tag:blogger.com,1999:blog-23681518.post3392185411536437817..comments2023-10-14T04:05:08.546-07:00Comments on Diary of a Technocratic Anarchist: Sampo: The return of Darwin...Forrest Higgshttp://www.blogger.com/profile/17208965471464716174noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-23681518.post-88266010120106072962011-05-22T07:17:58.065-07:002011-05-22T07:17:58.065-07:00When you say that you can't get the extruder t...When you say that you can't get the extruder to "work properly", could you be a bit more specific?Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-5341775738953160532011-05-22T02:23:02.450-07:002011-05-22T02:23:02.450-07:00I have a bfb v2 kit, I have been struggling to get...I have a bfb v2 kit, I have been struggling to get the extruder to work properly, I'm giving up with it.<br />Now I'm looking for a compatible design, wich I can build without having a working reprap.<br />Any ideas appreciated.sanpedrohttps://www.blogger.com/profile/10540042539924369285noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-32730359423221155142011-05-10T12:25:37.103-07:002011-05-10T12:25:37.103-07:00I love the Sampo reference! wonderfully obscure.I love the Sampo reference! wonderfully obscure.Bubackhttps://www.blogger.com/profile/15400025861976580291noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-83046103879754168162011-04-27T18:56:53.399-07:002011-04-27T18:56:53.399-07:00LOL! I haven't put any grease on them yet. T...LOL! I haven't put any grease on them yet. They came with some light machine oil on them which has no lubricating effect whatsoever. I've greased xy and they work fine. I'll get around to z in the next few days. :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-41902798334428391502011-04-27T17:59:56.235-07:002011-04-27T17:59:56.235-07:00Great work. I do have a question... those linear b...Great work. I do have a question... those linear bearings on the Z slider rods .. how they hell are they suspended on the middle of rod .. they should be sliding to the bottom of the rod due to gravity itself .. maybe you put too much grease in them?Bogdan Kecmanhttps://www.blogger.com/profile/09655477648123886945noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-25306491045754699142011-04-27T11:48:39.890-07:002011-04-27T11:48:39.890-07:00The solution to avoid cracked parts when using Acr...The solution to avoid cracked parts when using Acrylic is to always have a softer material that the nuts bed into this also provides nut locking.<br /><br />A low cost thread-locking fluid is a pot of discarded nail polish/varnish they come with neat little brushes. Having 4 daughters it cost nothing to get a discarded pot of nail varnish.<br /><br />Else any $1 shop will have nail varnish if you have them in the USA.<br /><br />Or you could just use two half nuts if Nylocks are not easily avalible.<br /><br />I use Half nuts as they fit flush in a fixit block. Printed parts could also be designed to have a nut counterbore like a fixit block has.Anonymoushttps://www.blogger.com/profile/11790019375326311849noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-52664724907841181312011-04-27T10:48:02.480-07:002011-04-27T10:48:02.480-07:00Hi Forrest,
I've heard similar stories of Acr...Hi Forrest,<br /><br />I've heard similar stories of Acrylic machines falling apart. It's the main reason why the Ultimaker has only birch wood and Delrin. Delrin is much tougher for mechanical parts. Wood isn't as binary (under tightened or cracked) but has a wide range where you have a good mechanical bond without damaging the plywood sheets and bolt-heads will have enough friction without washers or anything. Much faster to assemble.<br /><br />I've never liked the PCB as structural part of the Mendel either. I've heard PCBs can damage during long periods of flexing. Of course many people solve this by putting a piece of MDF below it and reinforcing with that, but still, yu have very limited stiffness in the X direction compared to what is possible with Darwin with much less material/weight. Tall objects will become less accurate at the top when printing at higher speeds because they'll swing along (inertia of the printed parts), also, the moving head will still cause the X axis to flex.<br /><br />Forrest, I've made a part that allows you to make sure the Z-stage <br />isn't over constrained.<br />http://www.thingiverse.com/thing:1441<br />I'm sure you'll find a way to do this without adding another unique part.<br /><br />Putting the bed on 3 rods seems to me to be the better approach to prevent jamming of the Z-axis and and twisting the bed. I've had problems aligning the bed on both of my Darwins and on my second Darwin I converted it to this setup.<br /><br />It seems like you're going for serial kinematics? Will the X motor be stationary or stacked onto the Y axis? I would suggest making it stationary.<br /><br />B.t.w: I like how you've kept the part count low. Also allows for more attention can go into optimizing these building blocks.Erik de Bruijnhttps://www.blogger.com/profile/09433438819279256757noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-73708106082403501132011-04-27T09:23:00.065-07:002011-04-27T09:23:00.065-07:00The problem with Rapman is that it is made of lase...The problem with Rapman is that it is made of laser cut acrylic. Tighten the nuts too much and it cracks or shatters. I'm using printed parts on my new printer. Ordinary lock washers work fine on it. :-)Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-61352702343468705292011-04-27T09:13:10.389-07:002011-04-27T09:13:10.389-07:00Why not use some thread-locking fluid? I don't...Why not use some thread-locking fluid? I don't have a single nylock on my mendel, as I like to be able to take things apart without replacing the nuts.Anonymoushttps://www.blogger.com/profile/12435736504052277412noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-79002854971076568932011-04-27T08:24:05.570-07:002011-04-27T08:24:05.570-07:00Metric Nylocs are hard to come by here. :-(Metric Nylocs are hard to come by here. :-(Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-23681518.post-30345372614079947012011-04-27T08:02:43.748-07:002011-04-27T08:02:43.748-07:00"The net effect of this was that I keep a bow..."The net effect of this was that I keep a bowl beside my Rapman to collect the constant drizzle of nuts and bolts which unscrew themselves and fall on my work table."<br /><br />I replaced all the nuts that fell off with Nylocs. (locking nuts)The Editorhttps://www.blogger.com/profile/01641247429615484542noreply@blogger.com