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I am working on a project that requires exact zeroing on an exact point on my spoil board ...
I am looking for a 0.250 ID too with a dead center point on opposite end of the 0.250 end that I can slide over my 0.250 end mill to quickly find dead center ...
Anyone ever hear, see, or build such a device
Thanks
Bear
Yes....my late father, who was a toolmaker, gave me one when I started my apprenticeship back in the late 50's when I worked with him on the mills......it's called a sticky pin.
It's simply a piece of Plasticine with a needle embedded in it that you stick on the end of a cutter, run it at a couple of hundred revs then true the point up with the edge of a 6" ruler.
Once the point is running true you apply it almost down to the marked off position not touching it etc.
I used it for almost 40 years, still have and use it,...…. I bought a wiggler set too, but the sticky pin allows you to attach it to a tool already in the chuck whereas the wiggler needs to be in a drill chuck etc.
Ian.
Interesting ..I see a lot of uses for such a "tool" to speed up some processes and lessen waste ..surprised there is not someone commercially building these in at least the main spindle collet sizesQuote:
Originally Posted by handlewanker
Is there a way to harden Plasticine as the stuff I know of.. is soft and stays malleable(like kids play dough) ..so I don't comprehend how it would hold the pin ..or even how you would reasonably for insertion .. center the pin ..looks like all my other stuff ..I will have to build my own "center stick" / sticky pin
Thanks
Bear
The needle and plasticine sounds like an easy idea :-)
For a double ended end mill, I guess you'd have to get one and make your own pointy end...
For a zero reference position, how about:
1. Home your machine (assuming the homing positioning is accurate and repeatable)
2. Manually move to some easy X and Y offset (100 x 100mm) and set new zero's
3. Mark the position with a Cross-hair position for a fixture
4. Mount a fixture suitable to use for the offset reference 0, 0
When you need to go there, home the machine and apply the offset then zero the co-ordinates.
Yes, flexibility......that is the beauty of it's simplicity.....the pin is a long needle or unheaded pinQuote:
Originally Posted by Brokenbear
When you stick the ball of Plasticine on the end of say a drill you then roughly centralise the pin, which is embedded in the dough, then rotate the drill at about 200 or 300 rpm...…. the pin will run out but if you apply the edge of a 6" ruler carefully against the point of the pin it will flex in the dough and run true......instant centralised point for picking up cross lines or edges etc.
There is a pointer in the Wiggler set that is applied the same way, but with that you need to have an empty drill chuck to hold it in, but the principle is the same, only the Plasticine is more versatile with already mounted tools.
I still have my original ball of Plasticine with the pin and it's 60 years old now......you could say it's a family heirloom.....LOL.
BTW....be warned, that pointer in the Wiggler set is quite a lethal piece of gear.
It is held in a spring loaded holder, that you hold in a drill chuck etc, and the principle is the same for setting it, but when you apply a ruler to the side to make it run true any amount of over correction will make it flick out sideways in a 100mm arc of pointed and very sharp steel...…..it can rip your hand open in the blink of an eye, so when I use one I always use a 12" ruler to true it up, that keeps your hand out of the way of the needle point if/when it flicks out sideways.
Ian.