Project - PID on Lee Pro 4 20 furnace

[HATCH]

I will have a look at it, its really not a big problem since the error is consistent, i set it to 950F and it always shows 700F in the pot with a RCBS probe.

At room temp does it show room temp + 250f?
Or does it show room temp plus a smaller amount?

I would say the issue you are having is that you have the wrong setting in your PID controller for the Type of TC you have hooked up to it.

at 698 F (370 C) a type J TC will read 20.745 millivolts while a type K will read 7.65 millivolts. That is a huge difference.

Keep in my that the MV above is not exact as we aren't factoring the junction temperature but its close enough.
I would verify the setting in the PID controller first and go from there.

[Lightmkr]

Do you have to program the PID each time after removing the power?

[Frozone]

No, Only if you change the device being controlled.
Like if you switch between a melter and a lube/sizer.
Or for that matter if you used a 10# then changed to a #20 pot, a retrain would be good.

[Lightmkr]

Thanks! Building one now Auberins delivery was two days.

[Lightmkr]

I have to thank you all. It came out great and works very well.

[rasto]

Hi there.
I am desperate. Everything is wired as it should be, the C100 is switching but the relay doesn't react at all.
The relay itself is good because I tried it separately with 4V and it was switching.
The temperature displays exact, everything seems to be working but there is no output.

[Norbrat]

The controller I purchased was set up for a relay, not an SSR. Go through the instructions to see if you can change the output type from relay to SSR.

Actually, if you bought a cheap Rex C100 (likely a chinese made knock-off), it could be relay only, and won't work with an SSR. Have a read through this Brewers forum http://www.homebrewtalk.com/f170/rex...d-ebay-254480/ about these problems; you may be able to fix it by removing the relay in the PID and jumping the terminals.

[rasto]

Thank you it seems to be my problem as well, I am about to change my relay to SSR.
I rebuild it according your posted link and it works as it should.

[Norbrat]

I bought this one http://www.ebay.com.au/itm/110761287592 and even though the description says it has an SSR output, it didn't.

So I also removed the relay and jumpered the pins, and now it works fine with the SSR.

[motorcycle_dan]

I am in the proccess of building one for a member on here..

Okay I'm in the market, How much to build one for me? Be happy to pay pal or ? you some operating capital. Let me know with PM

[HATCH]

I could build you one but you can just buy one here --> http://castboolits.gunloads.com/show....php?p=1631493

[Norbrat]

Went to use my cobbled together PID for the first time yesterday, plugged it in and nothing!

Now what? Surely my el cheapo Chinese knock off PID wouldn't die that quickly! I'd only hooked it up temporarily to test it a couple of times and it worked then.

Check that 240V is getting to the PID; tick!

OK, pull it out of the housing again, and guess what? Dummy here had hooked up the 240V to the alarm output. OOPS!!

Seeing that there hadn't been any release of the critical conductive smoke, hooked it up correctly, crossed fingers, plugged it in and Bingo!! All Good!

And after the learn cycle, it happily kept the pot within 5 degrees of the set temperature.

Now the question is; how accurate is a Brownells thermometer? It was sitting on 660°F while the PID told me it was at 720°F. I didn't calibrate the thermocouple, but it did show ambient temperature before the pot starting heating, so I figured it must be close enough.

[Mal Paso]

60F is a lot, any chance of borrowing another thermometer? I've noticed with my Lyman dial thermometer, which is similar, the reading lags in both directions when compared to the PID.

[Norbrat]

I might ask around the gun club if there is anyone else who may have a thermometer I can borow.

But I'm starting to suspect it's the thermocouple/PID. I cast some more yesterday and had the PID at 750 to start with. I was still getting voids in the nose, much like oil in the mould, so I let the mould cool down and cleaned it with paint thinners. Still no good. So kept cranking up the PID until it was 825 and the thermometer was showing 760; finally fill was good, sprue was setting in about 2-3 seconds instead of immediately and I was starting to get the light frosting I'm used to seeing with this mould when running well.

I silver soldered the thermocouple into the bottom of the pot, so I'm not sure if that may have affected it; probably not.

I might try boiling some water in the pot, although that is still 500 odd degrees below the running temp. Or I may try melting some pure lead and see how close that is to 625 degrees.

I suppose at the end of the day, it doesn't really matter what actual numbers are displayed on the PID, as long as I know where to run it for each mould and that it keeps the temps pretty constant.

It seems to be doing that, so thanks again to all for the info in this thread; no doubt it will make casting life easier for me.

[Mal Paso]

I silver soldered the thermocouple into the bottom of the pot, so I'm not sure if that may have affected it; probably not.

Both my pots have the thermocouple silver soldered in the bottom. My first try the junction (tip) was right at the bottom and I experienced Thermal Drain. I think the effect was to read lower than actual. The probes now project 5/8 inch into the pot. Once I corrected the problem the Thermometer and Pid were within 10 degrees. There should be a calibrate function. If it says 825 to get good boolits I'd use 825 for now. The consistency is what's important. I dropped my pour temperature considerably when I no longer needed a safety margin above what the Lee Control would fall to.

[Norbrat]

Yeah, I'm not getting too worried about it. I'll just run it at whatever works best.

Numbers really don't mean much, as long as the alloy temp is held reasonably constant.

Thanks again.

[wool1]

Had to post this.....Absolutely love it!

Here is the front panel of the controller. This is also taken from the manual but I thought I'd throw it in here to give you an idea of the flexibility of this little device.

1. PV display: Indicates the sensor read out, or process value (PV).
2. SV display: Indicates the set value (SV) or output value (%).
3. AL1 indicator: It lights up when AL1 relay is on.
4. AL2 indicator: It lights up when AL2 relay is on.
5. A-M indicator: The light indicates that the controller is in manual mode. For the controllers with the Ramp/Soak option, this light indicates that the program is running.
6. Output indicator: It is synchronized with control output (terminal 7 and 8), and the power to the load. When it is on, the heater (or cooler) is powered.
7. SET key: When it is pressed momentarily, the controller will switch the lower (SV) display between set value and percentage of output. When pressed and held for two seconds will put the controller into parameter setting mode.
8. Automatic/Manual function key (A/M) /Data shift key
9. Decrement key ▼: Decreases numeric value of the setting value.
10. Increment key ▲: Increases numeric value of the setting value.
    
    
    
    
    
    
    
    
    
    

[Racenviper]

Finished my first PID tonight and it works great. Thanks for this sticky. One question, I'm building two for many uses, I have spend the last two hours search and reading PID threads looking for which stored values I need to record if I change the use of my PID's. I know I have read it here, just can not find the thread.

[Frozone]

P I D

(10char)

[Racenviper]

Thanks, Frozne