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3-Plate Method, Surface Plates?

middle.road

Granite Stoopid...
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OK, so, I going to open up a discussion on this far-fetched thought. (Blame the Cerveza... :grin: "
I case you haven't seen 'The Haul' click -=- HERE -=-

With so many at my disposal. . .
Is it possible to true up surface plates using the 3-plate method?
A 'brief' review of YouTube last night and I'm not sure this is possible, but it makes sense to my addled mind.

First - there is the matter of picking up and 'flipping' one plate onto another.
Secondly, there is the matter of picking up and 'flipping' one plate onto another.
Thirdly, there is Honey's patience with this entire fiasco...

But I'm curious, what do y'all think? :cower:

Back in the day when I needed to get plates calibrated I'd just call a service, and then stand there watching as they worked their magic.
Of course this time around I don't have a company that is paying the charges.

Last Thursday morning I submitted requests for surface plate calibration to two companies that have locations in Nashville and Chattanooga .
Have not heard back from them...
 

Bob Korves

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It is entirely "possible" to make a flat plate using the 3 plate method. It is also fussy and will take you forever from scratch, at least to do it right. The first accurate plates were made using that method. Then they mostly stopped using it, at least for getting something done, not just proving a concept. These days, there is no reason for using the three plate method for any useful reason, but rather only to prove it can be done. Instead, use an autocollimator and repeat-o-meter, along with the necessary skills, and then get on to your REAL project, whatever you want to make flat...
 

middle.road

Granite Stoopid...
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It is entirely "possible" to make a flat plate using the 3 plate method. It is also fussy and will take you forever from scratch, at least to do it right. The first accurate plates were made using that method. Then they mostly stopped using it, at least for getting something done, not just proving a concept. These days, there is no reason for using the three plate method for any useful reason, but rather only to prove it can be done. Instead, use an autocollimator and repeat-o-meter, along with the necessary skills, and then get on to your REAL project, whatever you want to make flat...
The problem is that I don't have access to an autocollimator or a repeat-o-meter... :grin: Wish I did!
There's not even a calibration service in East TN that I could find.
Now if I could run down to Tifton, GA and visit Keith, then maybe. . .
Or else if I was located near you guys in central CA. :cool 2: (What a weekend get-together project that would make!)

It was just a thought I had before I picked them up on Tuesday given what I have to work with.
But then after tossing them around this week. . .
 

matthewsx

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How flat do they need to be for your shop? If it were me I'd be inclined to use them as-is until I came upon a project where I knew they needed to be better.

John
 

Aukai

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Last December the wife, and I spent a week in Nashville, and had a blast, I even remember most of it.....continue on....
 

Bob Korves

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You might start out by checking out these companies, just the start of looking at this search: "surface plate calibration east tennessee"

 

middle.road

Granite Stoopid...
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Strange how Google works sometimes.
I had done the almost the same syntax, but I had inputted 'East Tennessee surface plate calibration service'
Neither Optimal nor Certified showed up. J.A. King did though, they're one of the two that I submitted a request to.
Doesn't look like there are any in the Knoxville area, though there is one up near the Tri-Cities, but they don't list surface plates on their site.
Perhaps I'll get lucky and find a service out of Nashville or Chattanogga that combines trips.
Of course first, I have to get the one(s) I'm keeping mounted properly and not on a dollie.

Here's a funny one. I was checking out one service that came up in searching and here's their list:
  • Threaded Ring Gauges
  • Dial Indicators
  • Optical Comparitors
  • Snap Gauges
  • Depth Gauges
Comparitors? :confused 3:


You might start out by checking out these companies, just the start of looking at this search: "surface plate calibration east tennessee"

 

Janderso

Jeff Anderson
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How did the Egyptians create giant flat one piece stones? They must have used the three rock method (Flintstones)
Or had help from ET.
There was a Youtube on the 3 plate method recently.
 

middle.road

Granite Stoopid...
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This had to have been a fun gathering:

You might start out by checking out these companies, just the start of looking at this search: "surface plate calibration east tennessee"

 

Bob Korves

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This was the fun gathering at my former shop, Randy Richard was there with his plate:
 

vocatexas

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I would love to have one of those 24x36 plates, but I'll bet shipping would be astronomical! Great haul you got there!
 

middle.road

Granite Stoopid...
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So while trying to repair the engine hoist and dealing with the 90° weather we're having I remembered a few things from my Metrology days.
With the temp here bouncing between 90° during the day and the high 60's at night the plates can't normalize.
I'm going to have to install some sort of A/C in the shop, make some more room, and then wheel these granite slabs in and let them sit.
It'll more than likely have to be one or two at time and then let them soak and acclimate and then start to measure and check them out.
Not enough floor space and too many slabs. :grin:
I did asked my Better Half if I could move them into the living room... Since I do not have the new floor installed - yet. :cool 2:
 

westerner

If you are gonna be stupid, ya gotta be TOUGH!
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I believe I do not regret NOT having the need or patience for this level of accuracy.....
If I have to acclimate my great huge chunks of granite to achieve the level of precision I need, it will feel more like a job than a hobby to me.
 

Bob Korves

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If you let the shop air easily get to all the surfaces of the plate, the plate will have equal temperatures from that aspect. Radiated heat coming from something like a hot tin roof above and a cold floor below can mess it up, so insulate or otherwise make the floor and the ceiling show the same temperatures to the plate top and bottom -- at least as good as possible with what you can cobble together...
 

middle.road

Granite Stoopid...
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Had a brainstorm of an idea this morning over coffee.
The 36' car hauler storage trailer we have has an RV type A/C unit on it.
So....
Went out to the trailer and of course it doesn't work. -hehe
 

NCjeeper

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Did any of the local companies get back to you on calibrating them?
 

middle.road

Granite Stoopid...
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Did any of the local companies get back to you on calibrating them?
Nope. Wish we were near SoCal about now, I know where I'd go...
And if you watch Stan's BarZ shop tour of Standridge out in SoCal from (5) years ago, The dude Mike made an interesting comment
about some companies that offer 'calibration' services... So time to do a bit more in-depth research.

What I would like to find, is a couple of those hooks he's using when placing the plate on the SG.

 
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