[SS2S-Main] Re: temperature controller with arduino

  • From: Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx>
  • To: "sugarshot@xxxxxxxxxxxxx" <sugarshot@xxxxxxxxxxxxx>
  • Date: Mon, 30 Jun 2014 10:57:01 +0200

Wow! This information is great. Tim, the spreadsheet is a great tool. Thank 
you. There is much information, so I need to sort the key concepts. 
- First, I have understood that for the isolation, the best material (and 
cheapest) is rockwool, right?. Does this serve? 
http://www.leroymerlin.es/fp/16658460/lana-de-roca-cloiselene-15-ud&idCatPadre=244052&pathFamilaFicha=3818
- With regard to the heating source, seems like a good idea to use a hair 
dryer, an air gun or even a bathroom dryer. With this, we avoid the need for a 
fan and a heat source separately. 
- It seems that the most important issue is to control the temperature. As I 
said at the beginning of the conversation, I have a PID and thermocouple. Can 
we use it? Lately, the team is not characterized by a time of economic booms, 
so we must save the maximum, as much as possible. 
Thoughts?
From: tyoung489@xxxxxxxxx
Date: Mon, 30 Jun 2014 00:23:55 -0700
Subject: [SS2S-Main] Re: temperature controller with arduino
To: sugarshot@xxxxxxxxxxxxx

Opps, 
I noticed that in the SS2S Curing Oven spreadsheet that you need to widen the 
width of column "J". 
Currently the value in cells J5 & J6 is 1.5 but because the column is too 
narrow so it is displaying the number 2. 


It shouldn't affect the calculations but it is confusing.


On Mon, Jun 30, 2014 at 12:00 AM, Tim young <tyoung489@xxxxxxxxx> wrote:






















Hello all,

First off have you looked into the
possibility of using an industrial oven at a local University or a local
Business?  They may be receptive to
helping out a grass roots project like this.

I
did some poking around & put together a little interactive spreadsheet of
Basic Oven Parameters. This will help you evaluate more than just this one
heating project.


(sorry all dimensions are USA, I put in some conversion info)

You can vary the:



   Interior Oven Dimensions 

  
Values for insulation (R Value & Thickness)

  
Starting Temperature

  
Maximum Temperature

  
Weight of product

  
Specific Heat of product

   Time to reach Max
Temperature

and it will tell you:

  
Watts to heat product

  
Heat loss in watts   Total Watts


   Interior surface area
in Square Feet 


NOTE: 

Total
Watts
= (Watts to Heat Product + Heat Loss Watts) x 1.6

This should account for Door heat
loss, Probe heat loss, etc.

If you are only going to build the
oven for this project, with the conditions you gave (80-C) you should be OK
using polyurethane or
polyisocyanurate rigid board for insulation. 
If you need to go to 200-C you should use Mineral / Rock Wool Batts (Not
loose wool).  You may find that the
mineral wool is less expensive than the foam insulation anyway. 

Vicente,
with the example you gave, there is very little wattage required for this 
project.

If
you want to keep the cost at a minimum you should use the PID (REX-C700) you
already have. 

 

With
the PID you set the target temp & the controller automatically adjusts the
heater output so you don’t radically overshoot the set point temp.

 

With
the amount of curing you have to do I would get a timer & a six-pack of
beer or a bottle of wine. 

 

If
you need to go from 25-C to 80-C at 10-C / Hr, then break the job in to 20-min
increments.

1st
20-min 29-C, 2nd 20-min 33-C, etc till you get to 80-C. If you then
set the timer for the soak time required for the Composite System you’re using
and the PID controller will maintain the temperature..

 

The
least expensive way to obtain your original stated desire of having a system
that has a programmable controller with an interactive graphical interface
would be to go with the BCS-460. I understand your budget doesn’t allow you to
purchase this. Perhaps you could hold a fundraiser to purchase one. Or perhaps
there is a Home Brewer of Beer in your area that already owns one that you
could borrow.
Here's a link to a simple Curing Oven



Airframe Composite Curing and Post Curing 
Ovenhttp://www.privatedata.com/byb/rocketry/composites/ovens/Airframe%20Composite%20Curing%20and%20Post%20Curing%20Oven.html








 

 







On Sun, Jun 29, 2014 at 9:52 PM, Peter Johansson <rockets4kids@xxxxxxxxx> wrote:



On Sun, Jun 29, 2014 at 8:40 PM, Nathan Asdourian <rawliquid@xxxxxxxxx> wrote:






[ ... arduino ... ]



The Arduino is an incredibly awesome tool for its intended purpose:

Enabling artists to produce interactive art.  Beyond that my opinions

of Arduino drop off dramatically.  (I'll reserve the remainder of my

rant until asked.)



> That said, it should be taken into consideration that you could get an

> actual pid controller for around the same price as an arduino uno r3.



I too would agree that a COTS PID controller is the preferred way to

go *IF* it includes the capabilities to do the temperature profile out

of the box.  If you need to add a microcontroller to the PID box to

adjust the temperature, you are doing things completely wrong.



[ ... description of software functionality ... ]



I think we should let the person who volunteered to write the code

make a proposal as to what features he is willing to provide.



-p.






                                          

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