Is there an actuator that can operate in 100-200 °C

Hardware
1

Hey,

TL;DR

Problem: I need to control an old furnace
Context: Only spot for an actuator is in top of it where a lot of heat comes up and will melt plastic.

Context:
I have an old furnace that I need to control remotely and inside of furnace shell there is controlling mechanism that has pin that can be pushed in or a turning valve. With a bit of ‘engineering’ I could use one of these https://www.amazon.de/dp/B01HBCWW96 to actuate a pin however… I read that they push their pin down then they heat up… and the only place I can mount one is at the top of furnace and it gets hot water will boil off it in an instant, so I am worried it would melt any plastic actuator.
I can use servos and mechanical linkages to get into an area that has temperature that should be more sain though any plastic parts can be significantly weekend.
So… what do I buy?

2

Perhaps be clearer on what this “actuator” is doing? A photo of the “pin” perhaps?

3

Sure.

Here is a part that has the pin I want to control. This reguliator part of right by fire dish so I would mount a fin metal tube with a rod inside of it to transfer force from actuator outside of furnace body.
Problem is pin is pointing up and… heat goes there too.

4

So are we talking the Actuator pin or the Control knob?

5

Either. They both just push down on same control valve. One is rotation other vertical motion. I focused on actuators because I saw them being used for temperature control systems and I have not seen any devices that can control a turning angle that would fit this.

6

How about a cam? Could be controlled by a rod off to one side?

7

First I am assuming you are talking something like a cam shaft:

image
image950×700 31.1 KB

that would drive a pin up and down.
Interesting idea would be a little tricky to find a right cam to do this but it could work though I do it though my problem is control of turning radius.
I actually have a large dial of the side that can be turned that rotates a head 90 deg that I can link with a slot in control nob in the regulator.
image
image715×674 55.7 KB

The best option I found to control rotation via home assistant was via a servo (Home Assistant & ESPHome Servo Example (Step-by-Step guide) – Siytek). I am worried that even if it is at an angle the temps are still going to be too much for servos and will just melt/soften the plastic to point it is no longer functional not to mention that the basement is damp, that is one more reason why I was looking at actuators (they have an IP rating)

8

IP ratings relate to water and dust ingress.

9

I imagined something self-built, but i’d probably struggle with the tools I have.

Funny though the control knob looks plastic.

10

Yah the knob is plastic cover though it quite a chunk of material, so much higher thermal mass as well as no real stress put on it and servos have some fine parts that get me worried.
I think a stepper motor could do the job. I think I will use something like this https://www.youtube.com/watch?v=h64QsAV51Ng to try control the knob.

1 Like