Help me find a modern use for this tool

[mklotz]

Even as a kid, I was a tool aficionado. My Dad gave me an old Starrett tool catalogue and in it I discovered planer gauges. I had absolutely no use for one but I wanted one! Then, as now, they were brutally expensive but I loved the look of them. They shouted intricate, technical mystery and artistic form. I guess I thought it was "cool" long before that word had that connotation.

Recently I had an opportunity to buy a used planer gauge for a comfortable price, so, like all old men reliving their youth, I jumped on it.

Planer gauges were designed to set heights in a tool known as a ..wait for it...planer. For the benefit of the kids on the forum...
A planer was a large tool with a fixed table to which the work was attached. Above the table was a movable frame that carried a cutting tool. As the frame moved, this tool "planed" material from the work to produce flat surfaces. It was roughly the mechanized, metalworking equivalent of what woodworkers do when they plane a board. Planers were a tool of the early metalworking era and have largely disappeared today, replaced by large mills.

As the photos show, the tool consists of a triangular frame. The angle of the frame looks like 30 degrees but is a puzzling 26.9 deg*. The hypotenuse of the triangle has a T-slot into which is fitted a movable carrier. The carrier has a precision flat on its upper corner that can function as a variable height gauge. Two other flats, one horizontal and one vertical, have tapped holes that accept the accessory knurled extension that is a precise 2.5" in length.

I'm not old enough to have ever used one of these so I can't elaborate on its intended use. I'll never own or use a planer so I really don't care about how they were used in the old days.

What I'm looking for is ideas for modern uses for this tool that capitalize on its accuracy, i.e., no paperweight or doorstop suggestions. I'm looking for some creative ideas, something beyond the obvious...

square
height gauge
26.9 degree angle gauge
slot width transfer gauge
DI carrier

--
* The 26.9 deg angle puzzled me enough that I undertook to measure it accurately. Using the tool itself, I could get a fairly accurate measure of the rise/run ratio for the sliding element. The ratio came out to be 0.5071. If we take the acrtangent of that, the result is 26.889 deg, very close to the 26.9 deg I measured with an electronic inclinometer.

That ratio is suspiciously close to 0.5 (corresponding to an angle of 26.56 deg) and, given the possible errors in my measurements, it could well be that. OTOH, the utility of such a mathematically simple ratio in this tool isn't at all obvious.

As soon as our weather warms I'll set up to do a high accuracy measurement of the angle using a sine bar and report on the results.

In the meantime, I have a thread pending in HSM to see what wisdom I can glean from the clever monkeys over there.

[C-Bag]

I owe you one Marv. I've been jonesen' for one of those for years. I just assumed they were somehow for a wood planer for like making veneers or something really precise and luckily I don't have a wood planer either.

Only 3-4yrs ago did I find out about shapers upon seeing a couple on the local craigslist. At that time metal planers were mentioned but I've never seen one. I'd not put two and two together until now. So I owe you for keeping from buying another terminally cool tool that I don't have an immediate use for.

I did just find an Atlas 7b shaper that I'd expected to be to expensive but when the guy said $125 and it had everything including the vise I just couldn't pass it up. It also turns out I have several projects it's well suited for and after watching an instruction vid on it is going to be very handy for what I'm doing.

I had guessed I could use the gauge for a machinist jack, but the expense always kept away. Isn't it funny that it's for a defunct machine tool, but still is very expensive. Almost every time I see somebody selling off grandpa' old machinist tools there's one in there, and they are usually the most expensive. I guess because they look on eBay.

[Toolmaker51]

Mklotz and C-Bag...
Planer gauges represent a desired height, typically before the work piece is mounted. It prevents tools impacting material; instead of trying to eyeball tool path. Works in milling machines or surface grinders now, as well in planers and shapers decades ago. The incline's purpose is to allow settings in very small increments. A height gauge is used primarily; or, compared to gauge blocks with indicator, measured with micrometer, calipers etc. The expense now is usually because others are +$ too. Those opportunists scoop toolboxes at garage sales, wire brush the s__t out of it, surf ebay for like items, and slap on price tags. They're easy to spot. The description lack detail, wrong, general tripe, 'need help identifying' etc.
Sure! Where's my percentage for critical info?

Not exactly a machinist jack; but inspectors will use them in a similar manner, i.e. testing an unknown angle, with a sine bar. The incline is not steep enough to descend on it's own. They'll tap it down while traversing the part [on sine bar] with an indicator. The nicest have a fine-adjustment screw too. At evident zero, [representing hypotenuse] lock the planer gauge clamp. Measure gauge height for [side opposite] in solution of angle. Hundreds [?] of times easier than exchanging jo-blocks, feeler gauges, or the like.

So there's more. I smell a new thread. We don't charge for that here.

[Frank S]

Not all planer gauges have the same slop angle, nor do they all have the same top slide fixture There is a guy on the PM site who gives a fairly good account of some of the other uses that he uses his for
Planer/Shaper Gage - Useage
Look for post #4

[mklotz]

Not all planer gauges have the same slop angle, nor do they all have the same top slide fixture There is a guy on the PM site who gives a fairly good account of some of the other uses that he uses his for
Planer/Shaper Gage - Useage
Look for post #4

Thanks for the pointer. Actually, most of the uses he mentions are already covered in my list of uses with which I am already familiar.

I'll take your word on the differing slope angles since I've never handled, much less measured, any other gauges. Nevertheless, I think it's not by accident that a respected maker like B&S would pick such an unusual, non-integerial angle. Knowing the angles of other gauges might provide some good clues to this puzzle.

Maybe it's like the Morse tapers. The original makers of the gauges were shooting for 30 degrees, missed it by a little, and the error has been dutifully reproduced by makers ever since.

Nevertheless, it's highly suspicious that the angle has a tangent so close to 0.5. As soon as I can, I'm going to attempt to measure it more accurately than I have so far. It may well be that the small deviation from 0.5 that I've seen so far is due to crudity or carelessness on the point of the inspector.

Everything on this tool is set up to be used for measuring. The little "chair" on the sliding element has a back that is precisely (3 digit) one inch and the seat is precisely 5/8" from front to back. And, as I mentioned, the length of the cylindrical extension rod is precisely 2.5". My gut feel is that, with all those built-in precision measurement features, the angle of the gauge can't be some random, accidental value.

[mklotz]

Well, it finally warmed up and I measured the angle the way the pros do. You can see the setup and the results here...

http://www.homemadetools.net/forum/a...7213#post85264


Earlier I had measured it using a bit cruder method. That method is described in post #5 of this HSM thread...

Planer gauge angle questions

which, for your convenience, I've reproduced below...

I still haven't gotten around to measuring the angle with a sine bar but I did attempt to do something a bit more meticulous than what I did yesterday.

The movable part of the gauge has an L-shaped structure on the right side. It looks a bit like a very uncomfortable chair to me so, to simplify the description, I'll refer to it that way.

In the first picture, the center square from my combination square is being used to establish a vertical at the right edge of the triangular frame. The front edge of the "seat" of the chair is butted against the vertical, thus aligning it to the right edge of the frame. With the slider locked in this position the height of the seat above the base of the gauge was miked to be 1.021".

In the second picture, a 1" spaceblock has been interposed between the edge of the seat and the center square vertical. Thus the slider has been moved horizontally a precise inch. In this position the height of the seat was miked to be 1.531"

The rise/run ratio is thus 1.531 - 1.021 = 0.510. Taking the arctangent of this ratio yields an angle of 27.02 degrees, slightly larger than my cruder measurement of 26.9.

[trwalters001]

... ideas for modern uses for this tool.

Hi Marv,

What timing!

I was watching a Youtube video a few days ago ("Setting Precise Angles for Woodworking"), and he talked at length about planer gauges. He uses his (mainly) to set the height of a sine bar. I thought (and you'll understand) "I gotta GIT me wunna thim!"
So I immediately found a great deal on a Starrett on ebay. Ordered and received.
You can see the video at:

Tim Walters
Atlanta, GA

[Dr Stan]

I worked as a toolmaker for several years and have two planner gages. For the most part I've used them for measuring wide slots (just like an adjustable parallel) instead of setting tool heights.

[Harvey Melvin Richards]

I have 3 planer gauges. A cheap import version that I don't worry about, a Lufkin and a Pratt and Whitney (P & W bought out Lufkin and made precision tools for a short period). The Lufkin and P & W are both beautiful tools. Both have wood boxes, 2 extension posts and 2 scribes. They also both have a fine adjustment, something that seems to be rather rare. I use them occasionally, but I mostly just fondle them.

[bluegrallis]

I worked as a machinist, tool maker and machine repairman for most of 40 years. The angle of the tool is not important for it's intended use. It is set to a certain height by use of a micrometer or a height gage and used to set a precise angle with a sine bar or sine plate.