RE: [CAD_CAM_EDM_DRO] Re: 3D Printing

> On 12/19/2012 2:02 AM, Tony Smith wrote:
> > DIY temperature control isn't worth the effort these days. I mean:
> > https://www.sparkfun.com/products/306, sheesh.
> >
> > Tony
> In keeping with the subject, the Reprap extruder and the heated build
> platform don't even use PID. I expected PWM modulation, but it is just
> sensed with a 100K thermistor and turned off and on.
> The Arduino does it, but a simple dedicated circuit would do it just as

well.

> It uses a cheap MOSFET as a current amplifier (can be thought of as a

solid

> state relay) to switch the power using the small logic signal from the

Arduino.

> I have seen electric skillets modified to use as heated build beds.

I thought they were a little bit fussier about temperature control. So it's
basically bang-bang control, same as some soldering irons, laminators or
even the skillets you mention.

They'll overshoot a bit, PLA isn't bothered by that much?

I used the DX PID on a powder coating oven, you need to have the temperature
within a few degrees for that. I could probably use that for PCB reflow as
well.

So for Mach3 you can have the PID and you need two control pins, or a DIY
using a few bits & pieces plus the Arduino.

Tony