Hi Tim, Unfortunately, we can not spend $ 180 on this system. On the other hand, given that the PID is the best option, we can opt for this. We have a PID we bought last year. PID is REX-C700. I also have a thermocouple type K 2 meters in length. So we can use this. Now the question is, what fan?, What resistance?, What power? Opinions?, Comments? From: tyoung489@xxxxxxxxx Date: Sat, 21 Jun 2014 21:04:29 -0700 Subject: [SS2S-Main] Re: temperature controller with arduino To: sugarshot@xxxxxxxxxxxxx Hi, Depending on how you locate the heaters you may find that you'll have problems maintaining uniform temperature throughout the oven with your planned dimensions of 2 x0.5 x 0.5 m (Free). Long oven shapes are more difficult to keep at a uniform temperature. Long oven can be beneficial if you have a process that requires different temperatures along the route through the oven tunnel. In a tunnel oven you are normally applying spot heat directly or via infrared. In a convection oven, like what you want, the heat is applied indirectly via the surrounding medium, air in this case. Normally the heat source is not directly in the area with the product your heating. You want some heat barrier (wood, steel, or aluminum plate) between it & the product to avoid spot heating. Larger ovens would use a supply fan with additional stirring fans to maintain uniform temperature. Just for consideration. This could all be inside your plywood & foam box. Heater section with stir fan(s) -> Aluminum plate barrier to direct heating -> oven space with stir fan(s). Also you can often get lower cost fans if the motor is mounted outside the oven with only the blade in the heated space. The control portion of your job requires nothing unique that requires new research or development efforts. This is a straight forward case of application engineering for this cure oven. It seems to me that with the Arduino you're starting from scratch to re-develop the wheel. This may be fun but is unnecessary with the abundance of low cost, off the shelf controllers, & software available. Granted these weren't available 20-years ago but neither was the Arduino. The design, testing, & debugging of the software interface for the controller is where you'll be spending or wasting your time, depending upon the results. The BCS-460 is a fully debugged Temperature Controller with Everything you want & much more. $180. Graphical, Web, & Smart Phone Software Interface. 8 Programmable outputs each with 8-stages. 4 Sensor inputs You can pre-program & also interact with the settings on the fly. http://www.embeddedcontrolconcepts.com Graphics Screenshots http://www.embeddedcontrolconcepts.com/screenshots.html The BCS-460 has 4 temp sensor inputs. These are any ntc 10k ohm thermistor that you can get 100 for $8 plus shipping online or $0.75ea plus shipping from SparkFun. For your curing operation you will want to know the temperature of the part, not just the oven temperature. What is often done is to use a scrap or dummy piece of what you are curing & embed the sensor at the spot that the temperature is most critical to sense BCS-460 Controller Graphical, Web, & Smart Phone Software Interface (These will do what you ask of them. Don't get tripped-up by what they're called. Curing a composite part is less sophisticated than running a Brewery) https://www.brewershardware.com/BCS-460-Brewery-Control-System.html iPhone Interface Demo http://www.youtube.com/watch?v=4r9hCVYSt2Y Software Documentation http://wiki.embeddedcc.com/index.php/Main_Page Other Electronics starting around $15 (some of these have the ability to output to your computer some come with software) http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1311.R1.TR8.TRC1.A0.H1.Xpid+temp&_nkw=pid+temperature+controller&_sacat=0&_from=R40 On Sat, Jun 21, 2014 at 4:02 AM, Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx> wrote: Hi, The main idea is to made a home oven from plywood and foam insulation. I planned dimensions of 2 x0.5 x 0.5 m (Free). With these dimensions we can cure any parts necessary for SS2S project. Recall that the largest piece so far is the nosecone (1507 mm). For smaller piece, and in order not to waste energy, I have thought the manufacture of a partition. You're right about the fans. I'm sure I can get some free fan oven, as well as resistence. The objective of using arduino, is the possibility of developing a graphical interface in which to determine the temperature rangesSubject: [SS2S-Main] Re: temperature controller with arduino From: tyoung489@xxxxxxxxx Date: Fri, 20 Jun 2014 17:30:38 -0700 To: sugarshot@xxxxxxxxxxxxx As much fun as it is to play with Arduinos it's a waste of time & money.Programmable PID Temperature Controller with single or dual sensors can be purchased on eBay for $15-$60. Where will you be placing the temperature sensor for the controller, embedded in the part or on the surface? Or are you going to try to run the oven at the desired temperature and guesstimate the time it takes for the part to equilibrate? I believe that would problematic and take longer to achieve your cure. I think that the manufacture of the composite materials should be able & more than willing to provide you with general propose curing methods & procedures. Are you building your own over with strip heaters, fans, etc? Or are you planing to interface the controller and fans to an existing oven? For convection circulation you only need constant speed fans and if you plan on using axial flow computer type fans be aware most are rated to 60-C or 70-C. You can get 105-C rated fans but not from an old computer. sofasco.com is one of many places you can get them. You could use standard fans but it anyone's guess on how long they'll last. If the parts are small you can buy small electric convection ovens sold as Toster/Pizza ovens.Check Walmart, Best Buy, Target, eBay, Amazon. Sent by Timothy Young iPad On Jun 20, 2014, at 4:01 PM, Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx> wrote: Florin that's perfect. The system must be simple (as cheap as possible). With a source of heating (resistance) and several computer fans to circulate the air. Arduino must be able to control the temperature (using the resistance and the fan) according to a predefined schedule. A program is for example: 20 ° C to 100 ° C by increments of 20 ° C / h. 5 hours at 100 ° C. 100 ° C at 20 ° C with a decrease of 20 ° C. Ideally develop a graphical interface to vary these parameters at will. Date: Sat, 21 Jun 2014 01:32:37 +0300 Subject: [SS2S-Main] Re: temperature controller with arduino From: florin.mingireanu82@xxxxxxxxx To: sugarshot@xxxxxxxxxxxxx I can help with the temperature controller but I would need more precise specifications: like temperature range, control "band" etc. On Fri, Jun 20, 2014 at 10:16 PM, Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx> wrote: Hi,Anyone know how to make a temperature controller with arduino to make a home oven to cure composite? The idea is to monitor several computer fans and thermal resistances. Must be able to follow a cure profile and decreased with increases in temperature curing. Any volunteer? CheersVicente Alvero -- Florin Mingireanu Romanian Space Agency Str. Mendeleev 21-25, et. 5, sector 1, 010362 Bucuresti, ROMANIA office tel. +40-21-316.87.22; +40-21-316.87.23; cell: +40-757-768971 (primary phone) fax +40-21-312.88.04 florin.mingireanu@xxxxxxx http://www.rosa.ro