Thread type on a JT Turning Precision Vacuum Adapter?

[Paul Heely]

I'm re-working my vacuum plumping setup. I have a JT Turning Precision Vacuum Adapter for my PM3520 Lathe. I've measured the old fitting and the size appears to be 1/2". What I'm unsure of is if it's an NPT thread or something else. Any easy way to tell, or anyone know offhand? I'm replacing the old plastic elbow fitting I had with a brass one and don't want to force the wrong thread in there.

Paul

[Steve Eure]

Are you referring to the handwheel inside threads? I don't have a PM, but do own a Laguna and the thread pitch is a 5/8 NPT. They may be the same, but not sure.

[Paul Heely]

I'm referring to the vacuum adapter that was made by JT Turning tools before JT passed away and the business closed down. Here's a pic for reference.

473378

[Jason Edwards]

It's a standard 1/4 NPT (national pipe thread). Those are about 1/2" in outside diameter, the the 1/4" designation actually refers the the ID of heavy wall pipe. Any hardware store will have the fittings you need. Very common and 100% standard.

[Paul Heely]

Thank you, Jason. I'm learning a lot about NPT sizing as I design this system.

Paul

[Robert Hayward]

An FYI for anyone wanting to buy a vacuum adapter like the one JT used to sell. Rubber Chuckey picked up the design and modified it slightly and sells them. More money that JT used to charge but excellent quality.

[Jeffrey J Smith]

An FYI for anyone wanting to buy a vacuum adapter like the one JT used to sell. Rubber Chuckey picked up the design and modified it slightly and sells them. More money that JT used to charge but excellent quality.
Robust also sells one modeled on the JT Turning Tools version (https://www.turnrobust.com/product/vacuum-adapter/) I thought they were machining them there, but may have miunderstood Brent. They bought them from JT originally.

[Paul Heely]

An FYI for anyone wanting to buy a vacuum adapter like the one JT used to sell. Rubber Chuckey picked up the design and modified it slightly and sells them. More money that JT used to charge but excellent quality.

Thanks for the info. I've been looking for a second adapter like the JT style and did not realize the Rubber Chucky folks were making one.

Paul

[tom lucas]

An FYI for anyone wanting to buy a vacuum adapter like the one JT used to sell. Rubber Chuckey picked up the design and modified it slightly and sells them. More money that JT used to charge but excellent quality.

This is good news. It's a great chuck system. I may have gotten one of the last JT systems sold. I spoke with Tom and he shipped mine just 2 days before he passed away. It was sad, but I was glad for the pleasant interchange we had over the phone.

[Jason Edwards]

Although it doesn't say so on the Rubber Chucky website, their vacuum adapters are made by Robust. Robust started making them after Tom at JT passed away. Before that both Rubber Chucky and Robust got theirs from JT. Robust changed the design a little bit to differentiate from the JT version.