Saturday, March 26, 2011

It's Alive! Alive!

Great progress. The Reprap software is running properly on my laptop, it is talking to the main board which is talking to the stepper controllers. All 3 axis are now moving although I have a problem with the Z axis. It only moves up, not down. I think that the belt is too tight so I will do some troubleshooting tomorrow. I have started to assemble the extruder and, since I have a week off now, I should be extruding plastic within a few days.


Thursday, March 17, 2011

Great Joy in Mudville!

Good news. My new main board arrived from Techzone yesterday and I immediately sequestered myself in the fortress of Solitude (formerly the daughter's playroom) to check it out.

I plugged the USB/ITE cable in and, with breathless antici..........pation, compiled and attempted to download the firmware. It was apparent from the start that something new was going on since the red LED began blinking along with the steady green one that I have been seeing all along. The board behaved exactly as described in all the online resources and the firmware loaded successfully. The red LED then settled down into a steady 1 Hz blink just as it should.

So, long story short, I had a bad board. I don't believe that the board was bad when I received it. There were a set of check marks on the back indicating that it had passed all the testing prior to shipping. I think I may have sent some current through it incorrectly when I was figuring out how to wire everything up. Techzone was not the culprit here, just my own clumsiness (again).

I have a long weekend now so I hope to work out all the remaining small things and have the beast up and running by Sunday. As long as family responsibilities don't get in the way. Amazingly, my wife has been very understanding, and tonight she actually referred to the Mendel as my "Happiness Machine" when I was coming down here to work on it!

Tuesday, March 15, 2011

Big News! AdderFab!

The University of Washington has become a major source of innovation in the use of powder bed printers with new and inexpensive materials. Professor Mark Ganter and his students have been experimenting for several years and have produced some amazing results. Today they tease us with the announcement of something really fantastic - the AdderFab 3d printer. It is a powder bed printer using an off the shelf HP print cartridge and assembled using fabbed parts which are very similar to Mendel parts.

From their video it is apparent that AdderFab prints quite slowly at the moment but Mark says that they will be working over the next few months to speed it up before releasing the design as an open source project. Most of the home built printers of this type have used the whole X-carriage from a commercial inkjet printer which has both advantages and disadvantages. On the upside the X axis movement can be handled by the existing printer carriage hardware but it also means that every printer has a unique design if it uses a different printer as its' parts source. The design of a standard X carriage, once the bugs are worked out, will make this design much more reproduceable.

This is exactly what I was planning on doing as my next project after I got the Mendel working. Of course, with my limited engineering skills, I would not have produced anything as nice as what I see from the Open3DP group so I will be happy to build their design and avoid having to figure things out on my own.

Having both machines raises the possibility of creating items that are assembled of parts printed in multiple materials - plastic parts from the mendel and ceramic or glass parts produced by the AdderFab.

Monday, March 7, 2011

Some Progress But ...

I have managed to make a bit of progress but I still don't have the electronics working properly.

I lost a couple of weeks on other projects. I upgraded all of the PC's in our house to windows 7 (except for my trusty HP tablet which will stay on Ubuntyu Linux) and fought my way through the various issues that cropped up. Then I moved my entire shop from the large family room in the basement to our spare bedroom. The room was used as a playroom by our daughter but, since she is now 16, it is available for other purposes. It took a couple of days to get everything moved and organized but I am finally ready to proceed.

I sat down last night and worked on the firmware again. I had been using version 22 of the Arduino IDE but the various forums recommended going back to version 18 to solve my problems. As soon as I started using the earlier version I had some success. Both the G-code Interpreter and the Extruder firmware compiled immediately.

I was able to load the extruder firmware onto the board and it was really satisfying to see the green LED's start flashing as it was running. This proves that my USB board and the 6 wire cable that I made up are both working correctly and that the IDE is able to communicate with the board using that path. Unfortunately none of this made any difference when it came to loading firmware on the Sanguino board. All I get is a steady power light when I plug in the USB cable. When I attempt to upload the firmware I get a messages from the IDE that indicate that everything works fine but there is no indication that anything is getting to the board. The power light stays green but there is no flashing or blinking to indicate that anything is loading or running. No amount of playing with the reset switch has any effect at all.

I was interrupted last night and didn't get time to do much experimenting so I will try again tonight and see what happens. In any case, I am getting closer to having a functional machine.

Also, I ordered a couple of additional motor controller boards (I fried one) and some additional opto-endstops. If I don't fry any of my endstops I can use the new ones on my next project.