Made (assembled) a PID controller

[jsheyn]

Just assembled my first PID. Seems to work really well....it will get about 15 deg over set value....any tips or tricks you PID experts can offer?

[kitsap]

Make sure your TC is not touching the bottom or edges of your pot. Then fill your melter with alloy to about 3/4 full and look through your Auber controller instructions to start the auto tune cycle. It will take several minutes to complete.

Doug

[dikman]

I like your custom rangehood. Very classy!

[el34]

Is the thermocouple directly connected to the controller's terminals? If not, did you use an inline connector specifically designed to be used with a thermocouple? Did you splice regular wire onto the thermocouple wires to lengthen it?

If the pot settles to a consistent temp (15-20 minutes after it reaches set value) and you know it's off, you can give the controller a correction factor, check the instructions. But that's probably not the cause.

Copy that on the cool range hood

[jsheyn]

Thanks for the tips fellas! Yep that range hood is compliments of my daughter....and usually anyone who sees it smiles including me.

So now to the meat and potatoes... I am a mold snob and only have RCBS molds. But recent I bought from a member an NOE 358477. I've never casted with aluminum before. I set the PID to 685 and off I went...after a thorough cleaning and warm up of the mold

I'm pretty happy with results

[jsheyn]

Is the thermocouple directly connected to the controller's terminals? Yes it's hooked up directly to the controller



Did you splice regular wire onto the thermocouple wires to lengthen it?
No, the TC came with 5' of wire .... More then I need

If the pot settles to a consistent temp (15-20 minutes after it reaches set value) and you know it's off, you can give the controller a correction factor, check the instructions. But that's probably not the cause.

Once i got moving things stabilized and the temps were 3 or deg works like a champ.

As of right now it works great! Got some learning to do and a whole mess of reading!

[jmort]

"I am a mold snob and only have RCBS molds"

Interesting, RCBS is the best of the best. Who knew?

[jsheyn]

Yep best of the best!!

[el34]

As of right now it works great! Got some learning to do and a whole mess of reading!

And a whole lot of simplified casting!

Next step- mold temp control. Automating that will be cool.

[Frozone]

.... Automating that will be cool.

I have a number of instrumented molds, and a PT100 based digital pyrometer to read their temps.
It's amazing just how both wide and narrow the sweet spots are on some molds.

Some molds have more than one sweetspot as well.
On some molds, it may drop clean and shiny at (say) 340º.
But at 350º boolits starts to stick, then 15º above that the mold loosens up again before it starts to frost at 375º.
Or on another boolits are wrinkly below a certain temp but frost only ~10º above where it begins to cast clean.

Using the sprue freezing time as a guild isn't all that accurate either.

I have started keeping a note book with data on my various molds - every one is a little different in how hot it wants to be and what melt temp it wants for a given alloy.

<edit>

Yeah, I know, it's a little ridiculous.
But I was curious and after experimenting on a couple of molds ( the ones that like to be difficult ), I just couldn't stop
I have (I think) 10 molds instrumented now and I am going to do the others too.
Except for some of my older Ideals unless I can find a good non invasive way to do it.
</edit>

[el34]

Personally I don't think it's ridiculous at all. There's big agreement that mold temp is just as important as pot temp. There's a pretty nice move to PID controlled pots but controlling mold temp is in the form of "cool it off on a wet towel every once in a while" and "learn to regulate your cycle time". No doubt skilled casters can work with that, like how a master chef works magic by gut feel. But nothing will beat automated mold temp regulation, heating and cooling, once it's practical. I've been mildly envisioning a method but have no doubt you will be the innovator.

Then it'll be a matter of discovering the pot and mold temp combinations that deliver consistently good results, by the numbers.

[dikman]

Ridiculous? I suppose some might think so, but I wouldn't - no more so than attempting to monitor the hardness of different alloys. It's simply another potential variable in the process of casting boolits. Enquiring minds need to know these things.

[JASON4X4]

you will love the pid I have been using one I made for a while. don't think I would ever cast without one now.

[Walter Laich]

+1 on the PID. I know you can cast without one but I do this for the fun of it as much as anything else and the PID sure does add to the enjoyment

[tward]

Jsheyn, those are some pretty Boolits, nice job. Bought one of frozone's PID and love it! Tim