How might one best cut recesses inside a drilled

[mecompco]

blank? My project consists of a drilled blank (either wood or plastic) with about a .6" ID. I want to use O-rings inside to retain a removable tube. I'd like the recesses for the O-rings to be at least .5" from either end of the blank. How would you go about cutting these? TIA for any suggestions!

Regards,
Michael

 

[Herb G]

You'll have to make your own tool much like a peppermill recess cutter.
Check out the Sorby Crushgrind tool for the concept.

 

[mecompco]

You'll have to make your own tool much like a peppermill recess cutter.
Check out the Sorby Crushgrind tool for the concept.

Herb, yes, I see the concept. I'd like to see a close-up of the cutting edge of that tool. I have some .125" 1080 high carbon steel on hand that I think would work--I don't see that there will be too much stress on the tool. I've also got some .25" 1084 steel if that might be more appropriate. I'm thinking I could get away with just hardening the tip and leaving the rest "soft". Thanks for the suggestion and I welcome any feedback on the design of the tool.

Michael

 

[rholiday]

You could also grind allen wrenches.
Link to Wood Magazine article -- https://www.woodmagazine.com/woodworking-plans/lathe-and-turning/small-tools-for-tiny-turnings

The article has some drawings of the grind.

Bob

 

[chartle]

or use hardened nails. Just shape the head.

 

[mecompco]

Bob and Cliff, thank you. Since this is likely a one-off project, I think this is the route I'll go.

 

[Scotty]

Dental pick

 

[Herb G]

Yeah, come to think of it, a cut nail would be perfect for this project.
I have a big box here if you can't find some locally.

 

[mecompco]

Yeah, come to think of it, a cut nail would be perfect for this project.
I have a big box here if you can't find some locally.

I appreciate that, Herb. If I can't find some locally, I'll hit you up. Honestly didn't know they made "hardened" nails but it sounds perfect for this little tool.

Michael

 

[chartle]

Yeah, come to think of it, a cut nail would be perfect for this project.
I have a big box here if you can't find some locally.

I appreciate that, Herb. If I can't find some locally, I'll hit you up. Honestly didn't know they made "hardened" nails but it sounds perfect for this little tool.

Michael

Masonry nail.

 

[Penultimate]

Or you bore one end then turn another part with a tenon, insert the o-ring then press in the tenon piece.


Sent from my iPad using Penturners.org mobile app

 

[Herb G]

Yeah, come to think of it, a cut nail would be perfect for this project.
I have a big box here if you can't find some locally.

I appreciate that, Herb. If I can't find some locally, I'll hit you up. Honestly didn't know they made "hardened" nails but it sounds perfect for this little tool.

Michael

Masonry nail.

Cut nails are case hardened too. A flat nail would be perfect for making such a tool.
A little work on a grinder to get the right profile & you're all set.

 

[skiprat]

Yes, it can be done, but I'd have a few practice runs first. One run to establish the width and depth of the groove for the o-ring. Then probably taking the o-ring in and out a few times to sneak up on the acceptable grip on the tube.
I work a lot with o-ring gas seals and you will be surprised how much effort it may take to pull something out, after pushing it in. Will you be able to lubricate the o-ring with a smear of silicone grease or something?

Will your project perhaps allow a friction fit like you get on a slimline twist mech? A little dimple or two to offer resistance will be a lot easier to make.
You could put the dimples in the same place the 0-ring groove would have been rather than on the removable tube, so it won't be seen. Of course, I'm assuming you would have a tube within a tube...:wink:

Heck, even a very slight bend in the removable tube could work if your project allows :wink:

 

[chartle]

Yeah, come to think of it, a cut nail would be perfect for this project.
I have a big box here if you can't find some locally.

I appreciate that, Herb. If I can't find some locally, I'll hit you up. Honestly didn't know they made "hardened" nails but it sounds perfect for this little tool.

Michael

Masonry nail.

Cut nails are case hardened too. A flat nail would be perfect for making such a tool.
A little work on a grinder to get the right profile & you're all set.

If I understand the application, my thought is that you could grind the head in a way to create a single tooth 90 degrees to the shaft of the mail. Then the nail glued into a handle.

 

[mecompco]

Yes, it can be done, but I'd have a few practice runs first. One run to establish the width and depth of the groove for the o-ring. Then probably taking the o-ring in and out a few times to sneak up on the acceptable grip on the tube.
I work a lot with o-ring gas seals and you will be surprised how much effort it may take to pull something out, after pushing it in. Will you be able to lubricate the o-ring with a smear of silicone grease or something?

Will your project perhaps allow a friction fit like you get on a slimline twist mech? A little dimple or two to offer resistance will be a lot easier to make.
You could put the dimples in the same place the 0-ring groove would have been rather than on the removable tube, so it won't be seen. Of course, I'm assuming you would have a tube within a tube...:wink:

Heck, even a very slight bend in the removable tube could work if your project allows :wink:

Thanks for the suggestions. Inner tube will be straight glass, so no bends or any easy way to dimple.

I've also considered that perhaps a spring something like the PSI Seam Rippers use would work. I've made some of the PSI perfume atomizers and they use a larger version of that spring to retain the glass vial within.