One man's epic journey to create a personal 3-dimensional printer
without breaking the bank.
Thursday, September 3, 2009
Welcome to The Pit of Despair!
As I mentioned earlier, my build chamber will be 8 ½ x 11 x 10 inches. The supply bin will be half that size. There will also be a small chute (henceforth known as “The Pit of Despair”) so excess powder can be collected . I chose to construct the bins out of some 12 inch wide melamine shelving which I salvaged. I hate cutting large pieces on the table saw and these were already the right width. I only had to cut them to length which made it much easier to keep them “square”. Also, they don't need painting or sealing. I had a problem with the clearance on one side of the printer. The printing area started about ¼ inch from the cartridge cleaning/parking station. I solved this by topping that side with a piece of aluminum angle.
For the platforms I used more of the melamine shelving. I edged the platforms with felt weatherstrip. This seems to slide nicely on the melamine and should give me a good enough seal. I might have some leakage at the corners but if it's a problem I can always remove the platform and vacuum it out. I used roller skate bearings on the build platform and where the poles exit the bins. I used Teflon sliders on the supply bin because they were cheap and I don't need the same precision on the supply side. The pole is a piece of galvanized conduit which I attached with some pipe fittings and set screws.
The lead screws and nuts I removed from automotive jacks. I figured if they could lift a car they would be more than sturdy enough. A trip to the junkyard netted me 2 jacks for $5. What a deal! (It did take me a couple hours with a hacksaw to remove the screws and nuts so maybe it wasn't that great a deal) A while back I picked up 2 surplus steppers with gearboxes from www.allelectronics.com. They were like $15 each and I couldn't pass them up. I'm glad I didn't because they are perfect for this project. The gear ratio is 18:1 so there is plenty of torque to lift the heavy bins full of plaster. It took a little Macgyvering to attach the screws to the gearboxes.
Now that the bins are complete, they need to be installed under the printer.