Welcome, Guest. Please login or register.
10-20-2020 -- 00:23:08

Login with username, password and session length

Top 10 Posters

flew-da-coup (1303)
Hawaii596 (1015)
USMCPMEL (856)
griff61 (580)
Hoopty (548)
docbyers (544)
MIRCS (535)
CalLabSolutions (521)
PMEL_DEVIL-DOG (509)
Thraxas (498)
Members
Stats
  • Total Posts: 19243
  • Total Topics: 3646
  • Online Today: 75
  • Online Ever: 242
  • (04-19-2014 -- 19:20:34)
Users Online
Users: 0
Guests: 55
Total: 55


Author Topic: All Surface Plates  (Read 10189 times)

Offline MIRCS

  • 7-level
  • ****
  • Posts: 535
  • Action Taken: +9/-3
    • Email
All Surface Plates
« on: 08-02-2004 -- 21:59:10 »
All Surface Plate TOs

A-1: Surface Plate Calibration Using Electronic Height Gage (Use Only For TIs 12 or Smaller)

A-1.1 Set up TI as you would for any other method as determined by size. (i.e. draw lines and borders)

NOTE
For 12X12 use 1 borders.

A-1.2 Place the TI on top of the Leveling Plate.

A-1.3 Level the corners of the TI by using the electronic height gage.

A-1-4 When the TI corners are level to within 10in, Start by moving every on the first line and record the readings.

A-1.5 Start on the second line and record the readings. Repeat for all remaining lines.

A-1.6 Make a chart and store near the TI.

A-1.7 Annotate Certification Label with the grade the TI was calibrated to and the location of the calibration chart.

Offline howiesatwork

  • 3-level
  • **
  • Posts: 32
  • Action Taken: +0/-0
    • SE Labs
All Surface Plates
« Reply #1 on: 02-09-2005 -- 10:32:49 »
It seems to me there is a shortcoming in this method.
The reference surface plate used as a base the whole setup is made on must be more accurate in flatness than the TI, as the base of the height gage must be moved over this surface to gage the TI surface.  
Any variations in the supporting reference plate will be telegraphed into the measured errors.
It's okay to be ignorant, as you can always ask questions, but there is no cure for stupidity.

Offline MIRCS

  • 7-level
  • ****
  • Posts: 535
  • Action Taken: +9/-3
    • Email
All Surface Plates
« Reply #2 on: 02-09-2005 -- 14:15:23 »
That is why the small plate is placed on a leveling plate and then leveled using the height gage. All error introduced by the bigger surface plate is then removed.

Offline howiesatwork

  • 3-level
  • **
  • Posts: 32
  • Action Taken: +0/-0
    • SE Labs
All Surface Plates
« Reply #3 on: 02-10-2005 -- 08:28:38 »
Quote from: MIRCS
That is why the small plate is placed on a leveling plate and then leveled using the height gage. All error introduced by the bigger surface plate is then removed.

It only makes the 4 spots that were measured at the corners a known distance to the reference plate.
Now, if the reference plate has a bow in the middle referenced to the end points where the stand for the indicator was when it was "levelled", an uknown error is introduced.
This is just one axis.  There are three more.
For this to work, your reference plate will need to be really flat, seeing that the specs for a 12X12 AA plate are tighter than that of the reference plate.
One more source of error:  Indicator stand base size and height and reach of the arm of the stand will multiply the error of the reference surface...
Why not do it with a Planekator?
You do not need to place the Planekator on the surface of the 12X12, but will need to raise the bases off the reference surface, spanning over the smaller plate, so you can measure with an indicator.  I don't have a picture of it, but it does work.

Autocollimator or laser is the easiest way to do all this anyway...

Howie
It's okay to be ignorant, as you can always ask questions, but there is no cure for stupidity.

Offline MIRCS

  • 7-level
  • ****
  • Posts: 535
  • Action Taken: +9/-3
    • Email
All Surface Plates
« Reply #4 on: 02-10-2005 -- 13:05:22 »
No kidding that an autocollimator or laser is the easiest way. The three footed leveling plate that the 12x12 is sitting on will take the larger plate out of the equation.

Offline howiesatwork

  • 3-level
  • **
  • Posts: 32
  • Action Taken: +0/-0
    • SE Labs
All Surface Plates
« Reply #5 on: 02-11-2005 -- 02:41:47 »
Where is the base of the Electronic Height Gage sitting?
On the 12X12?
It's okay to be ignorant, as you can always ask questions, but there is no cure for stupidity.

 

DISCLAIMER:  This site is not an official US Air Force site, it is intended for private use only.  It is not endorsed, in any way, by the US Air Force, the DoD, or any other governmental agency.  Additionally, all information found within this site is just that, it is NOT meant to be used in place of authorized publications.


All logos and trademarks in this site are property of their respective owner.

All forum content is the property of the respective poster, all the rest 2004-2017 by PMEL Forum.