matthiash 0 Report post Posted November 18, 2013 in Accuracy of printed parts Hello, I really enjoy printing with my new Ultimaker. Nevertheless I know observed several times that the scale of printed parts is not accurate. I m printing parts for a mechanical prototype, which should be mass produced out of aluminum next year. In the cad drawing the part has a size of 50 mm x 149 mm. When I imported the stl into cura the measures were still the same. Nevertheless the printed part had measures of 49 mm x 142 mm. I searched on cura for settings to maybe solve the problem but I couldn't. For me it sounds like a problem with the gcode, but I have no idea how to handle it. Did anyone observe the same problem? Would very much appreciate your help. Cheers, Matthias Share this post Link to post Share on other sites
illuminarti 16 Report post Posted November 18, 2013 in Accuracy of printed parts UM1 or UM2? Anything non-standard about it? You might see differences of a mm or less on X-Y dimensions due to shrinkage, etc. But 149 v 142 is way off from what you should expect. It seems like the steps-per-mm calibration is probably wrong in your firmware. Share this post Link to post Share on other sites
matthiash 0 Report post Posted November 18, 2013 in Accuracy of printed parts It is a UM1 standard, I m using it since last week, everything is standard. How can I adjust the steps-per-mm calibration in the firmware? Can the shrinkage be reduced by using a heat plate? Share this post Link to post Share on other sites
illuminarti 16 Report post Posted November 18, 2013 in Accuracy of printed parts No, heated plate might help if the shrinkage is causing the print to warp or crack - but that's usually only the case with ABS. It's just a fact of life that plastic shrinks slightly, and there's nothing you can do about it. Injection molding has similar challenges. Do you have an Ulticontroller? If so, look in Control -> Motion for the steps per mm settings, and report them back. If not, there's a gcode that shows the settings, but I'm not sure - maybe M503, but I'm not sure if that supported in UM1 standard firmware. Try sending that to the printer using Cura, Pronterface, or whatever you connect with. Share this post Link to post Share on other sites
IRobertI 428 Report post Posted November 18, 2013 in Accuracy of printed parts I think Pronterface spits those values (along with other config values) out as soon as you connect to the printer. Share this post Link to post Share on other sites
matengi 0 Report post Posted November 19, 2013 in Accuracy of printed parts Do the differences change after rotating the part 90°? The shrinkage is extremely unbalanced, 0.5% vs. 3.5%. Share this post Link to post Share on other sites
gr5 900 Report post Posted November 20, 2013 in Accuracy of printed parts In the cad drawing the part has a size of 50 mm x 149 mm. When I imported the stl into cura the measures were still the same. Nevertheless the printed part had measures of 49 mm x 142 mm. WTF? That's a typo, right? Seriously? If it really printed 7mm short then something is very very wrong. With heat off place a ruler on your bed. Move the test head to a postiion over the ruler and then move the test head 50mm. It should move 50mm. Not 48. Pronterface is a very useful tool for messing around - moving an axis 10mm at a time or whatever and for examining and changing the steps/mm values. Share this post Link to post Share on other sites
gr5 900 Report post Posted November 20, 2013 in Accuracy of printed parts If that was a typo then I have totally different advice... Share this post Link to post Share on other sites
