I just posted a new article titled, Casting with a PID Controller.  If you’re interested go to the following link:

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From now on it will definitely be a part of my casting process.

Wayne

Wayne  - where did you get that small box the controller is mounted  in? I have mine suspended with wire-ties and would like to "clean it up". Thanks.

kkid66 wrote on Aug 22^nd, 2015 at 9:02am:


It's a small laboratory hot plate to preheat the mould.  Works great.  I can resume casting after a break & the 1st bullet that drops out of the mould weighs the same as the rest.  They are available used for around $50.  Here's a similar one on eBay

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There are others of various sizes.  They can get expensive, even used.  Run a search on eBay for "thermolyne hot plate".  Be sure to get one that is adjustable.  The temperature adjustment is not precise.  I set mine at around 450 degrees as measured by a hand-held thermocouple based thermometer.

Wayne

Glen, here is one site you can get a project box from, they have several that will work with a PID and come with a precut hole for the PID. (You need to Login or Register to view media files and links)

Sam

I'm not saying melt temp is not important, but I have found mold temp much more critical in getting +/- .1 or .2 gr.

Schuetzenmiester wrote on Aug 23^rd, 2015 at 12:00am:


I agree and did considered getting this
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But I was not excited about having a thermocouple attached to my mould and also having to deal with the line.

BTW, if you can get anything close to +/- .1 to .2 gr. your a much better man than I.  Even with a PID controlling the pot and a constant cadence, the best I can do is +/- 1.5 gr. for a nominal 400 gr. bullet.

Wayne

texasmac wrote on Aug 23^rd, 2015 at 1:38am:


The thermocouple attached to the mold is a bit of a pain at times; but I got used to it once a procedure is worked out. The vast majority of my 215 gr .33s are +/- .1 gr.  When I was casting 550 gr 45s, they stayed +/- .2 most of the time.  Once the mold is preheated to the proper temp the first bullet out can be within that tolerance and usually will be.   I have watched the pot temp closely and my Lyman usually stays within 25 degrees unless I drop too many sprues in at once.

I just use a Fluke Type J thermocouple that works with my electrical meter since I already had it.  I drilled and tapped an 8-32 screw in the lower corner of the mold to attach it. 

Schuetzenmiester wrote on Aug 23^rd, 2015 at 12:00am:


I think you are 100% correct about that.  The mold will cool and heat much faster than the melt will.  From what I can see, a consistent rythm is one of the most important things you can do.  At some time I'll build a PID controller just for fun, but I don't have any trouble casting really nice bullets without one.  But I do watch the temperature closely and keep an eye on when the heater cycles on and off.  If it tries to come on and th desired temperature has been reached I just move the knob a hair lower. 

But I think it is a nice idea.  If you can reduce another variable without a lot of effort i certainly won't hurt.

Chris.