• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You
  • June Project of the Month (Click "x" at right to dismiss)
[4]

Small surface plate tester

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

38super

Swarf
Registered Member
Joined
Apr 23, 2018
Messages
11
Likes
5
#1
Was watching Rahn Repeat-O-Meter vids from Oxtools and NYC CNC . Great for 24x36 plates or larger but too big for a 12x18. Did a little resizing and used set screw/ball bearing pivot instead of a flexure. Fleabay 0.0001 dial indicator ($26). Button on side locks the pivot arm when not in used, unlocked it limits 0.030" travel. Not a daily use tool, but handy if buying a used surface plate.

http://s1333.photobucket.com/user/F-4CWeasel/library/Rahn Style Surface Plate Tester?sort=2&page=1
 

Ray C

H-M Supporter - Sustaining Member
Staff member
H-M Supporter - Sustaining Member
Joined
Nov 16, 2012
Messages
5,215
Likes
1,393
#2
Looks really good. Ever since Tom Lipton and Rob Renz have been dedicating time to surface plate analysis tools, I've been tempted to know how flat my plate is which is 18x24".

If you took photos while you made those, consider posting them here. Folks would love to see it.

Welcome to Hobby Machinist...

Ray
 

Eddyde

Moderator
Staff member
H-M Supporter - Sustaining Member
Joined
Oct 13, 2014
Messages
1,292
Likes
1,008
#3
Welcome HM! Nice project and and please post some pictures, we'd like to know more about your project? I have a 18x24 plate I bought new 25 years ago, curious to know how accurate it still is.
 

38super

Swarf
Registered Member
Joined
Apr 23, 2018
Messages
11
Likes
5
#4
Last edited:
[6]
[5] [7]
Top