I just bought a "wedge-type" tool post for my new to me South Bend 9A. I cannot mount it due to the lack of a proper t-nut. I contacted Jeff with Tools4cheap and he doesn't have one, but mentioned that I could machine one with a four jaw chuck and my old tool post. One of the best things about buying this lathe besides it being in great shape was the amount of tooling that came with it. So, of course I have a four jaw chuck and not one, but three or four tool posts. Anyway, could anyone describe the process to me of machining the t-nut? I have a Bridgeport mill, but am currently rebuilding the head. Also, I would just like to know the process so that I could add that knowledge to what little I actually know already...
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Qusetion
- Thread starter geraldsd
- Start date
See the attached PDF; at the end of the day, you need something that looks like what's shown.
First, do you have a bandsaw? If so, cut the sides of the piece (keeping the hole centered) to the same width of the widest part of the T-Slot in the compound.
Keep in mind that with a 4J chuck, you can hold any piece that is round or has an even number of sides. If you don't have a bandsaw, you can trim the lengths of the piece by doing an interrupted cut.
Once the piece is trimmed to the width of the slot, you'll center the existing blank face-wise in the chuck so the hole is in the middle and you'll do an interrupted cut on the face, to make that collar. To get the piece to protrude from the surface of the jaws with enough exposure to cut the collar, temporarily place a piece of stock behind the piece and press it up against the chuck face. Remove the temporary "shims" after you've tightened the jaws. Never spin a chuck with anything that's not clamped in the jaws.
Done!
Word of caution! Your lathe has a screw-on chuck. When making interrupted cuts, each little impact tightens the chuck and it can get stubbornly affixed to the spindle. -While doing the interrupted cuts, take light cuts and check once in a while that you can still unscrew the chuck.
Have Fun
Ray
View attachment QCTP-Tnut.pdf
First, do you have a bandsaw? If so, cut the sides of the piece (keeping the hole centered) to the same width of the widest part of the T-Slot in the compound.
Keep in mind that with a 4J chuck, you can hold any piece that is round or has an even number of sides. If you don't have a bandsaw, you can trim the lengths of the piece by doing an interrupted cut.
Once the piece is trimmed to the width of the slot, you'll center the existing blank face-wise in the chuck so the hole is in the middle and you'll do an interrupted cut on the face, to make that collar. To get the piece to protrude from the surface of the jaws with enough exposure to cut the collar, temporarily place a piece of stock behind the piece and press it up against the chuck face. Remove the temporary "shims" after you've tightened the jaws. Never spin a chuck with anything that's not clamped in the jaws.
Done!
Word of caution! Your lathe has a screw-on chuck. When making interrupted cuts, each little impact tightens the chuck and it can get stubbornly affixed to the spindle. -While doing the interrupted cuts, take light cuts and check once in a while that you can still unscrew the chuck.
Have Fun
Ray
View attachment QCTP-Tnut.pdf
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Wow Chuck, I got tired just looking at your pictures! That was a lot of work. Nice job.
The quickest and easiest (not the BEST) way to make a T-nut is just make the whole thing round. One diameter to fit the top slot, one diameter to fit the bottom slot. Of course you then have to drill and tap for whatever size bolt your tool holder uses.
As I said, this isn't the BEST design because the nut doesn't have as much bearing surface in the slot. Another option is to make the larger diameter bigger than the bottom slot and then cut the sides to fit the slot. This will increase the bearing surface, though still not as good as the rectangular nut.
Just offering a couple options for you.
Steve
The quickest and easiest (not the BEST) way to make a T-nut is just make the whole thing round. One diameter to fit the top slot, one diameter to fit the bottom slot. Of course you then have to drill and tap for whatever size bolt your tool holder uses.
As I said, this isn't the BEST design because the nut doesn't have as much bearing surface in the slot. Another option is to make the larger diameter bigger than the bottom slot and then cut the sides to fit the slot. This will increase the bearing surface, though still not as good as the rectangular nut.
Just offering a couple options for you.
Steve