Methods of finding center of a worn shaft?

[mac1911]

Measure and lay out a center on a worn shaft.
I can pick up a tad of the original dia near the base where it did not wear down. Aprox 1/2 of the shaft dia is intact.
Im just trying to figure out best way to mark the center
I know there are these tools , one I have is way to big. I dont know what sizes they come in.
My current approach will be best guess on dia ,half the dia with the caliper and scribe ad many lines ad I can?

 

[GeneT45]

If you throw it in a 4-jaw and center it (as best as possible) what's the runout? If it wore evenly, that might be sufficient. Is the full-diameter base part big enough to indicate with a dti? How critical is the outcome?

GsT

 

[homebrewed]

A little more information would be helpful. Can the unworn section be mounted in a lathe? How accurate does the center need to be?

 

[mmcmdl]

If you have a vee block , touch off the top and lower height gage 1/2 the diameter of the shaft and scribe perpendicular lines to achieve center . ( if you have these tools )

 

[rodm1]

You probably are going to won't to dust off that .0001th indicator on this.

 

[OTmachine]

If you have a vee block , touch off the top and lower height gage 1/2 the diameter of the shaft and scribe perpendicular lines to achieve center . ( if you have these tools )

That ….. is to easy.

 

[mac1911]

That ….. is to easy.

None of those tools. So looks like I
Added tools to make , lol
Wait I do have a V block but the shaft is to short to stick out to scribe it .

 

[mac1911]

If you throw it in a 4-jaw and center it (as best as possible) what's the runout? If it wore evenly, that might be sufficient. Is the full-diameter base part big enough to indicate with a dti? How critical is the outcome?

GsT

Not critical , just needs to be round again. Although The remaining non worn section has just enough to catch the edge of thre Caliper Jaw edge.

FWIW this is what Im doing.
Im not looking to ways to fix it
Just methods to try and find the center.
Even ways to draw it up.
I dont have much in the way of drafting or machining education and limited tools. Very new to it all.

Magnetic chuck project

Picked up this chuck a while back for scrape price. It worked but just not 100% I did get it apart and found its just not traveling that last bit to get the plates lined up correctly. I am not a machinist and often these small jobs can be frustrating as how to approach a repair on this...

www.hobby-machinist.com

 

[rjs44032]

Oh you have a center finder already. That's how I would do it. Use it to scribe several lines through the middle of the object. X marks the spot.

Best Regards,
Bob

 

[mac1911]

Oh you have a center finder already. That's how I would do it. Use it to scribe several lines through the middle of the object. X marks the spot.

Best Regards,
Bob

The center finder I have is huge. The Dia of the part hardly shows
I would like to find one for small diameters. Are they sized for certain dia?