I have written this instructable because I wanted to use my rotary attachment for my laser cutter and I wanted to share how to do something slightly different from the normal flat engraving that I do.
To do this you will of course need access to a laser cutter and a rotary attachment. I know that not everyone has one of these machines, that’s life. I don’t own a high performance sports car, I don’t moan about it, that’s just the way it is.
So if you haven’t got a laser then you won’t be able to use this instructable to the full but you might find it interesting.(hopefully). There are of course other ways to engrave glass but this one uses laser power which is cool!
Access to laser cutters: There are a number of community groups, Techshop, colleges and schools who allow access for those who don’t have their own. I am fortunate to have my own machine because I saved long and hard for a piece of equipment I wanted to use as part of my hobby and leisure time. I got mine from Thunderlaser in China. I recommend them most highly.
Important: Each laser machine is different, read the instructions for your machine and don’t assume that these instructions will suit.
Engraving on a round object requires you to set the machine to understand that it’s going to be working on the Y direction and U (rotary) direction.
Safety: Lasers can, if used incorrectly, cuase permanent damage, fire, burns etc. Just be aware of any dangers, risks and hazards.
Step 1: Setting Up the Software.
Software will vary from machine to machine. On mine I need to let the software know the diameter of the object to be engraved and the position of the engraving on the object. It is important to ensure that the engraving fits around the circumference as well. You will need to work this out (3.14 * ½ diameter of object).
Using your software set up the parameters. For mine this meant entering the settings menu and inputting the diameter of the object.
Laying out the text and graphics in the drawing pane, setting its position and for some reason flipping (mirror imaging it.)
Set the engraving settings for the laser based on the material, in this case glass. My machine came with a set of tables which gave outline settings for materials.
I have started to keep my own record of what is the best setting for each material I use. I do this on small cards which have a sample of the material and the settings recorded on it.
Because glass reflects the laser beam it is a good idea to either mask the outside or put something dark inside the object to be engraved.
Step 2: Setting Up the Hardware
On the laser machine itself remove the honeycomb table and replacing it with the rotary attachment. This is a heavy bit of kit which needs to be carefully lined up parallel with the axis. I decided that I would mark this position on the bed of the machine for future reference.
Lower the table (Z axis) to its lowest position and mount the object to be engraved.
The laser head needs to be positioned above the object so that is directly over the X axis.
On my machine once the rotary attachment is plugged in and turned on it disengages the X axis control so that you can manually position the laser head.
Step 3: Positioning and Measuring
Check the position of the engraving carefully by measuring from the Y axis and matching this against the graphics on the software.
Adjust accordingly. Then check that the laser head will not foul anything during the engraving. Failure to do this could damage the head and/or the rotary attachment.
Once you are sure that everything is correct set you are almost ready to engrave.
Step 4: The Object to Be Engraved..........
Top Tip: I always put a layer of painters tape on the object so that I can see exactly where the engraving will take place. By doing a trial run with the settings set to half the normal power it is possible to ‘kiss’ the tape with the laser burning a light image to check layout and location. You can see this in the pictures above. (slight brown image).
I have also found that a better finish is achieved if the laser head is set to do two passes of the design, one with the head traveling Y direction and one X. This was just from experience and trial an error.
Not all glass etches well. the better quality the glass the better it will etch. This I have learnt by trial and error.
Some glasses are so thin that they break as soon as the laser hits them.
Wine bottles etch very well and it is my plan to etch and then reuse them of other uses in the home.
I will post some pictures shortly.
Step 5: Volume/quanity/loads of Them.....
I engraved wine, beer and cidre bottles, carboys, some drinking bottles, wine glasses and a couple of Maglites. My practice ones were all wine bottles because they are cheap and I have plenty (any excuse for a glass or three:)
- Bottles are easy to do but can be difficlut to hold.
- Carboys need a special stepped holder. (see pictures)
- Water/drinks bottles usually acrylic or PET but check before starting. Don't touch anything with chlorine in them for fear of damage to machine.
- Maglites are easy to etch and look really really cool.
- Wine glasses, you only need to hold the base as there is no pressure on the actual glass by the laser itself.
Step 6: Large Objects - Securing in the Attachment.
For large diameter objects like the carboys I needed a secure way of holding them to prevent slipping during the engraving and a secure way of holding large glass objects.
I made some stepped rings from laser MDF which I glued together ready to be mounted in the chock of my rotary attachment. A modification has been to add some rubber strip for extra grip. I will be making a second version of this holder for wine bottles.