Saturday, March 29, 2014


I have been so extremely busy at work lately that I decided I needed to print something fun to take a moment and relax. I decided that I would print the featured thing on the thingiverse which was an elephant that is printed all at once but has 2 movable pairs of legs. Elephant . This was a great print. After it got started I decided to walk away for a while since it was going to be a few hours. When I came back this is what I saw. The print had "completed" and I was left with an open shell!

I was a little frustrated after having all that time pass and this was the end result. I then took a look at the Gcode file and sure enough it stopped at a height a few mm shorter than what it was supposed to be. I tried slicing the file a few more times and still ended up with the same/similar gcode file. What was going on?

I wasnt going to give up so I left the elephant attached to the print bed while I figured out a plan. My soft stops for the printer are set at twice the height of the print so that couldnt be the issue. There was just something wrong with the gcode. I never did find out the exact cause but I eventually got it to slice with the full length in the file. I then opened the gcode file for some editing. 

I measured the height of my print by stepping the nozzle up and down in pronterface until it just touched off the top of the print. I then took the gcode file and deleted all the lines of code (except the opening settings at the start of the file) up to the height that I touched off at. I then added a line of code to the starting line that made it move up to height higher than the elephant before it would move to the first print point on the file. 

After a few times of trial and error and adding and deleting sections of code to hone in on the correct height I was able to finish the print!

So you will notice the elephant is printed laying down. The legs are then able to be stood up due to the way they nest in the print. You can tell where it had messed up because the seem was shifted a little forward but it still finished the print. 

You'll notice how crappy my trunk looks. This is because of a known issue with my printer that I need to fix. There is a terrible amount of backlash in my extrusion gear. When it does a "suck" maneuver in the code the gear turns backwards. It then takes a few mm of material before the gear catches and starts extruding again. 

Time to print some new extrusion gears!