Means of "Min Draft"

[SeasonLee]

I have seen plus draft or minus draft callout on the drawings before, but I haveen't seen "Min Draft" so far, anybody knows what means of it?

Thanks

Season

 

[ajack1]

I would guess it means the designer knows that draft will be needed if the part is produced in certain ways but has no idea how much and cannot be bothered to find out so has just put the limits on there and minimum draft.

 

[steveapathy]

As ajack said, it seems as though it's an attempt to say they really want 0° draft, but they'll accept small amounts of draft as needed to produce the part. They should probably specify a maximum allowable draft and work with the fabricator to determine how small they can make it.

 

[HGMorgan]

That part appears to be an injected mold part.
There has to be draft on both sides of boss walls so the part will come out of the mold.
Back in the day when we did a lot of injection molds, we would put in 1/2 of a degree of draft, if eng didn't specify draft.
However, you have to meet tolerances.
This part has the hole tol +/-.005, so we would make the mold to be .0025 bigger dia at the top on the inside hole.
The outside wall would be bigger at the bottom.

Harold G. Morgan
CATIA, QA, CNC & CMM Programmer

 

[pmarc]

Without a reference to a standard or most likely to a company spec clarifying the real meaning of MIN DRAFT notation, it is simply subject to multiple interpretations.

Perhaps MIN stands for MINUS, perhaps it means something totally different. I am afraid the only person knowing exactly the meaning of the callout is the author of the drawing. According to one of the fundamental dimensioning rules this is way not enough.