Re: [CAD_CAM_EDM_DRO] Maybe OT, reprap build started

Thanks for your candor. This finally tells me what I really wanted to know,
and allows me to conclude without regret that I will not at this time
attempt to build a 3D printer. It pretty much confirms my initial
impressions. The machine probably works mostly but would require far more
attention and tweaking than I care to spend on it, even if I get the
"approved" hardware. Looking at the documents I saw the packet based
communications protocol for use between the control software (ReplicatorG, I
presume) and the dedicated controller board. I can't fault the developers at
RepRap and Makerbot for making the electronics and software proprietary.
Nothing wrong with protecting one's intellectual property. I can fault them
for claiming that it is "open source." That is simply a lie. It's the same
tactic used by a lot of open source software projects. Technically the
source code is published but there is always some missing piece or the code
is so convoluted that it is effectively useless to anyone but the insiders.
There are lots of ways to do that, and you can even find software designed
specifically for that purpose. The whole concept masquerading as some sort
of great humanitarian breakthrough is really just a way to get people to
work for nothing. The truth is that the guys at RepRap and Makerbot would
rather not have anyone building 3D printers without buying the parts from
them. Again, nothing wrong with that, it's the American way. I simply don't
want it badly enough to pay their prices. These machines look like a great
next step for kids moving up from Lego Mindstorm or the like, or for
hobbyists wanting to tinker with CNC, but the existing designs would put me
on a proprietary treadmill I don't want to get on. The lack of support for
RS274/NGC or any industrial standards I can see makes it too susceptible to
getting jerked around by people whose interests don't align with mine. But
the discussion has been interesting and informative.

--Phil M.

----- Original Message -----
From: "Mike Payson" <mike@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, October 09, 2011 11:45 PM
Subject: Re: [CAD_CAM_EDM_DRO] Maybe OT, reprap build started


> On Sun, Oct 9, 2011 at 11:10 PM, Phil@Yahoo <yahoo@...>
> wrote:
>>
>> 1. How tempreature and feed rate is regulated in RepRap.
>
> Temperature depends on the material being printed. I typically print
> 1.75mm PLA filament at 170c, and ABS at 200c. 3mm filament requires
> higher temperatures, and different plastics or formulas of those
> plastics (or even different colors) can require higher or lower
> temperatures. Feed rate depends on the printer. Speeds from 20mm/sec
> to 300mm/sec are possible.
>
>> 2. What sort of protocol is used to control temperature & feed (simple
>> on/off?)
>
> Depends on the firmware. Most use simple on/off, but some use PID.
>
>> 3. Minimum requirements for a 3-axis machine to be used for 3D printing
>> with
>> available CAM software & Mach3 or EMC2.
>
> It is possible to use EMC, and presumably Mach3 as well, but it is
> generally not recommended. Most people will be happier driving the
> printer with one of the dedicated boards that have been mentioned
> earlier in the thread. Those boards get far more development and
> support. If you try to use EMC you are pretty much on your own (there
> is a small community of users, but probably under 5% of total reprap
> users).
>
> Among the advantages of using the dedicated electronics is that you
> can run the printer off any PC, you don't need a parallel port, and
> you can use your printer for other things while you are printing, you
> don't need to worry about screwing up your print (I am printing now
> and have about 20 programs running and a ton of browser windows).
>
>> 4. How to minimize the odds of being bitten on the butt if I start
>> building
>> support hardware.
>
> The answer to this is basically the same as above-- your best bet is
> to stick to the standard hardware. Things change rapidly, but we do
> try to maintain compatibility with older hardware for as long as
> possible. There are some changes that cannot maintain compatibility--
> for example the next gen electronics will run on a whole new processor
> architecture (ARM Cortex-M3 instead of AVR), but the old electronics
> are going to remain usable for quite a while still (we are in a very
> different position now, then when we changed from Gen3 with DC
> extruders to the new stepper extruder electronics. Future improvements
> will be directed primarily at usability, but the general functionality
> is not likely to change with the new electronics).
>
> These probably aren't the answers you were looking for, but they truly
> are the best advice. I wish I could give you more advice on using EMC,
> but I have not really paid attention to it. Googling for "EMC RepRap"
> provides a bunch of information, so I will leave it up to you to dig
> deeper.
>
>