Induction brass annealer redux

[normmatzen]

The sparking 104 1KV capacitor is 0.1 uF and 1 KV rating. But, you don't know the construction of the capacitor without more data. If it is a common bypass capacitor, it may not have a good dissipation factor and high RF currents may severely overheat them. Try replacing with a high current rated RF capacitor.
A lot of this value capacitor are used for bypass capacitors to supply short transient currents for filtering out fast switching transients. That and bypassing power supplies to hold AF and RF feed-back to a minimum.

 

[golong]

I decided to make it easier (less expensive, so really just easier on my wallet) and went with the 750 as the only DC to DC relays that I was finding for the 1000 were well above $50 each. The plan always was to power the relay switching with the RP (now Arduino). The 750 will only be powering the induction board (through the relay, switched by the Arduino). I have a nice little 12V switching PS that I will run the fans, pump, and step down to power the computer.

@GrocMax - without this thread I do not know that it (creativity) would happen, at least in my case. It is far different to throw hundreds of dollars at a "could work" as opposed to expanding on something that others have done and been willing to tell about it. Without this thread, I would have saved a few hundred at first by raiding my computer graveyard in the basement for power and fans, used the coil that came with the heating board, abandon the fuses, etc., likely just to turn around and buy an AMP months later after suffering multiple component failures (I am over the inconsistency I see in flame annealers). Would much rather build something that I can personalize to the way I want to operate, than get forced into a work stream.

Based on the program selected, I should have brass height, current, induction initiation, induction time, and data logging for a given cartridge. The Arduino learning curve does not seem to be that bad so maybe I can pull it off. The more I play with the stepper motor, the more it may be better to have it raise and lower a tray inside the case that has the induction unit on it, rather than raising and lowing the ram platform. It may make the routing of the coolant lines a bit interesting, but it should take away the over-engineering that would be required to keep the ram platform steady (can likely nix the platform all together, just staying with a direct attach assembly). Will see - still a long way to go before I get to that part.

 

[dskogman]

Yes, A big thanks to the originators Gina and Eric and everyone that contributed to this thread
I've done a fair bit work with RP's and Arduino's so I'll try to help out where I can. I'm a software guy not hardware so be gentle.

Arduino is a better option than a Raspberry PI for this application. There is no operating system getting in the way screwing up timing, adding overhead, start up/login/shutdown, etc. There is also no built in UI, file system and lots of other nice features. Programming is 'C' so fast and efficient and not so easy for beginners.

Small Servo's, Motors, and Stepper motors can be driven directly off the Arduino but in practice you will need a separate driver board (shield or breakout) with independent power supply to do anything useful.

Steppers are limited to about 1-2 amps per channel and are not particularly powerful or fast without going to expensive drivers/steppers. If you need to move less than 180 deg a servo might be a better option.

I am using an Arduino UNO processor with a separate servo motor driver, photoresistor sensor, and LCD touchscreen. The servo drives the shell trap door, the LCD screen is used to enter anneal times and start/stop butttons, and photoresistor to trigger the inductor and timer.

Here is a screenshot of the LCD screen and a video showing the shell holder operation and SSR control. Now if I can get a working induction unit I can put it together.

 

[GrocMax]

The great part about the microcontroller plus LCD screen deal is once you've determined proper settings for various brands/types of brass you can just set up a simple menu system of cartridges for one touch control of the process- current limit if used, anneal time, cartridge position in coil etc.

Programming is a bit much for me so I chose the all analog route.

The stepper driven rotary platform is pretty neat.

 

[Mike17]

@dskogman

Really good idea with the servo!
I also started with an arduino version (mega2560, lcd 4x20, rotary encoder,.. ) .
Mechanically I have some trouble with the trap door.
I still looking for a solenoid that fits to it.
Maybe the solution with the servo is easier ...
Which servo are you using?

Btw. I use the sensor shield for the mega. This makes cabling much more comfortable.

Mike

 

[GrocMax]

Just a thought, but with a stepper and the rotary shellholder, you could set both case height, and case drop via a stepper motor. Connect two steppers on top of each other, shaft of bottom motor to case of upper motor, top stepper sets the height, bottom one rotates both the upper motor and the shellholder. Or vise-versa, probably 500 ways to do this.

 

[dskogman]

I used a servo I had left over from another project so you could probably get by with a smaller one. It is a HiTec HS-5485HB ball bearing hi torque servo from Servo City.
You also need a separate servo driver like this
https://www.amazon.com/gp/product/B01D1D0CX2/?tag=accuratescom-20.
Or
https://www.adafruit.com/product/815
The Adafruit site has real documentation and instructions as well as software libraries.

 

[Mike17]

I'm not familiar with servos, but the are a lot of application notes where the servo is directly connected to the arduino.
Do you think the separate servo driver is required?
Or is it for protection purposes?

 

[dskogman]

I have not had much luck driving them directly off the Arduino. I have one small one that works ok that way, none of the bigger ones do. The main advantages of a separate driver is it has separate power and an independent clock which eliminates servo jitter when the Arduino is doing something else. Serial I/O in particular like to a display will cause the servo to jump around. If you're only controlling a small servo and not doing much else it may work fine.

 

[golong]

@dskogman - which LCD screen are you using?

I am still waiting on a few parts, but the basics of the robotics will be:
12V 30A PS for the Arduino and kit
MEGA
TB6560 driver against Nema 17 26Ncm (36.8 oz in)
SunFouder relays using opto-isolation
8mm linear motion rods/bushings
Cylewet stop switches

The stepper will drive the screw raising and lowering the induction board platform. The stop switches will be used to reference Zero, and prevent a runaway. I will also be using shaft collars just to make sure.

I have not committed to an initiation sensor yet. I will talk with the machine shop next week and see if they can make the ram out of Derlin. If they cannot, then I will probably use a reed switch. If they can, then the plan is to use a laser emit and optical sensor to create a trip beam. I don't want to use this method if the ram is aluminum or steel since the laser would bounce.

 

[dskogman]

I used a 4D Systems display module. They have a lot of different sizes and options to choose from:
http://www.4dsystems.com.au/group/LCD_Displays/
I went with the 3.5" capacitive touch module with bezel (gen4-uLCD-35DCT-CLB) since I had one already but a smaller one would have been fine for this. Mouser carries them in the US.
This is not a beginner level project

 

[golong]

Not a bad price for that display. I have kind of been ignoring that portion since I originally planned on using an RP, with commands and logging being done OtA. Not having much experience with Arduino I was thinking of either push-button or turn dial to select the brass, or using an Android phone app. But, that display has me expanding my options.

 

[Gina1]

Not a bad price for that display. I have kind of been ignoring that portion since I originally planned on using an RP, with commands and logging being done OtA. Not having much experience with Arduino I was thinking of either push-button or turn dial to select the brass, or using an Android phone app. But, that display has me expanding my options.

Gosh darn, you all make my head spin. You would think this was an electronic/micro proc site, rather than a fire arms site.

LOL, you guys have just taken the original basic GinaErick brass annealer and run away with it. I know, I know, just building a better mouse trap. But Hey.. That's what it's all about.

When you get done, I'm sure everyone would like to see your designs.

Good luck

Gina

 

[golong]

WARNING -- ExpressPCB download.

If you have downloaded ExpressPCB, be aware that the download is marked as suspicious for trojans by several scanning engines. I pulled the current version through a commercial sandbox the other day; the download is bad. Online scan tools show prior versions were also bad. This link (it is not a download) takes you to the report for a couple prior versions:
https://www.reverse.it/search?query=ExpressPCBPlusSetup.zip

I know OrCAD Lite was mentioned in an earlier post as an option. Another is the free version of Eagle (https://www.autodesk.com/compare/eagle-vs-eagle-premium).

Anyway, if you downloaded ExpressPCB, they may have legitimately inserted the code (will spare the technical details), but even if they did, I would not want it on my machine.

 

[dskogman]

Got a new induction unit and it works fine so the original was clearly defective
Got it all hooked up and did some testing

I am using the larger induction unit and 36v power supply like targetshooter which draws about 18 amps unloaded and 24 amps loaded. My coil is a little larger so takes longer than I want so I'll play around with it some.

 

[golong]

Got a new induction unit and it works fine so the original was clearly defective
Got it all hooked up and did some testing
>snip<

Looks good! Hopefully you did/can get credited back for the defective unit.

 

[dskogman]

How hot is too hot for the inductor board?
Put a little smaller coil on and got the time to 4 sec on a 6.5x47. Ran about 50 thru as fast as they would go and the big capacitors got to another 190deg F.

 

[Gina1]

With the smaller coil ( I assume ID)(what size) How much current are you pulling from your power supply, 36V or 48V ? Early on in this thread I noticed that the caps get hot and added a cooling fan over the induction PCB. GrocMax also added a heat sink to the base of the inductor PCB.
Things you may want to try.
Gina

 

[dskogman]

Added another fan, heat sinks and cooling vents and it runs much cooler. It's drawing over 30 amps at 36v and 1000w according to the gauge and 4 seconds to anneal 284 brass. I have the 50 amp inductor board and 1000w power supply so it's at the limit if the gauge is correct. The coil is 1 1/8 at the bottom an 7/8 at the top. I also sprayed the coil with plasti-dip to insulate it

 

[Gina1]

Neat design...Nice.

Yep your at the limits. power wise. Any limits on your duty cycle ? Other than the time it takes to feed one case after another?

Glad the extra fan, heat sinks and cooling vents worked out for you.

Long way from the "basic" design.

Congrats...

Gina