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PID build, lapping and other fun stuff....

Posted: 31 Dec 2015 00:10
by DaveInGA
I've had a Lee 4-20 bottom pour pot sitting brand new in a box for several years and have been using a Lee 10 pound bottom pour for my reloading needs. Many times, when I've been casting with two identical six gangers making a LOT of bullets, I've wished I had that 20 pounder up and going.

But I held off, because I promised myself when I bought it I was going to do two things to it:

1. Build a PID controller for it right off the bat and have finely controlled heating, eliminating the need to rely on Lee's control and a thermometer. This was/is going to allow me to focus on my casting and not worry too much about the pot.

2. Before using the pot the first time, I am going to lap the valve with grinding compound (two grits) and then apply anti-seize per what RD has done with his.

Well, my 10 pounder and my old thermometer both died recently, so I'm going to be forced to get this new pot going. I've got my new PID components and a box ordered off of ebay.

Once that's completed, I'll need to repair the old pot to get the lead out of it (It was full when it died.).

Two more things to add to the list.

Re: PID build, lapping and other fun stuff....

Posted: 31 Dec 2015 07:32
by Ranch Dog
Always something going on for sure if you are really into the subject matter of this forum. Two years ago I had a Lee Pro 4-20 growing cold on me after approximately 15 years of hard use. I bought all the replacement parts for it and it was supposed to be one of last year's project. I guess I ought to add it to my project list for this year as I would like to dedicate it to my linotype & Pb alloy use.

Re: PID build, lapping and other fun stuff....

Posted: 31 Dec 2015 08:04
by daboone
I bought a PID controller from a guy over on Cast Boolits a few years ago. It just seemed like a hassle to fuss around gathering all the parts and learning to read the schematics. I honestly don't know why nor can I justify why I did as it wasn't that I couldn't keep my Lee pot within a +/- 50 degree range using either of the RCBS or Lymans thermometers at that time.

Now that said I must admit it's kinda nice to turn the setup on and walk away and not worry about keeping and eye on the initial heating up. I can come back 30 minutes or an hour or so later and it is right at the preset temp. Also after an hour or so of casting I need a break. I can again walk away for that break and trust that the pot's temp will not have wandered of in some undesired direction. So I am glad it turn out to be a good way to spend some money.

The hotplate I got at Goodwill was another big time frustration reducer. Having the molds pre heated sure does reduce the time to get production rolling. Also a second Lee pot to have a pre melted refill for the casting pot sure keeps thing rolling too. That refill pot also gets the sawdust treatment/fluxing so my PID controlled pot stays very clean.

One final comment on my setup is just having a nice platform and plenty of space to set up for my casting day. I do it outside. I have a cheap tin shed to store this set up when not in use. A bottle of D-Lead hand soap by my sink. I'm not sure that it really makes a difference what soap is used if I take the time to seriously wash my hands. I've had my lead levels tested 3 time over the last 20 some years and it's never been a issue.

Re: PID build, lapping and other fun stuff....

Posted: 01 Jan 2016 10:18
by DaveInGA
daboone,

What setting/temperature do you keep your hot plate at? I bought and tried one out in my last casting session with my old pot, but the failing pot kept me from dialing in the hotplate and getting it right. Knowing about where it needs to be would help me immensely.

Thank you,

Dave

Re: PID build, lapping and other fun stuff....

Posted: 01 Jan 2016 10:41
by daboone
Dave I honestly don't know the temp but the setting on the old used Goodwill hot plate is just below medium. But at that setting I only need to 1 to 3 pours (I guess that is about 450 to 500 degree?) to get perfect drops.(Well there are some days where the moon phase or some black cat in the area or maybe my attitude aren't in sync and I end up with culling/recycling the whole batch, shut everything down and %@*&$ away.)

Re: PID build, lapping and other fun stuff....

Posted: 02 Jan 2016 00:22
by DaveInGA
daboone wrote:Dave I honestly don't know the temp but the setting on the old used Goodwill hot plate is just below medium. But at that setting I only need to 1 to 3 pours (I guess that is about 450 to 500 degree?) to get perfect drops.(Well there are some days where the moon phase or some black cat in the area or maybe my attitude aren't in sync and I end up with culling/recycling the whole batch, shut everything down and %@*&$ away.)
That sounds like me the last time I tried to cast when I was unknowingly dealing with both a failing pot and a failing thermometer. Frustrating to say the least.

Re: PID build, lapping and other fun stuff....

Posted: 02 Jan 2016 05:28
by Ranch Dog
daboone wrote:I bought a PID controller from a guy over on Cast Boolits a few years ago.
For anyone interested, here is the link to the controller referenced in daboone's post: PID Temperature Controller's

Re: PID build, lapping and other fun stuff....

Posted: 02 Jan 2016 08:26
by daboone
DaveInGA wrote: That sounds like me the last time I tried to cast when I was unknowingly dealing with both a failing pot and a failing thermometer. Frustrating to say the least.
There is a saying that "A man who has 2 watches never knows what time it is!" I'm quite certain that is true about casting thermometers. :twisted: I have an RCBS, Lymans and one from Rotometals. They all look pretty much the same but not one of them give the same reading in the same pot. :?

Re: PID build, lapping and other fun stuff....

Posted: 03 Jan 2016 11:30
by Missionary
Greetings
Had two thermometers in ILLinois for a while but that was not a good idea. Brought one down here and am happy in both locations "knowing" what the lead temp is.
Keep reading about the PID's but it seems hurtful to have a control that costs far more than the pots I use.
Mike in Peru

Re: PID build, lapping and other fun stuff....

Posted: 04 Jan 2016 05:58
by Ranch Dog
Missionary wrote:Keep reading about the PID's but it seems hurtful to have a control that costs far more than the pots I use.
I hear you Mike!