DIMENSIONING
DIMENSIONING
(OP)
What is the correct method for calling out features (holes)located on a bolt circle on a drawing?
I believe it should be, example;
4X (qty) Diameter (symbol)hole size
EQ SP BC Diameter (symbol) size of bolt circle.
Checker says;
4X (qty) Diameter (symbol) hole size
EQ SP Diameter (symbol) size of bolt circle followed with BC.
I believe it should be, example;
4X (qty) Diameter (symbol)hole size
EQ SP BC Diameter (symbol) size of bolt circle.
Checker says;
4X (qty) Diameter (symbol) hole size
EQ SP Diameter (symbol) size of bolt circle followed with BC.





RE: DIMENSIONING
4X Dia (symbol) .XXX
EQ SP Dia (symbol) .XXX BCD.
Some checkers like having callouts too wordy.
Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)
RE: DIMENSIONING
RE: DIMENSIONING
Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group
RE: DIMENSIONING
9X ø.125 THRU
9X 40°
ø6.250 BC
Also, if it is clear that the BC is a BC, then you do not need to have BC on it. It is not in the standard, but that does not mean that you cannot use it. The previous information is if you are stating that you follow the ASME Y14.5M-1994 standard.
Marcelino Vigil
GDTP T-0377
RE: DIMENSIONING
RE: DIMENSIONING
RE: DIMENSIONING
These need to be considered in the final solution.
RE: DIMENSIONING
But, there has been a lot of times I have not used it and the holes were not eq sp because machinist's didn't understand.
Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)
RE: DIMENSIONING
At the risk of being accused of pedantry and assuming you’re working to ASME standards:
Equally Spaced should be EQLSP per ASME Y14.38-1999 Abbreviations & Acronyms.
EQ is actually Equation per same spec and SP is Space (amongst others).
BC is in the standard as bolt circle but not BCD (and no D isn’t the standard combination form for Diameter).
You can also have a Pitch Circle, PC or a Pitch Diameter, PD but PCD isn’t listed.
That said I’d be tempted not to bother with bolt circle or equally spaced and to use Positional Tol instead with the angle given, something like figure 5-8 in ASME Y14.5M - 1994
4X dia (Hole Diameter)
(basic) 4X 90°
(basic) dia (Bolt Circle Diameter)
Just remembered back in the UK we use to say equispaced not equally spaced. This is one of my many British Drawing isms my Checker used to point out.
KENAT, probably the least qualified checker you'll ever meet...
RE: DIMENSIONING
Thanks for the reminder. You're correct.
Using 'basic', you do not need to call out bolt circle.
It's been a while for me.
Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)
RE: DIMENSIONING
RE: DIMENSIONING
That said I’d be tempted not to bother with bolt circle or equally spaced and to use Positional Tol instead with the angle given, something like figure 5-8 in ASME Y14.5M - 1994
4X dia (Hole Diameter)
(basic) 4X 90°
(basic) dia (Bolt Circle Diameter)
The whole point of a symbolic standard is to make the specification universally ledgible!
Additionally, 7X dia (Hole Diameter)...with... basic [360º/7] (when the spacing is a long or repeating rational number)
Paul
RE: DIMENSIONING
KENAT, probably the least qualified checker you'll ever meet...