Bill of Materials

I work for UTA and I'm building the cartesian robot but when I look at the bill of materials one thing I notice missing is a summery of items or part description. This would be helpful to know total length of rod needed, or all bolts in one location to make ordering easier.

Also a link where you could purchase these would be nice.

If one doesn't exist I would be willing to create one.

I also had a question what is "Foot spacer"? or "Capa".

Also on moulding your own gears why not add buying some as an option. I'm sure they can be found and cheap.

I'd like to see answers to most of these too -- although, I haven't yet read the whole site, so it may be there somewhere!

I do know that capa is a new material that's being tried out -- it's a polymer made from starch -- a clear plastic-like material, that's more capable (shapes can be made from it "through the air", without much supporting structure underneath), and potentially can be made from plants that you grow, unlike plastics like Polymorph. There are some pictures of this in the blogs.

I think Zach is working on a SQL databse for the BOM which would more easily allow us to generate summary views of the materials, etc. I don't know the current status on that work though. I suspect no-one wants to take the time to generate summaries manually, when the more automated, database-driven approach is "coming soon".

There is a brand new RRRF store at [parts.rrrf.org] which will (in time) sell many of the needed parts, kits, etc. It's great to see this getting started.

As for why make your own gears... the "Rep" in "RepRap" means replication -- so (as I understand it) making your own *everything* is a basic design goal, as much as possible anyway :-) Buying a kit or manufacturd gears or whatever will make it easier for some builders, but ensuring the thing is replicable is a big part of the whole experiment. Minimizing the number and complexity of "external" (non-replicable-by-RepRap and a human with a minimal set of hand tools) parts needed to build a RepRap machine is therefore very desirable and very positive for the project, even if it increases construction time for each individual builder compared to buying more pre-made parts.

Jonathan

actually, CAPA is a low melting point plastic, known as Polymorph, or Friendly Plastic in the states.

as for the other one... its probably some small part. i agree we should have more informative things up on the wiki there.

Two thoughts:

(1) Links to images of each part would be very cool. Or inline images if sufficiently small?

(2) Links to one (or more) supplier web pages for each part would be neat too.

As we (you!) start to put together "kits", adding this sort of info might be reasonable doable? You'll know where you bought the part (link to supplier page), and you'll have one to photograph with a digital camera, so you can add an image of it!

Maybe the SQL BOM database parts table needs fields for image filename, and a related supplier table that includes a URL field which can link to a specific web page at that supplier about that part? Then, auto-generating the Wiki BOM page becomes "a simple matter of programming" :-) :-)

Jonathan

ZachHoeken Wrote:
-------------------------------------------------------
> actually, CAPA is a low melting point plastic,
> known as Polymorph, or Friendly Plastic in the
> states.
>
> as for the other one... its probably some small
> part. i agree we should have more informative
> things up on the wiki there.

OOPS. Sorry, yes, I was mixing CAPA up with PLA, I think.

Am I making the same mistake as Leeb in thinking that Capa is Polycaprolactone? Am I also wrong in thinking '... its probably some small part.' shouldn't really be the reply of a researcher building the thing?
Was considering doing it myself but with the BOM thread going only this far...can someone please just tell us all about their experience doing it/where can I find a basic outline/tutorial?

Steve, Lee's mixing up Capa with polyactic acid (PLA). CAPA is probably identical to Polycaprolactone, but either no one's asked the manufacturer or they're not telling.

I believe so far the best was also the first. Adrian assembled the first Darwin directly from the instructions on the main site (check the main blog). It apparently went smoothly without any real trouble spots. I don't believe this included the extruder head, however.