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View Full Version : For someone who rarely does threading, these turned out pretty well.



winchman
09-30-2012, 01:49 PM
A comment on a recent post pointed out the need for a thread protector on my friend's Atlas lathe spindle. I couldn't bring the lathe home, so I found the dimensions for the 1 1/2x8 thread, and turned a male thread on a short piece of aluminum.

On my next visit, I borrowed his faceplate, and my threaded stub fit perfectly. Then I turned the thread protector, using the stub to check them.

http://img.photobucket.com/albums/1003/winchman/Kellyslathe006_zps763c6e44.jpg

Mike Burdick
09-30-2012, 02:54 PM
Winchman,

Nice job!


Everyone that has a threaded spindle should take the time to make a "thread gauge" for their spindle as you did for your friend. It will come in handy when one gets a new face place, chuck, or whatever for that lathe!

tyrone shewlaces
09-30-2012, 03:59 PM
Just to expand on Mike B's suggestion to have a "thread gauge" for their spindle:

We all know that threads have a tolerance range and any particular piece can have the actual pitch diameter fall somewhere inside that range. For a lathe spindle, I like to make a gauge so the actual pitch diameter is within a couple tenths or a half thou using three-wires (since they are cheap) to check that it is so. Nice to have the shoulder and all there to have a complete copy of the nose to work with. Probably not really necessary since the things you install on it just have to be within the tolerance range too, but it doesn't hurt.

I made a plate for a buddy's chuck once and the three-wire thing allowed me to go to his place and measure what he had and go home to do all the machining there. It fit really nicely and now he owes me a big favour hehe.

Good job on yours. You used a good method and it came out real nice.

gwilson
09-30-2012, 05:51 PM
When I made a lot of steel spinning chucks,I made myself a duplicate of their spinning lathe's spindle to keep in my shop. Last thing you want to do is find a fully contoured chuck won't thread on!!

sasquatch
09-30-2012, 06:03 PM
Great job Winchman , looks great!

alanganes
09-30-2012, 06:35 PM
Very nice. I need to make a protector for my Sheldon as I am about 90% of the way to completing my 5C collet setup. I've been planning to do a "spindle thread gage" for my lathe for a while. This is a bit of inspiration to do so.

In reality, I do find it a bit funny that we are all surprised when we cut threads and they actually fit. Why is that exactly? We are after all a bunch of machinists, right? Most here have at least decent machines with which to work, if you set things up well and set the lathe to cut the correct pitch, and pay attention, what's the big deal?! I know that lots can go wrong, etc., I've made most of those mistakes, too.

Not poking fun at you in any way, I'm pretty happy with myself when stuff I do comes out as planned, too. I guess it is that sense of satisfaction that keeps us doing this sort of stuff as a hobby, right?

justanengineer
09-30-2012, 07:59 PM
I believe it was me that made the original suggestion, and coming from someone who has had the "joy" of repairing spindle threads before (aka. the reason I have a very complete set of thread files), thanks! Glad to hear that your work turned out as planned, sounds like time to crack a cold one and enjoy the evening.



Everyone that has a threaded spindle should take the time to make a "thread gauge" for their spindle as you did for your friend. It will come in handy when one gets a new face place, chuck, or whatever for that lathe!

My $0.02 - if you have a "spindle" adapter that adapts lathe tooling to a rotary table as many do/have made, these will also work if accurately made, and can save a bit of $$/time/effort in making a special tool.

oldtiffie
10-01-2012, 04:43 AM
It should be noted that this only applies to lathes with a screwed nose for a backing plate etc.

If you make the protector too "neat" to/for the male thread there is a good chance that the pitch diameter for the protector will be too small.