hole diameter and call out question
hole diameter and call out question
(OP)
We make some parts with a pattern of holes on a 28-3/4 inch "bolt circle), dimensioned as shown in the attached image.
There is no "tolerance block" in the drawing format/border.
What is a (the?) correct interpretation of the 1-1/16 inch hole size tolerance, and how close each hole must be to the 28-3/4 inch diameter.
thanks,
Dan T
There is no "tolerance block" in the drawing format/border.
What is a (the?) correct interpretation of the 1-1/16 inch hole size tolerance, and how close each hole must be to the 28-3/4 inch diameter.
thanks,
Dan T





RE: hole diameter and call out question
1. The size tolerance depends on the block tolerance for fractions (if there is one).
2. At MMC, the hole must be within +/-.005 of your bolt circle and +/-.005 of the specified angular orientation.
I'm sure that there are others here who will feel that this explanation is simplifying it too much and will expound on the correct interpretation for you.
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: hole diameter and call out question
RE: hole diameter and call out question
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
RE: hole diameter and call out question
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: hole diameter and call out question
You can make the holes as big or small as you like and technically you aren't wrong.
Because of this I believe you MMC is down to 0 hole size on the -ve sice and is infinite on the plus side so your holes can be almost anywhere as they increase in size.
Ask the customer or whoever for the hole tolerance. You may want to double check there is no reference to standard drill tolerances anywhere.
If you can't get information from your customer or whoever made the drawing and you have to make a guess, I'd suggest assuming typical drill tolerances for the holes. For dia 1.063 this would be +.012 -.001. However there is risk associated with this approach.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: hole diameter and call out question
Chris
"In this house, we obey the laws of thermodynamics." Homer Simpson
RE: hole diameter and call out question
WE are the customer ;).
This is a translation by an experienced Pro-E contractor of a drawing dated 1963, of a part that evolved from parts first made in 1950.
The hole is described as a 1-1/16 inch drilled hole on those sacred parchments.
Dan Timberlake
RE: hole diameter and call out question
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: hole diameter and call out question
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: hole diameter and call out question
RE: hole diameter and call out question
thread1103-235569: Calculating Positional Tolerance may be of assistance in this.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: hole diameter and call out question
"In this house, we obey the laws of thermodynamics." Homer Simpson
RE: hole diameter and call out question
The more I think about it, the more I agee with ringster, if you have the mating part info re-calculate the tolerances and apply them to the updated drawing.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
RE: hole diameter and call out question
Chris
"In this house, we obey the laws of thermodynamics." Homer Simpson