.002 English or .002 mm? Very big difference. .002 mm is only about 80 millionths of an inch. Autocollimators are measurement devices used to measure flatness on a surface plate. It is called "shooting the plate". Autocolliminators are electronic now, and very accurate. They aren't hard to use, but pretty fussy - and the surface is going to have to be pretty smooth. I believe that the machinist handbook will give instructions, and a description of a grid pattern to use. A plate that large is going to flex, gravity wil affect it. So will heat. And after moving, it will probably change some more. I would shoot it after it has been installed, if it is a critical use item. A couple of items come to mind:
1) the plate should locate on 3 points. More is not better.
2) the plate clamping should be limited to the area within a triangle formed by the locating points.
3) A Michigan outfit, Mitchell surface plate, can check it for you, and they have certs. I guess that $500 or so would cover it? They used to do our plates when I worked for GM. I don't know where you are at, so I don't know if that is practical. There are other folks out there, but they are the guys we used to use.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - A Cautionary Tale - by Ian Minshull. In the early 1950s my father bought an Allis Chalmers B and I used it for all the row crop work with the mangolds and potatoes, rolling and the haymaking on our farm. The farm and the Allis were sold and I have spent a lifetime working on farms throughout the country. I promised myself that one day I would own an Allis. That time event
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
