Project - PID on Lee Pro 4 20 furnace

[OpenNRG]

uglysteve - Tried to find a larger copy of your Avatar in your profile. Is that a lead meltdown on your shelf upgrade?

[uglysteve]

uglysteve - Tried to find a larger copy of your Avatar in your profile. Is that a lead meltdown on your shelf upgrade?

Why yes it is.

[uglysteve]

Who do I believe? My lyman thermometer or my PID? They differ by about 80 degrees.

[Rhoa4396]

If it were me, I'd believe the PID first. I suppose the easiest way to tell, is to take a reading of the temp of a known alloy and see what temp it slumps at.... then melts at. then you would know which is correct.

Ken
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[Beagle333]

Mine is off by 50, according to my PID.

[fred2892]

My Lyman thermometer is off by 120°. Measured against my PID and 2 other digital thermometers. I'd believe the digitals every time. The Lyman is leaving me now, soon to feature on ****bay.

[Mike W1]

I'll keep my stem thermometer. I know how far off it is compared to the PID and it'll still be useful for alloying.

[snuffy]

[QUOTE=uglysteve;2749027]Who do I believe? My lyman thermometer or my PID? They differ by about 80 degrees.

[QUOTE]

Lower your pid temp to 212 degrees, turn it on.(from a cold temp---) See if water boils. If you're on a mountain, then check how much lower a temp water will boil at. That all assumes you have some room on the top of your alloy. That should give you a baseline. Also check the Lyman thermometer at the same time.

[10x]

Built a controller using a REX C100 PID
This PID has an internal relay that is not heavy enough.
I removed the internal relay and put two jumpers to #4 and #5 terminals to get voltage to those terminals - This voltage is enough to run a 25 amp SSR.
This runs my lee pot at 350C (the REC PID is supposed to be switchable to F but it stays in C no mater which value I set the internal switch)

The REX PID was $12.00, the SSR was $2.50, the K thermo couple was $2.50, the high amp connectors (80 were $4.00) The wall cord was salvage off of a deep fryer, the outlet was 70 cents. This PID will keep a clean pot at 350C (348C to 360C) and gives excellent heat control. Total cost about $21.00.

My next project is to salvage a PID and SSR out of discarded electric stove and see if I can make it work as a temperature controller. The Rex C-100 came with a preset max at 400C, that was easily changed to 600C - way higher than the controller will ever have to work.

[dikman]

10x, I did the same thing. Yep, only reads C (which is no big deal, seeing that's what we use in Oz). Set mine to match the K-probe (1300C!). Cheapest setup you can get (although it took a bit to work out the commands, my understanding of Chinese being nil).

[10x]

Who do I believe? My lyman thermometer or my PID? They differ by about 80 degrees.

PID and thermocouple technology are extremely accurate, I have a cheap Ebay digital thermometer with a K thermocouple. I have checked it in pure lead and various known alloys - pure lead goes into solid at 620 degrees F. Water boils at 208 degrees F. at this elevation (depending on barometric pressure), My cheap ebay digital is bang on.

I used it to verify the melt and temperature of the PID and K thermocouple - it is within 1 or 2 degrees C:

[10x]

10x, I did the same thing. Yep, only reads C (which is no big deal, seeing that's what we use in Oz). Set mine to match the K-probe (1300C!). Cheapest setup you can get (although it took a bit to work out the commands, my understanding of Chinese being nil).

The instruction sheet that came with it was in one language - Chinese. I downloaded 3 different manuals for it off the internet and worked through the settings with all three.
The hint is in the connections on the back - match those to the REX C-100 in your hand and you should have a manual that is close.
The most difficult part of this will be to put this into a coffee can to keep fingers away from 120 or 240 volt wiring.

And the advice and experience in this thread helped a great deal..

[Lead]

What would you charge to rig me one up if I decide to do it, so far mine holds 750 degrees on five .

[MO Fugga]

What would you charge to rig me one up if I decide to do it, so far mine holds 750 degrees on five .

I have about $150 in mine, minus the ammo box. Not exactly a logical business venture. The experience of building it means more than it's actual usage. It'll be months before it gets fired up again.

[10x]

I have about $150 in mine, minus the ammo box. Not exactly a logical business venture. The experience of building it means more than it's actual usage. It'll be months before it gets fired up again.

I have about $22.00 mine - ebay parts

[clytle374]

Had to show some pics of my conversion. Bought the PID and thermocouple, the rest was scrounged from scrap. The box is welded up from 1.5x3x.125 aluminum C-channel, arm, and bottom supports are from other C-channel from a product that didn't sell. Tuning was a bit of a challenge since I'm used to servo PIDs and not waiting minutes to get the result of each try. Overshoots about 18F on initial warm up and holds pretty good after that. The PID would start throttling with almost 100F before the set point until I turned off the AI dampening. Been thinking about adding a kill switch to shut the heater off when the arm is up.
Cory

[jayhkr]

How come when I look up parts on Ebay, I never find them that cheap? I've been holding off to build one, but I think my time is near......very near if I can build one for under $30. I have an old .50cal ammo can I can use as the housing.

[clytle374]

How come when I look up parts on Ebay, I never find them that cheap? I've been holding off to build one, but I think my time is near......very near if I can build one for under $30. I have an old .50cal ammo can I can use as the housing.

I think mine was about twice that(parts came from auberins), was a lot of work building a box and the arms out of what I had on hand. Being new to casting, the PID was pretty vital to me getting any kind of consistent bullets.
Cory.

[jayhkr]

So did some searching on Ebay and came across 3 "auctions" that I wanted to get opinions on.

First one is: TA7 SSR PID Ends in about 20 hours, but before I placed a bid I wanted to know if this unit would get me everything I needed, except for something to house it in.

Second one is: Dual Digital F/C PID This one didn't come with a probe that I could see that I goes into the lead so I wasn't sure if this would work for our application.

Last one is: Digital PID F/C SSR PID This one I think is the same as the first so if the first one can be had cheaper I would assume go that route?

I only ask this as I'm on a limited budget right now and I want this to be my first main purchase before I start casting actual bullets. I'll definitely put the PID to use when I cast my fishing sinkers, but as far as boolit casting goes, this is my first step, so I can insure good quality boolits later on. I saw a heat sink somewhere on this forum too (can't remember or find it ATM) that was about $8-10 bucks too I thought I would get.

I plan on either using my father-in-laws .50cal ammo can as the housing unit, or building one out of wood that I can then make air vents in and add a computer fan to as well. Any suggestions are welcomed and I appreciate all the help!

[dikman]

Jay, if you want to find cheap parts you'll have to source them from Hong Kong/China. Be aware that some cheap PIDs are relay drive, not SSR, but this can be fixed if you open it up and do a wee bit of soldering. Just read the ads carefully.
Any of those you've listed will work fine, the Mypins have the advantage that you'll get English instructions (not always the case with overseas units, but nothing that can't be overcome).
Unless you want to drill a hole in the bottom of your pot for the sensor, you'll need one that has the sensor at least 4" long to mount from the top.
The 25 amp SSR will work fine, but make sure it is either mounted on a heatsink or onto a metal case (if you use the metal ammo can that should be fine). A 40 amp is better, if you can get one. Once up to temperature a 25 amp SSR will barely get warm, but during initial heatup is when it is likely to get hot as it is passing the maximum current for a long period until it's up to operating temp. (That is why I decided to fit bypass switches to mine, once they get near operating temp. I then switch in the PID).

I notice that the first one has a reserve on it, so it's a good bet that it won't go cheap.