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Tools and Surface Plate Questions

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Splat

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So I'm starting to do more projects now that require more accurate measuring than I've been doing. I don't do many big >12" parts so I'm considering a 12x18 size plate. I can pick up locally a grade-B Standridge surface plate via McMaster Carr (love that place!). I know I can get much cheaper via Woodcraft or MSC but shipping is killer or the quality might be/is suspect. From what I've read most home shops are using the 12x18 so I think I'd be ok with that size. Any opinions on the size? How are you guys supporting your plate?

As far as measuring I now have: good 123 and few angle blocks, good set of parallels, good hole gauges, good analog and a decent digital micrometers. Should I get a height gauge, combo square set, or something else? I'm leaning towards a height gauge but but figured I'd ask you guys. If height gage what type? Vernier, dial, etc? Thank you.
 
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JimDawson

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I personally prefer vernier height gauges, pretty much bullet proof. A dial is OK, but I wouldn't have a digital as my only height gauge, and I do own a cheap one, guaranteed that the battery will be dead just when you need it.
 

mmcmdl

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Height gage will measure and scribe lines . Surface gage has many uses . You'll use them all . I'm getting ready to unload a lot of both . :encourage:
 

benmychree

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I have both a vernier height gage (12" Starrett with 50 division vernier) and a few sizes of surface gage. The surface gage is good for rough layout work and many other jobs, if used on the surface plate for layout, a rule holder that clamps your rule vertically is handy; also I would not be without a combination square set, and don't settle for cheap crap, buy a (very) good name brand; I found two sets at an estate sale, both unused B&S from the 1940s, one resides in my wood shop, the other in the machine shop.
Bottom line, I mostly use the height gage for any and all layout work.
 

darkzero

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I have a import 18x12 grade a granite w/ ledges that I got when enco was selling them for dirt cheap with free shipping. I get by with it but I really wish I had a bigger one. I also have a 12x9 that I picked up from my local MSC when they were cheap but I only use it for lapping. Perfect size for standard sheets of sandpaper.

I agree, I prefer vernier height gauges too but I use a 6" M-DRO/SRA digital most of the time. I like my 12" Mitutoyo vernier, it's in nice condition & it always goes back into the wood case when not in use. But most of the time it's too cumbersome to use. So I bought the 6" digital to use for laying out lines. Compact, much easier & quicker to use. I just leave it out. Yeah it's Chinese so it likes to eat up batteries but I still like it.

I don't work on big stuff & I easily run out of room with a 18x12. I'd say if you're able to, get at least 24x18 (or bigger) but that's about the size where the price jumps (from what I remember). Size of the plate doesn't dictate what size parts you can measure, remember you need space for the measuring tools to sweep the part, etc.

That reminds me, I need a smaller surface gauge too, my Starrett surface gauge is kinda of too big. Well I guess it really means that I need a bigger surface plate (wish I had the room). :)
 

mikey

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I have a 18 x 12 and it is good enough since my work tends to be on the smaller side. I also have a little 8 X 12 Starrett toolmaker's flat for layout work. Depending on what you need to do, I would suggest you consider:
  • A height gauge - if you want a good one, look for a dual column Mitutoyo. Very rigid, heavy and accurate in the thousandths. My most used one is a little 6" Starrett dial height gauge - light, fast, accurate and easy to use. If you can, buy a carbide scribe for your height gauge; they last forever. Most height gauges can hold an indicator with the right attachment.
  • Surface gauge - get a big, heavy one and maybe a small one for basic layout work. These also hold an indicator for assessing flatness, just like the height gauges do. If you plan to do layout work with a surface gauge, buy a rule holder as this will save you time; Starrett makes a nice one or you can make your own.
  • Cylinder square - useful for checking if a square is actually square. I want a 6" high cylinder square but don't own one yet. I have a little 3" Murkens magnetic cylinder square that is perfect for evaluating how square a vise or angle plate is; very useful.
  • Make a box or at least a lid to cover your surface plate when it isn't in use. If you don't cover it then you'll sit something on top of it and nothing should touch the surface except for your measuring tools.
Here is some info from Starrett on supporting your plate:


How should my surface plate be supported? Does it need to be level?
A) A surface plate should be supported at 3 points, ideally located 20% of the length in from the ends of the plate. Two supports should be located 20% of the width in from the long sides, and the remaining support should be centered. Only 3 points can rest solidly on anything but a precision surface.
The plate should be supported at these points during production, and it should be supported only at these three points while in use. Attempting to support the plate at more than three points will cause the plate to receive its support from various combinations of three points, which will not be the same 3 points on which it was supported during production. This will introduce errors as the plate deflects to conform to the new support arrangement. All Tru-Stone steel stands have support beams designed to line up with the proper support points.

If the plate is properly supported, precise leveling is only necessary if your application calls for it. Leveling is not necessary to maintain the accuracy of a properly supported plate.
 

hanermo2

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I feel that the quality of the surface plate is immaterial for those using scribing etc. as their main marking out technique.

Airy points are also immaterial until one gets into volumetric single microns.
Aka x by y by z measurements for some datum in 3d space.

S:
Look at suburban tool videos on cylindrical squares and lapping.

A gage block set / stack can give a very good 1 micron (2 micron) length.
So will any medium-good import micrometer set.
 

Moderatemixed

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Initially I bought a 12 x 18 surface plate from Lee Valley Tools here in Canada. It was great, but I found it to be too small. I could measure or lay out most of the time but was putti g my height gage or surface gage onto the bench, which meant wiping the bottoms of each over and over. While it may seem trivial, after a while it just becomes aggravating. I purchased a second 18x12 plate (a Starrett) on Kijiji, Canada’s version of Craigs List for $100 and put them side by side which was ok, but not ideal. To my point then...... I ended up with a 24 x 36 x 4 Starrett, toolroom grade plate and I LOVE it. My wife sewed a vinyl cover for it and not once have I remarked that I wished it was smaller. My shop is 11 x 10 and that plate takes up a bunch if realestate, but it is worth every inch to have it. It cost me $250. I sold both 12 x 18’s; the Lee Valley one for $50 (lost $10) and the Starrett one for $150. Get a good plate and buy the largest one you can afford/have space for. And be patient, one will crop up. I only wish that there were people in Canada who could do the calibration/resurfacing like there are in the States. My plate is good, but I’f like it calibrated and cannot find anyone in Ontario to do so. As for height gages, Starrett or Mitutoyo digital all the way. Verniers are great, if you can figure out how to read them......

Cheers all.


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francist

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Initially I bought a 12 x 18 surface plate from Lee Valley Tools
Do you mean the 9 X 12 from Lee Valley? I don't remember them ever selling a larger 18 X 12, but if they did I should have bought it. The 9 x12 is a nice surface indeed a bit tight for anything bigger than a few inches square.

-frank
 

Bob Korves

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If you buy a used surface plate, you have an unknown. You are not likely to be able to check it with any reliability by yourself in your home shop. Buying a used plate by brand name and paying more for it is about the silliest thing I can imagine. They are all chunks of rock that look visually flat. I bought my 18x24x4", 2 ledge for $50 off a rack behind a machine shop, covered with junk and grime. I "guessed" it was in pretty good shape by chasing various indicator setups and straightedges around it and scratching my head. A group of local hobby machinists brought their plates to my shop and Standridge granite dropped by to calibrate the 5 plates. Mine ended up costing ~$103 to be calibrated to AA grade and certified to A grade. It turned out to have a .003" "hole" in the center. To be used for precision work, guessing will not do. A friend bought a very nice pristine looking 24x36" Starrett pink plate for a pretty high price, and it turned out to have a .005" hole in it, and had to be taken 400+ miles to Standridge's facility in SoCal to get it calibrated, they will not remove that much in the field. IF THE PLATE HAS NOT BEEN IN YOUR POSSESSION AND UNDER YOUR CONTROL SINCE IT HAS LAST BEEN CALIBRATED, IT IS NOT A SURFACE PLATE, IT IS "AN UNKNOWN KINDA' FLAT LOOKING ROCK." No exceptions. The idea of a surface plate is it being a known flat plane reference surface in your shop. If it is not a known quantity, it is worthless for that job. If you want to use it only for simple layout work or for lapping non critical parts, stacking parts and tools on, eating your lunch, a tombstone, or some other non precision use, then go for it. Just don't hope that it is something it is not.
 

Moderatemixed

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Do you mean the 9 X 12 from Lee Valley? I don't remember them ever selling a larger 18 X 12, but if they did I should have bought it. The 9 x12 is a nice surface indeed a bit tight for anything bigger than a few inches square.

-frank
Yes, sorry. It was some time ago. The plate was very good however.


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Moderatemixed

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Bob is extremely knowledgeable and operates to a tolerance much higher than I. While I don’t have the entire chain of custody clearly mapped for my Starrett 24 x 36, my point was to say, buy the biggest that you can afford (cost and space limiting). Further that for the hobby Machinist, most surface plates, morsels of granite from counter top shops or even plate glass will suffice. If you are building the space shuttle replacement along side Bob then finding a hole .003 deep could be a problem..... I on the other hand am ok with that as a tolerance. All with a grain of salt....


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Meta Key

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so I'm considering a 12x18 size plate. I can pick up locally a grade-B Standridge surface plate via McMaster Carr
I use a 12 x 18 pink surface plate (Starrett) and I've been frustrated only a few times in 20 or so years of use. It fits nicely on a Kennedy roll around that is dedicated to the job. I got it with the factory offered cover and also have an additional layer of padding under the cover.
291038

The height gage is a Swiss Etalon of about the same vintage. It's 18" high and I've appreciated the height a few times. The surface gage on the left is a Starrett and the stubby one on the right is shop made.

The most important tools in the drawers are two nice sets of Jo Blocks which I use A LOT. Also, various other measuring and layout tools as you would expect.

(And, for you guys in Hawaii, that's two feet of snow outside the window...)

MetaKey
 

Bob Korves

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Bob is extremely knowledgeable and operates to a tolerance much higher than I. While I don’t have the entire chain of custody clearly mapped for my Starrett 24 x 36, my point was to say, buy the biggest that you can afford (cost and space limiting). Further that for the hobby Machinist, most surface plates, morsels of granite from counter top shops or even plate glass will suffice. If you are building the space shuttle replacement along side Bob then finding a hole .003 deep could be a problem..... I on the other hand am ok with that as a tolerance. All with a grain of salt....


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My post was directed to all those reading this thread who might be considering purchasing a surface plate, Moderatedmixed, not directed toward you personally or your posts here at all. I have seen many here and elsewhere who seem to have incorrect (in my mind) ideas about purchasing used surface plates. When buying one used, we have no idea how it might have been used or cared for. That was (and is) my message. I am just another hobby machinist who cares to understand what I think I know, what I don't know, and how it affects my results. I do the best I can with what I have, as do we all. Much of the work in my shop is pretty crude.
 

mikey

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(And, for you guys in Hawaii, that's two feet of snow outside the window...)
Yeah, I noticed that right away! Alas, it's 79 degrees here and not a snow flake in sight ...

Nice set up you have there, by the way. I'll have to look for a dual column Etalon - never knew they made them!
 

Larry42

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I bought an 18x24 grade B from Shars with their steel stand. The stand supports the rock in three places. I don't work on large parts but I wouldn't get a smaller plate. I have no way of checking the trueness of the plate other than my gage blocks and dial test indicator, and moving about the surface plate I haven't been able to detect any variations. This is of course a very limited method because it is only comparing areas that are relatively close to each other. I also have a, less than ideal, import, dial ht. gage. Used for "close enough" ht. measurements and scribing layout lines. The two have very different uses so I would guess both are needed by most people.
 

Dabbler

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I have an 18X24 Mit AA grade plate, and it seems perfect size for all the work I do, and some of it gets near to being too big, but so far, it has sufficed. I do know of a shop I can work at that has a Mit A grade 36X48 I can use for the really big stuff.
 

Cadillac

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I have a 18x24 and it gets tight on some things. Blueing up parts eats up space quick. Then swinging gauges aroundfeels like I’m always on the edges of the plate. I’d go for the biggest you can afford. Shipping is a killer thankfully Im close enough to pickup than deliver. I use 12x18 cast iron ones for simple scribe and layout work near the machines, auction purchases.
 

KMoffett

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For something as heavy as a surface plate, check with McMaster-Carr on shipping cost before you order. I got stuck with a $69 freight charge on a 1"x10' $7 PVC pipe from them because it was over 8 feet. Anything that exceeds FEDEX or UPS "limits" goes "$$$ freight $$$". :(

Ken
 

Moderatemixed

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My post was directed to all those reading this thread who might be considering purchasing a surface plate, Moderatedmixed, not directed toward you personally or your posts here at all. I have seen many here and elsewhere who seem to have incorrect (in my mind) ideas about purchasing used surface plates. When buying one used, we have no idea how it might have been used or cared for. That was (and is) my message. I am just another hobby machinist who cares to understand what I think I know, what I don't know, and how it affects my results. I do the best I can with what I have, as do we all. Much of the work in my shop is pretty crude.
Hey Bob, no disrespect intended. I thought I had made that clear. You are far more advanced than most and see things from a different perspective. That’s what makes these forums great; collaboration. In my line of work we call it “Crew Resource Management” or CRM for short. I was just clarifying my points as they were more from a Kindergarten perspective than yourself at the College level, figuratively speaking. Regards all.


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eeler1

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Tom Lipton recommended getting a small plate cheap from Shars and doing all the abrasive work on it, saving your bigger, more accurate plate for precision work. I think my 9x12 Shars cost $35 with shipping at $45, or thereabouts. It’s reserved for abrasive and small non-critical work.

Agree with Bob that used stones, unless recently calibrated and certified, are a bit of a crapshoot. I think the point was to not pay too much for used unless you can verify it’s flat. Get it cheap enough and you can afford to have it calibrated if you decide you need to.
 

Toolmaker51

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It's not mentioned descriptively, but used surface plates abound. In more accurate environments they are resurfaced on a regular basis. I've never seen a used plate for sale that was hopeless, depending on next owners commitment.
Check with a local machine shop that gets their plate re-certs on a predictable schedule; have your plate there to save a service call charge. Reimburse them or arrange with the plate inspector and pay him direct. Done this many times over the years; they pocket a little cash for themselves. Your 12 or 18 x won't take them an hour.
When you run across a plate deal use a good straight edge, a bright flash light and feeler gauges. Check across corners and a grid divided by thirds or so. Put equal shims under ends of straight edge and start with feelers .001 or .0005 under size of those at end.
Buy it, use it and wait for an opportunity to have it checked. It will withstand your individual private use decades.
 

petertha

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re Lee Valley, not bashing them because they offer some nice (woodworking) tools via their own Veritas line plus some other name brands. But they also have a increasing proliferation of Chinesium. Again, nothing wrong with that but I would suspect theirs isn't appreciably different than Busy Bee or similar vendors. For $54 (and that's deflated Canuck bucks) seems like decent value. Just not sure I would rely on all those decimal places LOL. I'm not even sure how Joe Hobbyist could verify it independently. One of the issues I'm noticing is shipping weight. There are some comparable offshore offerings through tool catalogs like KBC & Travers, but as they get larger footprint they also get thicker which means more weight. So sometimes what you are able to pick up locally counts for something too.

http://www.leevalley.com/US/wood/page.aspx?cat=1,43513,51657&p=32526
 

Dabbler

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I have both BB and a Lee Valley surface plates, and they seem ground to very acceptable precision. I needed a little larger for the work I do, hence the 18X24 Mitutoyo. Within my measuring instruments limits' I cannot tell the difference between any of them.
 

38super

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Found a 3 stack of 18x24 surface plates, including my 12x18 reconditioning cost for all will cost between $325 to $450, Average wear 0.0004", worst 0.0007" (might cost a bit more). Ace (Glendale) and Precision Granite (Santa Fe Springs) are local to me. Reconditioning a surface plate is not that bad if the purchase price is reasonable. Group reconditioning spreads the travel fee. Made a small version of the Rahn RoM, hard to interpret on long slope wear troughs.
 

Bob Korves

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Standridge (which is also named Precision) Granite of Santa Fe Springs can do work on surface plates in their factory workshop for pretty cheap, even if they are out by a few thousandths. On the road, where they lap by hand using diamond dust and cast iron surface plates to do the job, .002" is about the most they will do without incurring extra charges. Standridge will often do them while you wait. They also have some very good deals on surface plates, angle blocks, and other products that are "blems." Only problem for me is that it is more than 400 miles away...
 

Dabbler

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Bob, think how far it is for me to go there!
 

macardoso

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I bought a 18x24 Grade B Import locally from a tool supply shop. At $90 and no shipping charges I couldn't complain. I haven't outgrown it using a 7x26 table size benchtop mill or a 12x36 lathe so far. I am not doing NASA level parts or super precision scraping so the Grade B import was acceptable. The grain size on mine is rather large and the finish isn't the same as some of the Starrett ones I've used but I'm happy with the purchase. Plus I can carry it by meself, definitely couldn't move the 24x24 without help.
 
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