tag:blogger.com,1999:blog-6231145519414010443.post7046811397646021468..comments2014-08-14T04:07:32.995-07:00Comments on Theodleif's Reprap Zone: Warping - Some FindingsTheodleifhttp://www.blogger.com/profile/00403715154016713362noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-6231145519414010443.post-45926984281182284412013-01-07T00:08:16.013-08:002013-01-07T00:08:16.013-08:00I've resolved this issue by lowering the headb...I've resolved this issue by lowering the headbed temperature from 80 to 55 degrees. I print at the lowest temperature possible, usually 185 degrees. This totally reduced any warping. I clean the mirror with a mixture acetone/water and wipe them dry till they fell quite tacky. On large objects with small footprint I add a skirt layer without a distance to the object. Called brim in slic3r. This adds additional adhesion. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6231145519414010443.post-53664697111029505332013-01-02T11:27:45.093-08:002013-01-02T11:27:45.093-08:00i have had the same experience with warping. Setti...i have had the same experience with warping. Setting first layer temperature to the same like the others solve it. <br />Now i dont have any warping effects in my prints.<br /><br />I am printing PLA on Glass with HBP 60 degrees.<br /><br />Thanks for share your experience in your blog. <br />It saved many of my nerves :-)Comihttps://www.blogger.com/profile/11431075923932430250noreply@blogger.comtag:blogger.com,1999:blog-6231145519414010443.post-60534433743733232792012-12-23T17:21:17.408-08:002012-12-23T17:21:17.408-08:00Well, after looking through a lot of p-v-t diagram...Well, after looking through a lot of p-v-t diagrams of polymer plastics I am afraid that I missed your point.<br /><br />For an amorphous polymer like ABS the change of volume below Tg (glass transition temperature) is less than above. Shouldn't we expect warping forces to be higher above Tg then?<br /><br />For a crystalline polymer the case is very different. Crystallization depends (among other factors) on the cooling rate. The p-v-t diagrams have some very non-linear parts around (Tg + Tm)/2 where the crystallization mainly takes place. But they do not change much around Tg.<br /><br />The literature isn't very clear about if PLA is to be regarded as amorphous or crystalline. <br /><br />But in both cases it is not clear to me why you believe that warping takes place only below Tg. Theodleifhttps://www.blogger.com/profile/00403715154016713362noreply@blogger.comtag:blogger.com,1999:blog-6231145519414010443.post-46585193709487575042012-12-19T13:51:23.677-08:002012-12-19T13:51:23.677-08:00It is only the shrinkage from the glass transition...It is only the shrinkage from the glass transition down to room temp that causes warping. From the deposition temperature to the glass transition the plastic shrinks but it isn't hard, so doesn't stress the layer below. <br /><br />So when you reduce the deposition temperature it doesn't reduce the shrinkage that matters, which explains why it didn't get better.<br /><br />I suspect it warped more simply because each layer cooled quicker so started exerting force on the layer below sooner.<br /><br />nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.com