tag:blogger.com,1999:blog-23681518.post6645316650471222242..comments2023-10-14T04:05:08.546-07:00Comments on Diary of a Technocratic Anarchist: Printing light structuresForrest Higgshttp://www.blogger.com/profile/17208965471464716174noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-23681518.post-15252169840524950072010-03-07T08:30:48.101-08:002010-03-07T08:30:48.101-08:00Your truss idea is very interesting.
Is there a r...Your truss idea is very interesting.<br /><br />Is there a reason that the truss is a square in cross section instead of an equilateral triangle?Anonymoushttps://www.blogger.com/profile/06836846334307803624noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-71972108073848369482010-03-03T18:50:16.265-08:002010-03-03T18:50:16.265-08:00Howard23: I read over your blog entry and there&#...Howard23: I read over your blog entry and there's nothing at all to be ashamed of in it. You described exactly what you did and took excellent photographs to reinforce your descriptive text. I wish more people were as careful in their blogging as you obviously are.Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-27348857977174069282010-03-03T15:23:23.695-08:002010-03-03T15:23:23.695-08:00Well, you asked it. This will be my first blog. Do...Well, you asked it. This will be my first blog. Don't be too rude with me :o)<br /><br />Here we go...<br /><br />http://eudireprap.blogspot.com/2010/03/self-threaded-m3-nut-in-pla-filament.html<br /><br />Regards,<br /><br />Álvaro Deibe Díaz.howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-18427167536855593212010-03-03T13:51:33.515-08:002010-03-03T13:51:33.515-08:00This comment has been removed by the author.howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-47098660697476749582010-03-03T09:44:04.974-08:002010-03-03T09:44:04.974-08:00Howard: Blog it and send us a link! :-)Howard: Blog it and send us a link! :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-46956046323377828892010-03-03T09:29:37.544-08:002010-03-03T09:29:37.544-08:00I've been playing with some M3 nuts and PLA fi...I've been playing with some M3 nuts and PLA filament.<br /><br />First I threaded one end of a 300 mm long PLA filament, with an M3 die. Then added an M4 washer, and hanged the filament from the nut and washer, in a vice, and added weight to the other end of the PLA. The thread failed at 18kg (~40 pounds).<br /><br />With the thread made by the die, the nut screwed in the PLA very softly, so I assumed the die cut too deeply into the plastic. So I used the M3 nut to directly make a new thread in the PLA. This time the nut screwed much more tightly.<br /><br />Again, adding weight to the filament, hanged from the washer and nut, the PLA failed at 18kg. But the nut keep firmly screwed there. The fail was on the other end of the PLA! (the weight was hanged from an "o" made with the PLA filament; that placed too much stress in it). It seems like the thread can keep up to the tensile strength of the filament.<br /><br />I think it is easily possible to hang 20-25 kg from the PLA filament, keeping it straight, and pressumible more from ABS (I can't test this, though).<br /><br />If my numbers are right, your 40 cm long and 3 cm width beam, post tensioned with four PLA filament, one in each column, could hold a point load of around 7 kg (~15 pounds), or more from ABS.<br /><br />I have some photos to illustrate the "hanging", but I don't see how to include them...howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-32867903329433063902010-03-02T19:58:47.123-08:002010-03-02T19:58:47.123-08:00The raft is typically used to secure a tighter con...The raft is typically used to secure a tighter connection between the print object and the print table. It also serves to level out small variations in the print table surface.Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-38808109421094567402010-03-02T15:54:17.187-08:002010-03-02T15:54:17.187-08:00hey there, is it possible to use a sheet of paper ...hey there, is it possible to use a sheet of paper as the base as opposed to weaving the bottom layer? or is there another reason you have that thin layer at the bottom?Amr Malikhttps://www.blogger.com/profile/15709188003839003040noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-61181911500057737372010-03-02T14:36:49.095-08:002010-03-02T14:36:49.095-08:00I look forward to hearing how it works for you. :...I look forward to hearing how it works for you. :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-36180652802038143092010-03-02T14:28:02.735-08:002010-03-02T14:28:02.735-08:00Well, our Darwin has only minutes of life. We are ...Well, our Darwin has only minutes of life. We are tweaking it to try to get the first useful piece. At the moment, we have rafts, blobs, wasted plastic, broken extruders, you know...<br /><br />But I can try to thread an M3 nut over the end of a piece of our PLA tomorrow. I'll post a comment.<br /><br />:o)howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-72961987156947679602010-03-02T14:19:22.124-08:002010-03-02T14:19:22.124-08:00I see what you are saying, now. I wouldn't th...I see what you are saying, now. I wouldn't think that that would work. There is only one way to be sure, though, and that is to try it and see for yourself. Fortunately, having a Darwin you can do that. :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-49793627978014823922010-03-02T14:17:50.038-08:002010-03-02T14:17:50.038-08:00> How you plan to put it
> tension escapes m...> How you plan to put it<br />> tension escapes me, though.<br /><br />I thought that, perhaps, threading one M3 nut directly at each end of each plastic rod would be enough. The inside diameter of an M3 nut is around 2.6mm (and our PLA rod is 2.8-2.9mm width).<br /><br />The idea would be to have one piece of 3mm plastic rod trough the holes of each of the four corners of the structure. Each rod could be tensioned with two nuts, one screwed directly at each end of the rod.<br /><br />Not sure if my english will be up to the task...howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-46514394220027013132010-03-02T13:58:56.834-08:002010-03-02T13:58:56.834-08:00I designed it for a nice friction fit. The studs a...I designed it for a nice friction fit. The studs at the top fit into sockets on the bottom. It works fine. Once it is post tensioned it won't come apart until you remove the post tensioning rod. :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-35616833811146346452010-03-02T13:54:46.959-08:002010-03-02T13:54:46.959-08:00Very cool Forestt. How were you thinking you'...Very cool Forestt. How were you thinking you'd permanently attach two of these together? Some form of adhesive? Or some kind of mechanical catch that would snap together and then require much greater force to remove?BeagleFuryhttps://www.blogger.com/profile/03121457223922721364noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-68460038386126000482010-03-02T13:47:16.284-08:002010-03-02T13:47:16.284-08:00Hi Alvaro,
I've been using very thin threaded...Hi Alvaro,<br /><br />I've been using very thin threaded rod ~3-4 mm centrally located to do the post tensioning. The columns are hollow. I just checked and the void is only about 2 mm. The module could be sized up a bit to accomodate a 3 mm ABS filament I suspect. How you plan to put it tension escapes me, though.Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-61542526030111802692010-03-02T13:36:02.956-08:002010-03-02T13:36:02.956-08:00If the four posts are hollow (I think they are), w...If the four posts are hollow (I think they are), would it be possible to use four lengths of 3mm ABS (or PLA, or whatever you have in hand) to thread and post-tension each of the four posts in the final structure?<br /><br />Less vitamins, less parts to buy, cheaper... perhaps one M3 nut in each end of each 3mm rod could be used to adjust the tension.<br /><br />Oh, I'll introduce myself: I am Alvaro Deibe Diaz, from Spain. We are begining to (try to) print things with our first Darwin. We have, also, a beatiful set of plastic parts to make a new Mendel.<br /><br />Regards.howard23https://www.blogger.com/profile/07841577716159675301noreply@blogger.com