I had some weird deal today, having bought five height gages, out of which three are digital Mitutoyo gages, for $50. (but then, last night, I gave away 8 boxes of valuable metalworking stuff to an acquaintaince, so this may be the karma paying off). The obvious question that arises after this sort of transaction is, do I need a height gage, so I want to do a little survey.
Have you used a height gage and what is the point of a height gage, altogether, given that one has calipers and other similar devices.
Height gauges are useful when setting tool length parameters for CNC machines using individual tool holders in any of the various ATC styles. A base with a receiver for the spindle taper is used to zero the gauge and then the toolholder with tool is placed in that base and measured with the resulting spindle nose to tool tip distance entered into the CNC control. This is for the folks with the big machines though, most home CNC stuff isn't ATC and/or uses a tool length touch-off block to auto set the parameters. I haven't been involved in recent years, but I suspect auto length setting is common on new CNC machines, so the height gauges are probably going the way of the DoDo or at least the way of the HSM with a shop big enough for a big old CNC machine.
They're used for layout work on a surface plate and for precision measuring, particularly where you have to measure between a point or a max or min of a circle or radius versus a line -- say, the line between two points.
If you're familiar with surface gages (scribers used with a surface plate), one application can be thought of as a precision version of those. With an angle block and clamps to hold the work perpendicular to the surface plate, you can scribe lines that are precisely parallel and a precise distance apart. And there are many other scribing applications.
For measuring, they give you a way to measure distances from a datum line (a line you establish parallel to the surface plate) with great precision, especially when you're laying out or measuring on a piece of plate or sheet stock. For rough work you use the point of the scriber; for precise work, you use a dial indicator set against a stack of gage blocks and held in the chuck of the height gage.
It's an essential precision tool. Once you learn how to use one, you'll appreciate how many measuring jobs done in other ways are really crude and inaccurate.
You really need some illustrations to help make it clear.
On Thu, 10 Sep 2009 17:13:47 -0500, the infamous Ignoramus12651 scrawled the following:
When I worked as a Quality Assurance inspector, I used the height gauges to check hole placement for the manpack radio chassis and other panels. Nowadays, if I had one, I might use it to scribe lines for hole placement, using the extra adaptor so it didn't cause damage to my tool.
-- Government is like a baby. An alimentary canal with a big appetite at one end and no sense of responsibility at the other. --Ronald Reagan
Ed... Thanks... I want tio know your opinion... Here are pictures of the four gauges.
The first to the left is analog. Works great and is simple.
The next is a Mitutoyo Digimatic height gauge. Also works great and is also very straightforward to use. Needed a battery.
The next one is a Mitutoyo Heightmaster, and while swapping a battery made it power up, I have not yet figured out how to move it from zero and make it do something.
The last one seems to need an external power supply, which I do not have. I will stop by that factory tomorrow for other reasons, and will try to get the power supply if they can find it (they are moving).
So my question is, assuming the heightmaster works, what would be the most sensible one to keep in a manual shop. I lean towards the Digimatic battery powered gauge, for the simple reason that everything digimatic works great for me.
Let me know what you think. I know that you know a great deal about Mitutoyo anything.
1) Setting up for repeat checking of heights of multiple items to verify that they are all near enough to the designed dimension. Here, you use a dial indicator of sufficient sensitivity on the head. Use a stack of gauge blocks to zero the indicator prior to the start of the measuring run. (There are electronic indicators which can measure down to the micro-inch, if you need that kind of accuracy.)
2) Use with a scriber tip on the head to layout workpieces parallel to the edge which is resting on the surface plate.
3) With the right accessories, measuring the depth of a hole or the depth to a feature (step) in the diameter of a hole, or measuring the depth of a pocket and the thickness of the material under the pocket.
4) Use with a sine bar (and gauge blocks) to either scribe a line at a specific angle to the edge of a workpiece, or to measure the actual taper on something you are making or something which you have. (Set up the gauge blocks and the sine bar to produce the desired angle, rest the tapered piece on the sine bar, and run an indicator in the height gauge along it to measure the error in the taper (or 0.0000" for no error).
5) Longer overall travel than most calipers and micrometers. And since you calibrate it to zero with a stack of gauge blocks, less chance of error.
Among other things, this keeps your hands off the measuring instrument, so you don't cause the instrument to change dimensions as your hand heats it. Note that some micrometers have insulated pads to grip to minimize this problem.
Note that you usually don't use the scale on the height gauge, just the gauge blocks for zeroing -- or adjust the height for scribing to the scale on a combination square end down on the surface plate and held truly upright by the sliding head. But, there are times when the scale is useful.
How tall are your height gauges? I've got a 12" (B&S) and a 24" (Starrett), and would occasionally like a 36".
And do you happen to have a Scherr Tumico one in that collection?
We had one of those two-bar deals like the one on the left at Wasino. I never used it myself, so I don't know how they behave. They seemed to be pretty popular a decade ago or more; I've seen them in a lot of places.
The Digimatic is a good, basic digital. They're good stuff but the mechanical toughness of that Digimatic line in general (I don't know that particular model) is...shall we say, not quite Swiss. I'd probably go for that one for my own shop, though, because it's practical and because Digimatic stuff is functionally reliable and accurate. Also, Mitutoyo has always been really good to me about supplying information when I need it, and the tech people there now don't even know I used to be their agent and writer, so I'm not getting special treatment.
The plug-in model is not something I recognize. If it's not a popular brand, I wouldn't keep it myself, because getting info about it might be difficult. What's the brand?
As for the Height Master, that thing sells for over $2,000 new and it isn't really a height gage. It's primarily used as a gage standard for *setting* height gages, checking production tooling dimensions, etc. I forget how to use them but they measure in steps, using the top and the bottom of the individual steps as measuring surfaces. Somehow.
If I were you, I'd stop down to Aurora and see one in their showroom. They'll demonstrate it for you and tell about what you can do with it. They might even give you a manual -- yours looks like an E-Series 515, which I think is still made. If you got a deal, it ought to be a fun thing to have, but you probably could make some money on it, too. It will give you another decimal point in measuring accuracy over conventional gages.
FWIW, my height gage is a 30-year-old B&S vernier model in new condition, and I used it a lot in years past, when I was experimenting with toolmaking on a lathe (master watch plates and other precision jigs). I haven't used it in five years or more but I would be, if I were doing anything that required precise layouts on plate stock.
I'm partial toward them because they're a classic tool for helping modestly equipped shops to produce very high precision parts with old and simple machine tools, using nothing more than the height gage, a surface plate, and an angle plate to do a wide variety of measuring and layout. In a modern CNC shop, I have no idea what they use them for.
BTW, I've used that dial-indicator stand on the right of your photos a lot when we were doing runoffs at Wasino. With a digital indicator mounted on it, with SPC output, it's a complete SPC inspection station in a shoebox. Very neat, if you make a lot of parts.
Yes -- and it looks as though it can be zeroed to two reference heights.
Nice -- with switchable systems (metric or decimal inch). Easy to zero to having the scriber in contact with the surface plate for quick and dirty measurements.
Now -- about here is where I am supposed to be telling you that it is useless, and that I'll be glad to take it off your hands to save you the trouble of dealing with it. :-)
You did not include a critical part of it in the image.
I've never seen one with a digital readout before.
You note that the micrometer thimble at the top is direct reading to a ten-thousandth of an inch.
And the readout presumably covers a range of 0.0000" - 1.0000".
But what you did not show (except in the group photo) is the series of steps zig-zagging up the front.
Those are 1.0000" gauge blocks stacked and offset so you can take readings of the top of one or the bottom of the other.
With the micrometer thimble all the way down, the bottom-most block should be in contact with the surface plate that it is sitting on. (Well ... it looks as though the bottom most one is actually a 0.5000" block instead, so it does not actually touch the surface plate.)
Anyway -- with the micrometer thimble and the stack of built-in gauge blocks, you can set any height gauge to read accurately any height from 0.0000" to 17.9999"
I've got one by B&S, and Starrett also makes one. I've seen them called "Cadillac Gauges", though I'm not sure from where.
Look at MSC's site, item #06389852 for a 12.200" version with only a 0.2000" range micrometer thimble and no digital readout.
O.K. Then check out item #99290504, which is an 18.0000" one with a thimble range of 0.5000" Yours might be the 0.5000" range as well, I can't tell for sure from the photos. Run it though its range and see what it covers. (It should be the same range as the larger of the gauge blocks.)
Check the finish of the gauge block steps for rust. If you don't see any, spray it with CRC 5-56 (or is it 3-56) to protect it from rust.
Anyway -- the 18" one in MSC's catalog is selling for $4,080.00. It is something which *I* would never get rid of.
I've found a 12" version of what you have on eBay #110432966292, and that shows that all but the top and bottom blocks are 1.0000" ones. The top, and the bottom two seem to be 0.5000" ones.
He's starting out at $400.00.
There is another whose image is not coming up for me which is $1999.00 buy-it-now.
Note that if you search eBay on "Mitutoyo Master" you will find several of various styles, and some come with a riser block, which adds another 12" to the range.
Anyway -- I don't know what you paid for the lot, but you stole that one. :-)
You mean the one in Height-Gauges-0005.jpg? That also looks like a Mitutoyo -- but an older one.
But that isn't actually the last one -- you also have a stand, intended to hold a linear travel dial indicator, and provide fine adjustment of the head to zero it properly on a reference prior to using it to measure things in inspection. I find the ribbed baseplate to be interesting. Perhaps to make it harder for a piece of grit to get under the object being measured.
That -- and the "Height Master" for calibrating things. It does for you what a whole box of gauge blocks plus a lot of math would do.
I consider the "Height Master" to be an absolute keep. One of the others for daily use, and this one in place of a box of gauge blocks.
BTW You were asking what the uses of a height gauge were, and I already posted a general answer, and then later saw you mention the DRO on your mill for handling the layout needs. I would say, not everything.
One place where I used mine was in building some circular waveguide antennas tuned to specific channels. I took the formulas and wrote a C program to tell me the length needed given the frequency, and the ID of the aluminum pipe which I used. I faced off one end (with a modified live center combined with a small 3-jaw chuck for support), then took it to the surface plate, and using a height gauge set to the needed length using a stack of gauge blocks, I scribed a line fully around the other end before going back to the lathe to turn it to the desired length. I don't think that the DRO on a mill would help much for this. :-)
Here is the URL for the project web page I made for this project:
Yes, I like the fact that it is digital (no straining eyes to look at divisions) and it is less error prone than a manual one.
I think so.
That's what it looks like to me indeed.
That's the one, yes, 515-357.
But how would *you* actually use it in your shop. This is sort of what I am trying to find out.
I did not see that one.
Well, I paid $50 for all five pieces together.
Yes, that's what it is, it seems.
I think that I get it, more or less. I emailed Mitutoyo and asked for a manual for it.
You really would benefit from Perl for these sorts of purposes.
Well, you could mill the end of the pipe off, using the DRO, if you knew how much material to remove exactly.
Looks great. You can use that antenna with Aircrack-NG to hack into WEP secured networks that are relatively far away, so your presence would not be noticed. Aircrack-NG is not trivial to use, but not that complicated. I did experiment with it a few times and it takes 2-10 minutes to break into more or less any WEP protected networks. I never used the results of this to break into any computer systems, just experimented. Good choice of channel 6, also.
Ah, yes, I see that. It must be from before my time, so it's an antique.
Aha. Well, I think it's discounted, but it's still an expensive piece of stuff. As Don described it some of my memory cells re-fired; you've got the general idea now.
I'd still see the guys in Aurora. First, it's worth seeing the place, since you're so close. The showroom is open to the public -- or it was. Second, they know their stuff, and they'll show or tell you things you won't get in the manuals.
Right. Typical height gages come with one -- mine is carbide-tipped. And you can get accessories that do odd things. I've never needed them, but I've never used mine to its full capability, either.
Ah, smaller things, actually. The probe on a recording indicator drops fairly low below the clamp.
Mostly I've used them on small cylindrical parts, to measure length, and, with a little fussing, diameter.