SoliForum - 3D Printing Community — Precise dimensions?

Re: Precise dimensions?

2013-10-08T06:19:38Z

Thanks everyone! I have ordered some calipers and will start doing this.

Re: Precise dimensions?

2013-10-07T23:26:01Z

Do the steps/mm calibration after you know the flow rate is right (extrusion multiplier). You don't want to be using steps/mm to chase after an over/under extrusion problem, so dial that in first.

Re: Precise dimensions?

2013-10-07T22:54:45Z

The calibration process 2n2r5 means (I think) refers to the X Y and Z settings in the Firmware EEPROM settings, which you can find in Repetier-Host.

The technique is pretty simple. You print an object of known size (the nickle ring, or a cube like http://www.thingiverse.com/thing:45225), and then measure it carefully in all three dimensions, making sure you keep track of which dimension is which before removing it from the print bed. (Mark the front face with a Sharpie, for instance.)

Then you figure out a scaling factor that would convert its actual size to its intended size. For instance, if it's supposed to be 25mm and it printed at 26mm, the scaling factor is 25/26 or 0.961538. You do this for each of the three axes.

Then open the EEPROM settings and find the X, Y, and Z steps per mm:

Write down the numbers there, then multiply them by the relevant scaling factor, and put those numbers in their place.

Then print again. Rinse and repeat until it's as precise as you want it to be.

Re: Precise dimensions?

2013-10-07T22:51:00Z

Dimensions in X and Y will be affected by the amount of extrusion, so you need to make sure that if your extrusion width is set to .42mm, that it is actually extruding .42mm walls. You can verify this by printing a hollow cube with walls 1 perimeter thick. Vertical dimensions need to be evenly divided by the layer height, or they will be rounded. Also if you are squishing the first layer to get it to stick, the overall height will be shorter by a portion of the layer height. You can avoid that by setting the Z home to be where the nozzle just touches the bed, then set the extrusion width for the first layer to something like 200%.

Re: Precise dimensions?

2013-10-07T20:25:55Z

http://www.thingiverse.com/thing:84795 try running through this calibration process

Precise dimensions?

2013-10-07T20:20:24Z

I am printing a multi-part complex object with precise dimensions. I find that my Solidoodle 2 prints everything just a little too big using ABS (.2mm) so that I am having to sand the objects, or resize them in Sketchup using trial and error which uses lots of time and plastic.

Does anyone know a cure for this? Perhaps a multiplier that I can scale my dimensions so it will print a precise dimension? Or a setting in Slicer?