So I would like to build a PID control

[3jimbo3]

Ok I would like to build a pid control for my melting pot. I have a Lee production IV pot. It is the 110 volt model. I understand what a pid control does but will it help me or not make any difference in my casting? Do I just need an analog thermometer to get the same results?

[Spawn-Inc]

i haven't done alot of casting, but for what it's worth here is what i found.

it allowed me to casting longer with aluminum molds before it started frosting over.
showed me that without the pid system my lee pot on setting 6-7 got to +900F
was fun to build :)
and i've gotten better boolits as a result.

but yes you could get away with a simple thermometer, but you would be plugging and unplugging alot, or using a switch to turn power on and off. that is after all exactly what the PID does, but with more accuracy.

[3jimbo3]

I see. So if I build myself one is there some instructions I can get somewhere? Or a parts list I can go by? I know several guys have posted how they built their's and they look really good. I guess a diagram is more what I am looking for. The ones I have viewed here look simple, but electricity is not my friend and it usually wins when we battle.

[3jimbo3]

Oh ! I just found a diagram on here

[ratboy]

i built a controller for my pot. shiny. bought a 2nd controller(different brand) for a hot plate controller for my lube/sizer. not shiny. the theory is sound but i do not recommend the mypin TA4-SNR pid. it is difficult to get to work well. the instructions are nearly useless. buy a better pid unit.

[Frozone]

There is nothing wrong with the Mypin unit - It is operator incompetence.

How much instruction do you need?

To set the temperature:

Press "AT" (blue button).
The right digit of the lower display (the '1s' digit) should flash, and leading zeros
should appear in the upper display.


-----------------------------------------------------------------
If you press the "AT" button again the '10's digit will flash.
If you press the "AT" button again the '100's digit will flash.
If you press the "AT" button again the '1000's digit will flash.
If you press the "AT" button again the '1's digit will flash.
----------------------------------------------------------------

Press "AT" until the desired digit flashes then use the up/down arrow
buttons to set that digit to the desired value.

Use the "AT" button to select the next digit to change. Repeat for the other digits.

When the correct value has been set on all the digits, press the "Set"
button to lock those changes in.

To train the unit:

With the melt a little below desired temp. press and hold the "AT" button
until a small green LED above the arrow keys comes on.
When that LED goes out the unit is trained.

Almost the same as any other unit on the market.


If you can't read the diagram on the side in order to hook up the wires - you shouldn't be building the thing in the first place.

I have a 10% failure rate from a "recommended" supplier (type "A"), I have a 0% failure from Mypin. That's in a sample of 25 of brand "A" and 75 of the Mypins.
Yeah, use the other guys.

[ratboy]

i am competent at the construction. i understand how it works. either this unit is defective(which i am not ready to say) or my build is flawed. i set it in learn and let it go. it was left for 30 minutes to stabilize the temp. when it gets to its cycle point it for some reason stops using the input temp for control and just cycles the ssr on and off. this results in a slow climb in temp that does not end. i did use a 600w heater for a plate to warm 2 sizers and might have gone too far.
i cannot understand the chinglish instructions well enough to determine if there is a reset. i am now prepared to program it manually and see if i can get what i need. i was not saying that the mypin unit is unserviceable, i was merely suggesting a different unit that comes with better instructions as these are poorly written. the unit i used on the lead pot(i am not walking downstairs to see which one it is) works just as you suggest. i assumed this unit would as well. i have no other experience with mypin and am not trying to tell anyone it is a bad product. i simply stated i found it difficult to use. calm down

:coffee:

[ratboy]

also, i bought the unit off ebay and would not be surprised if i got a knockoff product. since you seem to have more experience with the mypin unit and state it is a good manufacturer.

[Frozone]

The main difference between many units and the Mypin is - the Mypin ships as a PI controller not a PID.
You need to turn on the D function in the main settings menu.

[ratboy]

O-really? well, that might explain why i can not get it to be happy. this is where the better instructions would have been nice.
ಠ_ಠ
can you tell me how to do that since the instructions only make me angry?
it would be appreciated.
i do like using the pid to control the lead pot and the sizer heater as it makes for less things to worry about and also makes getting consistent results easier.
adding one to the lead pot was something i wish i did much sooner.
i want to build a preheater for the molds and use a pid and hotplate. do you have a pid,ssr and tc kit?
i think i would rather get one from you than risk the ebay crapshoot again.

[HATCH]

I have a MYPIN on my master caster (automated).
It works perfectly.
Works so well that when I had to build my friend Wyman his control panel I recommended that unit was used as well.

[Frozone]

Press and hold set until the main menu is entered.
continue to press set until the 'D' parameter is displayed - it will say off in the lower display.
press AT and than press Up arrow to remove the 'off' ( the actual value doesn't matter) than press set.

Either press and hold set to exit the menu or just wait 15 sec or so.

Now retrain the unit.

[ratboy]

ok. checked d and found it to be on.:???: 85.9 was the current value. i am playing with retune and this is another area where the instructions are not clear. one paragraph states that the unit is in auto tune mode when the at lamp in on and another paragraph states it is in autotune mode when the lamp is flashing. i have tried tuning with the lamp in flashing state. this is when it heats, overshoots, turns off until temp is back to set temp then starts cycling and proceeds to keep climbing. i am trying autotune this time with the lamp on and the pid is currently cycling the ssr on and off.the temp appears to be climbing albeit very slowly. i am waiting to see if it gets to set temp and stabilizes or if it continues to climb.

[ratboy]

this behavior is nothing like the other pid i used on the lead pot. it is what you would expect. as ron popeil would say-set it and forget it.
autotune was easy to do. so easy the instructions were not really necessary unless you wanted to tweak. i am starting to think i got a bogus unit. i wonder if the ssr that came with it is a transistor with some hotglue and washers for weight and also junk. so far the ssr has been functioning fine but i also have not put a high amp load on it. i have been lucky getting stuff from ebay but might have got burned on this one.

[Frozone]

With the temp set and a little below desired value ( for example: set at 600º, 550º displayed as actual)

Press and hold AT until the small green LED over the down arrow key comes on.
When that led goes out the unit is trained.

Since I sell a lot of the Mypin units, I've been working on an instruction manual.
It's almost ready. Check my Vendor page to see when it's up and ready.

[ratboy]

understood. will keep an eye on your page. thank you frozone for your assistance with sorting mine out. as to the original posters idea of adding a pid to his melting pot, yes. do it. it makes it much easier to cast when you are only worried about mold temp.

[Bad Water Bill]

Keep this up and I might just have another project.:roll:

[3jimbo3]

Ok, will the heat sink keep everything cool enough or would a small fan help with cooling?

[dragonrider]

I was going to build one too, but I bought one from Frozone instead, whole lot easier and it works like magic.

[Springfield]

I run a 230v 1500 watt Magma pot and I don't need a fan, so I suspect you won't either. The instructions suck on the Mypin but the 2 units I have bought so far have worked fine. I did have one SSR burn out, though.

[ratboy]

I run a 230v 1500 watt Magma pot and I don't need a fan, so I suspect you won't either. The instructions suck on the Mypin but the 2 units I have bought so far have worked fine. I did have one SSR burn out, though.

i have managed to get mine working properly with frozones help. i agree the instructions suck but the actual unit works just fine.
i am not using a heat sink on the ssr for the sizer heater as the on time is so short i doubt it will ever get warm. i built my lead pot controller into a cast aluminum project box so the ssr would have a heat sink and have found it only gets slightly warm in operation. therefore i would suggest a aluminum plate as a heat sink or a proper one for a lead pot build just to extend the life of the ssr.

[3jimbo3]

i was thinking of using a small computer fan,(like the ones on the processor) just for added cooling. some electronics can be cooled too much, i don't know about the ssr though. if it don't need a warm operating temp, then cooler should be better. the box i am working on will have ventilation holes on the top and bottom to take advantage of the convection process of heat transfer.i just thought about putting the small fan on the heat sink to help cool the ssr, especially in the summer months, sometimes it gets pretty warm here. i may just be wasting time doing so though.

[Frozone]

I did have one SSR burn out, though.

But you didn't need a fan........ ;-)

You will have trouble using a computer PS fan - they are 12V.
Unless you Add a 12 V supply - there is no 12 V available in the box.

You can find small 120V muffin fans, but unless you live in a hot climate and have the unit out in the sun, I doubt you need one.
Just use a proper heatsink design and forget about it.

If you do put a fan in it. Use a bimetal switch to turn the fan on above ~ 110º. That way you won't over cool.

[3jimbo3]

As long as I don't overheat the pid the fan would just be a waste of time. Our summers here get pretty warm around July , August , and part of September. The humidty is the terrible part of our summers. When I cast boolits I'm inside, with a lot of ventilation, and it's fairly cool in the garage where I'm at. So if the ssr and other components are moderately tough, I won't need the fans. Thanks to everyone for your input, keep it coming please.

[Cane_man]

instead of a fan i may use a 40a ssr, this way it will be loaded about 20% of capacity (assuming 7a for a Lee pot) and should not get too warm, in theory anyway

[Cane_man]

+1 for Mypin, it works well and is priced right

[kdiver58]

I have a couple of questions on the Mypin controller. I only have one alarm available and am not using it. Is it better to set the alarm at zero or set it way over the temp range I am going to be using. Once it has reached the set temperature the controller is pulsing on and off with about a second between pulses. What have I set incorrectly. P was set to 2.0 , I was set to 400, D was set to 80, it's a K thermocouple, Hysteresis is set to zero . After running Auto-tune the P is now 6.91 , I is 124 and D is 31.12 . It's working fine I just need to know the pulsing is normal.

[Frozone]

Those numbers are about right for a full LEE 20#.

The pulse is normal and will very in width.

The PID will adjust P,I, D on the fly as well.

[kdiver58]

Thank you ..