# Spring Center (Metal Lathe, Mill)



## HMF (Oct 3, 2011)

http://www.projectsinmetal.com/free-project-plan-spring-center-metal-lathe-mill/

So what’s a spring center good for? Basically it helps the user tap a hole.

To use the spring center, insert it into the chuck on the mill, drill press, or lathe tail stock. Advance the spring center toward the tap until the spring is fully compressed. Begin tapping as you would normally, but let the spring center apply pressure to the tap while you concentrate on turning the tap itself. As a side note, the photo showing the spring center in use also illustrates a handy way to protect a part from damage. Thin pieces of metal (in this case a sacrificed diet Pepsi can) can be used to prevent the vise jaws from marring the part.

Using the spring center will help you start a tap with ease because it helps maintain tap alignment along the axis of the hole being tapped. All you have to do is concentrate on not breaking the tap!


----------



## kike (Oct 3, 2011)

very good device and good idea.


----------



## churchjw (Oct 27, 2011)

Great project.  I did not know about tapering the spring on applications like this.  That is a very good thing to know.  How did you get the taper on the springs?  I have made a spring loaded scribe for a CNC mill before but I used a heavy die spring for it.  It was this same design but for a different function.  It didn't look as nice since I have not taken the leap to try tool post grinding yet.  I have a duMore grinder but its a little on the scary side so have not tried it yet.  When I tap I use T-type tape wrench like this one http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=2619630&PMAKA=318-0042  And I wonder about combining your spring loaded part with one of these to make a spring loaded T-type handle. :headscratch:  You would have to be careful to keep the length as short as possible for small mills but I could see it being a handy tool.  I will put it on my list to work on.  Has anyone seen something like that?

Jeff


----------



## Tony Wells (Oct 27, 2011)

Couple of easy ways. If it's not too large a diameter, or hanging out too far from your collet of chuck, you can "slab" it on there by angling your tool at the desired angle and simply feeding slowly into the piece. This is not the preferred method, but if you can't do it the conventional way, by setting your compound at the angle and dialing across the face, it will work. You would probably want to touch it up with a file if you slab it on there.


----------



## Highpower (Oct 27, 2011)

mnmh said:


> Spring centers are very useful tools. Everybody should have one in their tool box. If you don't want to make one they are cheap to buy.
> 
> http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=5810267&PMAKA=325-5179
> 
> Ed


Agreed. If you look at the link Ed provided you will see that the 'tip' has a male and a female end. It is reversible.
The male end for larger taps that have a center hole in the end, and the female end for the tiny taps that have a pointed end on the shank.

Being the lazy oaf that I am, I bought TWO of those little spring centers so I can just grab one or the other, without needing to pull the plug and flip things around.
If that makes me a bad person, so be it.....


----------

