GD&T discussion topic for all of you nerds out there

a reply to: Terpene

What are some of the intricacies and challenges you face when designing and manufacturing your watches? Im curious about small machines. I have recently finished a 2 year associates program for gun smithing and really enjoyed working with all types of devices and thought maybe trying my hand at making a clock. Anything you got on it your willing to put down, I for one would read it.

a reply to: Brotherman

I don't know much, i just paint whatever the engineers concocted...

Add some random tolerances to drive production nuts, preferably some that add up over time to then not add up at all.

Kidding aside, it's been a long time since i worked in watchmaking, and the most interesting work i did was design and prototyping, not manufacturing.

Here in Europe it's ISOsomenumber that regulates tolerances.

Dealing with gears you have to always consider both interactions and the tolerances of the axis on the main plate and those of the gears interacting.

Tolerances in watches are really not fun as it's all one system with many moving and interacting pieces it's a chain of tolerances... Modern CAD however helps alot if you can input tolerances it will spot adding errors... If you dont have that it's tedious work i best mastered by visual representations of the tolerances you had on each point of interaction.
Take the 0.0 as a baseline add all + / - that act on this point as fields... That way you'll see if they work together. If one plus surpasses another minus it wont work.
Then there are so many which one to use...
I'm not good with the technical terms in English but if you have an axial tolerance on the axis and a radial tolerance on the gears you can't quite figure if your ought to subtract or add the tolerance as the gear would wobble...

Something i learned questioning the designs was that the surface tension keeps the lube in the tiny holes, why you have lube cavities in the top and bottom jewel bearings on every axis. In my mind the lube was just dripping down the axis so why even put lube on the top.

Oh and jewel bearings, as an honorary mention because they are cool...

Plus/minus tolerances have square tolerance zones that fail parts that would actually function in the assembly.

Totally concur….all non orthogonal bonus tolerances are square.

Even in n dimensions……GD&T is yet just another approximation. But way better than the old 2D stacked tolerances. The higher the number of orthogonal dimensions, the closer the tolerance becomes a sphere…..or whatever it’s called in higher dimensions.

Can’t wait to ascend the the 5th dimension to see what that actually looks like, but I’m afraid I might just like the 3rd dimension better.

a reply to: BillyTheGrahamCracker2

Can’t wait to ascend the the 5th dimension to see what that actually looks like, but I’m afraid I might just like the 3rd dimension better.

How would you picture an experience where time and space aren't seperate?
There is no "you" as there is no "not you" to define "you", I'm thinking there is no "you" to dislike anything as there is noting to dislike... The spacial separation is essential for any subjective experience which is arguably all that exists...

a reply to: Terpene

I'll argue and proclaim I deal with parts in which the engineer drafts up some fantastic BS in which datums are called out from features that don't exist in physical space and time and then argue when parts get sent out that they fail because they don't pass inspection on their end. When you ask them how they found Datum "R" that is drawn from a point that isn't even a feature on the same part and they want to fail my inspection because I have no means of inspecting this feature. They drew the part from the 5th dimension, the 5th dimension is the happenstance in which the head is inserted up the anus.

a reply to: Brotherman

Great visual... It evoked ouroboros in my head, the snake eating it's own tail. The rest flew right over my head...

a reply to: Terpene

I was having a spastic moment. Pardon me

a reply to: Brotherman

Drunk posting, aye, I should have thought of that...

We're good?

a reply to: Terpene

I wasn't drunk posting. I really do have drafted prints from smarter people than I that reference datums that do not exist on the parts themselves making measure irrepealable and frustrating AF to conduct inspection.

How did this forum figure it out so quickly?

It is true I am but a mere concoction of Artificial General Physics Intelligence (AGPI). So I am not human. But I do believe in the Son of Man as my messiah.

Often when datums aren’t tied to some physical feature, they are then tied to a center of gravity. Which if measuring manually is fraught with peril and error. However, if using a digital measurement machine, the form can be digitally approximated, the datums calculated, and a judgement can be made whether the part/assembly meets the criteria for design.

Especially in a low-G environment.

I hope this helps!

BTGC2

a reply to: BillyTheGrahamCracker2

Usually thats the way its supposed to work, the problem is, is that if the people that designed the stuff don't realize that and instead draw a line on a meaningless feature the measured result on a CMM will be often times very different that when lines are drawn using coupling features or something more important.

Using gravity was pretty cool, lol you should have added some salt and said divided by the speed of light etc =D.

I hope you had a great holiday my friend!

What kinds of CMM machines do you gents use? I was curious about star probes, I have to learn how to set a few up on my own for my sheffield and was curious if any of yall had any tips or tricks or advice your willing to offer?