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Taps for Oneway live center attachments

Steven Forrest

Steven Forrest

Joined
Dec 23, 2014
Messages
211
Likes
350
Location
Sebastopol, California
Hi, gang,
Recently picked up a Oneway live center. The basic tip is threaded 3/4 inch x 10tpi. Any recommendations for a proper tap to thread blanks for making my own attachments? Home Depot has one set of 3 (taper, plug, and bottom) made of carbon steel, or a single HSS one, each for about $20. I wasn't sure if there might be different pitches to the threads, etc. Any one with relevant experience/advice for someone who is new to the joys of tapping? Thanks.
 
They all have the same pitch. You can make any of them work if you bore and tap deeply enough that the device screws firmly against the flat face of the live center. The plug tap probably is the most convenient.
 
Steven Forrest said:
Hi, gang,
Recently picked up a Oneway live center. The basic tip is threaded 3/4 inch x 10tpi. Any recommendations for a proper tap to thread blanks for making my own attachments? Home Depot has one set of 3 (taper, plug, and bottom) made of carbon steel, or a single HSS one, each for about $20. I wasn't sure if there might be different pitches to the threads, etc. Any one with relevant experience/advice for someone who is new to the joys of tapping? Thanks.
Click to expand...

Or, .... you can buy 3/4 x 10 hex nuts. I picked up several at Lowe's a few years ago just for that purpose. I'm sure HD has them as well or even a hardware store. Drill a hole in a block of wood and epoxy in the nut. Just don't get any epoxy on the threads! :(
 
Done it both ways as Dennis and Tom have said. I didn't use epoxy, just drilled smaller hole all the way though and put bolt through hole to press the nut into place. Avoided the epoxy on thread!:rolleyes:
 
As John said pressure fit works great. Will work on unthreaded centers with straight turning sides.
A 1.5” diameter hole will pressure fit on the unthreaded mini lathe centers.
A turn or two of masking tape on the center will tighten the fit if needed

Also rubberchucky.com has lots of threaded items. Also they can be turned for special applications
 
Most critical is keeping the tap exactly vertical. I've missed a time or two, until I bought a hand taping machine. Expense, but I make a lot of my own tools and equipment. I have also returned the accessory mounted to the tailstock. I cut off a roofing nail, insert it where the lock bar goes in, and then wrap tape to hold the nail in. Put the assembly in the headstock, and true up your accessory.
 
Richard Coers said:
I have also returned the accessory mounted to the tailstock. I cut off a roofing nail, insert it where the lock bar goes in, and then wrap tape to hold the nail in. Put the assembly in the headstock, and true up your accessory.
Click to expand...
Drill bits work too.
Oneway suggests using a bolt for this. It works but now I have a Morse taper with a thread matching the tailstock.
 
If, like mine, your lathe has different Morse tapers in the headstock and tailstock, here is an alternate approach: Mount the bored and tapped device on the tailstock and advance the tailstock to bring the device to bear against a drive center, a piece of wood held in a chuck or whatever will provide rotational drive force without significate lateral force. Then, turn a tenon on the threaded end of the device to fit one of your chucks and true up the face of the tapped end of the device. Then you can mount the device in a chuck to shape the working end of the device (and perhaps reshape from time to time for different needs).
 
Dennis J Gooding said:
They all have the same pitch. You can make any of them work if you bore and tap deeply enough that the device screws firmly against the flat face of the live center. The plug tap probably is the most convenient.
Click to expand...
Had some time to kill today between games at my grandson's hockey tournament so visited local Princess Auto and happened on to a 3/4 10 tap. Have used a nut once before successfully but tap was calling me so I bought it! What size drill do you use Dennis?
 
DC3559B9-CA44-4161-B9A2-A292516CB44A.jpeg
Mike Brazeau said:
Had some time to kill today between games at my grandson's hockey tournament so visited local Princess Auto and happened on to a 3/4 10 tap. Have used a nut once before successfully but tap was calling me so I bought it! What size drill do you use Dennis?
Click to expand...
Mike,

Here’s what my iEngineer app says. I’d go for the 50% coverage. 75% is usually too much work.

Kind regards,
Rich
 
I have had a 3/4-10 tap for many years in both taper and bottoming - high speed steel of course stay away from carbon steel - I use them to make accessories in both aluminum and wood. If using wood you can get a usable thread if you soak the wood first with CA then when its time to true up the accessory put the center in the head stock, lock it and go to it.
 
Mike Brazeau said:
Had some time to kill today between games at my grandson's hockey tournament so visited local Princess Auto and happened on to a 3/4 10 tap. Have used a nut once before successfully but tap was calling me so I bought it! What size drill do you use Dennis?
Click to expand...

Mike, I do not remember and I am traveling now. Usually, the recommended drill size is stamped on the tap.
 
Richard Coers said:
Most critical is keeping the tap exactly vertical. I've missed a time or two, until I bought a hand taping machine. Expense, but I make a lot of my own tools and equipment. I have also returned the accessory mounted to the tailstock. I cut off a roofing nail, insert it where the lock bar goes in, and then wrap tape to hold the nail in. Put the assembly in the headstock, and true up your accessory.
Click to expand...
A very beneficial tip! Thanks for sharing it Richard.
 
Richard Coers said:
Most critical is keeping the tap exactly vertical. I've missed a time or two, until I bought a hand taping machine. Expense, but I make a lot of my own tools and equipment. I have also returned the accessory mounted to the tailstock. I cut off a roofing nail, insert it where the lock bar goes in, and then wrap tape to hold the nail in. Put the assembly in the headstock, and true up your accessory.
Click to expand...

As Richard said, correct alignment of the tapped hole is important for many applications. Not having access to a tapping machine, I use the following approach to boring and tapping the hole: I mount the device in a chuck and use a bit held in a Jacobs in the tailstock to bore the hole. Then, I replace the Jacobs chuck with the Oneway live center with the small aluminum cone center mounted on it. With the headstock locked and the tap in position against the bored hole, I bring up the tailstock so that the point of the cone engages the dimple in center of the end of the tap. By keeping the cone snugly against the dimple while screwing in the tap I can be assured of a near-perfect alignment. I use a similar procedure for making faceplates and other fixtures to fit on the 33mm headstock of my lathe. By the way, taking a quick look through my accumulation of taps, I find that almost all of the larger taps have a center dimple that can be exploited for other tapping applications.
 
I drill, then tap on the lathe also, that way everything stays aligned. I use a tap guide (part # 0375-0090 from www.wttool.com). The pointed end is spring loaded so when you reverse the tap to sever the chip you don't have to back out the quill as when using the live center. Not a necessary piece of kit but nice to have.

Tap guide.jpg
 
Clifton C said:
I drill, then tap on the lathe also, that way everything stays aligned. I use a tap guide (part # 0375-0090 from www.wttool.com). The pointed end is spring loaded so when you reverse the tap to sever the chip you don't have to back out the quill as when using the live center. Not a necessary piece of kit but nice to have.

View attachment 27595
Click to expand...
I just got one of those for Christmas, and it makes tapping a whole lot easier!

Rich
 
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