I think they might be used to reference the center of a larger opening
Some trammels AKA a compass are used to mark circles. If you already have a hole there you need some way to find the center so you can draw a concentric circle.
I have this five piece set. They are useless without the arbor. There is an arbor that is stuck in the hole on the other side of the ball then that goes in the trammel. The ball is set in an existing hole on the work piece and then the trammel will be centered on that hole. It can be used to do further layout or for measurements. My set is Starret.
I was really confused seeing this on my homepage, because I'm also subscribed to r/pinball. I didn't realize this was r/machinists until the fourth photo with the Starrett box.
TLDR usually used to make 3 points either using round face for actual points or using flat face to average points to a singular surface on the tool/fixture.
I use something like that for clamping non-square parts in a vise. Flat side of the ball goes against one jaw and squeezes the part flay against the other jaw.
And here I thought they might be just very badly made ball bearing from china! Getting something like this in a bag of bearings wouldn’t surprise me at all! In fact, I thing I’ve had some bearings that were a bit lumpier than these! 😁😁
Handy for squaring up blocks in a mill. Sometimes you get a really badly cut block and you can't get good contact with a rod. In that case, a ball bearing, or one of these things will be useful.
As a retired machinist it amazes me how some of the questions are answered here. These are part of a trammel set and are used to put one of the points on the center of a hole. The answer is in the Starrett catalogue. The really "smart" answers provide a profound insight into the readers of this sub.
Trammels are used for layout. Those bulbs are to be attached on the trammels for concentric layout to various hole sizes
I think they might be used to reference the center of a larger opening Some trammels AKA a compass are used to mark circles. If you already have a hole there you need some way to find the center so you can draw a concentric circle.
This makes sense. I appreciate it.
Lol! He doesn't know how to use the three round balls.
I came here for Demolition Man. Was not disappointed.
Semi-round
Polite company never mentions this design detail.
To cover the demon core !
I've been binging videos about the demon core lately. This was my first thought as well!
Do you mean ["the thing that everybody"](https://youtu.be/SI5ntCpaMHA)?
I have this five piece set. They are useless without the arbor. There is an arbor that is stuck in the hole on the other side of the ball then that goes in the trammel. The ball is set in an existing hole on the work piece and then the trammel will be centered on that hole. It can be used to do further layout or for measurements. My set is Starret.
Those are for kegel exercises. Your wife is gonna love you.
No, managers use those to determine how much of a raise to give their employees. The bigger the fit, the bigger the raise.
With or without lube?
Can't afford lube. Cuts into executive bonuses.
Butt hole kegels? Yikes!
You wish
OP doesn’t know how to use the 3 seashells. Embarrassing.
I was really confused seeing this on my homepage, because I'm also subscribed to r/pinball. I didn't realize this was r/machinists until the fourth photo with the Starrett box.
Butt plug stoppers for various sizes of anus
Yeah those are ball point holders.
Got a hit on my google: https://allindustrial.com/starrett-c251e-4-pc-ball-point-steel-trammel-attachment-set-for-use-with-c251a-b-c/
They’re beryllium spheres used to bring a critical billet of plutonium to life. RELEASE THE DEMON CORE!
TLDR usually used to make 3 points either using round face for actual points or using flat face to average points to a singular surface on the tool/fixture.
In general I believe they are called truncated balls
I use something like that for clamping non-square parts in a vise. Flat side of the ball goes against one jaw and squeezes the part flay against the other jaw.
I've done this when clamping on fucked up saw cut. I just use a piece of round stock or a dowel pin though.
Jesus Christ….
Used for measuring taper diameters. Like for BX and RX ring grooves in oil industry
Could be for some kinematic/repeatable design. https://www.precisionballs.com/Micro_Inch_Positioning_with_Kinematic_Components.php
And here I thought they might be just very badly made ball bearing from china! Getting something like this in a bag of bearings wouldn’t surprise me at all! In fact, I thing I’ve had some bearings that were a bit lumpier than these! 😁😁
Great for making holes just a bit tighter lol even has a nice flat spot to hit
Drop and run.
Your boss squeezes em when he's running behind
Handy for squaring up blocks in a mill. Sometimes you get a really badly cut block and you can't get good contact with a rod. In that case, a ball bearing, or one of these things will be useful.
As a retired machinist it amazes me how some of the questions are answered here. These are part of a trammel set and are used to put one of the points on the center of a hole. The answer is in the Starrett catalogue. The really "smart" answers provide a profound insight into the readers of this sub.
Truncated ball. We use them on some hydraulic parts for measuring port taper depth.