Hello all. Something is happening with my Reprap, and I can't explain it. Can you?
The specs: Mendel i2 with Ramps 1.4 running Marlin.
The background: I used Slic3r to get gcode that produced this cool gear bearing. (Thing 53451.) Slic3r produced gcode that delivered a high quality print in about 125 minutes.
Then, I replaced my printed pulleys and T5 belts with machined pulleys and GT2 belts. I updated my DEFAULT_AXIS_STEPS_PER_UNIT for x and y from 64 to 80.192. Using *exactly the same gcode* that was used above, I'm printing another gear bearing, but the print is going just ok, at best. The small perimeters (i.e. any gear teeth) appear to be printing as good as ever. The large circles around the outside, however, look a little sparse, as if there wasn't enough extrusion happening. I also have a gut feeling that these circles are going more quickly than they used to. That suspicion is buttressed by pronterface's shown time remaining. It's going to come in somewhat under 2:05. The size of the print is identical to the one I already have, so I think my steps per unit value is correct.
The mystery (to me, anyway): why should the steps per unit change have any impact whatsoever on the speed of the print, which was limited by various mm/sec and mm/sec^2 values in Slic3r and Marlin? Shouldn't that change be perfectly offset by my new pulley size?
Any advice or clues welcome.
Pics to follow.
The specs: Mendel i2 with Ramps 1.4 running Marlin.
The background: I used Slic3r to get gcode that produced this cool gear bearing. (Thing 53451.) Slic3r produced gcode that delivered a high quality print in about 125 minutes.
Then, I replaced my printed pulleys and T5 belts with machined pulleys and GT2 belts. I updated my DEFAULT_AXIS_STEPS_PER_UNIT for x and y from 64 to 80.192. Using *exactly the same gcode* that was used above, I'm printing another gear bearing, but the print is going just ok, at best. The small perimeters (i.e. any gear teeth) appear to be printing as good as ever. The large circles around the outside, however, look a little sparse, as if there wasn't enough extrusion happening. I also have a gut feeling that these circles are going more quickly than they used to. That suspicion is buttressed by pronterface's shown time remaining. It's going to come in somewhat under 2:05. The size of the print is identical to the one I already have, so I think my steps per unit value is correct.
The mystery (to me, anyway): why should the steps per unit change have any impact whatsoever on the speed of the print, which was limited by various mm/sec and mm/sec^2 values in Slic3r and Marlin? Shouldn't that change be perfectly offset by my new pulley size?
Any advice or clues welcome.
Pics to follow.