[Corleone]

  Does anyone know if applying finish to the inside of the cup affects sound quality?

It does, but how much is a matter of debate. I'd say keep the wood unfinished or try tung oil if you worry about the wood absorbing air humidity (especially if you use your woddies grados portably).

 

[fleasbaby]

Agreed...posted a response to the same question posted here:
 
http://www.head-fi.org/t/686212/the-great-grado-experiment-4-tonewoods-tested-more-to-come/150#post_10191791

 

[Corleone]

By the way: tung oil hardens the wood noticeably. I'd say you should stick with one coating on the inside and 3 or more on the outside.

 

[stjj89]

My newly completed set of walnut cups!
 

 
 

 

[fleasbaby]

Brilliant, I love the no-nonsense RS-style cup...what drivers will be going in?

 

[stjj89]

Brilliant, I love the no-nonsense RS-style cup...what drivers will be going in?

 
Thanks! Just my humble 8-hole vented SR60i drivers right now
 
Also, I was wondering if anyone could share how deep they cut the groove for the driver to sit in? I currently go 1/4" in with a 1 7/8" circular drill as per Bilavideo's original recommendations, but it seems to be slightly too shallow for my driver. Anyone doing a slightly deeper cut?

 

[fleasbaby]

I get Jim, the guy who makes my cups, to go in 10mm. I am thinking about trying a deeper hole to recess the driver a touch and see if it increases soundstage.

 

[ostewart]

I'll join the group with a humble pair of SR60's
 
4 hole vented drivers, dynamat on the back of the magnet, white mesh removed, quarter modded, recabled and different mesh:
 

 

[BLACKENEDPLAGUE]

Those look delicious

 

[ostewart]

I sanded the paint off the lettering, going for a stealth all black look, yummy

 

[ostewart]

BTW if anyone in the UK needs some fine Black Mesh (same as I used) I have plenty left over, I used a anti splash frying pan cover from The Range. Just pay shipping and i'll send you some.
 
Also got the classified in my sig.

 

[Corleone]

  My newly completed set of walnut cups!
 
 

Spoiler: Warning: Spoiler!

 
 
 
 

Spoiler: Warning: Spoiler!

 

 
Beautiful! I'm also a big fan of the cleaner oldschool looking Grado cups. I love how you managed to get the a look of audio equipment from the 70s and 80s. A slight step away from the Grado signature looks, so you've got something more unique going here! Did you mill your own cups?
 

  I get Jim, the guy who makes my cups, to go in 10mm. I am thinking about trying a deeper hole to recess the driver a touch and see if it increases soundstage.

 
+1
My SR-325 inner sleevs will have just this, so that it'll be possible to to recess the drivers slightly. The depth of the groove totally depends on the inner diameter of the cups. Notice how the first edge of the driver with approx. 44mm OD is almost 6,5mm high. The total height of the outer edges are approx. 9,5mm. This means that if your inner diameter is less than 44mm, then you will need more than 10mm depth. At 1/4" you're at 6,35mm, so you definitely need to go deeper! I'd say 1/2" or a little more if you want to experiment to gain soundstage.

PS. Your measurement system really sucks! ;D <3

 

[stjj89]

   
Beautiful! I'm also a big fan of the cleaner oldschool looking Grado cups. I love how you managed to get the a look of audio equipment from the 70s and 80s. A slight step away from the Grado signature looks, so you've got something more unique going here! Did you mill your own cups?
 

 
Thank you! Yes, I made my own cups by turning them on the lathe at my college's woodshop. My only issue with this way of doing it is that I keep tearing the end grain of the wood while turning it, which causes one side of my cups to look kind of rough, spotty looking. This is probably because of my technique and sharpness of the tool I'm using.
 
For my next attempt at these with cocobolo wood, I'm looking to try getting the cylindrical shape done on the engineering school's CNC machine, then adding the foam pad groove myself on the lathe. I'm hoping this would solve my end-grain problems and give me perfect cups!!

 

[Corleone]

   
Thank you! Yes, I made my own cups by turning them on the lathe at my college's woodshop. My only issue with this way of doing it is that I keep tearing the end grain of the wood while turning it, which causes one side of my cups to look kind of rough, spotty looking. This is probably because of my technique and sharpness of the tool I'm using.
 
For my next attempt at these with cocobolo wood, I'm looking to try getting the cylindrical shape done on the engineering school's CNC machine, then adding the foam pad groove myself on the lathe. I'm hoping this would solve my end-grain problems and give me perfect cups!!

Yeah you probably need to find yourself some nice guides on the web or youtube. I'm guessing that RPM and wood type will also be part of the equation. CNCing is totally awesome, but pay attention to RPM and inches per sec vs. wood type and hardness.

 

[stjj89]

My SR-325 inner sleevs will have just this, so that it'll be possible to to recess the drivers slightly. The depth of the groove totally depends on the inner diameter of the cups. Notice how the first edge of the driver with approx. 44mm OD is almost 6,5mm high. The total height of the outer edges are approx. 9,5mm. This means that if your inner diameter is less than 44mm, then you will need more than 10mm depth. At 1/4" you're at 6,35mm, so you definitely need to go deeper! I'd say 1/2" or a little more if you want to experiment to gain soundstage.

PS. Your measurement system really sucks! ;D <3

 
Actually, I use the metric system too! I just live in the US now so I'm just putting up with the measurement system here (that my woodshop uses) =)
 
So for a tight friction fit, would you say it would be best to just measure the outer diameter of the driver, cut out holes that are exactly that size, and sand it until the drivers fit? I've been drilling the center of my cup on a drill press using two circular drill tips: 1 7/8 inches 1/4 inch in, and 1 3/4 inches the rest of the way through. I can't get any more granularity than that using the drill tips available, and these measurements currently don't give me a tight friction fit. The CNC machine will probably offer more precision, so I'm planning to use the exact measured OD of the drivers for these holes when I make them on the CNC machine.