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Need help identifying this item

Etherizer

Plastic
Joined
Sep 15, 2016
I came across this "bar" in an old machinists tool box. Help me identify it. P1060942.jpgP1060944.jpgP1060946.jpgP1060948.jpg
The bar appears to have been scraped What is it called and what purpose does it have?
 
I came across this "bar" in an old machinists tool box. Help me identify it. View attachment 189222View attachment 189223View attachment 189224View attachment 189225
The bar appears to have been scraped What is it called and what purpose does it have?

May I please buy it from you at a fair price first, then tell you what it is afterwards?

I have a larger one. And a smaller one. This would be 'Goldilocks' in-between size.

Hint: Actual use involves skilled, tedious and demanding hard work. It makes some folks very irritable, can lead to high-blood-pressure, even if they fall in LOVE with that.

You'd really want me to take it off your hands to avoid that sort of risk, no?

:)

Bill
 
Sorry to deflate the mystery Monarchist has spun, but what you have is a high-precision angle straightedge. It's used for machine tool manufacture, repair, and reconditioning. The metal looks flaked because each side was hand-scraped to match a reference flat, and the work was done to ensure that the angle between the scraped surfaces is accurate and consistent. You use it to make sure machine tool dovetails are flat, straight, and accurate.

Having said that, you should definitely sell it to Monarchist for a reasonable price - he's a nice fellow and will know how to use it.
 
- he's a nice fellow and will know how to use it.

Plenty of folk would challenge one or both of those, but thank you!

Fewer would challenge that I do pay fairly and promptly.

As much because I am too old and too lazy to make my own as for any other reason, of course.

:)

PM coming with a genuine, not humorous, offer.

Cheers,

Bill
 
To add the angle may be a special angle which exactly matches the vee ways on one make of machine. If so this makes it most valuable to someone who works on that brands. For example my Harrison is 75 degrees not a more common 90.
Bill D.
 
Any slight rust will maske this worth much less. immediately oil all the faces and wrap it up in a dry place.
Bil lD.

Not all that much. They usually need re-scraped after long, imperfect storage, anyway. Buggers often move a bit when neglected - sometimes even when hung-up like a ham.

Bill
 
monarchist, so you would buy that without knowing the condition?

Sure would. Might have already. Offer was sent.

Foto ain't bad.

Can't f**k 'em up but so much.

I've been lucky enough to have to trash an item very, very seldom (busted coolant pump the last one..) ergo can still count meself well ahead, on average.

Last straight-edge but one I bought was 'East Bloc' made. Came clear out of Moldova with no problems.

Plus... if need be, I have a younger and more skillful guy as can re-scrape it for me at a reasonable fee.

Not as if I ever have to buy TWO of any given size and shape, so the long-term cost is not high anyway.

Advice in there somewhere to JFDI rather than lose sleep, grow an ulcer, or bust a vein worrying about the non-recurring small shit.

I drive a far harder route at the grocery store. Been eatin' longer and more often than buying scraping masters, so THAT pays-off.

Bill
 
From the photo, I'm gonna guess you will need to do some serious scraping, because the scrape marks on that one look to be pretty long, not the type made by anyone finish scraping it to a good surface.

As to the idea of the angle being important... not really. So long as it is more acute than the angle of the dovetails you need to scrape, it's fine. A reference angle can be short, although there can be convenience to a full length perfect angle reference, I suppose.
 
From the photo, I'm gonna guess you will need to do some serious scraping, because the scrape marks on that one look to be pretty long, not the type made by anyone finish scraping it to a good surface.

As to the idea of the angle being important... not really. So long as it is more acute than the angle of the dovetails you need to scrape, it's fine. A reference angle can be short, although there can be convenience to a full length perfect angle reference, I suppose.

No fear. I know what I need for what actually needs doin' with it here.

ISTR RK - proud to never set a 'not to exceed' price, as he has been - hinted at how he'd 'enjoy' scraping a certain Rivett lathe?

I figured if he was serious about the hours, that would run to no LESS than $30,000 before he tired of the 'enjoyment'.

You didn't perchance take him up on that open-ended deal, didja?

:)

Bill
 
To add the angle may be a special angle which exactly matches the vee ways on one make of machine. If so this makes it most valuable to someone who works on that brands. For example my Harrison is 75 degrees not a more common 90.
Bill D.

Welll.. unmentionable Lathe Shaped Objects with square ways and carriage aside, I haven't seen EITHER 75 or 90. A tad under 60 degrees is wot I'd call 'common'.

Angle on the reference/transfer prism should be less than included angle on the machine as well for general-purpose use. One ordinarily works but one surface at a time.

Bill
 
For example my Harrison is 75 degrees not a more common 90.
Are you certain of that? A dove tail 15 degrees off of plumb. Seems to ignore best engineering practice. And nothing like any Harrison I've seen.

How ever you're loosing me. "not a more common 90". That's what would be called a box way On a lathe?

(On Edit)

http://www.practicalmachinist.com/vb/general/sherr-tumico-level-tube-unit-325234/#post2833780

OP's disposing of gear. Put it on Ebay @ $50-$75. Scraping is suspect, but has the right shape to become a usefull tool if some one wanted to refine it. It ain't no ready to go Challenge straight edge.
 
Mystery steady rest - may fit Harrison?

I have a steady rest that was claimed to fit a Clausing 5900-series lathe, which it does almost fit - one can use it. But it isn't quite right.

For one thing, the Vee on the bed of a 5900 is 70 degrees included angle, but this steady rest is actually 80 degrees (well, 79.7 degrees, as measured with a dial indicator and a bunch of precision-ground rods of varying diameters). (The other side is a flat.)

Also, the center of the steady rest isn't exactly on the spindle rotation axis - off by something like 3/16".

People had suggested that it could be from a Harrison lathe, but that's 75 degrees, I gather.

Does anybody have any idea what my mystery steady rest is for?

I'd guess the Vee angle will sharply reduce the number of candidates.

Joe Gwinn
 
http://www.practicalmachinist.com/vb/general/sherr-tumico-level-tube-unit-325234/#post2833780

OP's disposing of gear. Put it on Ebay @ $50-$75. Scraping is suspect, but has the right shape to become a usefull tool if some one wanted to refine it. It ain't no ready to go Challenge straight edge.

The S-T level in that thread turned out a good one. So did the shorter Lufkin PM member Gernoff sold me and scraped in so very nicely.

OP there and again here "Etherizer" didn't respond to the offer for the vial. Nor has he to an offer for the prismatic straight edge herein.

I suspect he figures to double his money on ebay with this marvelous 'treasure', so we are probably wasting our time WHENEVER he pops in.

Bill
 
My number may be off for the Harrison angle. I was using it as an a example of what angle to match from memory. I meant the included angle of the two sloping sides.
Being almost but not quite vertical would make no sense and make it awfully thin with a 1/8" wide flat area on top.
Bill D.
 
A friend of mine had a Harrison lathe built around 1974, small lathe, 12" "toolroom" I think. He was very proud of it but when I asked about the obviously milled cross slide ways he said their milling was so accurate they didn't need to scrape them.
The dovetail SE in the photo looks to be solid, not made with lightening slots on one side, but as R. King says you need to alternate with a standard camelback for the flatness when you're using it because any SE with such a long aspect ratio will bend with weight.
 








 
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