Link length

Thought this might interest some.. I make my own links.. There is always that need for the exact length.. So years ago, I came up with a way to accurately make them.. Al Marvel provided me with several hundred blanks, with no holes.. There's a heat treat shop in Richmond, who brought them to the correct RC .. The link is quite important for smooth function.. I never egg out the SS hole, and run a link that is approx. .005 longer than necessary, and bury the extra length in a shallow groove in the slide stop pin..
 

This is to keep the barrel and slide locked a little longer while keeping the lockup on the lug feet and SS pin without riding the link? I'm trying to get a better understanding of the whole timing question.

Jerry, your jig for hole location is cool, but I'm missing something here.  If the groove in the slide stop pin goes all the way around its circumference, how is cutting a groove any different from just reaming the link hole a few thou larger?

Dr.Don wrote:Jerry, your jig for hole location is cool, but I'm missing something here.  If the groove in the slide stop pin goes all the way around its circumference, how is cutting a groove any different from just reaming the link hole a few thou larger?

Hello Don.
The groove does not go all the way around.
It only effects that portion of the link/pin  that would be in contact during TDC and at lock up..
I try for long lug foot prints for bullseye guns.. The longer the foot print, the longer the link has to be to allow for the arc of movement..  It's a juggling act since the system is radial, and barrel/slide movement is linear.   Much study on a cut away gun, and experimentation to get it right.. I leave a dedicated spin index set up with stops just for that purpose..

Thanks for clarifying Jerry.  That makes sense to me.  I try to set my links so they are long enough to lift the lugs over the "corner" so they don't bump the slide stop, but then free up so they don't interfere with the lockup on the lugs.  Usually for me that has resulted in the need for a little "ovaling" of the hole.  Your technique is clearly better if one is able to cut the groove only part way.  I guess it could be done by carefully turning the headstock manually and using very light cuts.

Looking at the stop from the left side, the groove extends from approximately 12:30/01:00  to 04:30/05:00 o clock...
This leaves the front of the pin  in tact to function normally  thru cycling, feeding.. I use a narrowed wheel on the surface grinder to cut the groove..and the stops on the spin index control the stop/start points..

Of course.  I didn't look closely enough at the picture and assumed it was held in a lathe collet.  I see now that it is setup on the surface grinder (magnetic chuck in the background).  Slick way to do it.  No access to a surface grinder here, so I'll have to find another way.

" />" />Don, this is how I do it.  Don't have a surface grinder either.

KC, that is a great idea/fixture.  Thanks so much for sharing.

Great and simple jig KC!

Both genius ideas.

kc.crawford.7 wrote:


Don, this is how I do it.  Don't have a surface grinder either.

You finally found a use for all those disposable chopsticks from Chinese takeout, I see.