DIY inductive annealing

Discussion in 'Ammunition and Reloading' started by GrocMax, Mar 9, 2017.

  1. GrocMax Active Member

    Member Since:
    Jun 12, 2014
    Message Count:
    166
    For those of you whom are truly interested and feel comfortable working on electronics, here's a project for you.

    Step one- best source for info is to read all 23 pages of this thread, there's a ton of info, parts lists, plans, diagrams, problems and solutions. Several different versions from simple basic low cost to much more complex case feed style.

    http://forum.accurateshooter.com/threads/induction-brass-annealer-redux.3908353/

    Once you get grasp on that, we'll do a Q&A, next I'll post my version schematics.
    wood chucker likes this.
  2. GrocMax Active Member

    Member Since:
    Jun 12, 2014
    Message Count:
    166
    [IMG][/URL][/IMG][IMG]

    This is the overall schematic of my machine.

    Below are the details of the sub board.

    [IMG]
  3. GrocMax Active Member

    Member Since:
    Jun 12, 2014
    Message Count:
    166
    The basic premise is to utilize the cheap inductive heating boards commonly available. This is known as a Royer oscillator. These units are dumb, they will take any amount of power and time you put to them till they blow up. In order to start the oscillation it requires a power supply of at least 30v and 5A switched on very rapidly with a fast rise time, thus the need for a HD relay or contactor, and the control system to operate them timed. A switching PS of at least 500w at 48v is recommended. A PS that can use a current limiting function works even better.

    A good amount of heat is created in the coil, so water cooling is a must. It can be as simple as a valve and hose hooked to your faucet and dumped somewhere else, or a pump, radiator and fan. In order to get consistent results from various brands and calibers of brass, you need a timer system and some way to adjust the case position in the coil. Timers can be as simple as the Sestos timer or as complex as a PLC or Arduino. Start and stop can be automatic via switches, or manual. The trap door can be as simple as a hand operated unit, or solenoid.

    My personal opinion is the money is best spent on a good full featured current limit adjustable PS, and cut the frills in other areas like cooling system or case feeding. The current limiting switch allows for easy repeatable setup for many different case sizes, and reduces the possibility of damaging either the induction board or PS itself from and overcurrent/overvoltage event. Without the current limit the coil needs to be matched to the PS closely and anneal times get very short or very long.
  4. boostless Active Member

    Member Since:
    May 5, 2014
    Message Count:
    201
    Seems like a decent project but I don't have the room for this stuff anymore. Wish I still had room for my reloading stuff
  5. spamassassin Well-Known Member

    Member Since:
    Aug 8, 2014
    Message Count:
    1,129
    Nice. /me begins ordering parts.
  6. GrocMax Active Member

    Member Since:
    Jun 12, 2014
    Message Count:
    166
    I'd like to point out it can be done cheaper and easier than my diagram, the fan controllers are advanced soldering (tiny 0.5mm pitch chips) and really not necessary for a functional unit. I do highly recommend the RSP-750-48 PS because its the cheapest one I can find that does remote current control. You need a 5v supply to use the current control, you can buy a 3 dollar 12v to 5v PS to do this rather than build a complex sub board. The optical switch can be operated off 12v with a resistor change.

    Also highly recommend using glue on heatsinks on the bottom of the induction board, the capacitors get H-O-T under continuous use, heatsinks and a fan they stay cool.

    If you loading room happens to have a sink handy you can delete the cooling system and just use faucet water which drops cost by at least 100 bucks, unless you already have the components.

    An old desktop or tower computer case is ideal. You could even salvage the use of the original PS for the 5v and 12v.

    It is not necessary to use 12v powered relay coils/contactors/timers, some folks use the 110v versions of these components.

    Idea for most of us is to use as many salvaged components as possible and keep design/fab within our own comfort zones. Got woodworking tools? Build it out of wood.
  7. GrocMax Active Member

    Member Since:
    Jun 12, 2014
    Message Count:
    166
    The Sestos timer is probably the cheapest and easiest way to get timer functions + relay outputs. There are four timers run in sequence, A-B-C-D, A and C have an associated relay output. It can be run either in single loop mode that requires a start signal to restart, or it can be run in continuous loop mode (no start signal or case switch needed).

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