Not to scale

My printouts are not coming out to scale. The length and width are produced to scale, but the heights of the printout is shorter than it should be. It is supposed to be 2" tall and coming out roughly 1.75" tall. What is causing this? Thanks.

 

Do you have a bottom cover on your printer with Z smooth rods that run to the top lid?

If so you should be using the Z steps value of 2560. This can be changed in the EEProm settings in mattercontrol or flashed with a firmware.

 

The EEProm settings get reset whenever you turn off your machine, so the permanent fix is to flash the firmware. Reply to Mike's question about the bottom cover and we'll help you find the firmware. He posted a link to it in another thread titles something along the lines of "How do you upgrade your firmware?" If it has the bottom cover, you're looking for RoBo3DR1V2. You'll need to install the Arduino software, open the Configuration.h file, and in there, there are parameters for steps/mm that look like (80, 80, 22XX, XXXX). Change the 22XX to the 2560 Mike recommended.

From what I've tested the 80, 80 are pretty accurate, but you can test this for yourself by moving the extruder to any point, measuring the distance against the threaded rod holders with some calipers, then telling the software to move the extruder on the X-axis by say 100mm, then remeasuring the distance and seeing if the calipers say it's moved by 100mm. I just found this out yesterday. The y-axis is a little harder since I haven't really found a good consistent spot to measure it against, but the same concept applies. If your calipers say the distance is less than the software said it moved, increase the steps/mm for that axis. If the distance is greater, decrease the steps/mm. I think the equation should be something like this newSteps=(actualResult/expectedResult)*currentSteps. So if you move it 100, but it moves it 105.3 with the default steps, you'd do (105.3/100)80 and get 84.24. Replace the 80 with 84.24 and try again. This same process can be applied to the z-axis.