Induction brass annealer redux

[Alan B]

Fun with CAD on another shelter in place day. This shows how the mini cartridge feeder, induction annealing coil, and a case holder setup could be configured for a compact case annealing system. The case holder base is rim diameter and height specific to center the case and place the shoulder just inside the coil. A holder can be printed for each case type and swapped easily for consistency. The dumping lever can be actuated by a second RC servo to drop the cartridge out of the coil. It could even be actuated by the same servo with the proper linkages. RC servos are consistent and easy to buy compared to other motors and solenoids, and they don't require high power circuits to control them. Quality metal gear types should last a long time. The induction timing and servo controls can all be from an inexpensive Arduino or most any other microcontroller, avoiding the expensive timer. Most microcontrollers have extremely precise timing capability. A stack of washers counterweights the dump lever.

 

[Alan B]

I designed a case feeder. It's on Thingiverse. Works pretty well too. https://www.thingiverse.com/thing:4257637

Very Nice Case Feeder jthor!

I was going for something smaller and very simple. Presently I don't have enough room for a large (like yours or the Dillon) feeder due to the shelving I have, but one of these days I'll reorganize the space. This mini feeder also requires a bit more effort to load up the cases so it is not as good for bulk feeding.

 

[Alan B]

Question - how much annealing heat at the neck would it take to overheat the base? I see folks concerned about this, so I did some calculations to see what it would take. If we heat the top portion of the case to 1000F, and the base is safe to 500F how much of the case would we have to heat to endanger the base?

The thermodynamics math is pretty simple, I won't show the details unless folks really want to see it.

Turns out we would have to raise half the mass of the brass to 1000F (where it starts to glow), and lose none of this heat to radiation/etc (put it in a perfect insulator), for the total case to reach 500F from heat propagation. I was going to cut a case below the neck and see about how much brass was being heated, but instead I balanced a case to determine where the mid-point was. We would have to heat all the brass above that point to 1000F to have enough heat to endanger the base. On a 300 win mag case (for example) the balance point is about 18mm up from the base, and the shoulder is at about 56mm. So half the brass "mass" is below 1/3 of the way to the shoulder.

Some heat propagates down the case during the heating, but clearly we don't heat anywhere near half the case brass to 1000F and the amount of heat that propagates from the neck down the case is quite small compared to what would be required to heat half the brass to 1000F and endanger the base.

This seems to be understood by many but I haven't seen it calculated in this simple way. Hopefully it adds some useful insight. I think it is important to anneal cases quickly but not too quickly. Going too fast makes it difficult to maintain consistency. Going too slow would allow more heat to propagate down the case and would also make consistency more difficult as the heat loss becomes significant.

So what is the best duration for annealing? We can adjust the power supply voltage to get near this value. Power goes up with voltage squared, so it doesn't take a lot of voltage adjustment to make a big change in the induction power and rate of heating.

My suspicion is that 5 seconds is a good time to aim for, but I don't have a precise justification for it.

What do folks think is a good duration to aim for?

 

[davexre]

Well, I've been annealing (correctly, it seems, based on the gage pin test) in about 2.3 seconds - but I'm using a smaller coil, and taking advantage of a current limiting power supply. However... I may be switching back to the 1" ID "normal" coil, because I'm planning on playing around with the pseudo-Aztec mode that some of the folks here have been talking about, and I don't think I can really do it properly when I'm banging hard into the current limit (and, honestly, what's the point of actually putting *less* power into the induction board as load goes up?). My times with the 1" coil were around 3-4 seconds, depending on brand of brass, for 6.5 Creedmoor.

The calculation you did is cool shorthand - good thinking!

 

[Brucey Boy]

Question - how much annealing heat at the neck would it take to overheat the base? I see folks concerned about this, so I did some calculations to see what it would take. If we heat the top portion of the case to 1000F, and the base is safe to 500F how much of the case would we have to heat to endanger the base?

Good info to have. You have eased my mind on something that I think about every time I anneal.
My concern with a lower powered supply (600W) has been the annealing time is significantly longer than with the 1000W power supply. My 6.5 Creedmoor is 8.6s for the 600W and only 5.6s for my previous 1000W which I managed to smoke when an errant case shorted against the coil. I had a 600W on hand and have been using that since. My concern has been the propogation of that heat down the case during that extra 3s of the annealing process. I even tried for a while, but not any more, dropping the cases to quench in water to stop the propogation. I am very comfortable with my annealing times thanks to Tempilaq, and the results are good having achieved 24 reloads with no split cases with the 6.5CM using Lapua brass. I only pensioned those cases off when I rebarrelled.

 

[Andrew1101]

3D Printed Mini Case Feeder Experimental Design. Might be useful for the annealer as well. Shown here on Dillon XL750 awaiting RC servo to drive it. The first servo only had 90 degrees, this is designed for about 135 degrees of travel.

Hi Alan, do you have any photos/video yet with the servo working?

 

[Alan B]

So far I've only tested with finger-drive and I haven't done video. The servos turned out to be 90 degree so I had to re-order (due in soon). The design is set up for about 135 degree servo travel. With finger drive I've tested a range from 223 Rem to 300 Win mag with 2 rotor sizes. Seems to work fine on this second prototype but I'll probably increase the rotor and hopper depth a bit on the next one. The design is parameterized so it is easy to size for a cartridge or change hopper capacity, but it seems to be quite non-critical. My biggest concern was the 45 degree case rotation in the funnel but that seems to work fine. The one issue I've seen during testing is using a rotor with a too-large slot can pick up 1.5 small cartridges and jam it. Just two rotor slot sizes seem to cover the range.

 

[jthor]

Very Nice Case Feeder jthor!

I was going for something smaller and very simple. Presently I don't have enough room for a large (like yours or the Dillon) feeder due to the shelving I have, but one of these days I'll reorganize the space. This mini feeder also requires a bit more effort to load up the cases so it is not as good for bulk feeding.

It's a tad smaller that the Dillon or Hornady Case feeder.

 

[dulcimer]

Annealer shelf parts came in today. This was based off of @SGK 's design and mentoring; thanks again for your help. I had to learn a little bit of Fusion 360, but the process was straightforward. I'm also impressed with Multi Jet Fusion 3d printing; the parts look great! The inserts required some sanding, but now have a nice press fit. It may be a while until I'll get a chance to assemble it onto the annealer, but I'll show the unit again once everything is working as intended.

 

[davexre]

Annealer shelf parts came in today. This was based off of @SGK 's design and mentoring; thanks again for your help. I had to learn a little bit of Fusion 360, but the process was straightforward. I'm also impressed with Multi Jet Fusion 3d printing; the parts look great! The inserts required some sanding, but now have a nice press fit. It may be a while until I'll get a chance to assemble it onto the annealer, but I'll show the unit again once everything is working as intended.

Yeah, that looks nice! What solenoid are you guys using for the trapdoor? I'm sure SGK's got it buried in the thread, but I wasn't super successful in finding it.

 

[dulcimer]

Yeah, that looks nice! What solenoid are you guys using for the trapdoor? I'm sure SGK's got it buried in the thread, but I wasn't super successful in finding it.

I believe it's this one here: http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-50#post-37250618; https://www.amazon.com/gp/product/B07DC7TBXC/
https://www.amazon.com/gp/product/B07DC7TBXC/?tag=accuratescom-20
https://www.amazon.com/gp/product/B07DC7TBXC/
But I seem to have ended up with this one personally: https://www.amazon.com/gp/product/B00LBQ229Y/?tag=accuratescom-20

 

[SinWolf]

Good day all,

So it probably took me around 4 days to work through the 103 pages...

First, thanks for everybody's contribution to this thread, especially @Gina1 and @Hollywood who started the initiative and who was willing to share their info.

When I got to around page 20, I already had made up my mind that I will use and Arduino with a touch screen... And as I worked through the thread I saw more and more people started going the PLC/Microcontroller route...

I do have a few questions... And I was set on the components needed... But nearing the end of the thread, I started to get confused again... Basically, one needs to decide if you will be doing a copper coil which is water-cooled, or the ferrite core which does not necessarily need water cooling and also makes use of a smalles power supply.

@oliverpsmile : Where did you buy your ferrite core from? Part number? And did you buy it already wound with Litz multistrand cable?

@SGK : I love your enclosure... You say it was custom build... How was it constructed? Is it a sheetmetal laser cutting and bending job? If so, are you willing to share the manufacturing details (CAD drawings and bending schedules).

@SGK : There has been a lot of mention that you should NOT drill two holes for the coil, but rather make a slot through the enclosure front panel (if you use a metal enclosure)… You have the 2 holes through the aluminum faceplate... No issues with this?

@SGK , @jthor , @dulcimer , @ernest , @mktacop : Are you guys willing to share your native files for the 3D printing designs? (should I rather PM to request these)… All of your tables are different, but never the less, all of them nice designs (hope I didn't miss anybody)

Then, in the first part of this 103 page thread, there was an improvement by making use of the adjustable current limiting of the more expensive power suppliers... The idea was to limit the current on smaller cases to move away from the sub 3 second annealing times... This idea then faded away and wasn't referred to later on... Is this still a good idea to implement? The current limit (and setting) could easily be implemented in the Arduino code.

@mktacop : Where did you buy the separate water reservoir / pump? Do you have some details on these please (part numbers) ?

There was also some discussions on the dropping of cartridge through the trap door, but I'm not sure a firm decision was made. Do you leave the case in the coil, power down the coil, then drop the case? Or do you simply drop the case and power down the coils simultaneously?

Is it fine asking all these questions in one post? Or should I rather split them up into several posts?


Once I have some answers, I will then start searching for the parts online and start to order them...

THANKS AGAIN for everybody's contributions to this thread

 

[SGK]

I believe it's this one here: http://forum.accurateshooter.com/th...-annealer-redux.3908353/page-50#post-37250618;
https://www.amazon.com/gp/product/B07DC7TBXC/?tag=accuratescom-20
But I seem to have ended up with this one personally: https://www.amazon.com/gp/product/B00LBQ229Y/?tag=accuratescom-20

These are much the same but I did make the mistake of buying one which required over an amp of current to activate. So watch for the current draw.

 

[SGK]

Annealer shelf parts came in today.

You went all out! Keep me posted.

 

[SGK]

@SGK : I love your enclosure... You say it was custom build... How was it constructed? Is it a sheetmetal laser cutting and bending job? If so, are you willing to share the manufacturing details (CAD drawings and bending schedules).

I used these guys https://modushop.biz/site/index.php?route=common/home They aren't cheap when you add up all the customization. But I couldn't get two holes in the right place if I tried to do things myself. So I used CAD software and had them do the drilling, cutouts and engraving with their machines.

@SGK : There has been a lot of mention that you should NOT drill two holes for the coil, but rather make a slot through the enclosure front panel (if you use a metal enclosure)… You have the 2 holes through the aluminum faceplate... No issues with this?[/USER]

No issues and I can't think of why there would be EXCEPT if you are going to have the work coil protrude through any sort of aperture then it will need to be soldered in place unless the holes are big enough to be able to withdraw the wider copper tubing that attaches to the induction board. One of the design challenges here is how to support the work coil and yet have everything easy to assemble (and potentially disassemble). I felt I needed to support the work coil on the fascia of the enclosure. Hence the plastic grommets etc. This may not have been necessary given how I had mounting the coil to the induction board. Certainly two slots cut down from the top of the enclosure would have made installation easier.

@SGK : Are you guys willing to share your native files for the 3D printing designs? (should I rather PM to request these)… All of your tables are different, but never the less, all of them nice designs (hope I didn't miss anybody)
[/USER]

Yes, sure. My advice is to think through the complete design before fiddling with files though. You have to figure out how everything is going to be mounted within the enclosure, how you are going to support the shelf etc.

 

[ilc]

I've been reading this thread for a couple of months, and collecting the parts for my build. Thanks to everyone, and in particular Gina and Erick, for sharing their ideas.

I noticed that some people are having trouble sourcing suitable solenoids, so I wanted to suggest an alternative that I have found, automotive door lock actuators. e.g.

https://www.ebay.com/itm/12V-Car-Au...-Door-Lock-Actuator-Motor-2-Wire/142824736508

They are about $5, have a stroke of 20mm (just over 3/4"), a force of 4kg (about 9lb), and are supposedly good for 100,000 actuations. There are two basic sorts, 2-wire and 5-wire; to operate a trapdoor you only need the 2-wire version, the extra wires are for sensing the position of the driver's (or "master") lock in an automotive installation.

A brief pulse actuates the plunger in one direction, and you reverse polarity to make it go the other way. Note there is nothing holding it in position once the current is removed, so you'd need to arrange a spring to ensure this. For example, have a spring keeping the trapdoor closed, apply voltage to the actuator to open the trapdoor against the spring, which then closes under the tension from the spring when the voltage is removed. Depending on the spring the passive closing won't be as snappy as the opening, those using a microcontroller could use two relays and reverse the polarity for closure.

I bought an actuator for a bit of a play around and haven't used it in a GinaErick build yet, but I thought some people here mind find the idea useful.

Good luck!

Ian.

 

[Brucey Boy]

Have a look at this solenoid. It is push pull and has 2kg of force with 'plunger return' when the activating current is discontinued, so no need for reverse polarity to return to start position.

https://www.ebay.com.au/itm/DC12V-L...222067?hash=item283ce35073:g:0MMAAOSwCJxaNGId

 

[SinWolf]

Hi guys,

For those of you that have done multiple cases... In reality... How much adjustment is needed on the shelf (height wise) ?

@SGK thanks for your reply and input... Yes, I will make sure of my design before I start the 3D printing etc.

 

[Andrew1101]

I've been reading this thread for a couple of months, and collecting the parts for my build. Thanks to everyone, and in particular Gina and Erick, for sharing their ideas.

I noticed that some people are having trouble sourcing suitable solenoids, so I wanted to suggest an alternative that I have found, automotive door lock actuators. e.g.

https://www.ebay.com/itm/12V-Car-Au...-Door-Lock-Actuator-Motor-2-Wire/142824736508

They are about $5, have a stroke of 20mm (just over 3/4"), a force of 4kg (about 9lb), and are supposedly good for 100,000 actuations. There are two basic sorts, 2-wire and 5-wire; to operate a trapdoor you only need the 2-wire version, the extra wires are for sensing the position of the driver's (or "master") lock in an automotive installation.

A brief pulse actuates the plunger in one direction, and you reverse polarity to make it go the other way. Note there is nothing holding it in position once the current is removed, so you'd need to arrange a spring to ensure this. For example, have a spring keeping the trapdoor closed, apply voltage to the actuator to open the trapdoor against the spring, which then closes under the tension from the spring when the voltage is removed. Depending on the spring the passive closing won't be as snappy as the opening, those using a microcontroller could use two relays and reverse the polarity for closure.

I bought an actuator for a bit of a play around and haven't used it in a GinaErick build yet, but I thought some people here mind find the idea useful.

Good luck!

Ian.

Hi Ian, a 2.2A current draw is a drawback depending on what you have available. The case trap door needs little force to open, far less than the force to lock a car door. It would throw over with a lot of force and you would need to brace the solenoid accordingly.
The small solenoids mostly come in 10mm draw and that is a bit under what is desired, but with a bit of filing of the trap door plate a 243 case can be accommodated. 15mm drawer solenoids are available and are around double the size of a 10mm draw and probably close to that of the unit posted. No matter what you choose just be aware they are inductive so a freewheeling diode across them will protect the contacts that power the coil.

 

[SinWolf]

I just finished my version and I want to say thanks Gina/Erick for making this open source.



here is a brief parts breakdown of my build...


Nextion Enhanced 3.5" Touchscreen (NX4832K035).


thanks
James

Hi James,

With the Arduino code you did, and the graphics... Do I definitely need the Nextion Enhanced NX4832K035, or will the normal one suffice NX4832T035 ??

I'm struggling with stock of the NX4832K035...

Thanks