Anyone on these forums selling inexpensive PIDs?

[HATCH]

I may be misunderstanding this last statement you made but what you said doesn't jibe with the various wiring diagrams that I've seen. Just relooked at several of them. I assume you mean killing the power to the PID with the switch which would make sense. If the PID isn't powered obviously the SSR isn't going to get a signal to switch the power on/off to the load (lead pot). That what you meant?

It’s what I said.
You switch the power to the PID controller itself.
That is just a 1/2 amp load.
No PID controller power means no SSR output which kills the power going to your furnace.

[mattw]

Just my 2 cents worth... My Mypin TA4-SNR pid died after years of use. I had an Inkbird sitting on the shelf, so I rewired for it and was back up and running on my lead pot. But, I do not like the Inkbird at all! If you just allow it to hold the temp, it does very well. But it has trouble regulating the temp with normal casting speed outflow and will always way over shoot on a 20 pound pot if you add warm but not melted alloy. I did finally find the way to set it up for autotune, that did help but not nearly as much as autotune on the Mypin. I will replace it with another Mypin, when I get the chance to do so.

[Dragonheart]

When it comes to what I call inexpensive PID's they are all made in China. I went with the Inkbird several years ago and it is still going. I also have had good results with two other Inkbirds. I didn't go with Mypin because originally reading the reviews they had a really high failure rate. I think to some extent product longevity is the luck of the draw. The problem I have is the documentation for all of the PID's seem to be really lacking, but that goes for all Chinese electronics in general.

I do agree the learning can make it worth the DIY and you can customize it as you wish, but if you just want one that works, DIY is not going to save a lot of money.

[HATCH]

Problem you run into is the Chinese clones of Chinese products.
Mypin has clones out there.
Some of the features such as auto tune doesn’t work on the clones

[Conditor22]

Hatch didn't mention: $ for
Terminal Barrier Strip Block Connector Bar for cleaner wire management
Fuses to protect the PID.
grommet or clamp to protect the wire going through the metal box.
I put feet on mine to hold it off the bench to help keep it cool (don't know if this was needed)
Optional panel-mount k type thermocouple connector so you can easily swap out thermocouples between oven/hotplate/pots (I'm not sure this is a good idea if the PID unit is autotuned to a certain piece of equipment).

Hatch could easily get the budget materials but he couldn't stand behind his products as he does.

In the time it takes most of us to rig one together Hatch can build 10 because he has the tools to do it right.

For me, cutting nice square holes in metal housings was a pain as was scrounging for materials,
but - I have more time than money, and have just enough experience to be dangerous and enjoy DIY.

I digress.

Do you mean inexpensive as in cheap or inexpensive as in quality for reasonable $?

[Mike W1]

Really I am not trying to be a pain purposely, I just don't get where you're coming up with the 1/2 Amp versus some other load unless you're wiring up 2 individual inputs.

[HATCH]

The switch goes where the green line is.
There is no switch before the fuse/circuit breaker.
The PID only draws less then 1/2 amp

[Mike W1]

OK. I see what you're getting at now, possibly saving any wear and tear on a $3 switch.

[HATCH]

I have built a couple hundred PID setups.
All of them have had a switch at the PID controller itself.

You can use a little 10 amp rated switch and by only using it to switch the 1/2 amp there is NO way you will ever burn up the contacts and it’s safer.

I could care less about a 90 cent switch failing.
What I care about is the contacts of that switch overheating and possibly causing a short.
By using a switch that is rated 20 times the load there is no way your gonna melt it.

[Mike W1]

Now I see what you had in mind. BTW I don't think that thing in the drawing I used is a circuit breaker now that I look at it a little closer. Looks like a DPST switch. Usually anyhow a 110v breaker does not break the neutral.

[Conditor22]

[HATCH]

Now I see what you had in mind. BTW I don't think that thing in the drawing I used is a circuit breaker now that I look at it a little closer. Looks like a DPST switch. Usually anyhow a 110v breaker does not break the neutral.

The thing in the drawing outside the box is a dpst switch.
I don’t use a fuse, I use a circuit breaker.
Fuses mean you have to buy and keep spares.

[Mike W1]

I have built a couple hundred PID setups.
All of them have had a switch at the PID controller itself.

You can use a little 10 amp rated switch and by only using it to switch the 1/2 amp there is NO way you will ever burn up the contacts and it’s safer.

I could care less about a 90 cent switch failing.
What I care about is the contacts of that switch overheating and possibly causing a short.
By using a switch that is rated 20 times the load there is no way your gonna melt it.

Well I don't have a EE, but a friend is, so I asked him about this. Course there's always lots of "ifs" when there's more than one way to do something. However, "if" you turn your switch off and the SSR has happened to fail, they generally failed closed so the power would still be going to the pot. Guess you just unplug the whole thing from the power outlet though.

[Dragonheart]

I have built a couple hundred PID setups.
All of them have had a switch at the PID controller itself.

You can use a little 10 amp rated switch and by only using it to switch the 1/2 amp there is NO way you will ever burn up the contacts and it’s safer.

I could care less about a 90 cent switch failing.
What I care about is the contacts of that switch overheating and possibly causing a short.
By using a switch that is rated 20 times the load there is no way your gonna melt it.

I have only built two PID boxes and converted a 30" oven to PID and it never occurred to me to NOT put in a switch, but what do I know compared to those posting on You Tube.

[HATCH]

SSR has happened to fail, they generally failed closed so the power would still be going to the pot.

I worked for a DDC company that did HVAC controls.
They have installed 10s of thousands of SSRs.
I can tell you that from my experience unless they are overloaded and burn up, if they fail, they just stop working.
I say IF they fail because unless they are overloaded or aren’t properly heatsinked, they generally don’t fail.
Out of 200+ units I have built , I have only had one problem with a SSR and it was a factory defect.
The SSR housing detached from the metal base. This caused the SSR itself to overheat and melt the plastic housing. On that unit the SSR did not pass current.
But anyway, we are getting into design and that is off topic as the OP is looking for a cheap PID.

[skud007]

I find that using old computer power supply boxes work well for these units. You can gut them out and cut out for your PID controller. I've built two this way and have about $35 into mine.