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HLV Taper Attachment Pivot Post Configuration?

gmoushon

Cast Iron
Joined
May 18, 2006
Location
Illinois
Another question regarding the HLV-H taper attachment casting project:

The casting instruction simply say to tap the support casting for the pivot pin. However, the original shows a (1) set "Screw" and (2) "Brass Plug" that engage a (3) "Pivot Post".

Taper Attachment Pivot Post 2.jpgTaper Attachment Pivot Post.jpg

Anyone know how Hardinge did this? Again, I'm trying to get as close to original as possible.

Thanks!
gm
 

L Vanice

Diamond
Joined
Feb 8, 2006
Location
Fort Wayne, IN
Hardinge will use a small brass plug under a standard set screw to lock a male thread that has a finely adjusted position rather than simply tightened all the way.

Do you need the thread size of the set screw?

Larry
 

gmoushon

Cast Iron
Joined
May 18, 2006
Location
Illinois
No...not the thread size. I'm looking for how the "Pivot Post" is shaped and how it's fixtured in the main support casting. Is the post fixed and the brass plug tensions the arm onto the post? In the photograph posted above, there is a steel insert in the bottom of the casting. (Thick red arrow.) I'm guessing that is what the post threads into?

The other area of confusion is the component shown in the parts drawing where I've drawn a thinner red arrow. It appears to have a tapered feature drawn with hidden lines. This looks to be a tapered washer that goes into the underside of the Pivot Arm and I assume it mates into a female taper in the support casting. I'm trying to understand its purpose.

I know its just a pivot point, but Hardinge must have had a reason for it.

Thanks again,

Gaylan.
 

L Vanice

Diamond
Joined
Feb 8, 2006
Location
Fort Wayne, IN
I took one of my taper attachments apart and took pictures of the pivot post.

The 1/2-20 threaded end has a 1/4" hex broached hole. The hex hole is a weakness in the design because previous owners messed up the hex while not understanding what the set screw does and trying to adjust the pivot snugness. If I were making a new post, I would either slot the end for a big screwdriver or silver braze a 1/2-20 set screw into some steel and then turn the taper. And I suggest annealing the brass plug, You can see the thread damage on my post from the plug mashing the steel threads.

The tapered end of the post mates with a reamed taper in the base casting. Careful adjusting of the post and then locking with the 1/4-28 set screw and brass plug makes the snug, but adjustable fit for adjusting the position of the taper bar. The 1/2-20 tapped hole is in the upper casting with the guide bar.

The parts list illustration is not meant to show you how to make all the non-cast parts like this post. You need detail drawings or good pictures of the small parts.

Larry

DSC02985.jpg DSC02986.jpg DSC02987.jpg
 

L Vanice

Diamond
Joined
Feb 8, 2006
Location
Fort Wayne, IN
Here are pictures of the tailstock end of the HLV (not -H) guide bar assembly. The HLV-H scale and index are different. The pivot post looks to be the same on either model.

Larry

DSC02988.jpg DSC02989.jpg
 








 
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