tag:blogger.com,1999:blog-4339813531032979196.post4943264319644054254..comments2024-02-28T07:32:59.864+00:00Comments on HydraRaptor: Polyholesnopheadhttp://www.blogger.com/profile/12801535866788103677noreply@blogger.comBlogger23125tag:blogger.com,1999:blog-4339813531032979196.post-767625962474384762023-11-19T02:07:21.004+00:002023-11-19T02:07:21.004+00:00Congrats on this making it into Orca Slicer!Congrats on this making it into Orca Slicer!ZorroBytehttps://www.blogger.com/profile/05489977845469480348noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-57411292612198783402013-04-06T09:17:01.712+01:002013-04-06T09:17:01.712+01:00I'm working on python scripting for Alibre Des...I'm working on python scripting for Alibre Design and I have baked in a polyhole function. Works nicely! See: http://www.britishideas.com/2013/04/06/scripting-polyholes-in-alibre-design/Andyhttps://www.blogger.com/profile/00507413948629417217noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-22259576134770936172012-03-03T21:55:43.866+00:002012-03-03T21:55:43.866+00:00I hacked OpenSCAD today for cylinder() to optional...I hacked OpenSCAD today for cylinder() to optionally take ir= ir1= ir2= inner radius, doing the same cos() calculation to set up vertecies that outline facets which are tangent to a circle of some inner radius.<br />Hopefully I'll get this patch cleaned up and submitted to the maintainers soon.Brian Olsonhttps://www.blogger.com/profile/06258128480111746553noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-66106751300847734142012-03-03T21:53:34.241+00:002012-03-03T21:53:34.241+00:00I wrote an extension to OpenSCAD today so that cyl...I wrote an extension to OpenSCAD today so that cylinder() can take ir= ir1= ir2= for internal radius. It does the same cos() computation to go from the near part of the facet tangent to an inner circle to the vertex positions that it normally describes.<br />Hopefully I'll get this patch cleaned up and submitted to the OpenSCAD maintainers soon.Brian Olsonhttps://www.blogger.com/profile/06258128480111746553noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-5565799192153488762011-12-18T10:42:07.876+00:002011-12-18T10:42:07.876+00:00Well if that was the case the internal square woul...Well if that was the case the internal square would come out the right size. Since is doesn't one of your assertions must be false. Either that or the version of SF you are using has a bug not present in the version I am using. <br /><br />There is no difference mechanically when drawing an internal or external square. The only thing that affects the dimensions differently is the filament width.<br /><br />You can rule out SF by checking the figures in the gcode. The external movements should be the original dimensions - 0.6 and the internal ones plus 0.6. Then both internal and external dimensions should be a little bit too small due to shrinkage when the plastic cools.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-25355748424186092852011-12-18T10:14:06.967+00:002011-12-18T10:14:06.967+00:00Thanks. my axes are calibrated to true position, n...Thanks. my axes are calibrated to true position, not edge if a print. If I place a 25cm ruler on the hotbed, and align 0mm with the hole of the nozzle, then ask "pronterface.py" to travel 25cm, I'll get exactly there - my hardware is calibrated by movement, not extrusion. Extrusion width is .6mm , same as measured width, and Extrusion height is 0.4mm.ANDhttps://www.blogger.com/profile/10449234216532082808noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-44212047515400274762011-12-17T23:21:12.853+00:002011-12-17T23:21:12.853+00:00Round holes come out too small for the reasons sta...Round holes come out too small for the reasons stated above. If internal squares and hexagons come out too small you are probably extruding filament that is wider than SF thinks it is. I.e. the flow rate is a little high. <br /><br />If the outside dimensions are correct it could be because you have calibrated your axes to compensate for the extra outline thickness and the shrinkage due to thermal contraction.<br /><br />The outside dimensions are the distance the axis travels plus the filament width reduced by the shrinkage (usually about 0.5%). The inside dimensions are the distance the axis travels MINUS the filament width reduced by the shrinkage. That is how you can have one correct but not the other.<br /><br />By measuring inside and outside (or a big object and a small object) and solving simultaneous equations you can separate the two errors.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-24192802480776084042011-12-17T22:35:56.653+00:002011-12-17T22:35:56.653+00:00Hi, thanks for interesting article.
please take a ...Hi, thanks for interesting article.<br />please take a look at this post: http://forums.reprap.org/read.php?154,109845,110409#msg-110409 - and the attached picture.<br /><br />- I too don't actually get it, why outer dimension is so perfect, and the inside is so bad..ANDhttps://www.blogger.com/profile/10449234216532082808noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-11566925136007683062011-06-07T17:36:57.868+01:002011-06-07T17:36:57.868+01:00I am not sure SF can do the kind of correction I u...I am not sure SF can do the kind of correction I use. The stretch module will make holes bigger I think, but it seems to distort things like hexagons according to the documentation. I have never tried it.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-36639947725485732812011-06-07T15:31:12.831+01:002011-06-07T15:31:12.831+01:00Chris (nophead),
Can you supply the answer as to ...Chris (nophead),<br /><br />Can you supply the answer as to what SF setting to adjust to print a hole to drawing/STL dimension? My holes and interior features are too small but exterior is good. http://www.thingiverse.com/thing:8285<br /><br />Thanks ---BAShttps://www.blogger.com/profile/11712266694307971483noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-10565944631670475072011-04-01T13:45:11.288+01:002011-04-01T13:45:11.288+01:00Ohh... I see, Cos(pi/n) is the shrinkage at the mi...Ohh... I see, Cos(pi/n) is the shrinkage at the midpoint of the segment... it would all be just fine if the midpoint of the segments were on the circumference, then your pi/2 segment length would work for anything more or less.. but your point was about the polygons being circumscribed and shrinking the hole size... dur.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-62102542640883630442011-04-01T13:37:35.525+01:002011-04-01T13:37:35.525+01:00"I think for large holes the length of the si..."I think for large holes the length of the sides tends to pi/2 but it is less for small holes, so no."<br /><br />It does seem that it is a linear issue, based on your own formula of 2x diameter... as for small holes, I don't understand your "no"<br /><br />but it does seem that a 1.6 mm minimum segment length in STLs could be used for most holes, even non-circular holes... does it follow or did I miss something?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-16961302670166478572011-02-12T09:25:42.841+00:002011-02-12T09:25:42.841+00:00Hi, nophead,
I keep coming back to your blog every...Hi, nophead,<br />I keep coming back to your blog every couple months when I get excited about building my own 3D printer and am always faced with the same conundrum: How do I find the latest, "best" design that you have without reading back through all your posts? Sure would be nice if you had an "index", that pointed to the latest design for each component, e.g., extruder, filament driver, table heater, etc.<br />Any hope that you (or some ambitious librarian) could provide something like this?<br />Thanks for all the great ideas and explorations,<br /><br />Mike<br />Palo Alto, CA, USAmikew67https://www.blogger.com/profile/04148419058550270162noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-24602116208747152782011-02-10T16:05:45.880+00:002011-02-10T16:05:45.880+00:00Why is it, when I get a bee in my bonnet about a n...Why is it, when I get a bee in my bonnet about a nophead post, I come to post comments and after typing about 3 pages of argument and counter argument it all becomes clear and I delete it all and say "Good work there nophead".. ;-)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-79389549405200687492011-02-10T12:34:34.996+00:002011-02-10T12:34:34.996+00:00I think CoCreate is script-able with LISP, so it s...I think CoCreate is script-able with LISP, so it should be possible but I have no idea how you enter and run scripts.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-27594322433484493882011-02-10T11:36:24.517+00:002011-02-10T11:36:24.517+00:00Thanks, nophead. Your explorations are great!
Btw....Thanks, nophead. Your explorations are great!<br />Btw., do you know any possibility in CoCreate (i'm using it, too) to port/use your transition scripts from OpenSCAD?Juppinoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-30673423714495962592011-02-07T19:54:31.375+00:002011-02-07T19:54:31.375+00:00I think the reason you are seeing a lot less shrin...I think the reason you are seeing a lot less shrinkage on your holes is due other printers suffering from a phenomenom where the first few mm (or more) of an extruded path is thinner than predicted in software. This tends towards a lack of inter-layer adhesion during the path and results in the corner-cutting being exagerated. A non-reversing extruder oozes as its not extruding, the barrel pressure drops as a result and all that gives a delay before expected extrusion rate begins. Oozebane is intended to compensate for this but very few people seem to bother trying to get it dialed in. I'm now running a stepper driven extruder and am having to re-adjust, although I think I'm now getting more accurate hole sizes.The Ruttmeisterhttps://www.blogger.com/profile/11935089208942075361noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-50159319734537153622011-02-06T05:29:20.702+00:002011-02-06T05:29:20.702+00:00Awesome with this I can do function like "acc...Awesome with this I can do function like "accurateHole" which will be based on your findings :-)prusajrhttps://www.blogger.com/profile/02516166336988590257noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-10611289206391727942011-02-06T05:02:38.245+00:002011-02-06T05:02:38.245+00:00Great post, as always :) but it solves only the op...Great post, as always :) but it solves only the openSCAD design. <br /><br />I still believe the solution need to be embedded into slicer rather then designing STL to fit the printer. I was playing with stretch plugin in Skeinforge for a while and when calibrated properly, I can "in most cases" get "almost all" holes to have exactly the designed size (so if your hole in STL is 8mm you will measure 8mm hole on printed part). Now looks like either Enrique changed the plugin a bit or my heated bed is too important variable but I can't get it right since I reactivated my heated bed and got this new batch of ABS..<br /><br />b.Bogdan Kecmanhttps://www.blogger.com/profile/09655477648123886945noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-51240441702912483592011-02-05T22:26:58.902+00:002011-02-05T22:26:58.902+00:00Your documentation and method of problem solving i...Your documentation and method of problem solving is outstanding!! Thank you for sharing your work in such a consise way it is very much appricated.Anonymoushttps://www.blogger.com/profile/11790019375326311849noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-45681708631100206132011-02-05T20:04:40.613+00:002011-02-05T20:04:40.613+00:00Chris!
You've really answered a lot of ques...Chris! <br /><br />You've really answered a lot of questions I had about this very problem. Thanks!Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-79067578078247354592011-02-05T19:16:27.576+00:002011-02-05T19:16:27.576+00:00I think for large holes the length of the sides te...I think for large holes the length of the sides tends to pi/2 but it is less for small holes, so no.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-8907505983749753472011-02-05T16:48:29.832+00:002011-02-05T16:48:29.832+00:00Is it possible that keeping a fixed side length $f...Is it possible that keeping a fixed side length $fs achieves a similar effect, if you scale the radius appropriately ?Mhttps://www.blogger.com/profile/05279969393617122722noreply@blogger.com