Machining Question: Reaming and Hole Position, Need some grounded "hunches".. |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Machining Question: Reaming and Hole Position, Need some grounded "hunches".. |
Brian Mifsud |
May 21 2009, 03:55 PM
Post
#1
|
Mechanical Engineer Group: Members Posts: 981 Joined: 3-March 03 From: Penngrove, CA Member No.: 384 Region Association: None |
I've been offline a long time, but I know there are knowledgeable machinists in the forum.
I have several 316 Stainless Steel castings where the hole for the shaft needs to be very accurately located on the centerline to prevent imbalance. This is an impeller that spins at 1200 RPM. The shaft hole has been bored on a lathe to .4981". The nominal hole size is supposed to be .4987 +/- .00025". The shaft which is supposed to insert into this hole is .4985". I have a .4990" cobalt tipped, straight flute reamer. Question: If I don't get the reamer to bore position dead co-axial, will the reamer change the hole POSITION? HOLE SIZE: I understand that the reamer is built to -.0000 +.0002", so in theory, I'd be taking up to .4990 + .0002 = .4992 Reamer Size .4992 -.4895 = .0007" clearance on the shaft to hole. But in removing that material, will the reamer follow the path of least resistance and stay dead co-axial to the bore location? Any variance off the impeller center axis cauese imbalance. Thanks Brian |
J P Stein |
May 21 2009, 07:03 PM
Post
#2
|
Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
A reamer will folow the parent hole.....if it's properly tapered.
Honing allows you to "creep up" on the required size....but you're gonna be there a while. |
Lo-Fi Version | Time is now: 16th June 2024 - 08:07 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |