Load DataTitan ReloadingInline FabricationReloading Everything
Lee PrecisionMidSouth Shooters SupplyRepackboxWideners
RotoMetals2
Page 5 of 5 FirstFirst 12345
Results 81 to 87 of 87

Thread: Pid

  1. #81
    Boolit Man


    Join Date
    Jul 2015
    Location
    Great State of W TN
    Posts
    86
    Noah Zark POST #54 is the finest description of PID controllers I can remember reading.
    Someone else still remembers Foxboro and Fisher pneumatic with the pen dragger charts.
    Don’t forget Hagan / Westinghouse boiler control that was a real work of art. No chart but the balance beams for gain were interesting
    I don’t know if I still have any pictures of one.

    I copied it and sent to an old work friend that retired quite awhile after I did

  2. #82
    Boolit Man


    Join Date
    Jul 2015
    Location
    Great State of W TN
    Posts
    86
    Quote Originally Posted by dearslayer View Post
    Currently only have a wire mounted that the probe drops down into but I don't like it because it's not sturdy enough to keep the probe straight down in the pot. The curly wire on the probe has too much tension wanting to pull it constantly. I want a different probe and the I will mount a proper solid bracket.
    This is a piece of copper tubing top slightly flared and bottom end bent over and silver soldered. There is a copper mounting strip silver soldered close to the top and held by the screw on the back of the pot.
    The probe is made from a piece of type K wire with glass sleeving and end melted together for the junction.

    I haven't seen it mentioned in this thread. The TC wires need to be terminated to Stainless steel. Copper will form a junction with the TC wire and add an offset.
    The little plugs mentioned in post 41 and on the commercial probes with plugs are SS

    Click image for larger version. 

Name:	100_8266.jpg 
Views:	30 
Size:	69.6 KB 
ID:	297385

    The old fishing sinker wired to the top of the pour valve operator helps keep the valve from dripping

  3. #83
    Boolit Master

    Mike W1's Avatar
    Join Date
    Nov 2008
    Location
    Rural Sumner, IA
    Posts
    1,317
    I don't know, but I suspect RKC of Japan may have been the original manufacturer of REX C-100s. I have 3 of them purchased before I ever noticed the Berme (spelling?) units on ebay. I had correspondence with RKC themselves and they stated their's were all marked Made In Japan. Some time ago I wanted a spare unit and ordered one on ebay. Picture in the ad showed Made In Japan but the one I actually received did not have those markings and the box although colored the same said RKC Monitor. Ebay refunded my funds but didn't ask for it back. So I hooked it all up and tested it out pretty thoroughly. It seems to be OK but near as I can determine also cannot be switched to Fahrenheit. I remember someone on here I believe that had their troubles with the Berme but do not recall what issues they had at the time. RKC makes several model of REX's and have not noticed any knockoff's of the the higher numbered models.
    Mike

    Benefactor Member NRA
    Life Member Iowa Firearms Coalition
    US Army Vet

    There are two ways to conquer and enslave a nation.
    One is by the sword. The other is by debt.”
    John Adams 1826

  4. #84
    Boolit Man


    Join Date
    Jul 2015
    Location
    Great State of W TN
    Posts
    86
    I couldn't get SL8 (PV bias) works either.
    That's to remove offset in PV ie to tune out sensor offset so PV is correct.

    But then for the price I don't care if there is a 3 or 4 degree offset in PV.
    Heck all I am doing is controlling my pot temperature and it's closer with a PID than I ever managed before.

    The Berm unit seemed to control the working temperature just fine before the casting started.
    EDIT: I shouldn't have counted my chickens before they hatched. I'll update after more testing

    I also dump the spruces back into the pot.

    I do auto tune after the pot is at working temp. That's the area of PV I want regulated.
    The time constant of keeping a pot of lead at casting temperature while adding a few spruces or cull bullets is not related to bringing ingots up to casting temperature.

    My original Yokogawa can handle all kinds of break points and time constant changes in multiple stored patterns / programs. But good grief it was K bucks way back and it is a real PIA to learn and program. Kind of like using a Nuc when is all that's need is a frag

    These REX controllers are as close to plug and play as I have seen. A real one may be in my future. No more knock offs
    Last edited by K7sparky; 03-14-2022 at 11:33 AM.

  5. #85
    Boolit Man


    Join Date
    Jul 2015
    Location
    Great State of W TN
    Posts
    86
    SSRs

    HATCH in Post #40 is the only one so far that I think got the heat sink correct.
    Maybe his dealing with them for over 25 years explains it.
    Just screw it to the metal box.

    As noted his post the LEE 4-20 pulls around 7A max

    Most SSRs are 2 junction devices. Silicon Junctions typically have an on voltage drop of 0.6V. Larger devises that are lightly loaded usually have a bit higher drop so lets say 1V per junction.

    The SSR would have a 2V drop and pass 7A. That's a grand total of 14W to dissipate.
    And that's only when it's on. Melting ingots at the beginning is the only time that will happen.

    When my pot is at temperature and I'm just tossing in cull bullets and spruces my Yokogawa runs around 30% output.

    I haven't bothered to get out a stop watch and try to figure out the REX duty cycle but it better be 30% also.

    With the pot at temperature the SSR is OFF 70% and ON 30%
    The SSR is dissipating around 4.2W

    OK! enough of the calculations.
    For shucks & grins, how does my LEE 4-20 do at cold pot?

    Click image for larger version. 

Name:	100_8315.jpg 
Views:	22 
Size:	55.5 KB 
ID:	297515

    Excuse the fuzzy picture, a flash washes out the PID & Fluke displays
    I didn't verify the current.
    I consider 1C for PV to be cold pot
    It's hard to read in the picture. The SSR is the 40A that came with the kit.
    1.02V (across the SSR) X 7A = 7W worst case dissipation.
    The rather constant 1V drop across the SSR with changing current smells like a FET is buried inside.
    The SSR is sitting on a small Aluminum plate just to give me a warm fuzzy feeling
    Last edited by K7sparky; 03-13-2022 at 11:52 AM.

  6. #86
    Boolit Man


    Join Date
    Jul 2015
    Location
    Great State of W TN
    Posts
    86
    Addressing a failed SSR
    Like HATCH I've never seen a failed on.
    Failed on could be gating circuit bad or shorted output device likely a MOSFET.
    It takes power to gate so that wouldn't seem likely but if it were happen the dissipation would be no more than Cold Pot.
    Shorted output device has essentially 0 Ohms so dissipation would be 0W

    Failed open / off I=0 therefor dissipation =0W

  7. #87
    Boolit Buddy
    Join Date
    Oct 2019
    Posts
    248
    Quote Originally Posted by MrWolf View Post
    Been a long time since casting due to injury, divorce, and move, but I remember bending a coat hanger. Hopefully, I will be in a position this spring to have everything set up and good to go. Been a long journey.
    I was re-reading this old thread to refresh my memory for some new PID designs. How are you making out?

Page 5 of 5 FirstFirst 12345

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check