PID settings, long heat time

[bootsnthejeep]

Curious about other people's PID heat times. Initial heat up is no problem, I'm getting the bench set up while it heats up, but when I add sprues and castoffs back in, or add ingots, when the temperature drops about 200 degrees, it takes about 10 minutes to come back up to temp. Just wondering if there's a setting I should monkey with, or if this is just normal.

The problem is I'm running a 10 pound Lee pot, and with those 4 banger NOE moulds, I'm just starting to make hay when I've got to stop and refill the pot, and the mould is cooling down.

Boots

[tomf52]

I use a cheap single burner electric hot plate with a buffer of a piece of 1/4" aluminum plate to keep the mold up to temps while the casting pot recovers it's temp. Yes it is normal for it to take a while when adding more lead to the pot. Try adding a smaller amount more regularly as you cast and the temps should not drop as drastically.

[Walter Laich]

I realize that $$ is often a factor in the type of equipment we use but I had the same problem with the pot taking 'forever' to get back to casting temp after adding lead.

One of the main reasons I went to a larger pot.

[Lee W]

bootsnthejeep,
When the pot is heating up, is the controller turning on and off?

If it is, something is wrong with the settings.
If it is not, the pot does not have the power to recover from adding cold lead any faster.

[fecmech]

Lee 10 lb pots and 4-6 cav molds are not compatible IMO. The heating element is not of sufficient wattage to keep up with the demands of a 4 or 6 cav. About the only way I think it can work is if you preheat the mold, do not add the sprus in (or if you do ,do it as you cut them) and run the pot dry without adding lead. I got rid of mine because of that. When I first started casting I used a Lyman(Saeco) 10 lb pot which kept up with a 4 cav and adding 1 lb ingots as I cast, BUT it was a 1000 watt pot not 500 like I believe the Lee is.

[HammerMTB]

bootsnthejeep,
When the pot is heating up, is the controller turning on and off?

If it is, something is wrong with the settings.
If it is not, the pot does not have the power to recover from adding cold lead any faster.

What he said.
My PID controller works fine on my 20 lb Production pot.
I now use my 10 lb Lee pot for pure, and only cast 2 cavity or less from it.
It's not the PID- it's the heating element.

[Echo]

What fecmec said...

[bootsnthejeep]

Yeah, that's pretty much what I thought. The PID has been really great as far as not having to worry about the metal temp, but now I just don't have the capacity to keep up.

I need to get my Saeco up on its feet, bit its only a 10 pounds too, don't know if I want to go to the trouble of piggybacking the lee onto that as a preheater, or just get a 20 pounder and be done with it.

My old man bought a Lee 4-20 at a gun show two years ago, and I don't think he's ever even plugged it in. He gave me most of his moulds anyway, still not sure why he bought it at all. :) Maybe I'll see if I can trade him out of it.

[Longwood]

Yeah, that's pretty much what I thought. The PID has been really great as far as not having to worry about the metal temp, but now I just don't have the capacity to keep up.

I need to get my Saeco up on its feet, bit its only a 10 pounds too, don't know if I want to go to the trouble of piggybacking the lee onto that as a preheater, or just get a 20 pounder and be done with it.

My old man bought a Lee 4-20 at a gun show two years ago, and I don't think he's ever even plugged it in. He gave me most of his moulds anyway, still not sure why he bought it at all. :) Maybe I'll see if I can trade him out of it.
You might try pre-heating your ingots and sprues on a hot plate.

[bootsnthejeep]

That would definitely help. Its on the list. I want one for my moulds anyway.

[fecmech]

Boots--If you have an old Saeco they were 1000 watt pots and can keep up with a 4 or 6 cav with no problem. I'm not up on PID controllers but if you could tie it to the Saeco and just let her rip. Preheat your mold on the top flange and place your ingots on the flange as you cast to preheat them. I used to cast for a couple hours that way with my Lyman/Saeco and 4 cavs. Pop the ingot in the pot and place another on the top flange to preheat, worked great.

[HammerMTB]

I'm not up on PID controllers but if you could tie it to the Saeco and just let her rip.

I just have a TC dedicated to each pot and can transition the PID controller to the one I want with a moment's plugging. If ya only had 1 TC as long as you remove it from the lead while it's still molten, you'd be GTG.

[fecmech]

Hammer--I'm guessing a TC is a temp controller?? Does this set in the molten metal and then cycle the power off and on at the plug to maintain temp??

[Dalerj]

Who makes the PID controller? Can you tell us more bout it? What type thermocouple is used? Thanks-D

[HATCH]

Hammer--I'm guessing a TC is a temp controller?? Does this set in the molten metal and then cycle the power off and on at the plug to maintain temp??

TC= Thermocouple
Its the probe that measures the temperature. Not the device that turns it on and off. Thats the PID.


Ok, I got a plan that is easy to do.
Get one of those 3 into 1 outlet adapters
Something like this
http://ecx.images-amazon.com/images/I/41-E%2BULQyDL._SL500_AA300_.jpg
Plug a lamp into one and the pot into the other.
If the lamp stays on the entire time while it tries to recover the 200 degree drop then you need a bigger pot.
But it the lamp cycles on/off then you have a problem with the PID or SSR.

[Matt_G]

Who makes the PID controller? Can you tell us more bout it? What type thermocouple is used? Thanks-D

Lots of good info in this thread (http://castboolits.gunloads.com/showthread.php?t=34547).

[HammerMTB]

Who makes the PID controller? Can you tell us more bout it? What type thermocouple is used? Thanks-D

My PID controller is home-made, from a PID I got in a group buy, and an SSR (solid state relay) I got off Evil-Bay. As was said above, the TC is a thermo-couple. I use a K-type, but I think most PID's will take J or K type, and you just program what you're using. In the case of the complete controller, the rest is just wires and a box to hold it all in.
Here's a pic
http://i172.photobucket.com/albums/w15/HammerMTB/DSCN3358.jpg

The big black plastic box holds it all in.
The solid state device on top is the PID controller.
Left of that is the SSR, you can see it labelled. Don't mind the 12V converter, at the time I needed it, but figured out how to wire the whole thing without using it.
Not pictured is the TC or lead pot.

[ChuckJaxFL]

Which PID are you using, and what are your P, I & D settings?

[HammerMTB]

Which PID are you using, and what are your P, I & D settings?

It is a JUMO iTRON 32. Take a look here (http://www3.jumo.de/pio/JUMO/en_SE/prd/70.2040/jumo-itron-04-08-16-32-compact-microprocessor-controllers.html)
The settings are done automatically, when the unit is first started.
Learn about a PID controller here (http://en.wikipedia.org/wiki/PID_controller)

[ChuckJaxFL]

I'm familiar with PIDs. I use one to control the RIMs loop for my beer brewing. Basically I recirculate water/wort/beer over a heating element to maintain 152 degrees, or 154 degrees, or whatever temp I want, with precision. I found that the autotune on my PID worked, but it wasn't ideal. I ended up tweaking the settings manually to get it working the way I wanted.

It's worth a shot.

There's a download at the bottom of this (http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=106&zenid=3d757eacbfb99d7be6cb7ae6d0c651ba) page for an instruction manual. It won't apply fully to your PID, but might give you an idea of what to expect when you start tweaking the PID and damp settings. The dampening setting is what I had to reduce, for the same symptoms you describe.

If you make the problem worse, you should be able to autotune it back they way you had it, and you've lost nothing but some time.