Category Archives: Swaging

So… What Have I Printed?

Since I got this printer on 9-3-2013, it’s been used for over 238 hours of printing (that’s over 9 hours a day of printing!).  So, what have I printed?


Successful prints:  These either worked as expected the first time (about half of them) or required several iterations to get them ‘done’.

  • Pen & pencil holder (downloaded from Thingiverse)
  • Rifle scope zoom rings (that I designed)
  • 3 versions of RCBS decap / primer catchers (Thingiverse / revisions by Lon)
  • Derim cup (that I designed)
  • Piston, rings and rod (downloaded from Thingiverse)
  • Core swaging catch tray (that I designed)
  • Bleed tray (that I designed)
  • Core shaker (that I designed based on another’s work)
  • Customized iPhone cases (downloaded from Thingiverse & modified)
  • Ford V6 engine block (downloaded from Thingiverse)
  • Clips to mount plexiglass to the printer frame (that I designed)
  • Model railroad track clips (downloaded from Thingiverse)
  • Proof of concept for brass sorting (that I designed)
  • Reloading die holder (that I designed)
  • Lego-style pieces (downloaded from Thingiverse)
  • A plastic bullet (that I designed)

Works in progress:  These still require some work…  either I need to modify the design (the die plate holder), or the model is complex and requires a more advanced approach to printing.

  • Model windmill (downloaded from Thingiverse)
  • Reloading die plate holder (that I designed)

Several of these were just for fun – to see what the printer would do.  Most, though, solved specific problems.  Would I have spent money on equivalent commercial products?  Probably not for many of them.  In many situations, the equivalent products cost more than I was willing to pay (I know…  so I bought a 3D printer instead).  However, some are invaluable – and others are interested in purchasing them.  In any event, I’m still blown away by the technology & the possibilities – I’m turning bits into useful objects right here on my desk!


Speed to Market – Transformational Technology

After about 3 weeks with my printer, I’ve decided to take the leap and offer 3D printed objects for sale.  To be sure, it’s a bit of a leap of faith – I’ve gone from “hobby & home use” to taking orders in that period of time, with no previous 3D printing experience.

One of the interesting aspects of this is demonstrating how this technology can truly revolutionize ‘speed to market’.  When I got the printer, I had a couple of ideas for products that would serve a niche market… In the week between ordering the printer and receiving it, I quickly evaluated and then learned (just the basics) of a CAD program.  I spent several days of that first week designing several of my ideas, turning them from thoughts to bits.  Then, over the next 19 days (which included a 4 day business trip), I was able to learn the basics of printing, iterate through several design changes on each of the items I’d drawn, send them for testing and offer them for sale. In less than 3 weeks.  That’s transformational technology! In that same time period, I’ve come to know (virtually) a couple of people – Lon in particular – who have provided timely advice that’s minimized my learning curve and kept things that could have derailed on track.  That highlights another key aspect of the technology curve – how the internet is central to enabling this journey.  I’m pointing out the obvious now, but with a reason – I remember a few short years ago when this would have been impossible. Even IF I had a 3D printer then, my ‘market’ would have been folks I could reach through classified ads in specialty magazines delivered by the postman.

WIll it be successful?  Can the printer (and can I) deliver on the expectations I’ve set?  Time will tell.  To be sure, there are some risks.  But, I’m also taking a measured approach – this isn’t an endeavor where I’ve taken out ad space on a major site and shouted from the mountaintops…  I’ve identified a narrowly focused niche market (that I’m part of) and provided small solutions to every day problems.

There are a couple points of potential failure that need to be considered.  Will the (relatively) unproven printer be up to the task?  What if demand exceeds my capacity?  Will I ever sleep?We’ll know soon. I’m writing this in the hours before openly announcing product availability on a forum. I’ve hinted at offering them for sale – and my latest post on one forum generated significant interest… and there is a line forming.  Wow.

So, here we go!  With the encouragement and support of several key people, I’m off!


Putting the Pieces Together

Kind of like building blocks, I’m taking what I learn and then adding to it.  In this case, the original design for this core swager was 100 holes.  Because of the warping problem, I divided the part into quarters and printed them separately.  I still had some warping, but after printing the first few my ‘mentor’ suggested something that helped a ton!  Since I knew the basic concept worked, and while I worked on solving the warping / shrinking problem, I printed enough pieces to make a whole top piece.  Next step – combine them.


When I brought up glue, my ‘mentor’ seemed to scoff (if you can infer emotion in an e-mail without emoticons).  Not glue, ABS slurry (pieces of ABS melted in acetone).  Easy enough and I certainly have enough scrap ABS built up!  While I don’t know the strength of the joint yet (it’s still drying), this is a common practice for 3D printers.

The other obvious takeaway here is that 3D printing isn’t limited to objects that are the size of the build plate.  Pieces can be printed and bonded as necessary to create a much larger object. Even a car!  Check this out.

The pieces that make up this top plate of the core shaker are a hodgepodge of proofs of concept; the amount of warping on the bottom varies as I worked out the kinks.  The white one?  Yeah, that’s what happens when you’re tired & trying to get a print started before going to bed.  I told it to use the wrong extruder (…that was loaded with white ABS instead of black). Oh well – great visual reminder for me to check all of the details twice (or, from an earlier post, ‘measure twice, print once’.  Yes, sometimes I’m a slow learner.



Working Proof of Concept

After several setbacks, I have a working proof of concept for a core shaker, adapted from a design from a member over on CastBoolits!  It’s not perfect, but it works.  But, there are still several problems to solve:

  1. I’m still fighting some lifting / warping on the bottom, even though this print is much smaller.  However, even though the bottom is a little bowed, it will still work.  It’s not as pretty as it could be though.
  2. My hole sizes may be a little large.  I’m finding that with ABS, holes (in particular) tend to shrink from the size they’re drawn at.  So, after my first prints, I had to enlarge the holes but I didn’t know for sure how large to go.  After a few trials, I went with a 7.4mm (.291″) on the drawing.  That translated to a 6.6mm (.259″) hole in the plastic.  That works for the jackets, but the cores tend to hang up on the edges of the jackets as they’re going in the holes.  This may also be solved by making one of the trays a bit higher (so the core is at a steeper angle falling into the hole and less prone to catch on the lip of the jacket).  Or, a combination of both.
  3. Combining pieces together.  As drawn, I included a small cut / relief on the base edges thinking they’d align well and be a place for the glue to go.  But, with the warping, those edges may need to be at the top, and I’ll glue these together sitting face down.  These pieces will make a good test for that.
  4. Layer alignment.  Right now, nothing is implemented to align the top & bottom layers.  I’m thinking of putting little nubs on the bottom layer that would align with small divots on the top layer.
  5. The fence.  This part (should) be simple :).  This should just amount to a box.  But, given the warping / lifting, I anticipate the size of the completed box is going to cause some problems.

So, in case I jumped into the weeds and the concept of this ‘core shaker’ doesn’t make sense, here’s a brief explanation.  The cores need to go into the jackets; doing it manually takes time. After stacking the black tray on the white tray & surrounding both with a fence (the index cards for now), empty jackets are poured onto the top of the black tray.  Shaking the whole thing around causes the jackets to tip & fall heavy-end first into the chamfered holes.  Then, cores are poured on top of the black plate and shaking again causes the cores to drop down the holes and into the jackets.  Lift off the top plate and you have them all sitting up, ready to be picked up individually for the core seating die.



Trying Again – Core Shaker

This one is a bit of a challenge… After learning more about how to control some of the variables, I’m trying again. All it needs to do is stick to the plate & not warp!


Update:  Unfortunately, after approximately 6 hours of printing, I came to the realization that this print was doomed.  Although not as severe as before, two of the corners started to lift & warp.  Because of the tolerances required of this part, this would impair its function.

Back to the drawing board – the next approach will be to design this part in separate pieces, which I’ll glue together after they’re printed.  So, the entire assembly will require 9 pieces – 4 for each section of the two trays and 1 for the case that will hold the two trays.


Busy Week!

My world includes a full-time career that has its own demands for my time.  Notably, it pays the bills :).  This week, I have limited time and access to my tools…  so take this opportunity to read some of the material I’ve updated in the ‘Swaging‘ section of ‘Making Your Own Bullets‘.

I’ve added quite a bit of content to the ‘Swaging Equipment‘, ‘Cleaning Brass for Jackets‘ and ‘Annealing Jackets‘ subsections.  In these sections, I’m laying out the choices I’ve made as a new bullet swager, and I’m starting to detail the processes I’m using.  If swaging interests you, this is a great starting point to begin understanding what you’d need to do to create your own projectiles.



Swaging Catch Tray – Done!

Another milestone today.  Overnight, my ‘catch tray’ finished printing.  In the thread over at Castboolits, a member that I’d already printed & boxed up an RCBS decap tray for expressed interest in my design.  So, since I’m still cautiously jumping into this, he is my first official beta tester.

For those not familiar with swaging bullets, here’s a video showing cores being swaged to weight.  They’re falling out into my new catch tray.

The lead cores you see were originally stick-on wheel weights (almost pure lead).  They were melted and cast into rough cores using a purpose-built mold.  These cores are what’s inside the jacket of a bullet.  The rough cores are swaged to a specific weight (the weight of the cores + the weight of the jacket = the finished weight of the bullet).  Consistency in weight is very important – these will become 55 grain FMJ bullets when they’re done.

When the cores are swaged, they are compressed under tremendous pressure, forcing the extra lead out through a hole in the side of the die (and into the small cup at the top of the press in the video).  Then, when the handle of the press is lowered, the core is ejected and it drops into the catch tray.


Second Swaging Accessory

I’m focusing first on swaging accessories; the second piece in my “set” of items I want to design and print finished up overnight.  This is a ‘derim cup’.

Derim Cup Assembly

Derim Cup Assembly

A derim die takes a piece of empty .22LR brass, and pushes it through the die to flatten out the lip.  That creates the jacket for a .224 (for .223 / 5.56) bullet.

The derim cup catches the jackets after they’ve passed through the die.  This is a problem that can be solved many ways – using an empty soda bottle or hose, for example.  But why do that when I can print one, and it matches my press?

The whole assembly comes off the die easily and separates at the base so the cup can be emptied.  This one is sized to contain my typical batch of jackets that will go on together for further processing.


Day 1 – The Outcome

Ta da!  When I left for work in the morning, my newest creation was printing.  When I came back, it was done – it’s a “bleed tray”.  When swaging lead cores, they’re pushed through the die and the excess lead bleeds off through a hole in the side of the die.  Unfortunately, it drops to the floor.

This simple bleed tray solves my problem.  It’s not revolutionary, but it represents a huge breakthrough in how technology is accessible for us to solve problems.  More to come!

Bleed tray that catches extruded lead from a core swage die.