Induction brass annealer redux
- Thread starter Gina1
- Start date
BobB1691
Silver $$ Contributor
Dave What kind of brackets are they on your table? I've been trying to figure out how I'm going to do my, but that setup is perfect.
Bob
Bob - those are "STC-R Roof Clips" - Home Depot SKU is 464-163. They were 63 cents each
I stole that idea from a guy on another forum who used this thread to build his own GinaErick, and built his platform using those same brackets. He had better knobs than my thumbscrews, though... ha haBobB1691
Silver $$ Contributor
Thanks Dave I think they will work great!!Bob - those are "STC-R Roof Clips" - Home Depot SKU is 464-163. They were 63 cents each
Bob
Hi Gina
All works well around 46 volts but draws too many amps to what you say we need to control to
Wind it down to 42.83 and get 7.5A then goes to 15.10A without a case in and with a case in get 18.54A but does not heat the case very fast ???
Have put bigger wires from supply etc to board and made little difference and unsure why this is happening ?
The coil is correct size and coils not touching,tried 2 different volt/amp meters and read the same ???
All worked really good at higher voltage and but about 22A but power unit says 12.5a max like you say but only doing a couple of cases at a time and no issue yet !
Any ideas of why this might be happening ??? Thanks
All works well around 46 volts but draws too many amps to what you say we need to control to
Wind it down to 42.83 and get 7.5A then goes to 15.10A without a case in and with a case in get 18.54A but does not heat the case very fast ???
Have put bigger wires from supply etc to board and made little difference and unsure why this is happening ?
The coil is correct size and coils not touching,tried 2 different volt/amp meters and read the same ???
All worked really good at higher voltage and but about 22A but power unit says 12.5a max like you say but only doing a couple of cases at a time and no issue yet !
Any ideas of why this might be happening ??? Thanks
Ross...
It is a relativity simple design broken down to it's components (removing the coolant system, timer, and trap door) To check things out connect the inductor PCB to the PS through the power/contactor relay only (turned on by the timer) for just a second or two to keep the coil from over heating without the coolant system connected. At 43 volts you should draw no more that 8.6 amps without a case in the coil (as you say your coil is good.. no shorted windings). Drawing any more than that leaves only one thing.... The inductor printed circuit board. Your PCB may have a shorted MOSFET, but in any case looks like your board maybe bad.... Sorry
Hope this helps
Gina
It is a relativity simple design broken down to it's components (removing the coolant system, timer, and trap door) To check things out connect the inductor PCB to the PS through the power/contactor relay only (turned on by the timer) for just a second or two to keep the coil from over heating without the coolant system connected. At 43 volts you should draw no more that 8.6 amps without a case in the coil (as you say your coil is good.. no shorted windings). Drawing any more than that leaves only one thing.... The inductor printed circuit board. Your PCB may have a shorted MOSFET, but in any case looks like your board maybe bad.... Sorry
Hope this helps
Gina
Ok thanks for that will do and was my thought that the PCB could be dodgy for some reason !Ross...
It is a relativity simple design broken down to it's components (removing the coolant system, timer, and trap door) To check things out connect the inductor PCB to the PS through the power/contactor relay only (turned on by the timer) for just a second or two to keep the coil from over heating without the coolant system connected. At 43 volts you should draw no more that 8.6 amps without a case in the coil (as you say your coil is good.. no shorted windings). Drawing any more than that leaves only one thing.... The inductor printed circuit board. Your PCB may have a shorted MOSFET, but in any case looks like your board maybe bad.... Sorry
Hope this helps
Gina
Just a quick update - my coolant pump seems to have a leak. I believe the case and/or tank got cracked during shipping, from the look of it (I can see the stain from coolant in part of the crack, anyway). It only leaks when it's warm, which is amusing. I've attempted the ol' JB Weld fix... ha ha. If that doesn't work, I'll order another. It'd be nice if they shipped them in something other than a bubble padded envelope, but... oh well. Inexpensive, if I have to order another pump.
I would... but I already applied JB Weld to it... so I'm not sure it's return eligible anymore I did some nosing around, but the other PC related cooling options are quite a bit more expensive. I could buy 4 of these pumps and still not spend the same as a different solution there might require. We'll see what happens here - if I end up needing a second one, and it leaks, I'll look for a different solution.
I did some nosing around, but the other PC related cooling options are quite a bit more expensive. I could buy 4 of these pumps and still not spend the same as a different solution there might require. We'll see what happens here - if I end up needing a second one, and it leaks, I'll look for a different solution.
dskogman
Gold $$ Contributor
Update on my blown induction board. I got a new board and added another SSR to make it “double pole” but that caused more problems. Anneal time doubled and ended up blowing the new board after about 50 cases 
Now I have two blown boards and one DOA.
So I pulled a good capacitor off another board and replaced this one, took the second SSR off and got it running again. Got out my infrared temperature gauge out and found the temps at the bottom of the front outside caps was getting over 250 deg and rising when I fed cases as fast as I could (90% + duty cycle). That is with heat sinks on the bottom.
I found that it heats up quickly but also cools pretty quickly so I moved the fan from the top to the side and added another fan on the other side to get the temps under control. I then ran 300 284 cases thru it @ 3.5 sec, 22 amp, 36v, 785 Watts (1000 watt power supply) and the temp didn’t get over 165.
I am going to add some temp sensors to monitor the temps and shut it down when it gets too hot.
Now I have two blown boards and one DOA.
So I pulled a good capacitor off another board and replaced this one, took the second SSR off and got it running again. Got out my infrared temperature gauge out and found the temps at the bottom of the front outside caps was getting over 250 deg and rising when I fed cases as fast as I could (90% + duty cycle). That is with heat sinks on the bottom.
I found that it heats up quickly but also cools pretty quickly so I moved the fan from the top to the side and added another fan on the other side to get the temps under control. I then ran 300 284 cases thru it @ 3.5 sec, 22 amp, 36v, 785 Watts (1000 watt power supply) and the temp didn’t get over 165.
I am going to add some temp sensors to monitor the temps and shut it down when it gets too hot.
Dsk...
I'm not sure what is happening with your PCB's. I've had my original GinaErick going since July 2016. Have gone through 1,000's of cases, one hundred at a time, with no over heat problems.
I'm not saying the SSR is causing you problems, but that is the big difference between the original design. For what ever reasons the contactor/relay is causing no problems.
Just some thing to think about.
Gina
I'm not sure what is happening with your PCB's. I've had my original GinaErick going since July 2016. Have gone through 1,000's of cases, one hundred at a time, with no over heat problems.
I'm not saying the SSR is causing you problems, but that is the big difference between the original design. For what ever reasons the contactor/relay is causing no problems.
Just some thing to think about.
Gina
He's using a different induction board, though - that could be part of the issue?
dskogman
Gold $$ Contributor
It’s the bigger 50 amp board and 1K power supply. Also slightly smaller coil to get anneal times down.
My guess is that even though it’s rated at 50 amps it’s not a 100% duty cycle. You can watch the temps rise when it’s running and drop when it stops. With one fan on top it gradually creeps up. With two fans on the side it can pretty well keep up.
The difference i think is the original design uses a timer with a built in delay to load another case which gives a cool down period. I have a photocell to start as soon as a new case is dropped so there is almost no cool down before it starts again if you throw them in as fast as you can.
My guess is that even though it’s rated at 50 amps it’s not a 100% duty cycle. You can watch the temps rise when it’s running and drop when it stops. With one fan on top it gradually creeps up. With two fans on the side it can pretty well keep up.
The difference i think is the original design uses a timer with a built in delay to load another case which gives a cool down period. I have a photocell to start as soon as a new case is dropped so there is almost no cool down before it starts again if you throw them in as fast as you can.
The photo in reply #832 above shows a missing high frequency capacitor which is part of the paralleled set of capacitors that tune the output coil to the desired frequency. This message is an indication of how important the high frequency capacitors are to reliable use! Operating capacitors at 10's of kHz and very high circulating current demands VERY high quality capacitors and one cannot cut corners here! As frequency goes up, especially with high value capacitors, the dissipation factor of the capacitor goes up causing high heat due to excessive power dissipation within the capacitor.
By the way, the two round toroid cored inductors on either side of the capacitor bank are the inductors I was writing about a few days ago.
The current in these coils WILL NOT stop as soon as the power relay opens! The back emf of the coil will keep current flowing for a finite time even if the across contact voltage must rise to thousands of volts! That, is why you need some capacitance across the input and ground pins of the osc. board, to buffer that current till it dies out.
By the way, the two round toroid cored inductors on either side of the capacitor bank are the inductors I was writing about a few days ago.
The current in these coils WILL NOT stop as soon as the power relay opens! The back emf of the coil will keep current flowing for a finite time even if the across contact voltage must rise to thousands of volts! That, is why you need some capacitance across the input and ground pins of the osc. board, to buffer that current till it dies out.
Could be
You could be right. With my 3 seconds delay to load anther case in, I figure my duty cycle is about 60%. The capacitors did get warm/slightly hot, after 100 cases. Also I'm running less current than he is. 43 volts @ max 12.5 amps, total 537 watts. I'm happy with low and slow, besides sitting at the bench annealing is relaxing. Only takes less than 15 minutes to anneal 100 cases, which is more than I would shoot in a day at the range.
Gina
You could be right. With my 3 seconds delay to load anther case in, I figure my duty cycle is about 60%. The capacitors did get warm/slightly hot, after 100 cases. Also I'm running less current than he is. 43 volts @ max 12.5 amps, total 537 watts. I'm happy with low and slow, besides sitting at the bench annealing is relaxing. Only takes less than 15 minutes to anneal 100 cases, which is more than I would shoot in a day at the range.
Gina
What I've done, so far, is to run about 50-75 and then pause for a minute or two, and give things a chance to cool back off. I've only judged it by coil temp via my hand, so far.
Right now, I'm running about 625 watts at peak (13-ish amps at 48v), and I have 2 seconds between cases. That results in 63-75% duty cycle, depending on which cases I'm annealing. It would be easy to program in a longer pause for different cases to keep duty cycle around 60%, and it would still be plenty fast enough. With the photocell arrangement, you could just take longer to drop the next case?
Right now, I'm running about 625 watts at peak (13-ish amps at 48v), and I have 2 seconds between cases. That results in 63-75% duty cycle, depending on which cases I'm annealing. It would be easy to program in a longer pause for different cases to keep duty cycle around 60%, and it would still be plenty fast enough. With the photocell arrangement, you could just take longer to drop the next case?
dskogman
Gold $$ Contributor
Adding a minimum time between cases is easy now I know what the problem is. I’m also adding some temperature sensors to provide thermal protection.
The cheap harbor freight IR temperature gauges work really well to find hot spots on the board.
https://m.harborfreight.com/Non-Contact-Infrared-Thermometer-With-Laser-Targeting-69465.html
The cheap harbor freight IR temperature gauges work really well to find hot spots on the board.
https://m.harborfreight.com/Non-Contact-Infrared-Thermometer-With-Laser-Targeting-69465.html
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