Discuss all sorts of topics relating to fabrication: from techniques to tools to materials used. http://dev.forums.reprap.org/list.php?70 Sat, 21 Nov 2009 04:51:43 -0800 Phorum 5.2.11 http://dev.forums.reprap.org/read.php?70,30222,30222#msg-30222 http://dev.forums.reprap.org/read.php?70,30222,30222#msg-30222 Hello,

please, how suitable is PLA for surface treatment? I mean, if I would like to make the surface smooth, is it possible e.g. to rub it with a sand-paper?

Ecir Hana]]> Ecir Hana Fabrication Tue, 17 Nov 2009 09:10:07 -0800 http://dev.forums.reprap.org/read.php?70,30069,30069#msg-30069 http://dev.forums.reprap.org/read.php?70,30069,30069#msg-30069
I'm a French student studying the DMLS process and I'm very interesting in what are you saying, but I need some help.

I know that DMLS machines tend to be hard to set and position work accuratly. There are two main issues associated with accurate work location on DMLS machines:

* The build platforms upon which the metal is sintered do not have any form of positional location to the main build chamber within the sintering machine.

*The datum point for the laser in not known. The laser has a home position that is based on the positioning of the mirrors that reflect the laser beam into the build chamber.

So I'm looking for a procedure to allow the datum position of the laser to be measured and thereby related to the position of the fixture.

Thank you]]> Sofienne Fabrication Sat, 14 Nov 2009 09:17:32 -0800 http://dev.forums.reprap.org/read.php?70,30040,30040#msg-30040 http://dev.forums.reprap.org/read.php?70,30040,30040#msg-30040 original McWire was to mill circuit boards. I've been following the instructions for the McWire Cartesian Bot on the RepRap site, which built on the McWire design, and which is apparently generalized for RepStraping purposes and not necessarily for milling circuit boards.

My question is, can I use the RepRap host software to mill circuit boards, which is essentially a subtractive process, rather than building up an object layer by layer? Any tips for configuring the host software to do this?]]> Matt Gilbert Fabrication Fri, 13 Nov 2009 21:26:18 -0800 http://dev.forums.reprap.org/read.php?70,29780,29780#msg-29780 http://dev.forums.reprap.org/read.php?70,29780,29780#msg-29780
I've contacted the designer and found her quite interested with offers of samples etc. but as I haven't built my reprap yet I can't do very much. There's a 'drop-in hackwarium' on Saturday 14th in Bethnal Green which might be of interest to someone.

www.sugru.com
www.formerol.com

-adrian (a different one)]]> agodwin Fabrication Sun, 08 Nov 2009 05:20:17 -0800 http://dev.forums.reprap.org/read.php?70,29305,29305#msg-29305 http://dev.forums.reprap.org/read.php?70,29305,29305#msg-29305
Thanks in advance.]]> jeffpark_ Fabrication Thu, 29 Oct 2009 12:32:15 -0700 http://dev.forums.reprap.org/read.php?70,29304,29304#msg-29304 http://dev.forums.reprap.org/read.php?70,29304,29304#msg-29304
I am one of the founders of contraptor.org I thought about reaching out to the reprap community to show you guys our progress and possible reprap applications.

The framework is all easily made from local hardware stores or can be bought pre-made.

This is a dremel based CNC mini router we have tried out.

I am in the process of designing a contraptor compatible extruder however I have not got a chance to pickup the new version (2.2?) hardware yet. Anyhow, I just wanted to reach out and tell the community about our progress and I hope we can possibly work together soon.

ril3y
contraptor.org
]]> riley porter Fabrication Fri, 13 Nov 2009 00:12:37 -0800 http://dev.forums.reprap.org/read.php?70,29303,29303#msg-29303 http://dev.forums.reprap.org/read.php?70,29303,29303#msg-29303
Murray]]> murd Fabrication Fri, 30 Oct 2009 16:19:09 -0700 http://dev.forums.reprap.org/read.php?70,29100,29100#msg-29100 http://dev.forums.reprap.org/read.php?70,29100,29100#msg-29100
Where can you buy it?

PLA doesn't seem to available anywhere. Makerbot doesn't have it, and BitsFromBytes doesn't either. Where can you get PLA???]]> ziplock Fabrication Wed, 11 Nov 2009 13:02:52 -0800 http://dev.forums.reprap.org/read.php?70,28272,28272#msg-28272 http://dev.forums.reprap.org/read.php?70,28272,28272#msg-28272
Utilizing the DMLS process, metal parts of the most complex geometries are built layer-by-layer (down to 20 microns) directly from 3D CAD data, automatically, without tooling. The parts have excellent mechanical properties, high detail resolution and exceptional surface quality. The process melts the metal powder entirely, creating a fine, homogenous structure.

Benefits

DMLS enables the formation of cavities and undercuts which, with conventional methods, can only be produced with great difficulty, if at all. Additionally, when a part needs to be tested and re-designed over and over, the lead time for receiving a traditionally tooled part can create a large bottleneck in the final production process. Previously, casting the part was the only traditional means of bypassing this process. However castings had limitations and depending on the functional needs of the prototype, a cast part could possibly fail if performance tests are desired on the prototype.

Now, GPI reduces the design phase timeline from weeks to days for the delivery of parts, allowing time for multiple redesigns and builds. Depending on size and geometries, in some cases the turnaround time for a part can be as little as a few hours. Furthermore, these parts can undergo functional testing in the environment for which they were designed. This technology opens up the ability for designers to imagine the impossible solution, because it is now possible with DMLS.

DMLS AND PROTOTYPING LINK CLICK HERE TO LEARN MORE]]> Tim Ruffner Fabrication Fri, 13 Nov 2009 02:01:28 -0800 http://dev.forums.reprap.org/read.php?70,28207,28207#msg-28207 http://dev.forums.reprap.org/read.php?70,28207,28207#msg-28207 www.nasa.gov]

is there any way we could see something in that direction in future models?
I know there were some plans on Metal printing. But melting a wire with an electron beam sounds like a creative idea.]]> mostley Fabrication Mon, 12 Oct 2009 19:17:14 -0700 http://dev.forums.reprap.org/read.php?70,28073,28073#msg-28073 http://dev.forums.reprap.org/read.php?70,28073,28073#msg-28073
[gonplastic.en.made-in-china.com]

We might pick up strength and lose some warping (or gain some! testing...), but I do expect higher rates of erosion in nozzles.]]> SOI Sentinel Fabrication Tue, 29 Sep 2009 08:34:18 -0700 http://dev.forums.reprap.org/read.php?70,27834,27834#msg-27834 http://dev.forums.reprap.org/read.php?70,27834,27834#msg-27834 At first I thought I modelled my bits wrong, then I though it might be a problem with Skeinforge.
Now after several hours I think that the Ponoko template is somehow scaling stuff up.

I created a simple 10mm cube and copy pasted a layer into another document, and printed it out with a regular printer, as this is what I found to be the actual size of what is laser cut.
when I paste the same layer into the Ponoko template, it gets scaled up, and i've gone though InkScape up ad down, I can't see why it would do that.
Anybody got a clue?]]> Grogyan Fabrication Tue, 20 Oct 2009 21:40:56 -0700 http://dev.forums.reprap.org/read.php?70,27430,27430#msg-27430 http://dev.forums.reprap.org/read.php?70,27430,27430#msg-27430 RyanHendrickson Fabrication Sat, 12 Sep 2009 04:21:02 -0700 http://dev.forums.reprap.org/read.php?70,27272,27272#msg-27272 http://dev.forums.reprap.org/read.php?70,27272,27272#msg-27272
Couldn't it be possible to use PET as feedstock for newer RepRaps? Everyone can get it very cheap and as it seems it's very similar to PLA being used for developing the new RepRap.]]> JoR Fabrication Mon, 21 Sep 2009 11:29:41 -0700 http://dev.forums.reprap.org/read.php?70,27143,27143#msg-27143 http://dev.forums.reprap.org/read.php?70,27143,27143#msg-27143
I'm trying to build a full mechanical Reprap.
Full means that there is no computer : programming is mechanic too !

My firsts drawings show that the strength of materials might be a problem.
I have to check it : I'll do it first in my computer (Bubuntu).

What "easy to use" free software do you prefer for CAD ?

Thanks.]]> RedGuff Fabrication Mon, 19 Oct 2009 22:39:54 -0700 http://dev.forums.reprap.org/read.php?70,27142,27142#msg-27142 http://dev.forums.reprap.org/read.php?70,27142,27142#msg-27142
During the print, I saw the machine walking around the boundary of the object without extruding. I think it's the "orbiting" mentioned in the doc? (I don't know what does it mean yet)

What the purpose of doing orbiting?]]> sam0737 Fabrication Mon, 21 Sep 2009 17:05:36 -0700 http://dev.forums.reprap.org/read.php?70,27044,27044#msg-27044 http://dev.forums.reprap.org/read.php?70,27044,27044#msg-27044 www.inhabitat.com] that there is talk of conductive adhesives. I wonder if these would be useful in the never ending quest to enable RepRap to build itself - and in particular to build circuit boards and attach components to them.

David]]> davidgoodenough Fabrication Sun, 04 Oct 2009 12:19:39 -0700 http://dev.forums.reprap.org/read.php?70,26480,26480#msg-26480 http://dev.forums.reprap.org/read.php?70,26480,26480#msg-26480
The plan is to make a spar out of a cylinder of mylar and foam to put braces on. Any suggestions would be very nice.]]> RyanHendrickson Fabrication Fri, 11 Sep 2009 18:47:27 -0700 http://dev.forums.reprap.org/read.php?70,26181,26181#msg-26181 http://dev.forums.reprap.org/read.php?70,26181,26181#msg-26181
I was asked to print a series of models that show various computational stages of a 3d object. The models a very bulky so suitable for printing, the only problem is overhangs. I have been trying with Skeinforges support setting but cant find satisfying parameters. Anyone has tips on using Support material? Temperature settings for ABS etc.

Thanks for the help!]]> unfold Fabrication Tue, 11 Aug 2009 11:52:28 -0700 http://dev.forums.reprap.org/read.php?70,26027,26027#msg-26027 http://dev.forums.reprap.org/read.php?70,26027,26027#msg-26027
[www.tapplastics.com]

Does anyone know of any other suppliers in the US or have experience with TAP products (quality, service, etc.)?

-jeff]]> jeffpark_ Fabrication Thu, 29 Oct 2009 15:20:32 -0700 http://dev.forums.reprap.org/read.php?70,25985,25985#msg-25985 http://dev.forums.reprap.org/read.php?70,25985,25985#msg-25985 www.solutions4plastic.co.uk]

Did someone already the idea of using this material for support ?

I don't have a RepRap yet but I am starting to gather part to make one.]]> lcomtois Fabrication Thu, 06 Aug 2009 09:08:42 -0700 http://dev.forums.reprap.org/read.php?70,25894,25894#msg-25894 http://dev.forums.reprap.org/read.php?70,25894,25894#msg-25894 Wade Fabrication Wed, 05 Aug 2009 12:49:40 -0700 http://dev.forums.reprap.org/read.php?70,25675,25675#msg-25675 http://dev.forums.reprap.org/read.php?70,25675,25675#msg-25675
I know little about thermoplastic processing, and I'm curious about what materials, finishes (and mold release compounds?) are used to let the molded part come out of the mold, without such a fight that the parts or mold are damaged. Are the molds "simply" highly polished metal? or do they have some special coating that thermoplastics don't stick to very well. Similarly, if one wanted to roll/squeeze one prismatic solid into another size/shape cross section (think of wire drawing), what material/finish could be used to make a die or rollers that the plastic wouldn't stick tightly to?

I'll do some googling, but I thought I'd query the group in parallel.

FYI, I'm interested in exploring how to recycle scrap plastic into either usable structural shapes (e.g. bars and plate stock.) and/or as an alternate path to creating filament. Somebody (Forrest?) demonstrated that melting scrap in a shallow pan resulted in a solid layer with few voids. That sems to get around the (major problem of) transforming scrap (or granules) into a bigger, void-free solid. This is a slower process than one-step injection molding, but in a bootstraping, distributed reprap economy, speed isn't as important as reducing the barriers to entry.

So perhaps filament could be made in a series of steps:

ground scrap => solid plate => sticks or spiral coil => roll/draw sticks into filament.]]> Larry_Pfeffer Fabrication Thu, 30 Jul 2009 20:15:38 -0700 http://dev.forums.reprap.org/read.php?70,25625,25625#msg-25625 http://dev.forums.reprap.org/read.php?70,25625,25625#msg-25625 [www.thingiverse.com]
[www.thingiverse.com]

How is this done? I tried printing a replacement screw for a Fisher Price activity center but the thread is a complete mess. Which is btw very logical since it is in fact a very low angled overhang...
Is this done with support material?]]> unfold Fabrication Sat, 01 Aug 2009 03:10:41 -0700 http://dev.forums.reprap.org/read.php?70,25543,25543#msg-25543 http://dev.forums.reprap.org/read.php?70,25543,25543#msg-25543
Threaded rod costs a lot more that solid rod. The BOM for the Cartesian bot calls for 7612 mm of threaded rod, most of which is used in the diagonal braces, where the threading is only needed at the ends for adjustment. So, can one just get a $10 die and mild steel and thread the ends of the rods for the diagonal braces? Any problem I am not seeing with that? This is my first reprap. Does any one know what diameter rod you need to thread with M8 die?

thanks reprappers,

Guy]]> Guy Fabrication Sat, 31 Oct 2009 23:32:28 -0700 http://dev.forums.reprap.org/read.php?70,25236,25236#msg-25236 http://dev.forums.reprap.org/read.php?70,25236,25236#msg-25236
They sure know how to do a lot with a little.

[redalyc.uaemex.mx]

Especially cool that it can handle surface mounts (claims downto 0.5 mm but I wonder if my banana fingers could do that)

In the paper they mention that threading the wire was the most time consuming part.

After the threading you would scrape the insulation on the component side and then just solder the components.

I was thinking, maybe a toolhead with an insulated copper thread could "sew" its way somehow or maybe one could make small "bows" and use the regular toolhead to glue the bowed thread, making the plastic sheet as you go.]]> mimarob Fabrication Tue, 21 Jul 2009 11:59:08 -0700 http://dev.forums.reprap.org/read.php?70,25002,25002#msg-25002 http://dev.forums.reprap.org/read.php?70,25002,25002#msg-25002
there's a google group named aerogel @ [groups.google.com]

the world needs some "open source aerogel" :)]]> jdp Fabrication Sun, 26 Jul 2009 13:28:49 -0700 http://dev.forums.reprap.org/read.php?70,24971,24971#msg-24971 http://dev.forums.reprap.org/read.php?70,24971,24971#msg-24971
Who are the best sources of the sticky stuff in theses geo-locations?
(very ambiguous question) How much sticky stuff can I expect to use on a 5 x 5 x 5 cm model?

Many thanks in advance!]]> Tjam Fabrication Tue, 14 Jul 2009 02:08:50 -0700 http://dev.forums.reprap.org/read.php?70,24862,24862#msg-24862 http://dev.forums.reprap.org/read.php?70,24862,24862#msg-24862
Could someone advise me how to implement a 2 minuite or so cooling period after the base layer is printed. As mentioned in nopheads post; [objects.reprap.org]
I can manually pause the print on the rapman, however the heater turns off during this period and molten plastic drips from the extruder, meaning it really needs to do the whole startup sequence again.
I imagine this could be done by directly writing gcode, im not sure how to add a pause in gcode for a specified amount of time?
However i am trying to print off many 100's of test pieces, small 3cmx3cm rafts, and so an automated way of adding in the cooling time would be much better.

The aim is to ultimately publish the results, including on the arxiv.org. As it seems that so far, all the materials research on fused deposition modelling has been done internally by the engineering companies who design the commercial 3d printers.
Ill be making another post about this in more detail soon- as id like to upload some .gts files of some tensile test strips (ASTM D638-IV) and get the community to produce some to there best ability and mail them to me, i will then have an info on the average ability of the reprap design as a whole. By the way this is with the polymer physics department at Leeds University.
Thanks
John Mooney]]> QIX_Leeds Fabrication Wed, 22 Jul 2009 20:16:08 -0700 http://dev.forums.reprap.org/read.php?70,24532,24532#msg-24532 http://dev.forums.reprap.org/read.php?70,24532,24532#msg-24532
I browsed onto this that sounds ideal.
[www.patentstorm.us]

Its a thermoplastic that sounds like it can be extruded like any other, plus its water soluble.

This is just one method, what are others?]]> Grogyan Fabrication Fri, 26 Jun 2009 15:05:18 -0700