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 Oven > > > http://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. >> >> >