” wing nuts
  • (16)  5/16” washers
  • several  drywall screws

We had Home Depot cut the particle board in half for us, and all the 2x4’s in half as well.  Thus everything fit pretty easily in the back of Eric’s truck.  We came back and started assembling, basically making it up as we went.  We took two of the 2x4’s and attached them together with the two door hinges so that they swung out.  Then we took each 4x4 piece of particle board, and added a frame made up of the 2x4’s along three of the four sides, securing the boards to each other and then flipping over and securing them to the particle board with screw from the top. Finally, take the two 4x4 sections and lay them so the open ends of the frame point at each other.  Line them up to be as flush as possible, and then use the set of hinged 2x4’s to make the fourth side of each frame. This will join the two sides together through the hinge.  When open, the force of gravity on the center of the table will hold the hinge closed, but lifting up on the middle of the table will cause the table to fold in half.  Ours turned out to fold beautifully, which is remarkable since we were just eyeballing everything.

Th add the legs, we cut the remaining 2x4’s into ~25” sections.  We then lined up the legs in the corner of the bottom frame 2x4’s, and cut two 5/16” holes through the fram and the leg.  We then secured the legs to the frame using the bolts, washers, and wingnuts.  This allows them to be removable so the table can collapse when the holliday is over.  Fully assembled, the hinge+gravity trick works, but was pretty unstable.  The real solution is to add another to the center of the table, but we were out of wood (due to the fact we originally cut 3’ legs, which were too high), so we wound up just screwing in cross braces across the joint that I’ll have to remove in the future.

With the platform now set, I’ve laid out my simple track plan.  A basic oval around the outside with a curvy point-to-point track in the center.  It should work out rather well.  I also got my shipment of 5V relays in, so I started to try and coax the STAMP to trigger one to no success to far.  They require mroe curren than a stamp can supply.  I have some opto-isolators that I need to figure out how to use that should do the trick…