Machinist's Minutes: Lathe taper attachments

For a short tapered cut it's not necessary, but for a long tapered cut or tapered threads it can be invaluable.

[jasonhull]

Took me three days to set up my taper attachment for the first time. Now it’s about 15-20 minutes from start to chips dropping. That dead space or backlash you were talking about was the biggest issue I was fighting against. Once I figured that out I was golden. This is 100 on topic well explained. 👍

[tasengineering]

Pushing into the taper sounds like its locked in. Other people I talked to always quized on having a taper turning attachment, most strayed away from having 1 to me. Nice adlib.

[wesleyashley]

After years of making tapered threads and finding I'm very limited in how heavy a cut I can make before it becomes a curved or wavy taper I came to the same conclusion as you. If you want to make medium to heavy cuts with a taper attachment, set it so the cross slide (x axis) is traveling toward the metal not away from it as it cuts. This is backwards from what seems normal. You can still make pretty accurate cuts the other way but it has to be light cuts because the back pressure from the cutting tool must not exceed the friction of the cross slide. If it does it will move in the slack or slop of the lead screw in the cross slide. Also lathe tools are designed to cut while being pushed down so cutting on the back of the turning axis allows this when the spindle is spinning in reverse. If you want to make a right hand thread while traveling out of the hole the spindle has to spin in reverse. You will also need to cut a thread relief behind the thread so you have a place to dial in before engaging to cut the thread.

[ypaulbrown]

John, glad I tuned my 13" South Bend running and it has a Taper Attachment....
you pointed out a lot of things to watch for that I had never thought Paul from
Florida

[alansawyer]

Very useful thank you for sharing. I have had some variable result using my Harrison M400 taper attachment. Regards Alan New Zealand

[johnnystanley]

Great information really cool to see it exsplained

[CNCLASERNord]

Hi Sir,
I'm watching your channel from Morocco, useful tutorial thank you for your explanation

[burtlade]

That's good information to know. Thanks Howee!

[nickleinonen]

I’ve cut tapers at work to clean up some of the damage on the rail wheel milling machine heads when I have them out for other service. It took a little messing around the first time I had to figure it out on the SM1660 I have in the maintenance dept workshop but once I got it figured out, it’s a relatively simple operation now. Most work is pulling the chuck (I turn it between centers with a drive dog) and loading the +100lb cutting head into the machine (mounted some barn door track above the machine to roll it in with a come along)

[southmaplegarage]

Officer Sweetchuck from police academy turned out to be a pretty badass machinist.

[melgross]

Some lathes had (have) a powered compound. I believe Monarch did, as an example. Not in all of their machines though. I never thought about the possibility of threading with it though. I don’t know if any of the ratios would work.

[RichFife]

I had this conversation the other day... but, I'm a fawking caveman when it comes to explaining things. I showed him this video and you could see the light bulb click on.
PERFECT TIMING!!!

[garyballard]

I have 3 lathes with taper attachments and no avoiding the slack/backlash. It can be very challenging cutting a 1* taper and threading joints such as NRQ, HRQ and etc especially when .001” in X changes Z by .034”…Looks like a 2 3/8 AOH your fixing to duplicate

[trottermalone]

Had an old Italian friend who told the story of having to cut an internal tapered thread like this as part of his Master Machinist examination for employment by Ferrari in Modena shortly after the Second World War. To grade his skill, they cut the work in half to measure the thread and examine the finish. In your case, how is an internal tapered thread gauged? How do you know when you are done? Did they give you a male to work against?

[samhiscox]

Blaa, blaa, blaa, cut it already Howie . And for gosh sakes buy a comb at the second hand store