Tuesday, February 21, 2012

Success and Disaster!

I have been unable to resolve my endstop issue so I will probably remove them and go to the limit switches which I have already tested and found to work fine.  In the meantime I decided to go ahead and test the machine without them by manually setting the home position and editing the G-code to remove the homing instructions.

Success - I managed to print a part on my second try.  The first time I set the extruder position too high and it simply sprayed the filament into a big pile even though it was moving correctly in the X and Y.  I still had it positioned about one millimeter too high on my second try but it created the outer shell of the part correctly.  The infill did not fare so well.  Since there were many quick movements and changes of direction the  filament did not have time to drop into position before the hot end moved. and the holes in the part were blocked by a mass of filament caused by the suspended thread being dragged over the hole before it dropped into place.  They could be drilled out however so I am counting it as a success.  Very big day and I was extremely happy.

Then the Gremlins arrived.  When I adjusted the height again and started the third print it stopped dead in the middle of the first layer.  I found that the green LED was no longer lit on the Sanguinololu and I got a message on the workstation: "USB port has exceeded voltage limits".  Now everything is dead so I believe that something has been blown on the main board.  Whenever I plug in the USB I get the "Exceeded Voltage" message and nothing happens.  Maybe a short?  One other disturbing symptom - When I power up the 12v supply the mosfet down by the thermistor connectors becomes immediately hot enough to burn my finger, and I mean immediately, like from cool to burning in less than a second!

So I may have a trashed main board.  Need to do some more troubleshooting but I am too depressed right now.  At least I actually printed something so that is progress.

Wednesday, February 1, 2012

Hardware Complete!

This is a real milestone for me.  I believe that all the hardware is finally working properly so I only have a couple of software issues to resolve. 

I replaced the endstops last night with a set of spares that I had bought with the original Techzone electronics.  I always figured that I would burn out one or two and they were cheap so I bought a full set of replacements.  These are slightly different from the ones I am replacing.  They have LED's on them so I can see that they are getting power and are working properly.

Unfortunately they don't seem to be doing anything.  It makes no difference whether the optical signal is interrupted or not.  I can jog all three axis in both directions even with a card inserted in the endstop.  I think that this is an issue in the setup in Sprinter so I am going to look through the configuration code today.

I also need to reinstall Pronterface since it won't load an STL file.  This shouldn't be a big deal since I have confirmed that my other computer, on which I also installed Pronterface, can load them just fine.  I probably messed up the install of one of the several apps that Pronterface depends on so I will clean it all out and start the install from scratch.

As a final note I should mention that I started working with Sketchup 8 this week.  I downloaded a free addon that allows import and export of STL files and I have been able to create a couple of fairly simple part files for items that I would like to print.  I found it simple to learn and easy to use.