Hi,
I was having trouble getting my circles to come out of circles. Once I'd rechecked all my steps/mm and sorted out an eccentric X axis pulley, I turned my attention to lash (using Skeinforge Lash plug-in)
I've used a lash calibration object from Thingiverse (Here: [
www.thingiverse.com], and also here: [
www.thingiverse.com]) and I've now got good results. I'm finding my circles are correct within approx 1 mm (over a diameter of 40mm) but I'd like to try and really tie it down.
The problem I have is that both the lash calibration objects involve quite small measurements. Instead of a 20mm cuboid with hole I'd like to be measuring, say, a 80 mm cuboid so my measuring error isn't so important. However, I don't really understand the theory involved, so can't work out the new lash figures.
The 20mm cuboid calculations require this:
- x-backlash = (measured object width + measured hole width - 30) /
4
(30 is the what the object width and hole width add up to be in a perfectly printed object)
But if I just scale everything up by 4 (80mm cubiod, 40 mm hole in centre) is my new calculation this?:
- x-backlash = (measured object width + measured hole width - 120) /
16
??
It's the "4" and "16" I don’t understand.
- Why was "4" the correct number for the 20mm cuboid?
- Is just scaling up to "16" correct for a 80mm cuboid?
Any illumination would be a great help
Thanks
Pete