Project - PID on Lee Pro 4 20 furnace

[mongoose33]

I've read all of these threads on a PID and I find my electronics knowledge to be apparently just short of what I need to fully understand all of it.

I was looking on Ebay; is this kit the kind of thing that would work?

http://www.ebay.com/itm/PID-REX-C100...item19f33b057b

I think I'd need a different thermocouple, but the price for the other two pieces seems remarkably cheap. They can be had from many different locations.

[mongoose33]

That unit will require 220vac to operate. Using the US 220vac of two hots, neutral, and ground is not real easy to set-up. If you are planning to build one for controlling a lead pot, the 40A SSR is overkill. A 25A SSR would be better. I would recommend a Mypin TA-4, as they are relatively inexpensive. Is your lead pot 110? If so, get a PID unit rated for 120vac. The SSR output will work with anywhere from 24v to 380 vac. The SSR is controlled by a low dc voltage from the PID. You would need a different type of probe, as the one you will receive might be good for a lubsizer setup, but not a lead pot or toaster oven. Feel free to PM me if you have any other questions about them.

OB

Thank you!

I'm going to throw this in here as I suspect there are others who may have the same questions. Don't know how I missed the 220-volt input; you're absolutely right, the 110 is what I need.

Since the MyPin is what others are using, I would like to go that way as well, just for continuity and support purposes. So, I searched Ebay for a MyPin and found this listing:

http://www.ebay.com/itm/MYPIN-Digita...item43cd88b510

Looks like it has the 110v input, the 25-a SSR as you suggested, and a thermocouple which isn't the right one for my application (which will be a 110v lead pot, the Lee). So I'd need to get a K-type thermocouple on top of that. Looking on Amazon, perhaps something like this?

http://www.amazon.com/8-8ft-Thermoco...k+thermocouple

Do I have that right?

*********************

My wiring diagram reading skills are at best fair; what helped me was this post from another thread:

http://castboolits.gunloads.com/show...l=1#post527081

This shows the wiring diagram for using a 110 volt approach. I don't know that this is the correct diagram for the Mypin controller but it finally answered one mystery I had, which is why only 4 terminals on the SSR. I couldn't figure out how the PID was controlling it, now I believe I understand--only the hot wire goes through it, not the hot and neutral.

So, to recap:

I'd need the MyPin PID referenced above on Ebay, plus the additional Type K thermocouple (the one which has a long probe), plus an enclosure and some sort of heat sink for the SSR. Wire and connectors I have or can easily procure.

Anything I'm missing?

Thanks!

[10x]

I've read all of these threads on a PID and I find my electronics knowledge to be apparently just short of what I need to fully understand all of it.

I was looking on Ebay; is this kit the kind of thing that would work?

http://www.ebay.com/itm/PID-REX-C100...item19f33b057b

I think I'd need a different thermocouple, but the price for the other two pieces seems remarkably cheap. They can be had from many different locations.

I suspect that unit will go from 24VDC to 220VAC
This is the spec sheet for the unit.
The photo shows an SSR but #10 on the spec sheet suggests it has a 250VAC 3amp rated internal relay.
If it does have the internal relay then the choices are a separate 12DC supply to switch the SSR.
Or you can remove the internal 250VAC 3 Amp relay and jumper to the terminals so the PID will switch the SSR Directly.

And that thermocouple could be made to work if mounted on the outer surface of the pot liner at the bottom of the pot. No holes needed, just contact with the pot.
A longer thermocouple in the alloy would give faster response when the alloy cools

[borg]

Is there a problem cutting off the thermalcouple ends and installing the panel mount connectors?
I will be using an ammo box and I would like to remove it to put in the box for storage.

[Sticky]

No, as long as you maintain the polarity of the thermocouple... (keep the same color wires to pins in and out of each connector). If you wire one backwards, the displayed temp will fall as the actual temp rises (reads backwards).

There are standard thermocouple connectors that are normally used. I have seen many on some of the builds on this thread (post #618) (usually yellow in color).

[10x]

Can the wiring cable to the thermocouple probe be cut and made shorter? 5 feet of wire is a lot to deal with when I only need 1.5 feet

[h8dirt]

IMHO, putting a PID controller on a Lee pot is like putting slicks on a moped. In the name of full transparency, I put a PID on my Lee Pro-20 -- just before it dumped 10 pounds of lead in my shop floor (again). I ditched the Lee, bit the bullet and bought a RCBS Pro-Melt. Best move I ever made.

[JonB_in_Glencoe]

IMHO, putting a PID controller on a Lee pot is like putting slicks on a moped. In the name of full transparency, I put a PID on my Lee Pro-20 -- just before it dumped 10 pounds of lead in my shop floor (again). I ditched the Lee, bit the bullet and bought a RCBS Pro-Melt. Best move I ever made.

I respectfully disagree. I see it more like putting a fiberglass dunebuggy body on a vintage VW bug chassis.
Making for a more fun package out of THEE inexpensive standby.

[borg]

Now Y'all did it, you made me spend too much money,, Ramon noodles, rice, and beans for the next month.
Ordered everything I think I need for the PID, even a new Lee 4-20. I already have two Lyman XX pots, but 10 lbs just don't cut it.
One question,, with a 25A SSR, do I really need a heat sink? It will be attached on the inside of an ammo box.
Thanks

[Sticky]

Probably not.. I used an SSR mounted to a steel plate that is normally used inside a Nema 12 enclosure and used no heat sink. It has been used a dozen times since I set it up and I have had no issues. It's a bit of a risk, a heat sink will usually extend their life, but.... a steel plate does act like a heat sink, as long as there is no heat accumulation in that area. My plate is free hanging, not in an enclosure, so there is no heat buildup. I did use heat sink compound to mount it to the plate for max heat transfer. So far, no issues at all.

[JonB_in_Glencoe]

borg,
my 25 Amp SSR is mounted to the aluminum kit box with thermal (heat sink) compound, no other heat sink. I've checked, by touching, the outside area of the case during the casting session, and that area never even gets warm. So I'd say no heat sink required. For ammo can mounting, I'd still suggest removing the paint and using thermal compound when mounting the SSR. Since I believe there is also no heat generated, if you don't have any thermal compound and don't want to seek it out...I'd just use some thick automotive grease to retard rust and grease will transfer more heat than nothing.
my 2¢

[10x]

IMHO, putting a PID controller on a Lee pot is like putting slicks on a moped. In the name of full transparency, I put a PID on my Lee Pro-20 -- just before it dumped 10 pounds of lead in my shop floor (again). I ditched the Lee, bit the bullet and bought a RCBS Pro-Melt. Best move I ever made.

I have a lyman bottom pour, an RCBS bottom pour and a Lee - With a PID controlled alloy of the same composition all will give the same bullet.
The lee is lighter, takes up less space, and if you treat it right and use a cookie sheet under it total alloy dumps are just a break in Casting.
Lyman and RCBS lead pots have drip issues too if the stars and parts do not align.
The Lee can be convinced not to drip with a bit of patience.

[dikman]

Nothing wrong with the Lee (once it's set up right, just needs a bit of work on it). If you're mounting the SSR to a metal surface then that will act as a pretty good heat sink - just make sure you clean the paint off first and ideally use a bit of heat-sink compound between the two.

[mvintx]

I've got a question about the fuse holder I bought to install with my PID. I picked up a Bussman in-line fuse holder at Home Depot and it came with a SFE fuse. Reading the literature that came on the packaging, it says it can be used only for 32 VAC max. I understand SFE fuses are normally used for DC. Do I need to get a different fuse holder or can I just use an AGC fuse rated for 125V?

[borg]

How many people here even use a fuse?
Just wondering if I even need to use one.

[Sticky]

The fuse isolates the electronics from the load. In the somewhat rare event of failure of either one, it will likely protect the other. Insurance. Not absolutely required, but a wise investment.

Most of the inline fuses are for auto applications and not rated for over 36v. Get a fuse clip/holder that screws to your panel or interior of your enclosure and snap an appropriate fuse in it.

[mvintx]

How many people here even use a fuse?
Just wondering if I even need to use one.

I wondered the same thing but since alot of other folks were putting them in theirs, I figured I'd do the same. There is not a whole lot of room in the Auber small box that many have used - that's why I picked up an in-line fuse holder. I'll bet I can use a 125V fuse since the wire is rated for 600V but I'll wait to see if the manufacturer answers my email.

[borg]

Does anyone still have the Mypin Manual that was posted in the Vendors section from a member that was banned?
I am electrically challenged and need a visual.
Thanks

[JonB_in_Glencoe]

Does anyone still have the Mypin Manual that was posted in the Vendors section from a member that was banned?
I am electrically challenged and need a visual.
Thanks

If you know the model number, the links in my post #599 of this thread may help you.

[mvintx]

I gave up on using a fuse so I built my PID a few days ago without one and I've got a couple of questions. Yesterday I ran my LEE PP IV with a set temp of 750. It ran for about an hour while I watched the temp fluctuation. The PID was set to learn mode (AT=1) and I started the warm up in manual. Once the temp got up to about 400, I pressed the A/M button and put the PID into auto.The best it could do would be an undershoot of maybe 10 degrees and then an overshoot of about 30 degrees. The thermocouple is 1/2" from the bottom and sides of the pot. Is that as good as it gets? How do you guys start your pot up? In MAN or AUTO or does it matter?