MTM Machine and Others:

For the last week or so, I have been learning about the MTM machine.    I found a set of plastic sitting next to a trashcan that had been mis-routed, but at the time I wasn't sure how poorly.     All of the pieces are very tight fits, and some holes are offset, so the task has been to try to put them together, and see if the errors can all be put in the same direction to get the pieces to work.

So far, it isn't as bad as it sounds -- the pieces were fitting together and I didn't know how messed up they were.    The main frame is assembled, the tray, and this week I worked on the head, which seems to have the most problems.

For the most part, the material is soft enough to mash into the correct positions.   The snap connectors are quite robust, even with large misalignments!   Great work Johnathan!

To raid the junk box, and reduce expense, I am looking at using found motors, etc.    For the positioning I am thinking:

Use a cable system for positioning similar to an old radio dial.
Use leadscrews I have laying around.
Order the expensive leadscrews from McMaster Carr.

I plan on replacing the head with something more universal to allow mounting other tooling for other purposes.

I don't have bearings, so those I have put on order this morning.

Videos of Johnathan explaining some stuff to the group are here:
(They are currently uncompressed... so they may be big!)

And photos of me beating on plastic:
beating plastic into position

Final Project Thoughts:

My initial interests are in low cost rapid prototyping techniques, and modular machine building/automation. Neil expressed that I should have a concrete end goal/design in mind, instead of a platform to build machines on, and a bunch of building blocks.

Three concrete applications that come to mind:

1. Miniature electronics assembly machine:

A small pick and place machine
Possibly adding solder dispensing, component placement, and board soldering.
Optionally, extend it to mill the board also.

References:
Board milling: MTM
Pick and place: open pick and place project homemade pick and place using aluminum angle CNC Mill turned pick and place
Board Soldering:

2. Object copier

Build out the rotary 3D scanner. Add a printing or carving machine, or additive machine to it (i.e. use MTM snap or another)

3. Machinable Wax Recycling Machining Center

We milled the wax, which can supposedly be reused. Add an attachment to a Modella class mill to catch the grindings, and form a new block in which to mill.
Alternatively instead of milling, look at an additive approach that uses recycled material.

Board milling: MTM
3D Printers: Utilimaker Reprap Makerbot
Material Recycling: HDPE for plants College Project

Near Term Approach:

Many of the above use the same underlying mechanisms. So:

Build/debug motor drivers that can be used for positioning.
Integrate some motors into a mechanical x-y-z type assembly.
Write code to send cad or other pc source to table.
Final decision on application.
Order any necessary parts.
Build end effector(s) depending on final application or supporting materials for end application.
Build controller for end effectors/tooling
Write PC code to send data to the device.

   Bask in success and watch it make things. :)

   The focus in the above is on the high level application.   For that reason I may combine some pre-assembled slides, or other mechanisms to compress development time for this initial prototype.

Notes:
   Video player to try when I get a chance: http://www.longtailvideo.com/players