Is It Possible To Make One Of These?

I believe the knurled bolt is probably made just long enough that it will tighten against the body before the balls break loose from the body. Otherwise if over tightened the balls could fall out.

little_sparky said:

heres a good insight, explains a lot. My question still is how they get the balls inside? and how they can champher the hole inside out so the balls dont fall out?

Click to expand...

My guess is that they make them on CNC equipment, which would allow them to add the slightest of interior taper while interpolating the hole with a smaller end mill. The axial bore down the center would be slightly larger than the balls, allowing them to pass into their respective tapered housings.

In a manual home shop, the way I would go about it is like this: drill the center hole along the axis, then cross drill the holes for the individual balls a bit over size (just a couple of thousandths of an inch) to their stated diameter. Then you can use a punch to disrupt the metal on the edge of the ball housing holes, just enough so that slightly less than half of the sphere may project from the hole.

Take a look at the ball oilers on various machines.

Anything I have seen like that ball arrangement, the balls are put in from the outside and the hole is then staked from the outside to keep them in place. Same process as Square Drive Ratchet Wrenches.

"Billy G"

little_sparky said:

My question still is how they get the balls inside?

Click to expand...

I have hydraulic valves with a similar detent mechanism. You put a bit of grease in each hole, drop a ball down the center hole, and let it fall into one of the holes and stick to the grease. They probably use some sort of fixture. A cone inserted from below would guide the balls into the holes. Once the center ball and the screw are in the balls can't move enough to get out of place. Another possibility is to simply press them in past the lip.

and how they can champher the hole inside out so the balls dont fall out?

Click to expand...

By opening up the hole below the lip with a boring bar or a stubby reduced shank end mill, or by swaging the edge of the hole. There might be a finishing operation that hides the evidence of the latter.

As others have said, the holes are initially large enough to drop the balls in, then, the edge of the hole is swaged, or staked, with a punch, to create a smaller diameter ring of metal at the mouth of the hole, which is smaller than the ball and prevents the ball from falling out.


Steve Shannon, P.E.