Induction brass annealer redux

[normmatzen]

Not quite. The resistor should be in series with the relay contact to load, not across the relay contacts. And, you don't need the capacitor as that makes the current surge worse.
Actually, you don't want any capacitance on relay contacts other than filter capacitors in the source and load. It is common tho to put a series resistor and capacitor across the coil instead of a diode to suppress flyback action when the relay is de-selected as the current flowing in the coil cannot stop instantly as it is flowing in an inductor (the relay coil) and it will generate a high flyback voltage surge potentially destroying the transistor (if present) driving the relay coil. Most folks now use a simple diode now to clamp flyback voltage, like a 1N4007 Actually any of that series 1N4001 thru 1N4007. The last digit indicates reverse breakdown with the 4007 at 600 V or so.

 

[Terry Altom]

Looks like the 1/4" ID hose I got from Lowes is larger than the 1/4" OD copper tubing I've got. How are the rest of you connecting the copper to vinyl ?

 

[Frog]

TalTom
Try some radiator hose clamps
If that doesn't work get some 3/16inch hose and heat it up in hot water like you said in an earlier post

 

[Jose_Luis_G]

Not quite. The resistor should be in series with the relay contact to load, not across the relay contacts. And, you don't need the capacitor as that makes the current surge worse.
Actually, you don't want any capacitance on relay contacts other than filter capacitors in the source and load. It is common tho to put a series resistor and capacitor across the coil instead of a diode to suppress flyback action when the relay is de-selected as the current flowing in the coil cannot stop instantly as it is flowing in an inductor (the relay coil) and it will generate a high flyback voltage surge potentially destroying the transistor (if present) driving the relay coil. Most folks now use a simple diode now to clamp flyback voltage, like a 1N4007 Actually any of that series 1N4001 thru 1N4007. The last digit indicates reverse breakdown with the 4007 at 600 V or so.

Not sure about what you explain, since my mother language is Spanish and I'm not an expert in electronics.
I just try to find my way in this matter, to solve a problem.
I already placed a 1N4007 welded to the coil leads, but it doesn't make any apparent effect, since the big spark still remains at the desconnection on the contacts.
I saw in YouTube the capacitor solution and, in fact, it works to what the tremendous disconnection spark is concerned, but it still remains the connection problem in the contacts. It seems that the discharge of the capacitor in some way makes the contacts to slightly weld.
At this point, I would kindly request you to make an easy wiring diagram so we can all understand your meaning, translated into images. It will be really appreciated.

 

[Terry Altom]

I've got the smallest hose clamps, but even those don't

TalTom
Try some radiator hose clamps
If that doesn't work get some 3/16inch hose and heat it up in hot water like you said in an earlier post

I've got the smallest hose clamps I can find. When they go down all the way, they're a little eliptical shaped and I can hear air escaping from the connection. I'll look for 3/16" hose, but with that I'm also concerned about the same problem then going from the 3/16" ID hose to the 3/8" ID hose.

I may try a few layers of heat shrink on the copper tubing to enlarge it enough for a nearly tight fit on the 1/4" hose I've got.

 

[itchyTF]

Not sure about what you explain, since my mother language is Spanish and I'm not an expert in electronics.
I just try to find my way in this matter, to solve a problem.
I already placed a 1N4007 welded to the coil leads, but it doesn't make any apparent effect, since the big spark still remains at the desconnection on the contacts.
I saw in YouTube the capacitor solution and, in fact, it works to what the tremendous disconnection spark is concerned, but it still remains the connection problem in the contacts. It seems that the discharge of the capacitor in some way makes the contacts to slightly weld.
At this point, I would kindly request you to make an easy wiring diagram so we can all understand your meaning, translated into images. It will be really appreciated.

The diode across the coil and the contact arc are two different issues and are not related. The diode clamps the voltage across the coil when turned off.

 

[normmatzen]

As long as there is a net DC voltage across the electrolytic capacitor, Capacitance is Capacitance!
Just with a points capacitor, the capacitor sees a voltage swing both positive and negative. The Electrolytic is designed to work with a DC bias on it as it doesn't like swinging negative. That is why in the "olden days" when you wanted a large capacitor for a cross-over network on your speaker system, you used 2 electrolytic capacitors back to back as the speaker signal is AC and each capacitor works on a half cycle.

 

[Gina1]

Same case size, different brass, different annealing times
Had an interesting experience annealing some of the new Norma 6mm Dasher brass on the GinaErick annealer. I shoot 6 Dasher and of course up until the new Norma brass showed up, I never had to change any settings on the annealer, with fire formed Lapua brass. For what ever reason (different bass formula or different case thickness) my anneal time has gone from 5.4 seconds to 6.6 seconds (using tempilaq).
Just thought I would pass this on
Gina

 

[Terry Altom]

Great info as always.

I've got mine "function tested" although I still have yet to solve a leak around the 1/4" ID to copper. My next attempt will be to build up the copper with a few layers of heatshrink. I considered a 1/4"-3/8" brass compression fitting, but those look like they might be very close together with one on each pipe off of the induction board.

Very cool to see it work, though.

 

[Freightdog]

Hi, I've been reading this thread with interest as I would like to build my own. My problem is the 48v power supplies are really expensive here (UK @£200), but I have a 12a 30v bench power supply. Do you think this would be sufficient instead of the 48v unit?

Also is there a definitive answer to using a 12v relay instead of the 120v contactor? I'm not keen on using (the equivalent) 240v!

 

[Gina1]

Great info as always.

I've got mine "function tested" although I still have yet to solve a leak around the 1/4" ID to copper. My next attempt will be to build up the copper with a few layers of heatshrink. I considered a 1/4"-3/8" brass compression fitting, but those look like they might be very close together with one on each pipe off of the induction board.

Very cool to see it work, though.

Cool.... Another one up and working, that's great. If you can find it, the very small screw clamps work well with the 1/4" tubing. Try automotive supply store.

Gina

 

[Terry Altom]

I'm using a 1/4"-5/8" hose clamp, but when it gets down to compressing the hose it enlogates. There's just enough space between the copper and inside of the 1/4" host to create a gap.

 

[Gina1]

Hi, I've been reading this thread with interest as I would like to build my own. My problem is the 48v power supplies are really expensive here (UK @£200), but I have a 12a 30v bench power supply. Do you think this would be sufficient instead of the 48v unit?

Also is there a definitive answer to using a 12v relay instead of the 120v contactor? I'm not keen on using (the equivalent) 240v!

Well... the spec's for the inductoor PCB are 12-50VDC. There was another fellow, one page back, that was talking about trying a 12V 50 amp PS. "bertn" I don't know how that worked out, but you could PM and ask.
12 volt relay could work, but one person had some problems with it burning up the contacts (arcing at disconnect).... Read the posts on the last few pages on this thread. It may have been that he was using a single pole, single throw relay. The original design, was to use a double pole, single pole relay/contactor. It maybe that by opening both the supply and return to the inductor PCB, at the same time, it prevents any arcing. Or that there is more distance with a contactor/relay between the contacts when it's open.
Hope this helps

Gina

 

[Jose_Luis_G]

Hi, I've been reading this thread with interest as I would like to build my own. My problem is the 48v power supplies are really expensive here (UK @£200), but I have a 12a 30v bench power supply. Do you think this would be sufficient instead of the 48v unit?

Also is there a definitive answer to using a 12v relay instead of the 120v contactor? I'm not keen on using (the equivalent) 240v!

My dear friend. Power is the name of the game.
Your power supply is, all in all, 360W and you need at least 500W to have something like this running.
Try to find any power supply, say in 24V, 36V or any other, with an output power of 500 to 600W, better 750W.
Check at Aliexpress.com once you get an extra dose of patience.

I'm the one having problems with a 12V single contact relay.
If you go for a cheap one, the contacts are so close to each other that may get burnt with the disconnection spark.
On the basis of using 12V DC, if I were in your shoes, I'd rather go for a double contact relay of good quality. Else you can use a mosfet.
In the case of using a mosfet, I'm in my way to test the IRFP150N and I will let you know if it works right or gets burnt also (I don't think so).

 

[GrocMax]

Great info as always.

I've got mine "function tested" although I still have yet to solve a leak around the 1/4" ID to copper. My next attempt will be to build up the copper with a few layers of heatshrink. I considered a 1/4"-3/8" brass compression fitting, but those look like they might be very close together with one on each pipe off of the induction board.

Very cool to see it work, though.

Try zip ties.

 

[GrocMax]

Seems to me getting a Dillon (or other) case feeder to work would be pretty straightforward both mechanically and electrically. Use the switch input on the case feeder tube to cycle the coil on timer and shut the case feeder motor off, use the trap door output to turn on the case feeder motor.

 

[GrocMax]

Also if the coolant flow requirements are very low volume, it would probably work just fine using convection cooling thus eliminating the pump.

 

[Gina1]

Also if the coolant flow requirements are very low volume, it would probably work just fine using convection cooling thus eliminating the pump.

You could try it. Would you be using an air pump ? Take my word for it, that induction coil does get HOT without coolant. Running at 48 volts and 12 amps = 576 watts Think how hot 6 100 watt bulbs (if you can still find then) would get.

Gina

 

[GrocMax]

OK reading the spec sheet for the timer control, its not clear but are the start/stop inputs momentary switch? Hooking up a case feeder becomes easy if they are.

 

[GrocMax]

Convection liquid cooling with a radiator just no pump. The temp differential causes a pumping action all on its own. I was reading thru the thread it was mentioned the coolant flow was very low with the pump on.

Radiator cold side on bottom, goes to bottom coil, upper coil goes to radiator top, coolant circulates on its own.

You could try it. Would you be using an air pump ? Take my word for it, that induction coil does get HOT without coolant. Running at 48 volts and 12 amps = 576 watts Think how hot 6 100 watt bulbs (if you can still find then) would get.

Gina