X-carve engraving on 1" copper discs

I’m having trouble getting my X-carve to engrave onto 1" diameter copper discs (16 gauge, ~0.06" thick). Here’s my approach:

  1. Attach 1" copper blank onto 12"'x12"x1/8" piece of PVC using hot glue
  2. Secure PVC to X-carve work area
  3. Design my engraving (simple initials for now) using Easel
  4. Place location for engraving to origin (0", 0"). Sure wish I could set origin elsewhere.
  5. Set disc thickness to 0.06".
  6. Set cutting depth to 0.02".
  7. Use 30* engraving bit.
  8. Start carve setting home position to be middle of 1" disc. set Z-axis by dropping bit onto top of copper disc before tightening.
  9. Easel says the bit is too large for the job so I have to ignore it since there are no choices small enough.
  10. Carve starts and the X-carve moves around a bit going up and down in various locations on the disc, but when it finishes the end product isn’t anything like the design.

My questions:

  1. X-carve doesn’t seem to be following the design patter at all???
  2. Why doesn’t Easel provide choices for engraving bits?
  3. Is there a way to set the origin to somewhere else on the work surface?
  4. What kind of engraving bit is best to use?
    Thanks for any help or suggestions provided.

Set your bit size manually to something small like .01 or .005. You may have to experiment.

Easel won’t cut where it thinks the bit will cut into the design.

As I do not use Easel I am afraid I am not able to help in that respect. But I do have a great deal of experance with engraving on the mill… I can point you to some good engraving end mills… Also do you have a multi-meter that can measure continuity? If you get a set of alligator clips and some wire you can set up a simple way to zero your bit (extremely important in engraving) If you put one wire on the disk and one on your end mill then lower it until the meter sounds, you will have a perfectly zeroed end mill. I would also suggest milling a flat pocket for your fixture to sit in so it is level in all respects to the mill for engraving.

You can look into these end mills for really fine detail engraving on copper and the like.: http://www.ebay.com/itm/30-degree-bits-for-scoring-or-engraving-sharp-point-narrow-tip-Kyocera-Tycom-/151845694455?hash=item235ab56bf7:m:mGN0iAahiwNTDaxhSLMgpoA

http://www.ebay.com/itm/60-DEGREE-MICRO-CARBIDE-ENGRAVING-TOOLS-NIB-Kyocera-Microtools-Kyocera-MIT-/151850433796?hash=item235afdbd04:m:mncm7BexXyjgFodb2O6hy6Q

http://www.ebay.com/itm/90-DEGREE-MICRO-CARBIDE-ENGRAVING-TOOLS-NIB-Kyocera-Microtools-Kyocera-MIT-/381372593147?hash=item58cb93f3fb:m:mQpBd5vvPQEgAgnuxK4xwZg

They are a bit pricier than a normal cheap V bit, but the results are fasr better with MUCH less burring. But be aware they need high RPM on the spindle and not too fast of a feed rate or they will damage the small tips.

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Thanks for the tip about using a multimeter. That worked well! I will definitely check out the bits you mentioned as I move forward learning how to get things done.

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This is a follow-up to my original post. I was able to confirm that my X-carve is moving as it should by trying some test engravings in PVC using larger text and images. I was also able to engrave the small image I want by manually setting the bit size. I learned, however, that hot glue may not be the best adhesive for this application. During the engraving the copper disc heated up and partially melted the hot glue and the disc started to moved around. That probably means I need to use cooling water during the process. That will be tried next.

One other idea came to me with regard to the location of the disc to be engraved and the origin. I’m still using 1/8" PVC as a support for the copper disc. I used a 1/8" bit to partially cut an outline of a circle in the PVC that is the exact outer diameter of my copper disc. Now I have a location on my PVC support where I can affix the disc that will be the same from one disc to the next. It also will provide a place for cooling water to go during the engraving.

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Looking forward to some pics of the setup if you get the chance.

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Yep, copper is a pain being so grabby.

You may consider making your blank holder from a piece of metal, this will transfer the heat away from your blank and possibly negate the need for liquid cooling.

If you can, try rubbing the top surface of the blank with a block of beeswax before engraving. It’ll add a little lubrication without too much mess, smells nice and can protect the engraved sections from oxidation before you finish the item.

If you are using discs it is likely the copper is machine rolled and punch press cut out, which means it’ll be machine hardened. You may get better results by annealing the discs first to make them softer.

Cheers

Ian

Below is a picture of what I’ve built so far for engraving the copper discs. Thanks to those who have replied and given me ideas to follow. I do plan to make the blank holder out of aluminum, but while I wait for it to arrive I decided to make a blank holder out of a 1/4" thick piece of Delrin.

The recessed area on the left is where I place a blank so I can set Z-zero. The recessed areas to the right are where discs to be engraved go. I’ve been using double-sided tape and it works well. All three recessed surfaces were done at once and they seem to do the trick with regard to having all discs on the same plane. I made deeper cuts around the middle and right recessed areas for cooling water run-off, but I’ve really not found cooling to be necessary. That’s probably because I am not engraving very deep and each pass is taking very little metal out of the blank disc. I’m sure I need to learn more about total depth of cut and depth/pass as I progress. I probably made a mistake when I used the same bit to cut the deeper circles that I used to cut the shallow recesses since the Delrin cracked around the bit. If I make another one of these in Delrin I’ll use different bits for the two cuts. So, that’s my update. I’m open to any comments or suggestions from those who know more about this process than I.

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Looks really good. :smile:

Depending how close to the edge of the disc you need to engrave to consider adding three tiny clamps around the circle to clamp the disc down.

Probably easier once your jig is aluminium but a small metal clamp and screw every 120 degrees around the disc would work with no glue/tape cleanup and would give a good metal to metal interface for heat transfer.

Engraving copper is fairly easy. Engraving copper well giving solid outlines with minimal cleanup is hard. Lots of experimentation with bits, rpm, depths, feed rates. I spent ages getting the perfect combo for the 0.7mm sheet stock I use but those numbers don’t work in any other copper sheet/flat copper products I have.

Only advice I’d have is find a combo that works then adjust feed rate up or down 10mm/min and see if it gets better or worse and adjust to the sweet spot. Then WRITE THOSE NUMBERS DOWN SOMEWHERE SAFE!!! :smile:

Good luck.

Cheers

Ian

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I had to give up on using my Delrin blank holder and the use of double-stick tape. I don’t think the tape held the blank securely enough since my engravings were rather rough. Instead, I’ve gone to using a thick aluminum bar (see photo below). I carved places in the aluminum that will hold the blanks in known spots (see hand-written X,Y coordinates) so I can center things as needed. I also drilled a couple holes for each position and threaded them for hold-down screws. I printed out PLA washers so I could hold the blank down without fear of scratching it. The resulting engravings are far superior to what I was producing and, for a beginner, things are progressing nicely. My next step is to try the bits recommended by Travelphotog.

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@DavidBurger - just wondering, since this post is so old, if you tested the bits recommended and if you could post any progress on your project. I’ve recently bought some commemorative Marine Corp coins, they’re blank on one side and have the logo on the other. I want to engrave names and other personalized details on the blank side for some friends, but was interested in your final process, bit recommendations and feeds \ speeds …

Thanks!

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yes I am very interesting in engraving cooper. also…I follow you …some new info…? thank you for the help…roberto…

Do you have any photos of your final discs? I’m kind of interested in this same process but really nervous to go all in if I’m not sure it works.

Hi, Joel,
I’ve recently changed (simplified, improved?) how I go about engraving these 1" discs. I no longer use the aluminum block with the round holders. Here’s a picture of my current set-up followed by an explanation.


Here’s how I go about getting these 1", stainless-steel discs engraved. I’ve used the same procedure for aluminum, brass and copper discs.
I start out with a scrap piece of MDF or particple board that’s mounted onto my waste board. In the photo you can see two of the mounting bolts. Using a 3/4" router bit, I make a leveling surface to be sure that my work plane is parallel to the X-Y plane of the X-Carve. I tape a angle bracket to the level surface. I make sure the angle bracket is aligned along the cut edge of the leveling surface so I know it’s parallel to the X-axis. I use the painter’s tape technique for fixing the disc to the level surface by first putting a piece of blue tape on the surface and on the back of the disc. I then use Gorilla Superglue to fix the disc to the leveling surface. For engraving I usually use a 0.2mm, 20-degree v-bit. To find the exact center of the disc, I put the bit I’m going to use in the collet (upside-down) and go through the following steps to, first, find the inside-corner of the angle bracket. I use a multi-meter in continuity mode and attach one lead to the bit and one to the angle bracket. I move the tip of the bit to a position close to the angle bracket along the X direction. I carefully, in 0.01" increments, move the bit until it touches the metal bracket (as indicated by the continuity tester of the multi-meter). I then back it off 0.01" and re-touch the bracket using 0.001" increments. I then raise the bit enough to just clear the metal bracket and move the bit half the diameter of the bit (in my case 0.125", so I move it 0.0625"). This places the center of the engraving bit right over the inside edge of the angle bracket. I then move the bit to repeat the process for the Y-axis edge. When moving the bit to find the inner edge of the bracket on the Y-axis keep track of how far in the Y-direction you move the bit so you can return it to the inner edge on the X-axis when you’ve determined the inner edge of the Y-axis. Once you’ve done both X and Y directions you should have the center of the bit directly over the inner corner of the angle bracket or X=0 and Y=0. From there, depending on the diameter of the disc, you move the bit to X=diameter/2 and Y=diameter/2. In my case, the discs I’m engraving are 25.3 mm in diameter so I move the bit, 12.65mm in the +X direction and 12.65mm in the +Y direction. Now, the bit is in the exact center of the disc. I raise the bit, remove it from the collet and turn it engraving-tip down. Lastly, I carefully lower the bit to find where it just touches the disc to be engraved. I’ll either use the multi-meter to do this or, simply, a piece of paper. I use Easel to design my engraving and choose 0,0 to be the center of the design. While in the design phase, I include a 1", outlined circle to help me place my design properly. Before I start carving, I delete the circle. This is way harder to explain than to actually do. Let me know if you have any questions.

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