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Multiple Copies of Bolt Patterns

Multiple Copies of Bolt Patterns

Multiple Copies of Bolt Patterns

(OP)
I have a part that has a bolt pattern repeated 4 times so I have;

(20X) DRILL & TAP FOR 3/8-16
X.62 DEEP EQ. SPACED
18 deg. APART ON A 14.063 dia. B.C.
TYP. 4 PLACES

Is the TYP. 4 plcs. at the end indicate this bolt pattern is repeated 4 times in its indicated areas correctly?

Thanks!

RE: Multiple Copies of Bolt Patterns

Good question, I am interested to see how others respond, It is ironic the standard does not try to be more helpful with simple stuff like this. I believe this is a result of the fact they intentionally keep parts so simple they don't need stuff like this, unfortunatley, in the "real world" we do, so we need a solution!
Here I am assuming then, you have (4) patterns of (20) holes?
The standard does show reasons for grouping and not grouping common holes like pattern tolerence requirement differences, they may be the same hole but the upper function is different.
I wish they would get into this though, do you say 4X 20X or  20X(4) places, etc.
Frank

RE: Multiple Copies of Bolt Patterns

When I hit snags like this I use the 'X' for the '20' and spelled 'Places' for the '4'.  To me it helps make the distinction, even though technically the 'X' and 'places' means the same thing.

However, I'd avoid using 'TYP' because of it's connotations.

Also, you have redundant information (for instance you don't need equally spaced & 18 deg - the explicit angle is probably the better of the two).

Also some of that information is better shown graphically than in a note - or on the actual drawing is it graphical and you put the note for the sake of this site?

If you are going to use notes I suggest making sure any abbreviations follow ASME Y14.38 or your approved abbreviation list.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Multiple Copies of Bolt Patterns

brunodg1,

   Those hole notes are not done much anymore.  It is not convenient for CAD, among other things.

   How about you specify 80X 3/8-16UNC .62DP (use the depth symbol).

   Show the pitch circles.  Apply 4X Ø14.063 to one of them.

   Show the angle between two holes on one of the circles.  80X 18°.

   This conforms to the standard, and I think it is clear.

               JHG

RE: Multiple Copies of Bolt Patterns


I would avoid words "DRILL", "TAP" and "TYP".

I would call it "20X 3/8", etc., etc., then add some FCF.

Then say "4X INDIVIDUALLY"
 

RE: Multiple Copies of Bolt Patterns

20X 3/8-16 X (depth symbol instead of X) .62 DEEP
EQ. SPACED on 14.063 DBC

Chris
SolidWorks 10 SP5.0
ctopher's home
SolidWorks Legion

RE: Multiple Copies of Bolt Patterns

The way I understand your posting, you have several of the same parts mounting to different mounting patterns of the same geometry. Figure 7-37 of the 2009 standard provides an example, if this is what you are refering to. If not I applogize for my misunderstanding.

Drstrole
GDTP - Senior Level

RE: Multiple Copies of Bolt Patterns

As Frank posted, it's not clear in the standard.  My suggestion and personal practice in these situations is to write out the variations that I can think of and figure out which one is most clear / least confusing, and work from there.

4 PLACES
20X
3/8-16  X .62 DP (or better, use the proper depth symbol)
EQ. SPACED

A couple things to avoid though; use of (round brackets) means reference, so you just maid the quantity reference.  TYP isn't allowed; use #X.  Avoid two-letter acronyms where possible; in this case you don't need "B.C.", just show and dimension it on the drawing; in fact, you don't need to note that the features are on the bolt circle in the note, just draw them that way.

Jim Sykes, P.Eng, GDTP-S
Profile Services  www.profileservices.ca
TecEase, Inc.  www.tec-ease.com

RE: Multiple Copies of Bolt Patterns

Jim,
That is an interesting point on the brackets, I had not even considered that as an issue. I notice I tended to do it (4) places and not (4 places) because something didn't look right to me, but, I could not pin my finger on it.
Frank

RE: Multiple Copies of Bolt Patterns

Do a detailed view of the hole pattern with 20X 3/8-16 X (depth symbol instead of X) .62 DEEP pointing to a hole. Dimension the bolt circle diameter and the 20X 18(degree symbol). Under the view name, put 4 PLACES.
 

"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

RE: Multiple Copies of Bolt Patterns

looslib,
I do think that is an excellent sugestion. I would like to have another standardized (well defined) option for use, say, when the pattern is not a small area easily broken into a detail view.
Frank

RE: Multiple Copies of Bolt Patterns

As has been noted, do not specify the method (drill, tap).
Do not make the quantity reference (20X) unless it is specified elsewhere.
Stating "EQ. SPACED" and "18 deg. APART" is redundant.
While the use of "TYP" is not expressly prohibited (used to be), it is not preferred and would not get a period if used, as it would not be confused with another term.  It does not add information to the drawing, and therefore should be avoided.
I agree most with Ben's method (12 Oct 11 14:45).
I have also worked at companies that require the full thread callout (3/8-16 UNC-2B), but I don't have ASME Y14.6 available to verify if that is a general requirement.

"Good to know you got shoes to wear when you find the floor." - Robert Hunter
 

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