Making an 18.8mm female joint - 420 Woodworkers help me out?

[Xe7en]

Howdy howdy! I was wondering if any of you custom builders might be able to help me out. I'm looking to re-create the 18.8mm female joint in wood. The end game here is to make a cover for a drip atomizer deck I have that will accept my 18mm stems.

I've looked into step bits, ball joint reamers, etc.. but haven't really been able to find the appropriate size / bit. I'm thinking I need to go from .56 -> .74 or 9/16 -> 3/4 in about an inch of length.

I haven't been able to find any bits / tools made for this purpose. Any ideas? I have limited access to tools but I do have a handheld drill, clamps, and a dremel with the drill press setup.

Thanks for any advice!

 

[Summer]

@phattpiggie, I know you're busy, but can you lend any insight? Not flagging Ed here, too, because he's super busy w/ the BF sale & a, rather, new wife, a, rather, new residence & 6 kids, 2 of them being rather new & one being an infant, & 2 dogs, 1 cat.

 

[phattpiggie]

@Xe7en glass joints are a 1:10 taper. I've seen a tapered reamer that would do the job but it was very expensive.
I made a piece with a 14mm female in and had to make a chisel to do it with.
Not being able to see inside I'm really not sure how accurate I made it. It vacuumed on a male joint so I knew it sealed well enough.
It's not an easy job without some specialized tooling.

 

[Xe7en]

@Xe7en glass joints are a 1:10 taper. I've seen a tapered reamer that would do the job but it was very expensive.
I made a piece with a 14mm female in and had to make a chisel to do it with.
Not being able to see inside I'm really not sure how accurate I made it. It vacuumed on a male joint so I knew it sealed well enough.
It's not an easy job without some specialized tooling.

@phattpiggie Ahh, that makes sense. Knowing it's a 1:10 taper might help me find a bit. I've run into a lot of expensive bits, but usually there are less expensive counterparts. It might be my only option with the gear I have.

How did you rig up the chisel? That's an interesting thought.. I also thought about getting a large bit and having a taper cut into it..