Custom 5c Collet Stop Stud

[Ulma Doctor]

Hello again!
i've been working out production of some custom shoulder bushings ,in delrin , for some conveyor systems i service.
i'll be making about a thousand bushings when it's all said and done, primarily in 4 outside diameters (.376",.438",.501",.626") but, thankfully all sharing the same inside diameter of .257".
sounds fair enough , but, here's the kicker- i'm only allowed about .110+/-.001" for the shoulder of the bushing.
that's not a lot of meat to grab ahold of...
i found previous attempt at a production run to go smoothly. i constructed bushings from spacers i had made for another job and repurposed them for this run to make sure the machine was set up as if i were to start running it for real.
i got about 10 bushings into the run before i saw an irritating hurdle, the bushing wants to spring and can easily dislodge from the 5c collet.

as you can see, the final dimension was too thick (.126") in the shoulder from a mock production run.
i have to be at .110" or so.
i needed a custom 5C collet stop that offered a little more support....

EUREKA!!!!!

Here's a shot of the working model as used!



it wasn't very hard to produce....
i had a commercially made collet stop that had a nice tool steel stud that didn't want to cut well.
so rather than completely messing it up i decided to get something softer to work with.
at the local hardware store they had 3' lengths of 1/2-20 all thread.
it cuts like butter and can clean up nice if you leave a little radius on the tool tip, i had a sharp tool and used the Hercus' auto feed to knock some threads off for grip clearance inside the 5C.


then i turned down the nose to .256" to a depth of .250" as a nice mandrel for the last order of operation.

here's the parts right before assembly and adjustment.

the bushing lower left was commercially made, i provided the 1/2-20 nut and a 5" section of all thread.

the collet stop worked like a charm and i was able to achieve .110" shoulders on 100 bushings in this run!

thanks for reading!

if you have other ways of skinning this cat, i'd love to hear them!

 

[brav65]

Nice work Mike. Are you able to charge your customer enough to make this a money making project?

 

[Ulma Doctor]

yeah Brooks,
the factory doesn't make the custom sizes that i'll be making so i have no competition that way.
the factory charges lots of dinero for their items anyway.

the first actual run will pay for the machine, and there should be many runs afterwards!!!

 

[brav65]

Nice! It's hard to communicate to customers the value of something that is custom made. I run into that all the time. Customer wants something specifically suited to their needs, then is shocked by the one off price. I nicely tell them to go by the "similar" product that is one half the cost, then increase the price when they call me and say they want me to go ahead after the less expensive option did not work. Material price increase!

 

[turnitupper]

Another use for the most versatile piece of kit known to man. The mighty All Thread. There should be an entire wing in the Smithsonian to extol its value.
John.

 

[brino]

Yeah, all-thread is good for many things, but in terms of this:

Another use for the most versatile piece of kit known to man.

I'd have to go with "a sharp mind"!

......and Mike's is a great example, it gets a regular work-out and is very useful even from a distance!

-brino

 

[turnitupper]

Brino,
Where would you have to go with a sharp mind?. Sorry, repartee frowned upon here . Been watching the Doc since I joined and don't disagree as he can do something like this which he may use thousands of times and is not very pretty but it is very effective, and then spend untold hours on something that probably will never be used but it is a work of art. One of my favourites and he is closer to you than me. My Mum said "Write with wit, without malice and you will be re-read".
John.