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Anyone had a granite surface plate calibrated outside of the workplace?

Spud

Diamond
Joined
Jan 12, 2006
Location
Brookfield, Wisconsin
Has anyone had a granite surface plate calibrated outside your Q.C lab / workplace and then transported it to your Q.C. lab / workplace ? Does a granite plate absolutely need to be calibrated onsite at the location it is going to be used in?

If I bought a used granite surface plate that was still under the calibration period, at auction, is the calibration void when I move it home?
 
you're OK

When I bought my big plate, they calibrated it in their lab, then moved it here. I had the same question and they said it was good to go.
 
We've done that with smaller ones. If it's convenient to move, they shouldn't care about transport. Unless you're dealing with AAA or higher cert standards, the thickness of the plate should negate any sag that might occur when moving. They'll set it up in their lab the same way you should be setting it up in your shop. Bigger plates that require heavy equipment to move are better done on site as the cost of having their tech come out to certify and possibly surface it will be less than paying shipping and handling to have it moved to their lab and then have their tech certify and possibly surface it. Many Metrology labs don't have the room to store and service large pieces like granite tables anyway.
 
Just make sure it's sitting on the feet/pads in the same location, you should be fine. I trace around the pads on all of mine with a Sharpie so if I have to move the surface plate they always go back in the same spot even if they come loose.
 
Be sure the company puts it on 3 pads (3 points). on it. Many use a hard rubber they glue to the bottom of the plate. I have also seen where they use white chalk to put an X on the plate showing you where to place the pads in the shop. Ive heard some use a hockey puck as the pad.
 
Why should a calibration lab use anything other than the mounting arrangements that the surface plate already has? If it's got feet then they'll be used. If it hasn't then it's pot luck.
 
The granite won't change from the trip, but you will want to make sure the conditions are similar.
The one that gets most people is temperature. If you can make sure the temperature above/below the plate is close you should be ok.

One of my former employers made sure to put their granite table in a well temperature controlled room in the center of the building with no exterior windows. That room having better temperature control meant that the room had it's own HVAC. Unfortunately the ceiling duct was directly over the table blowing down, and the result was that the top of the block was a few degrees cooler than the bottom in the summer, and a few degrees warmer in the winter. After watching the granite guy work on the table a few times I realized that it always passed (was lightly used) if the weather conditions were the same as the last time he had checked it, and needed a fair amount of work if they were opposite.

Yes, this also means the block probably cycled in/out of specification with large changes in outdoor temperature despite the fact that the room air temperature was relatively stable.
 
The lab I normally use would not be able to handle large plates at their location. I am not interested in a large plate though.

What is largest size plate do you all think is fine to have calibrated in a lab that won't warp when moving ? I am interested in a pink granite 3' x 2' x 4" plate. Do you think this is fine to have calibrated in a lab and then moved?


All the plates I have seen at auction come with a stand. I am mostly intersted in the mobile stands. I don't know if they use only 3 points to support a plate
Starrett Surface Plate Stand, Stationary Model, Plate Size 18" x 24" - 82224 - Penn Tool Co., Inc
granite-plate-stand.png



Does theShars stand use only 3 points to support the plate?
18" x 24" Granite Surface Plate Plus Stand Set Stand height 32"

Shars-stand.png
 
1. The largest one you can safely move. You don’t just throw these things in a cardboard box and plop them in the back seat of your car.
2. They should all be supported by 3 points, but it varies by manufacturer. The cart Faro sells with their arms for example supports the block at the 4 outer corners and to spots midway along the long edges. Good for keeping it from tipping when moving, but pretty poor otherwise. Then again, when you consider the typical tolerances of a Faro arm, it matters a bit less.
 
1. The largest one you can safely move. You don’t just throw these things in a cardboard box and plop them in the back seat of your car.
2. They should all be supported by 3 points, but it varies by manufacturer. The cart Faro sells with their arms for example supports the block at the 4 outer corners and to spots midway along the long edges. Good for keeping it from tipping when moving, but pretty poor otherwise. Then again, when you consider the typical tolerances of a Faro arm, it matters a bit less.


I am going to have my Tesa-Hite 700 , which I recently purchased used, on this plate.

So I shouldn't have an issue moving a 3' x 2' x 4" (or 6") pink granite plate ?

I have a crew-cab 2500HD pickup. I was planning on placing this on the floor in the back seat, on top of some styrofoam and blankets, and making sure it didn't move about.
 
At 6” thick that’s roughly 550 pounds. You have stronger friends than I do to get that in a back seat. I wouldn’t want that unsecured in my back seat in the event of a collision, but you may feel differently.
Styrofoam is great, but I’d have it strapped to a pallet in the bed if it was mine.
 
I am going to have my Tesa-Hite 700 , which I recently purchased used, on this plate.

So I shouldn't have an issue moving a 3' x 2' x 4" (or 6") pink granite plate ?

I have a crew-cab 2500HD pickup. I was planning on placing this on the floor in the back seat, on top of some styrofoam and blankets, and making sure it didn't move about.

"For reference". A tale of two plates...

#1: DIY go-fetch with GMC S-15 std cab 4-banger:

18" X 24" X 4 1/2" 2-ledge B&S Black, Grade B:

Go-fetch out of McKean in Ohio with some other stuff. I had confirmed plate dimensions ahead of time, fabb'ed a wooden "clamshell" case of double-thick 3/4" ACX ply and 2" X 6" frame, lined it with rubber doormat material. Painless. The "other stuff" being five Reliance RPM III DC motors of up to around 400 lbs, it seemed prudent to protect the plate! It was unharmed!


#2: Delivered by LTL carrier, last-leg was liftgate out of a terminal in Winchester, VA.

30" x 48" X 8" thick Herman Grade A four-ledge with factory steel stand:
About 1,180 lbs.

Small Tools, Cleveland ship such goods all the time. They had turned it upside-down atop triple-ply corrugated cardboard atop plywood atop TWO five foot by four foot wooden pallets, stacked.. with the steel stand also upside-down atop it. Padded and banded.

Worked a treat. No damage.

Was even cheap on the shipping. Liftgate service and all was only around $387 IIRC. Ever I need another, I'd go to them first.

Rigging that MASS is not real work.

Safely grasping the plate to flip it over without pucker-factor overload needs decent rigging-foo.
 
At 6” thick that’s roughly 550 pounds. You have stronger friends than I do to get that in a back seat. I wouldn’t want that unsecured in my back seat in the event of a collision, but you may feel differently.
Styrofoam is great, but I’d have it strapped to a pallet in the bed if it was mine.


Was planning on securing it to a plywood skid with casters, then get it to cab floor height with my high-lift pallet jack, then just slide it in. May work for the 4" version, but 6" might be problematic.

I guess putting it in the bed would be a lot less hassle. My truck has a pretty stiff ride though, being a 2500HD. So cushioning the plate with rubber mats and styrofoam should suffice ?
 
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Was planning on securing it to a plywood skid with casters, then get it to cab floor height with my high-lift pallet jack, then just slide it in. May work for the 4" version, but 6" might be problematic.

I guess putting it in the bed would be a lot less hassle. My truck has a pretty stuff ride though, being a 2500HD. So cushioning the plate with rubber mats and styrofoam should suffice ?

Thermite gave you the rare instance of a fully comprehensible post, worth needing the solid advice within it. Wooden box lined with the rubber/carpet remnant/floor pad/rigid foam of your choice would do nicely. Just don’t use styrofoam. That’ll crumble on the first hit if not nicely contained and leave you without padding on the second event. “Box” can be a relative term, but enough wood that an object of that mass won’t break out a corner in an emergency stop isn’t actually all that complicated.

Also an awful lot of pictures of granite surface plates strapped (with a corner pad if metal banding) to a common pallet. Must be some reason for all those pictures being there and I doubt they put them on the pallets just for the photo op.
 
Also sounds like you might not have the size picked out yet. While I’ve done plenty of good work on a little 8”x12” plate, I don’t like going below 2’ by 3’ once a height stand is involved. That’s the sort of equipment you’d like to be not moving on and off of the table, so you’re going to sacrifice a 1’ square just to store the thing. Add space for a notepad, a drawing, some parts you’re working on, and pretty soon that 2’x3’ is full. Easy enough to offload many of those things to a nearby tablet, but then you’re moving the table, don’t have all sides of the surface plate accessible, etc.

For whatever reason a huge portion of my surface plate time seems to involve someone else learning what I’m doing, taking notes, etc. As a result the extra open space is appreciated.
 
Was planning on securing it to a plywood skid with casters, then get it to cab floor height with my high-lift pallet jack, then just slide it in. May work for the 4" version, but 6" might be problematic.

I guess putting it in the bed would be a lot less hassle. My truck has a pretty stuff ride though, being a 2500HD. So cushioning the plate with rubber mats and styrofoam should suffice ?

Styrofoam is just a kit for mass-producing turds for angels.

You ever work architectural stone? Need a flagstone for a walkway, the slab goes under a steel rail with a line of teeth. slightly elevated rail, each side.

Hydraulics are applied, it snaps on that line .. same as a sheet of glass would.

Think of Granite AS a form of glass. Metamorphic rock IS such.

The stone itself is strong. Also stiff. Very.
That's WHY we use it for surfaces - references or durable decorative.

As with glass, doesn't BEND well. It WANTS to fracture under just the right sort of persuasion.

That's how mankind has worked and shaped it, lo a million years and counting before we had saws or waterjet. Which are both a lot older than you might think, BTW.

You need to prevent point, corner, or line loading and attempted penetrative IMPACT. Truckbed bouncing up and down is no big deal so long as it isn't loaded across a line - the counterpart to that stoneyard's splitter.

Different task than if you were shipping a wooden butcher block or a rackup of electronic goods that can stand a LOT more flex or dodge the bullet on point-impact.

Put it in the cargo bed. That's what the bed is for. On a truck.

Need cushioning? Make it resilient. Sheet of closed-cell elastomer. It needs very little to shape the energy curve.

That fake T-plate pattern grey urethane they sell for floor covering will do yah. Or doormats you can re-purpose later, as I did my ones.

Really paranoid? It's our Spud.. ever clever and creative at covering all the angles...

Space out four used tires, strap it atop like a raft.

Let it bounce..... same as that Jello you nailed to the wall in the loo last week as a Project Management Training exercise.

:)
 
I wouldn’t want that unsecured in my back seat in the event of a collision, but you may feel differently.

A few years ago I bought my surface plate (1200 x 800 x 160mm, 420kg = 930 lbs) used from a grinding shop that had shut down. The seller used a forklift to put it in the back of my Honda minivan and I drove home, about 300km, partly on the Autobahn and partly on some hilly back roads. At one point I was driving up a steep hill and the plate (which was on some blankets in the back) slid towards the back of the van. There were other cars just behind me, and I had some very unpleasant thoughts about what would happen if the rear hatch mechanism wasn't designed to withstand significant forces. As well as some additional very unpleasant thoughts about what would happen if I needed to make a sudden stop while driving at 130km/h (80 mph) down the Autobahn. I was very relieved to get home in one piece.

Next time I will strap it to a pallet and pay someone else to move it.

PS: to the OP's original question: as long as the plate is supported on the same three points for calibration as are used later, after transport, it's OK to do the calibration in one place and to use it in a different place. That's why you can buy a factory calibrated granite plate on a stand, ship it to your shop, and use it, without having to recalibrate immediately.
 
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As I haven't got my plate yet, what if any difference is there between the black and pink plates?
Aside from Starrett and Stanridge, what are some good brands?
And is there any reason to go for a plate with a ledge over no ledge?
Does it matter if I get a 4" thick plate instead of a 6" , because moving a 4" is a lot more convenient.
 
As I haven't got my plate yet, what if any difference is there between the black and pink plates?
Aside from Starrett and Stanridge, what are some good brands?
And is there any reason to go for a plate with a ledge over no ledge?
Does it matter if I get a 4" thick plate instead of a 6" , because moving a 4" is a lot more convenient.


The usual wisdom is that the black is stiffer and the pink more wear resistant - take your pick. The thickness is also sometimes determined by the material - pink plates a little thicker to get stiffness.

So, you can just get the 4" black plate, and unless you expect severe use it should last a long time before needing attention.
 
The usual wisdom is that the black is stiffer and the pink more wear resistant - take your pick. The thickness is also sometimes determined by the material - pink plates a little thicker to get stiffness.

So, you can just get the 4" black plate, and unless you expect severe use it should last a long time before needing attention.


Do they (pink & black) cost about the same to have a lab calibrate it?
 








 
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