Modding mechanical toaster oven switch for higher temperature work? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: March 11, 2019, 04:49:10 pm
content: I thought my little shop toaster oven can be converter for higher temperature work by putting firebrick lining in it. I see the current thermostat is basically expanding to close a contact.Can you file down and polish the mechanism to allow for higher operating temperature, using itteration and testing? I am not saying kiln work. I dont want to convert it to pid just yet. I like the mechanical adjustment.I wanted like 800f from it

author: daniel444
author_rank: Regular Contributor
timestamp: March 12, 2019, 03:00:28 am
content: you could bypass the bimetallic strip thermostat contact completely , and control the elements using a "4000w 220v AC SCR Voltage Regulator Dimmer"use a k type thermocouple to monitor the tempim not sure how you would fit the bricks in the oven unless it was a large size one ??

author: coppercone2
author_rank: Super Contributor
timestamp: March 12, 2019, 04:39:52 am
content: you cut em thin in half and lay it on the sides like a puzzleiam not looking for a red hot kiln, just more to get welding electrodes ready pretty much and do preheatingi want to know about the mechanical thermostat, I know how to do the electronic way and I have the tools and even a PID box to do so but that project is not worth it. I am curious about a mod that would just use a file.if you do a PID you would have to rivet or screw a small additional box to the side of the oven with panel mount for a PID box and heat sink for SSR etc.I just want to know about the function/modification of the mechanical switch.Another easy way would be to use KAOWOOL but it pisses me off (someone modded a regular cooking oven to melt aluminum by lining it with kaowool, but I don't like how it gets dusty.

author: daniel444
author_rank: Regular Contributor
timestamp: March 12, 2019, 05:31:11 am
content: post a picture of the switch in questiondoes the switch handle the full current of the heating elements ?does it have any metal plating on it ?could you use something like this ?https://au.rs-online.com/web/p/thermostatic-switches/2282541/

author: SparkyFX
author_rank: Frequent Contributor
timestamp: March 12, 2019, 07:05:53 am
content: Quote from: coppercone2 on March 11, 2019, 04:49:10 pmI always wondered how these switches work, how are they thermically coupled to the oven? Are they just some indirect reading and rely on thermal resistance of the materials involved and constant output power (and constant losses)? The additional insulation or changed layout might kill the plan to just modify the switch in such a case.If it´s a bimetal strip, its properties might also bea) not linear/too non-linear in the region you intend it to bring to, or much more susceptible to certain disturbance variables (ambient temp or so)b) changing distance from its heat source, adding to its non-linearityc) start to change counter-intuitively when mechanically weakening it in certain spotsDo you intend replace the heating elements as well?For me this would be too many new introduced problems and questions afterwards, PID control would be the way to ensure it will have the intended temperature, some functions extra are nice.

author: coppercone2
author_rank: Super Contributor
timestamp: March 12, 2019, 12:55:29 pm
content: alright I might take a picture its a dog to disassemble. I also like how small it is and how it looks like a regular toaster oven.