Author Topic: Clamps for a Height Gauge Scriber?  (Read 5082 times)

Offline Pete W.

  • Hero Member
  • *****
  • Posts: 852
  • Country: gb
Clamps for a Height Gauge Scriber?
« on: October 11, 2015, 09:26:48 AM »
Hi there, all,

This isn't so much a 'How Do I?' thread, it's more a 'How Would You?'.

First of all, a bit of background:  Some time ago, I bought a Rabone, Chesterman Height Gauge, here it is:



The trouble was, it had lost its scriber and clamp.  (I think I did post a mention of this some time ago.  Someone, somewhere must have a cupboard full of scribers and clamps because lots of the height gauges listed on eBay are scriberless and/or clampless!)

After some searching, I decided to grasp the nettle and buy a new scriber.  The Rabone gauge scriber-stub is imperial, ¼" by 0.600" as shown here:



So I looked for an Imperial scriber - the nearest I could find was a tungsten carbide tipped Mitutoyo item, shown here:



That is ¼" wide OK but is 0.500" high so I'd need a clamp with a capacity of 1.100".  The Mitutoyo clamp I bought has a capacity of only 1.000", shown here:



(One of the contributors to the Model Engineer site posted a Rabone Chesterman height gauge catalogue but it didn't have any information on the sizes of their scribers and clamps.)

So, here's the meat of my thread:  I have to make a clamp with the right capacity to attach the scriber to my height gauge; I have several ideas how I might do this, some by hewing from solid, some by fabrication.  Most approaches are laborious, none are snag-free.  The clamp has to have a truly rectangular, precisely ¼" wide aperture.  (Note that the Mitutoyo item has corner relief.)  I don't have a shaper or a broach and I don't fancy filing the aperture to size and shape.  I'd prefer a corrosion resistant material, stiff enough to retain its shape.  (So silver-soldered brass would probably bee too soft!)

So, Mad Modders, how would you make it???????   
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline j1312v

  • Jr. Member
  • **
  • Posts: 44
Re: Clamps for a Height Gauge Scriber?
« Reply #1 on: October 11, 2015, 10:15:56 AM »
Hi,

Why don't you get 0.1" or more from the scriber.
If you have or know someone with access to a surface grinder it should be much quicker that make a clamp.

Best,

Joe

Offline chipenter

  • Hero Member
  • *****
  • Posts: 909
  • Country: gb
Re: Clamps for a Height Gauge Scriber?
« Reply #2 on: October 11, 2015, 10:58:43 AM »
I have had sucksess with 1mm thick cutting disk for an angle grinder in a slitting saw arbor , on hardened steel cover everything up and take it off the height guage .
Jeff

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Clamps for a Height Gauge Scriber?
« Reply #3 on: October 11, 2015, 11:29:50 AM »
My approach would be to modify the scriber or height gauge. Check the scriber's hardness with a file. Even if its hard but not extremely so, you could cut with a carbide endmill. If totally soft then anything will work.

Ironically, I have 1 height gauge and 3 clamps of various sizes... :-)

Offline Lew_Merrick_PE

  • Hero Member
  • *****
  • Posts: 690
  • Country: us
Re: Clamps for a Height Gauge Scriber?
« Reply #4 on: October 11, 2015, 11:31:33 AM »
Not that it is trivial, but a pair of "plates" made from 16 gauge (or so -- 1.5 mm) sheet would be the cheeks to retain the scriber.  A pair of "ends" -- call it .010 inch (0.25 mm) wider than the scriber or mount could then be carefully pinned/riveted or soldered to the "plates" -- and then it is a matter of drilling and tapping for an appropriate screw and mounting a "clamp bar" to the screw.

???

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Clamps for a Height Gauge Scriber?
« Reply #5 on: October 11, 2015, 11:44:40 AM »
As an afterthought, and further to my earlier suggestion, the arm on your gauge seems thicker than average. It turns out I only have 2 clamps but they measure considerably smaller than what you're looking at. (0.780 x 0.350, 0.895 x 0.360)

Offline Manxmodder

  • Hero Member
  • *****
  • Posts: 739
  • Country: gb
Re: Clamps for a Height Gauge Scriber?
« Reply #6 on: October 11, 2015, 12:18:59 PM »
My preferred routes would be to thin down the scriber stem by 0.110" or slim down the outrigger arm on the height gauge by the same amount. That would,I think be easier options than making a new clamp from scratch......OZ
Helixes aren't always downward spirals,sometimes they're screwed up

Offline Jasonb

  • Sr. Member
  • ****
  • Posts: 451
  • Country: gb
Re: Clamps for a Height Gauge Scriber?
« Reply #7 on: October 11, 2015, 12:31:49 PM »
How much scriber height can you fit under the stub, there is not a lot of adjustment of Zero so before making a bigger clamp check that when the scriber is touching the marking table its not reading 0.100".

I'd take the metal off the bottom edge of the scriber arm if he height is OK.