I am about to create an oven with pid controller with ramp up temperature control etc. And i have 1 question …
In the specifications the prepreg mnufacturer say that the prepreg has
to be warmed with a certain pace . - For example 1 C per minute from 40 degrees until 90 degrees … WHAT will happen if i dont achieve this 1C per minute and i achieve 1.5 C /min for 5 minutes and then 0.5 C/min for 5 min and then 2C / min for 20 min util i get to the desired temperature…then result will be almost the same i will have gone in 30 min 30 C up …but it will not be as smooth as 1C /min ???
It can result in voids and some other things. I don’t think it’s a big problem and you probably won’t see anything. If you need to make high end stiff and strong parts it can be a problem. If you just make visual parts or not calculated don’t worry about it. But why this problem ? A simple PID ramp/soak controller solves this.
The problem is that when i want the oven to get from 78 C to 79 in 1 min and from 79 to 80 in the next min etc etc using a controller that turns on and of a 3000 watt element when the element kicks in from 79 maybe in 40 sec it will get to 81 …and then it will close until it will get to 80 and then again kick in to 82 for example util it will get to 81… in order to have exact ramp of c/min i think that the element together with the controller must be very good calibrated … and the person that i am planing to give him the manufacturing of my oven is telling me that he can achieve this ramp more roughly …lets say if i want 30 C in 30 min it will get there in 30 min but not by 1 C /min … maybe the first 10 degrees will get the in 7 min then it will stop and then again work to get another 5 degrees and at the end of the 30 minutes period it will have got to 30+ C but not 1C/min strictly …he said i have to allow for 2 C plus +/- for the actual result of the process … not the controller…the controller will monitor all the time the temperature but the element makes the work of the controller a little dificalt because it is on… or of
Don’t worry about it. Every oven and controller has that. Most controllers arrange the ramp better then you mention in your story. Make sure you have good air flow in your oven.
Where do you guys recommend I look for a solid, and affordable PID ramp/soak controller? I’m using actual household oven guts right now, but would like something a little more sophisticated, shortly.
I bought a PID from ebay… a little strange but was only $160 or so with the SSR and SSR heat sink. Seems to work fine for my needs.
Haven’t had any issues with ramp up. My parts have been coming out great. For aerospace stuff it’s more critical to follow prescribed recipes. For the stuff I"m making, I don’t need such rigor.