Well, here's what I'll do...
The following could be considered a draft for the tutorial on turning a pair of cups with a lathe. Any feedback from people is welcome, and considering I've done this a number of times, I may have skipped steps without thinking. So if there are any gaps in information, let me know and we can fill them in before finalizing things.
Keep in mind the usual disclaimers...
- Working with the following tools can be very dangerous... Saws and drills are one thing, but the lathe in particular needs to be used with great care.
- I've made no effort to outline the required safety measures that should be taken, of which there are many. If you don't know how to do it, don't. Find someone who can teach you and proceed only after you're comfortable with any of the steps going forward.
- Modification to your Grados is done at your own risk, with no warranty expressed or implied.
Unless otherwise noted, pictures were taken throughout the process of turning a pair of basic Maple cups. Different woods and shapes provide different challenges, and this should be considered when choosing your wood.
- Step 1 - Buy your wood
(Zebrawood Pictured)
For ease of turning, a 12" section of 3"x3" wood is recommended, but 6" sections can be turned. I get a lot of my wood from the local Woodcraft store, but there are a number of online stores and local lumber yards often have nice turning stock. My first cups were made with pieces of scrap 4x4 mahogany left over from a friend making a table.
- Step 2 - Take the corners off the turning stock
(Not Pictured)
Using a table saw with the blade set to 45 degrees, cut the corners of the turning stock. This will result in an octagonal shape that will be much easier on your chisels, hands and wrists, and will make the experience much more enjoyable.
- Step 3 - Mount the blank on the lathe and start turning
I use a number of different chisels when turning cups. Usually I start with a rough gouge to get the general shape. Once the shape has been roughed out, then other chisels can be used to fine tune the desired shape. The roughing is usually done at the slowest speed, and sometimes I'll go up to the next speed when finalizing the shape.
Keep in mind that you can't put material back on, so using calipers, check and recheck the OD of the wood. I usually keep it at least a tenth of an inch strong with the chisels, often more, and take it down to the final OD during the next step.
- Step 4 - Do any preliminary finishing you can on the lathe
You will save countless hours of sanding if you do as much sanding as you can while the wood is still mounted on the lathe. Depending on tooling marks, you can start with as rough a grit as you feel you need. Usually starting with 220, and progressing from there will yield good results.
- Step 5 - Separate the cups
You have a couple of options for doing this step. You can score the location of the cuts on the lathe, remove the wood and cut it with a band saw or hand saw.
Or you can use a parting tool and cut through a majority of the material while it's still on the lathe. This is by far the easier way to do it, and usually will result in a better edge. Either way you'll end up with something like this:
Then just make sure the ends of the cups are square and true and that you have a pair of cups that have the same outside dimensions.
- Step 5 - Drill the cups
Drilling the cups can be challenging. You can try to set up a jig to center the cups, or you can just eyeball it. Either way drilling a pilot hole to remove material and provide a place for shavings to exit can be a big help here. Using a forstner bit in the drill press, drill the screening side of the cup. Again, drilling this all the way through the cup will make things easier when drilling the larger hole that mounts to the driver enclosure.
Remember, all your work will be wasted if you are not careful centering the cups. Securing the cups can be done any number of ways... A vice, clamps, or gloves and sandpaper. A second set of hands here can really help.
It is also very important to make sure that the larger hole is drilled to the same depth on both cups. The chambers should be the same size, so if you drill press has a stop, set it so that both cups are identical.
- Step 6 - Drill the holes for mounting the headband and running the cable
(Not Pictured)
Using the original cups, recreate the size and locations holes for the C that mounts the headband. If you are not recabling your Grado, you can recreate the notch that allows the cable to stay in place while you slide the cup on. If you are going to recable, you can go with a cleaner look by drilling a hole and passing the cable through.
- Step 7 - Finish the cups
Now it's time for final sanding of the cups. Again, all the work can be wasted if you don't take the time to do this step right. Spend as much time as you can making sure all surfaces and edges are as smooth as you can get them. I like to start with the same grit I ended with on the lathe. This is also a good time to test fit the screens in the cups and the cups on the headphones. You can take off additional material on the inside of the cups to get the fit you want.
(Cups rough sanded and screens test fit, but requiring additional sanding and shaping)
Depending on your choice of wood, you may want to use something to add depth and color. Stains and oils all can be used. I like using tung oil, finished with semi-gloss lacquer. I've also used clear enamels with good results.
Once the finish has cured, it's time to reinstall the screening. You can reuse the stock screens, or use any number of materials. Grado uses hot glue to assemble their headphones, and this is usually what I use to reattach the screens. A tip here is to put the cup on the headphones with no screen with the bowl pads on. The cup should come down to the top of the pad. Mark the inside of the cups at the top of the driver enclosure for Step 8.
- Step 8 - Reassembly
The Headwize Grado Mods page has a ton of information on disassembly and reassembly, so I won't recreate it here. But you can use the marks outlined in Step 7 to know where the driver enclosure will rest. Make sure you only apply hot glue below this line. When you slide the cups on, it will push excess glue up towards the screens, so don't add too much. In the end you should end up with something like this:
To be honest, my HF-1 with the current Zebrawood cups are just friction fit together, and have been for months. If you are careful with your work and measuring, you won't need a lot of glue to keep things together.
- Step 9 - Enjoy
This is a very rewarding project. Now it's time to just enjoy the music!
A few other items of note...
- Cup depth makes a difference to my ears. The Grados seem to benefit from a deeper cup across the entire frequency range.
- Wood choice may make a difference, but I haven't done two cups of different woods with identical dimensions, so I can't say if there is a difference or how much.
- As with all DIY projects, you'll be disappointed if you really think this will save you money versus buying from an established company. That's not to say that it doesn't have its benefits, but unless you already have all tools and enough experience that you won't waste materials, there will be a large initial expense. Tools used include:
- Table Saw
- Lathe with quality chisels made of HSS
- Drill press with forstner bits
And then there's the fact that if you enjoy doing it, you'll find yourself doing different cups for your Grados just for a change!
- Sharp chisels are important, as are sharp bits.
- Total time investment can range from 6-8 hours, depending on your experience, how 'perfect' you want it to end up and choices you make along the way.
- Again, this can be a dangerous project, so be careful!
So, there's a draft. Hope that helps. If I get any input here, I'll try to incorporate as much as I can and eventually put together a new thread.
. I'll do some in progress pictures of my project and take notes so I can do a little write up. If you want I'll keep you posted so you can add stuff 2. LMK.
