Locational Clearance Fits

[cadman1964]

We typically build round tooling under 5" dia. Our typical clearance is .00015" total for locating fits. Now were getting in to bigger diameters. What is the role of the thumb for biiger dia fits???

Solid Edge V20

 

[drawoh]

cadman1964,

Look at the limits and fits section of your Machinery's Handbook. This shows the standard ANSI fits. This should provide you enough data to identify your current fit, and translate it to your new size.

JHG

 

[Tmoose]

Low speed naval shafting must runout less than 0.001 inch when assembled.

The change in centering of a part with 4000 rpm service speed must be << 0.0001 inch for G 1.0 balance to be maintained between balance machine and installation.

http://www.irdbalancing.com/downloads/TechPaper1BalQualityReqmts.pdf

I interpret your 0.00015" clearance as a diametral clearance.
There have been lots of posts on various message boards debating that "per side" or radial clearance is the proper interpretation.

 

[cadman1964]

Thanks, looked at that yesterday and figured it out. was just wondering if there was a rule of thumb.

Solid Edge ST3

 

[unclesyd]

Here is a Treatise on shaft design including interference fits.
There is a lot of information starting on Adobe page 38.

https://highered.mcgraw-hill.com/sites/dl/free/0073121932/365766/chapter07.pdf

The link should work, if not copy and paste.