Re: [CAD_CAM_EDM_DRO] Maybe OT, reprap build started

Thanks, but those URLs serve only to illustrate my point. For example, the
"schematic" on the extruder page is actually a picture of a schematic (a
.png file) which shows only the pinouts of the major components of the
board. It does not show how they are interconnected, nor is it complete. In
short it is useless, a pretense. Same thing for "source code." You can find
things like test programs to drive the extruder at a constant rate or to
read the thermocouple, but nothing non-trivial. By far the most space is
devoted to instructions on assembling the PCB. This "open source" project is
nothing more than a thinly disguised marketing program. Nothing wrong with
selling, but to do so under false premises is, in my opinion, despicable.
Technical aptitude or not, a liar is still a liar. (NOTE: I'm not calling
YOU a liar. I don't know who is behind the false claims. It's a matter of
principle. It's unethical.) These web pages look at first glance like a
trove of valuable information, but they are really little more than a sales
pitch. I'll withdraw my assertion when somebody shows me something
substantial that is useful without first buying something from the
promoters.

--Phil M.

----- Original Message -----
From: "Kevin Martin" <kpmartin@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Saturday, October 08, 2011 6:42 AM
Subject: RE: [CAD_CAM_EDM_DRO] Maybe OT, reprap build started


> Our extruder is described at
> http://reprap.org/wiki/Wade%27s_Geared_Extruder which is actually one of
> the better-documented parts of the printer.
> The electronics are described at
> http://reprap.org/wiki/Generation_3_Electronics/Tech_Zone_Remix
> The individual boards are described in pages linked to from
> http://reprap.org/wiki/Generation_3_Electronics, for instance our extruder
> controller 2.2 is described at
> http://reprap.org/wiki/Extruder_Controller_2.2
> The firmware is described at http://reprap.org/wiki/Generation3Firmware.
>
> That being said, all the stuff we have is at least a year old, and
> verifying that the above documents (which may refer to more up-to-date
> stuff) are still relevant to us is difficult. For example I thought we has
> the )optional) Thermocouple Sensor 1.0
> (http://reprap.org/wiki/Thermocouple_Sensor_1.0) but it turns out that our
> thermocouple sensor uses a different chip, one designed for monitoring
> NiMH battery charging. The board circuit is different but the board
> interconnect is the same. A firmware change accounts for the difference in
> the data generated by the two thermocouple controllers.
>
> Calibration (or lack thereof) is one of my major complaints about the
> whole field. There are calibration/tuning parameters wired into the source
> code, so to adjust them you have to load new firmware. Which requires
> building new firmware. Which requires being absolutely sure you start with
> the correct source code for the firmware you already have.
>
> Has anyone make up some tables for ...? Probably yes. Can you find their
> results? Maybe. Can you be sure their results are applicable to your own
> setup? Thanks to the versioning mess, probably not.
>
> -Kevin Martin
> the Papertrail Handmade Paper & Book Arts
> New Dundee, Ontario
> 518-884-7123
> www.papertrail.ca
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Phil@Yahoo
>
> Glad to hear that. So can you share some URLs? I'm not talking about
> drawings for bits of plastic, but about PCB schematics and microprocessor
> source code for things like temperature controllers. Also I'm wondering
> how
> to calibrate the extrusion speed to the head motion speed. Has anyone made
> up some tables correlating filament size with temperature and extrusion
> speed and nozzle size and head travel speed? That's where the important
> knowledge is if you don't want to re-invent the wheel. Moving things in
> X-Y-Z is the easy part.
>
>