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    Love Birds - Coin Cutting Tutorial

    love.jpgAuthor's Note: As I continue down this coin cutting path, I have found a few better ways of doing things, and have greatly updated this tutorial to reflect some better methods. This tutorial can be seen in a little cleaner format at:  http://www.coincutting.com/coincutting

    This tutorial initially began as a post of one of my projects but it got morphed into a pretty detailed and structured tutorial along with some video to make things clear. I have cut many many coins and over the course of the last few years, have worked out a method that has turned a painful process into a very manageable one. So this entry and the posts that follow it should help anyone that wants to give my method a try.

    Happy Cutting   ---------Randy


    Lesson One - Gathering the Essentials:

    1. Jewelers Blades. Pick up some 2/0 or 3/0 Pike from Amazon.com. The smaller the blades, the easier they break. Remember 2/0 is a larger blade than 3/0. Buy a gross, you will go through a lot, especially while learning. One additional note, if you are not used to small blade sizes, #2 is much different than #2/0. Make sure you order #2/0 or #3/0. #2/0 is larger and less likely to break than #3/0, but 3/0 will make a sharper inside corner.
    2. If you are doing detail, I would suggest starting with #72 drill bits from Sloans. Flying Dutchmans don't work, period. For beginner patterns, 1/16 from your big box store will probably work fine. The smaller bits are better at getting into very small areas but are more prone to break.
    3. 3-in-one oil or equivalent (for drilling)
    4. Superglue, preferably the new kind with a brush applicator
    5. Adjustable spring-loaded punch for creating an indention for drilling the holes. I like the "General 89" that you can get from Amazon.com or HomeDepot
    6. Ask around for Kennedy half dollars. If you want to try on something smaller (cheaper), you can shrink the pattern down to that size.
    7. If you want to start with smaller coins, you will need some thin wood to superglue the coins to so that you can hold it for the cut.
    8. Acetone (with a small jar to hold it). This is to soak and remove the superglue. Super77 just won't cut it for this.
    9. I use a typical magnifier, but along with that, I have the most powerful reading glasses I could find. You can probably get by without all that magnification for the starter patterns.

    To give you an idea of what you are in for, print the attached pattern out, then see if you can see this clearly on your scroll saw with your existing magnification.  If you print this at 100%, that will be Kennedy Half dollar size.  If you print it at 79.28%, that will be quarter-sized.  The pattern is one of my best selling coins and is the symbol of courage.  How appropriate for a starter coin.  Print it and tell me what you think.  The little red dot's mark the drill holes.

     

    Courage_Half_dollar copy.pdf

     


    Lesson Two - Getting the holes in the coin.

    While you are waiting on your order of Jewelers blades to show up, you can go ahead and get your coin ready to cut.  So that you know why I'm taking you through a few "easy" hoops, here is the issue you have with drilling the holes in the coin.  Unlike wood, if you drill in metal without Oil, you will mess up a lot of coins, trust me.  If you don't punch your starter holes first, the drill bit will wonder.  We can not put the pattern on before we drill, because the oil and drilling messes up the pattern.  (Early on, I used Supper 77, and the oil would cause the pattern to immediately lift).

    So,

    1. Take a good pair of scissors, and under your magnifier, carefully cut out the pattern, staying on the outside of the black line, but close enough that almost no white is showing. Take your time.
    2. Use CA (Superglue) to glue your pattern onto the coin. I found that using a thicker glue works best. Press the pattern down tightly so that all parts of the pattern are in good contact with the coin. Use Polyethylene gloves if you don't like to have glue on your fingers.  Use a thin CA (superglue), and with the Polyethylene gloves, rub a thin coat over the to of the pattern that is attached to the coin
    3. Use the spring punch to mark holes
    4. Put a little 3-in-1 oil in each punch mark, and carefully drill those holes. I also use a magnifier at the drill press to line it up. My eyes just aren't that good. Take your time, drill gently as small drill bits break easy.
    5. After the holes are drilled, wipe all the oil from the coin.

    Feel the bottom of the coin, de-burr if there are burrs on the bottom holes. The best way I found to do this is by turning over the coin, pattern facing down, placing it on a soft surface, and using the spring punch in each hole.

    This should leave you with a pattern secured to your coin. Sounds like a lot of steps, but it is just a few minutes in practice. As a beginner, getting the holes drilled and the pattern on was my greatest obstacle as I was trying to drill the holes without oil which caused me a lot of frustration. Once I got the above process down, this part that I dreaded became trivial and made the whole experience much more fun.

     


    Lesson 3 - Making those corners.

    1. If the corner is very steep, consider not turning at the end, but hitting it from both sides.
    2. If you are just starting the cut, cut directly to the line, back the saw up slightly, and grind the path another bladewidth wide. That should give you enough room to turn and resume directly along the line.
    3. Unless you have sharp corners or tight detail, go to a #2/0 or larger blade. Smaller blades break easier, with no benefit for many designs

     


    Lesson 4 - Yes You Can

    This is really less of a lesson, but more of an explanation as to why you might be able to do this kind of work even if you think you hands are too shaky, or your eyes are too bad.

    There are two very important things to understand:

    1. You can magnify the heck of things.  When you get older, you lose your ability to focus on things that are close.  Magnifiers and reading glasses bring that focus point closer.  Depending on the nature of your sight issues, with heavy reading glasses, and a magnifier, you should be able to regain that focus at a much closer distance, and as an equally powerful benefit, things are much much bigger.  Unfortunately, the more magnification, the closer you will need to be to your workpiece.  I have the magnifier right down close to the top of the upper arm, and my face right close to the magnifier.  I'm so close that often times when I break a blade, the top arm hits the magnifier, which in turn bumps my face.  When you sit down to cut, take a few minutes to work on the magnifier placement and your distance from the magnifier.  Unless you have other sight issues, you should be able to find the sweet spot, and see the pimple on a flea.  If you have other issues with your eyes that can't be overcome with magnification, then you might not be able to do the more detailed work.  Print out the sample pattern submitted above, look at it with reading glasses and the magnifier, and if you can get a clear image, you should be good to go.  You can only cut what you can see.
    2. Metal doesn't cut like wood, it is much much slower.  But, that said, because of the small scale, you don't need to go as far.  So, what this means, is that when you magnify the heck out of things, you see the pattern much bigger, and your cutting rate, because of the very small scale, perceptually is like working with wood on a larger piece.  This speaks to cutting at a smaller scale and maintaining control.  If metal cut like butter, we wouldn't have a chance.  So, cutting small isn't magic, and doesn't require superhuman cutting ability or superman vision.  So now you know my secret, I'm not really good, I just cheat.

    I'm not saying that you will not need to practice in the medium, like every medium, you will need to get a feel for how metal cuts, and like with wood, it will become more natural with practice. There are techniques that you will learn with a little practice, that makes some of this a lot easier.  We will cover these coming up.


    Video Demonstrations

    Here we go, a video for Applying the pattern.  Does this help to see those steps in action?  I'm a little nervous in front of the camera, so made a few verbal typos.  (Update:  I've updated my method for this above, which is easier.  The video below shows an older method where I use bits to align the pattern to the coin after drilling the holes.  This works well too, but is a little more hassle.  I hope to record my latest method to illustrate the simplified method.  The description of my current method is explained earlier in this thread.)

     

     

    I include below a brief video on how to polish the coins.  I have been cutting on coins that I purchase directly from the US mint, because they are a little crisper.  Since those don't need polishing, it has been many months since I did this, and forgot just how hot the coin gets.  I turned off the video and used some pliers to hold the coin to finish polishing it.  The difference in polishing makes is remarkable.  On the downside, glue doesn't hold as well on a polished surface.  If the coin project isn't too fragile, you would probably be better off polishing the coin after cutting it, so that you don't get pattern lift.

     

     

    polish.jpgAfter polishing the Quarter, I went through the process to attach the pattern.  I wanted to know how hard it would be to cut a quarter by holding it directly (without gluing it to a bigger piece of wood).  It has been a long time since I cut a quarter.  I was able to hold the quarter by hand and cut it fine, but I can see where that might give a newbie some issues.  Newbies should probably superglue the pattern to the sacrificial wood, at least with the quarter or smaller.  Below is the image of the quarter polished in the video compared to an unpolished uncirculated half dollar.  In-person, the difference is dramatic.

    As a bonus in case you want to do your own pattern, here is the Photoshop template for the 50 cent coin,  should also be able to open in Gimp and perhaps tools:  http://www.gloden.com/woodstuff/2015/_Template_50Cent.psd  You can always create patterns at this size, and shrink or expand for other coins as needed.

     


    Here is a video of the actual cutting.  Sorry, the video isn't polished, but you should be able to get the gist.

    If you can get anything from the video, this is what I hope you get:

    1. Grinding Technique:  During the video, the blade was getting quite dull, so the turns were becoming more difficult.  This allowed me to show you how to grind a corner.  Grinding a corner basically means you saw right up to the corner, or wherever you need a sharp turn, then back up a bit, press to the side and press forward to grind the kerf a little wider for the turn.  With sharp Pike blades, you can turn pretty easy without grinding.  With cheaper blades, you might have to do this, even when the blade is "fresh."  If the blade is getting noisy on the turns, better grind you some space to turn or you will be breaking that blade.  Also, even on straightaways, I'll stop backup and grind the line wide into the waste area.  This way, when the blade breaks, and it will, I will be able to get my blade back into the Kerf to resume sawing,  The first time you have to try to feed your blade right into a narrow kerf, you will understand why you create yourself "regeneration points".  Grinding is also how I fix a line that was cut a little wide.  You can just use the side of the blade to grind back to the line.  This is a very nice technique to tweak your cutting.  You may already do this in wood, you will probably do it more in metal.
    2. Manipulation of the coin is done with the fingertips.  Always try to keep multiple fingers pressing that coin down.  One little jump of the workpiece and the blade will catch and break.
    3. Notice that the video shows you my blade travel.  But as soon as the blade touches the metal, it totally stabilizes the blade.  This is why folks that have saws with blade travel can still cut detail.

    Bonus at the end:  You get to witness one of my many blade breaks which scared my cameraman (my 12 yr old son).  You can hear him say "My Goodness" as he tried to recompose himself.  🙂

     

     

     

    ---------Randy

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    Found something on google images that looked like it might be challenging, so I tried it.  Here is the result.

     

    --------Randy

     

     

    gallery_1770_540_6203.jpg

    h

    Hi Randy

    That is an amazing piece of work. The detail is incredible. ðŸ‘ðŸ‘

    I hope you do that video on your technique. I'm getting the popcorn ready. 😋

     

    Cheers

    Paul

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    Awesome work Randy.  I think you forgot one important thing.   The ability to hold your breath a really really long time :).  I do have a question Randy did you have to tune your saw so that the front to back and side to side variation was at a minimum?

     

    DW

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    ....... I do have a question Randy did you have to tune your saw so that the front to back and side to side variation was at a minimum?

     

    DW

     

    These don't have to be done on a well tuned saw.  I cut the love birds piece with noticeable blade travel.  Having no blade travel helps when you are lining up the cut, but if you start slow until you get that initial "bite", as soon as the blade hits the metal, the metal stops that travel and stabilizes the blade.  I need to get out the hex and re-adjust my saw to minimize travel as it just makes starting the cuts easier.  I've never adjusted the side to side as I don't notice having any of that.  I have my set screws locked in with locktite threadlocker, so they stay just proud of the inside of the clamp.

     

    ------Randy

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    That is one good looking cut.  The instructions are outstanding.  Thank you very much for taking the time to educate us all on this type of work.

    This is why I  am here to learn and be informed and your follow up on the questions is great.  Thanks again. You got me very interested in trying

    this out.

    jim

    penquin

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