Monday, August 24, 2009

Lots o Boards

The stepper controller boards arrived today.

Sunday, August 23, 2009

Back Added

I added a back to this to increase the side-to-side stability. It helped but not as much as I would have liked. Next up is adding motor controller board. The back can also serve as a mounting place to keep the PCBs out of reach when you are handling the bot.

Saturday, August 8, 2009

Electronics Melted

I have the motherboard working. I had 1 motor controller working. It melted. I saw silicon glowing red hot, and one of the pins melt. There was a lot of stinky black smoke in my bedroom. Not sure if the device was bad, the soldering job was bad or the motherboard was bad. It was the 12V supply that melted down. I need mother motor controller boards.
Here are some improvements that could be applied to the electronics:
-a fuse or some over current protection mechanism

Well this gave me a chance to improve upon the Green Monster's body; I am adding a back wall. The electronics will be safely hidden behind the wall.

Wednesday, July 29, 2009

Mechanical Parts Completed

WOW! That's about all I can say now. I threw together the Zstage and it looks great. It even holds up better than I expected. I was originally planning on putting two supports on the ends of the X rails to keep this from falling over but it doesn't look necessary now. As it is now this thing will have a range of 20" in the X direction, 16" in the Y direction and maybe 6" in the Z. The treaded rods are hanging down now, I need to translate those up to the top so I can access them with the motor. Also I've got some more room on the Z carriage if I go back to the laser.

In other news I got my motor controller working but only slightly, using the motors I "harvested" from a printer the controller only works with a supply from 6 to 8V. The power supply should be giving this 12V. I am going to try the controller tomorrow with some more "standard" motors. The motherboard is nearing completion. has a lot of good information.

well documented boards

Soldered up all of stepper motor controller. Used toaster oven reflow for the controller IC, not necessary spacing on pads very comfortable. Have not tested yet. Will test after oatmeal.
The motherboard I was getting ready to solder and The Dangler stepped in and asked me if he could do it. He wanted to show off for the lady in the room. (He stated that out loud.) The pictures shown here are his workshop and the finished product of the ICs on the motherboard. Very, very, very good work. THe final product of his soldering is pictured here also.

These boards are super well documented. I would like to make that clear. The circuit is easy to understand, and easy to assemble. I never looked at the documentation to solder up the stepper controller. I think that is a testament to the great documentation done by the RepRap team.

Tuesday, July 28, 2009

Z stage completed

Well almost, I need to attach the motor yet. I have not addressed where I'm going to attach the motor and what I will use for gears to spin the threaded rod. Perhaps acrylic?

Reaping the rewards of painful learning

"An expert is a person who has made all the mistakes that can be made in a very narrow field." -Niels Bohr
I made a lot of mistakes on the laser, and now I've got a pretty good handle on it. Yesterday I made a lot of progress on the laser and my acrylic Z axis, where do I begin?
Well first I quit my job on Friday, so I've had a lot of time to work on this project. It's still feel a strange feeling to not be busy doing something I don't like. I like this personal fabricator.
My parts from Makerbot came yesterday also after 4 weeks. I asked one of the founders to throw in two boards to make up for the mistake by throwing in two bare PCBs for the stepper motor controllers. They threw in two free PCBs, but they threw in the wrong PCBs!
Back to my Acrylic, I made this "capture nut" and press fit assembly to attach vertical and horizontal pieces. I made the gap to attach these 2mm larger than the material thickness; that was loose as a goose. I later made the gap the same dimensions as the material thickness and that works beautifully. It is a very tight fit, I had to do a little filing but once the pieces went in they were not going anywhere. I had a fear of the capture nut weakening the material, but 1/4" acrylic is very strong.

The picture here is the Z base with two press-fit supports attached using no capture nut, there is a nut in one piece but no bolt.