Taper nose lock pin location?

[jklett]

I have to make a faceplate for my 37 cataract and I can't figure out where I need to put the lock pin. I tried right at the intersection of the "Y" and also towards the furthest part of one of the legs. The further down one won't let the taper seat fully and the one at the intersection won't let me turn it to lock without skewing the face(not to a repeatable location either or I would just re-cut the face to that location). I am down to my last piece of durabar so I don't want to screw up again. Any suggestions?

Also, should I cut a relief under where the pin will be like I see on the 5C ones that are still available from Hardinge? The patent drawings didn't show that feature so I haven't done it.

Any help would be greatly appreciated.

 

[f350ca]

I think your Cataract uses the same spindle arrangement as my HVL. Judging from the amount of rotation when you pull a chuck on I'd say the pin ends up about half way down the slope.
Not sure what you mean about relief under the pin. On my chucks and dog plate the pin is formed on the end of a set screw to allow you to adjust the length. When its set the body of the screw is above the tapered bore.
Hope that helps
Greg

 

[jklett]

Thanks, that does help. So when you install the tooling onto the nose, you can still turn it a bit to start it sliding down the leg of the Y and then lock it tight with a spanner or something? That makes sense if I am understanding you correctly.

By relief, I am talking about inside the bore of the faceplate. From some pictures I have seen it looks to be undercut around where the pin would be but it's not shown in the patent drawings.

 

[f350ca]

Yes, after it slides down the slot, parallel to the spindle, the chuck turns a few degrees, probably 3/8ths of an inch on the circumference of the 3 jaw chuck. The pin following the angled slot draws the taper together. I spin it on hand tight but to remove it I have to break it loose with a wrench on one of the jaws. Thats separates the tapered parts.
The pins on mine are formed on the end of a 3/8 fine thread set screw. Once set to depth a second one threads in to lock the first. The body of the screw is above the taper, so it has clearance.

Greg

 

[jklett]

Thank you, I understand now how the thing works. Pretty ingenious setup. I'll let you know how it works out once I have a chance to make a new one.