Induction brass annealer redux

[Mike17]

@dskogman
Is your design adjustable in high?
Any recommendations how to attache the cylinder to the servo?

In the meantime I got the servo.
Tataaa....first time and it works without the servo driver very well. Thanks for the idea .

Anyway, I've ordered also the driver from CN.
As soon it is here I'll compare the two versions.
Mike

 

[dskogman]

Gina,
I noticed the amp reading takes a few seconds to ramp up so it's only at the max for a second or so. Is that normal or the gauge?

Mike,
The servo mount slides up and down in slots cut in front of the case and clamped with two Allen screws. You can kind of see them at the end of the video I posted. I'll probably make some spacers to put on the rotating cylinder to make it quicker to adjust.

To mount it on the servo you can use these :
https://www.servocity.com/standard-hub-horns
Just make sure you get the right number of splines.

 

[Gina1]

Gina,
I noticed the amp reading takes a few seconds to ramp up so it's only at the max for a second or so. Is that normal or the gauge?

Mike,
The servo mount slides up and down in slots cut in front of the case and clamped with two Allen screws. You can kind of see them at the end of the video I posted. I'll probably make some spacers to put on the rotating cylinder to make it quicker to adjust.

To mount it on the servo you can use these :
https://www.servocity.com/standard-hub-horns
Just make sure you get the right number of splines.

In the two basic units I built, on both of them when I am annealing, the current will ramp up. (about .5-.7 amps over the 5.4 seconds of my anneal time).With no load in the coil it is stable at 8.6 amps, so I don't think it is the amp meter. Most likely as the case gets hot it changes the load presented to the coil. IMHO.
That's the advantage with a constant current build, the one that GrocMax built. It adjusts the voltage of the power supply to keep the current constant.

 

[dskogman]

I measured the voltage drop across the shunt and it was 23.3 mv. The shunt was labeled 75mv at 50 amp so I am actually running 15-16 amps instead of 30+. Looked at the gauge closer and it is 0-100 instead of 0-50 Didn't think I was running it that hot.
This was from amazon so i'll send it back.

 

[Gina1]

I measured the voltage drop across the shunt and it was 23.3 mv. The shunt was labeled 75mv at 50 amp so I am actually running 15-16 amps instead of 30+. Looked at the gauge closer and it is 0-100 instead of 0-50 Didn't think I was running it that hot.
This was from amazon so i'll send it back.

Good find on your part. Your not he first one to come across this problem/parts mix up. So much of our parts come out of China and English being a second language to them, mix ups do happen.

Gina

 

[Jose_Luis_G]

Easy question for experts.
I have finally bought a 48V CC - 1KW power supply, since sometimes I was too short with some coil diameters.
I had a 48-500W before, and now I wonder if I can put both together.
Has anyone the slightest idea if this can be done?
Is it just by connecting both + and - output terminals in parallel, same as batteries?
Please enlight me.

 

[Gina1]

Easy question for experts.
I have finally bought a 48V CC - 1KW power supply, since sometimes I was too short with some coil diameters.
I had a 48-500W before, and now I wonder if I can put both together.
Has anyone the slightest idea if this can be done?
Is it just by connecting both + and - output terminals in parallel, same as batteries?
Please enlight me.

Jose... simple question... "why" The inductor PCB is rated for 1000 watts, if you got both power supplies hooked up in parallell (some how) you could draw way too much current into your induction PCB. Can you say smoke.

 

[normmatzen]

Gina1
If the existing 48 V /500watt supply did not sag under the existing load of the PC board, it will not produce any more power than the single 48V supply. Adding two 48 volt supplies in parallel will increase the capacity of the primary supply, but not of itself increase the output of the board/coil combination.

 

[Gina1]

Gina1
If the existing 48 V /500watt supply did not sag under the existing load of the PC board, it will not produce any more power than the single 48V supply. Adding two 48 volt supplies in parallel will increase the capacity of the primary supply, but not of itself increase the output of the board/coil combination.

Agreed..... except if Jose changes his coil design, as noted in his previous post. Also how much current being drawn from the power supply is dependent on the diameter of the case being annealed and how much of the case is in the coil. It would be easy to blow the inductor PCB if the power supply could deliver more than 1,000 watts.

 

[Jose_Luis_G]

Agreed..... except if Jose changes his coil design, as noted in his previous post. Also how much current being drawn from the power supply is dependent on the diameter of the case being annealed and how much of the case is in the coil. It would be easy to blow the inductor PCB if the power supply could deliver more than 1,000 watts.

You are right. I didn't thought of overloading the inductor PCB. It doesn't make sense to enable a higher power output for just nothing but burning the PCB.

Anyway... How should it be done? Just + with +, and - with -?
Has anybody tried to make such connection?

 

[Mike17]

@dskogman

I mounted a small disc to the servo. When I adjust to a higher position (1.5"-2.0" below the coil) the spline and the gear (metal) is getting hot by the induction.

Do you had the same problem?

Mike

 

[dskogman]

@dskogman

I mounted a small disc to the servo. When I adjust to a higher position (1.5"-2.0" below the coil) the spline and the gear (metal) is getting hot by the induction.

Do you had the same problem?

Mike

That's why I used the cylinder (made of Delrin) instead of a thin disk. It gets the servo away from the coil and keeps it from getting hot. It was actually left over from a case feeder on a "Skip's annealer".

Also got a new voltage/current meter with actual instructions this time and found out the display can bet set to either 50 or 100 amps depending on which shunt you use. I'm actually using 16 amps instead of 32 amps which is much more like it.

 

[Mike17]

It seems that a lot of us started with fire .
I also have the "Skip's annealer" parts over.
My material is called POM (hope it is the same ;-).
Are there more pitfalls?

Do you use the same VA-meter as before?

Actually I use a multimeter for controlling the current.
The ampere value from the installed VA is also wrong.
I've a 50A shunt. But the VA meter came with is for 100A. I couldn't find a way to switch it over.
So I also have to order a new one...

Mike

 

[dskogman]

This is the VA meter I used. There are a lot of them like it but this one includes instructions
https://www.amazon.com/gp/product/B01EUISFFE/?tag=accuratescom-20



The button in the bezel controls the range as well as other options. You can set it to blink if the voltage, current or power is over a limit.

Edit - It also runs off the line voltage so does not need a separate 12v feed.



I also found a voltage/current measuring module I can hook up to the Arduino and get rid of the separate meter altogether I may try.

 

[Gina1]

Nice find... Only gets better.

Gina

 

[Mike17]

I tried to measure voltage and current with the Arduino (voltage divider + ACS712-20) but I had no idea where to place the information on my small lcd and I don't want to add too much code in the loop for the annealing time (I already measure temperature).
So I decided to stay on the safe side and be independent from the Arduino.

Mike

 

[ottsm]

For my Arduino parts I'm using the following;

Parts from Amazon;
UNO R3 Atmega328p Arduino, the one I got included the USB cable.
DFRobot Gravity IO Expansion Shield V7.1, makes all the sensors plug and play.


Parts from Robotshop;
DFRobot I2C/TWI 4x20 LCD Module (RB-Dfr-146)
22cm 4-pin female-female Cable (RB-Dfr-311), got this for the LCD I2C connection
Octopus Voltage Divider Brick (RB-Elf-178), came with cable
Gravity Analog 20A Current Sensor (RB-Dfr-740), came with cable

Parts from Sparkfun;
Illuminated Rotary Encoder (RGB) 10982
Clear Knob for Rotary Encoder 10597
I made my own breakout shield for the rotary encoder. You will need some resistors for the LED's. DFRobot makes a Rotary Encoder but it is not illuminated. DFRobot also has a 10 turn Pot that is nice if you don't want to use an encoder (part#DFR0058, shown in picture below, believe the cable was included, uses a good 10K Bourns POT). Of course it doesn't have the push switch on it so a start push button that is separate will need added.

With this setup the following can be displayed;
Time Setpoint
Time Actual
Volts
Amps
Sequence step discription.

Photo's from my cell so not the best, actually LCD is clear and sharp. I'm also using a wireless Yun module with the Arduino, not necessary but I use this for development and it makes programming easier from across the air. I still am working on assembling the unit, I will need to add a photo sensor or some other sensor to detect if the case is ready. I've left the reading in mSec which it seems to do OK, once in awhile it will overshoot 1 mSec but I'm able to display voltage/amps/and actual time while also having the option to change the setpoint on the fly while the timer is counting up. Eventually I'll probably only show two decimal spaces. I've used about 30% of the Arduino's memory so far. The parts are reasonably priced.

 

[flagg]

I'm building something similar and stuck on the "sense the brass" part because with ir sensor is too crowded and I don't think a magnet sensor will work on brass

 

[dskogman]

I used these:

https://www.ebay.com/itm/Photoresis...432512?hash=item33c6e81c80:g:DsgAAOSwXeJXeok8

Clip the leads to the photo resistor and extend them with some wire so you can locate it close to the shell casing. Put it inside a tube to block off light from the side.

 

[alfack]

I like this guys' take on the whole idea, especially the adjustable height shell platform and the self-contained project box: