Go Down

Topic: dual PID temp control with lcd. (Read 1 time) previous topic - next topic

I am working on a conversion to use my sherline desktop CNC mill as a 3d printer.
I have an arduino mega rev2 board waiting for use and I am looking to design a dual temp monitoring pid system for controlling the hot end as well as the heated bed independent of the controller software. I have a 2x16 LCD and a rotary encoder as well as a good selection of momentary buttons for the user interface, I can get mosfets and thermisters as well as the heating elements or power resistors locally. I just have no clue on the code. Any help on this project would be much appreciated.

thanks.
Kevin G.
NSR Customs.

astrofrostbyte

I think most of this has been done already, take a peek at http://reprapbook.appspot.com/  or anything else google gives with : Arduino 3D printer.
Gear: Arduino- Uno,Due,Ethernet,  OLS, Buspirate, J-Link, TDS1002, Rigol DG1022

CoolJ

There is a pretty nice PID library already for the arduino.
http://playground.arduino.cc/Code/PIDLibrary
http://brettbeauregard.com/blog/2011/04/improving-the-beginners-pid-introduction/

If you don't need to measure temps over 300F, the LM34/35 monolithic temp sensors can save a lot of work. They are linear and will likely interface to the arduino with no additional hardware.
http://www.ti.com/lit/an/snoa748b/snoa748b.pdf
I don't know if they meet your requirements but, if you can use them, they save a lot of work. They can even be used with cheap DMMs for a direct temp readout.

Think about what you need the arduino to do.
1. Measure temp. (trivial)
2. Control resistive based heater relative to sensor feedback. (I assume)

I once did the same with analog hardware components to control a desktop mini fridge. If I had known about arduino then, it would have been a whole lot easier.

You could probably even get by with a simple high low switching setup and get by.

#3
Feb 26, 2013, 12:18 pm Last Edit: Feb 26, 2013, 12:20 pm by rockwallaby Reason: 1
I am pretty sure for a 3D printer you will be well advised to use a P, PI or PID control loop to control the temperature of your extrusion head heating element. Probably best to use a sensor that is fast and rugged as it will be right on the extruder if I recall. Possibly use a PT100 type RTD and bring that into some suitable electronics to feed an analogue input on an Arduino.

Try to find out if anybody else has converted such a CNC as yours for use as a 3D printer, as you can learn what difficulties they encountered.
I am sure there will be plenty of good reading to be had on the 3D printer forums to gain more insight.
paul alting van geusau

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy