SoliForum - 3D Printing Community — What is the best thing to print to measure calibration?

Re: What is the best thing to print to measure calibration?

2014-03-02T20:14:28Z

I made my own which I used to test for everything from wall thickness (extrusion width), to layer height, to circle roundness. Here is the link to the post, and the related files:

http://www.soliforum.com/post/48513/#p48513

Re: What is the best thing to print to measure calibration?

2014-03-02T19:18:57Z

http://blog.mcmelectronics.com/post/3D- … e_Sj5vD-Uk

Use this, it's the nickle test.

Re: What is the best thing to print to measure calibration?

2014-02-28T14:27:11Z

For X-Y, the thing that worked best for me was printing my electronics fan cover. The large size means that quite small calibration errors will result in the holes for the screws not being in the right spots. Small calibration cubes or coin holders and such don't show up small calibration errors.

Re: What is the best thing to print to measure calibration?

2014-02-28T03:10:30Z

Well, about 1% thermal shrinkage is reasonable, so that brings a freshly solidified '110mm' object down to about 109mm at room temp. Something else is going on if you've got 106.

Have you changed the steps-per-mm at any point? Your difference between small and large dimensions looks like a fixed error has been cancelled out with a proportional solution - e.g. outer layer thickness a bit more than the slicer setting, mechanical backlash (there will always be a little bit!), under- or over-extrusion, etc. Note also that a good-looking, sticky, well-filled and reliable print might not always mean the most dimensionally accurate one.

Consider calibrating anything proportional (e.g. steps-per-mm) to a large (100mm?) object (assuming the steppers are well-tuned, and the print isn't trying to run too fast), and see whether it improves. The small objects might be a little less accurate though, as the natural fixed error you have will be back and rather big-looking at that level.

If it was me, I'd be making a big version of the bottom layer of that pyramid (20 steps or so) and making a chart to see what the fixed/proportional/random components of my error were in x/y, and whether they were the same or different, to round down where the problem is likely to be...

What is the best thing to print to measure calibration?

2014-02-27T16:10:52Z

I've been using the 5mm calibration steps pyramid (the thing that looks like a q-bert arena) and my x and y measurements seem to be as close to design as i can get them. Withing .06 mm + or -. If I try to make larger objects, the hundredth of a mm multiplies. I printed the step cube @ 2x and it was off by 1.5 to 2 mm. I tried to print an attachment to the aluminum bed and it was off by 4 mm. Needed 110 mm and it printed the length @ 106). any advice?