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View Full Version : Magma's Master Pot Electronic Temp Controller



cbrick
02-28-2009, 01:54 AM
Just installed it tonight and it's really a trick gadget. The controller is a box that sits on the bench next to the pot; it has a green L.E.D. read-out that gives pot temp right from room temp up to its pre-set temp. Under the green L.E.D. is a red L.E.D. that is your set temp, just push the up arrow to raise the temp or the down arrow to lower the set temp.

Once the pot temp reaches your pre-set temp it shuts off and the power on indicator light goes out, the pot temp continues to rise a few degrees due to the heat already in the element. As the pot cools to the pre-set temp it turns on and the temp continues to drop a few degrees until the heating element gets hot enough to raise the alloy temp. There is about a 17 degree up & down temp swing as it cycles on and off. I think that the reason for this is that I welded the nut for the temp sensor dead center of the middle of the bottom of the pot to give alloy temp and not so much the heating element temp. Magma's instructions only say "bottom" of pot. Perhaps the temp swing would be a little less had I placed the mounting nut closer to the side and the heating element. Dunno, just a SWAG but I would rather know alloy temp anyway.

The reason I ordered this unit was the pot temp going up as the alloy level goes down, sometimes by 50 degrees, a common problem with electric pots. I haven’t used it enough yet to guarantee this problem is solved but I’ll wager it is.

As a side benefit, I was kind of surprised at how closely my Lyman thermometer matched the electronic temp readout through its full range from 200 degrees & up, I have always wondered about these thermometers accuracy and now I know, quite close. I also have an RCBS and a Tru-Temp and I'll check them against the electronic read-out.

I ordered the electronic controller and installed it myself but if you don't have access to a welder and aren't fairly adept at mechanical and electric problems I highly recommend sending the pot back to Magma and have them install it. The instruction sheet that comes with it is totally and completely useless leaving it up to you to decide which of the old & new wiring and parts to use, how to wire it and where to place wires and parts etc.

For me the electronic lead pot controller ranks right up there with the air pressure cylinder for the Star Lubri-sizer.

Rick

fivegunner
02-28-2009, 06:11 AM
How about Pictures? and whats the price? Thanks Frank:cbpour:

cbrick
02-28-2009, 10:32 PM
Here is the temp controller under the Master pot, This is the stand i built to raise up the pot to a comfortable level for casting. The picture on the right is a close up of the front of the unit. The up and down arrows are how the pot temp is changed (red numbers). The green number is the actual pot temp.

http://www.lasc.us/DSCN2047-9.jpg http://www.lasc.us/DSCN2030-9.jpg

The price tag is $220.00 including insurance and shipping.

RIck

Ron B.
03-06-2009, 10:14 AM
Hello Rick!
I'm impressed; very good information. One day soon I'd like to figure out an alternative myself; getting rid of the "in the way" mechanical thermometer all together.

Now, tell me; do you really use that pot? It looks brand new!
The only tell-tell evidence you've casted are the burn marks on the supporting board! I can't keep my RCBS ProMelt clean, no matter what I do! But, then again I use it from beginning to end; smelting, casting, the works. :)

Thanks,
GRB

cbrick
03-06-2009, 02:34 PM
GRB, the pot is about 4 years old and yes, extensively used. I do like to keep my equipment (and loading room) clean. I just had the pot dis-assembled to install the temp controller and used this opportunity clean everything up. The burn on the plywood shelf was a brain fade moment when I set an ingot mould on it to drain the pot, learnt my lesson and don't do that no more. Now when I fill an ingot mould I place a sacrificial piece of 1X8 on the plywood and let that get ruined.

The first time I cast after installing the temp controller I had the mechanical thermometer in the pot. I checked the electronic temp against the mechanical temp and they were very close through-out the temp range. Your right, it’s great to have the mechanical thermometer out of the pot and out of the way especially when ladle casting.

Rick

Bret4207
03-06-2009, 06:45 PM
Here is the temp controller under the Master pot, This is the stand i built to raise up the pot to a comfortable level for casting. The picture on the right is a close up of the front of the unit. The up and down arrows are how the pot temp is changed (red numbers). The green number is the actual pot temp.

http://www.lasc.us/DSCN2047-9.jpg http://www.lasc.us/DSCN2030-9.jpg

The price tag is $220.00 including insurance and shipping.

RIck

If you follow this link you'll see a ho'made PID controller that looks just about like the Magma and does the same thing for about $120.00. http://castboolits.gunloads.com/showthread.php?t=45733 Just in case anyone else wants one at less than full shot.

cbrick
03-07-2009, 03:07 AM
Story of my life . . . A dollar short and a day late. :-?

Bret4207
03-07-2009, 01:36 PM
I'm thinking about doing a PID on my SAECO, but a cheap Lee control might be more affordable and nearly as good in the long run.