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Old December 3, 2013, 09:55 PM   #26
mattL46
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@hibc the handle at the other end suggests to me that it rotates. Maybe to rotate the work while it is being machined. Although it is either frozen or mechanically locked in someway I haven't been able to figure out how to free it. The job is keeping me from being able to sit down and play with it. I'll have more info soon. Thank you all so much for the help!
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Old December 4, 2013, 05:52 AM   #27
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OK,my bet is that it draws the cone in tight,like tightening a vise..of course,Its a guess.
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Old December 4, 2013, 09:16 AM   #28
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Sure hibc but better than mine.
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Old December 4, 2013, 12:46 PM   #29
Dixie Gunsmithing
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Dixie,I'm following you,my question on whether the main shaft rotates or has spindle bearings within has gone unanswered.I'm guessing it does not serve as a rotating spindle.I think I see a tee-handle sort of drawbar arrangement pulling the cone in tight The cone may represent a datum.
What has me question it, is the cone is knurled, almost like its a large nob, made to be tuned by hand, hence the knurl. It looks like it has some sort of angle bracket on the other end, after I took another look, and it also looks to be a casting, so I doubt this is a shop made tool, but something that was sold with some type of equipment. About the only machinery I have ever seen similar bars around, have been turret lathes, large chucking lathes, and horizontal boring machines, but I may be dead wrong. Large chucking lathes have a feed assembly behind the headstock, so the part comes into the chuck from the rear, but to say for sure, I would have to research it, and one might find it in some of the older machine shop books.
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Old December 4, 2013, 12:55 PM   #30
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I have been following this thread from the start.
In my younger years I was a general job shop machinist and after studying the pictures for days and asking some of my old shop buddies we figured it out.
It is a "Hooduspuss"
A seldom needed tool but if your Hooduspuss breaks it is the only tool that will help repair it.
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Old December 5, 2013, 05:13 AM   #31
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I still do not know what it is,and maybe my line of thought is wrong.

Knurling can be done for a number of reasons.Often,gage and fixture parts will show knurling because dropping the piece is a bad idea.Oily fingers,etc.

Suppose a pallet of castings comes into your enterprise.Often.castings have little raised pads,datum targets,for setup.You may have 3 pads to rest like a stool on a table,two to go against a fence,and one to touch a stop.

Now,suppose we face and bore and chamfer the top of the casting,operation one,based on the datum target pads.

Sometimes,castings have problems.Maybe a core shift will cause the inside geometry to be offset from the outside geometry,and a wall or feature might not have enough material thickness.

So,maybe,after operation one,that cone is removed,by unscrewing the handle,the part is loaded on,the cone centers on the bore ,the handle is tightened,and some feature of the casting fits in the window with the depth mic to be checked for material thickness.

Now,the foundry sell castings,and it makes castings.The foundry needs a fixture like this so if I find non-conforming parts,I can call them and say "Check your parts,because ,on my identical fixture,I'm getting bad results"

My company may be working for Minneapolis Moline,and so maybe Minneapolis Moline needs an identical fixture.So,just to do business,the foundry makes some castings,my shop machines them,I keep one,foundry gets one,Minneapolis Moline gets one.

We communicate and solve problems via the fixture.


I could be all wrong,but I can see that tool doing that job.
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Old December 5, 2013, 07:27 AM   #32
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Now,suppose we face and bore and chamfer the top of the casting,operation one,based on the datum target pads
I worked many years in a machine shop,you name the piece of equipment
and I always thought we had it,that was until now.We had no datums.
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Old December 5, 2013, 09:41 AM   #33
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P:I fully understand what a datum is.Theoretical plane,axis,point,etc ...

We use surface plates,centers,etc to represent datums.

Now,if a casting has three raised pads that you might rest on a surface plate,machine table,etc...the noun is "pad",the descriptor is "datum"

What kind of pad?The one that rests on the representation of a datum.

If you are going to setup or inspect a casting,the pads are what is used to establish the part datum as designated on the drawing.

Now,if you go look in your Geometric Dimensioning and Tolerancing manual,see if you can find a symbol for "datum target " drawn on a raised pad.

Anything else?

Maybe with all your experience you could answer the OP's question.

Last edited by HiBC; December 5, 2013 at 09:57 AM.
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Old December 5, 2013, 10:02 AM   #34
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‘'”We had no datums”

And I claim I collect datums, I make datums and......I purchase datums. I was at a Gun show in Dallas at Market Hall, I walked up to a table and said “DATUMS!!”. the dealer said he did not have any datums, one shopper ask “WHERE?”, another happy shopper ask “What does a datum look like?” I purchased the +/- 15 pound box of junk for 5.00$.

polyphemus, it all started with a an arrow pointing at a line, the line is identified as ‘DATUM’, and for years that is all smiths and reloaders knew about ‘datum’. I made tools in the 70s, the only tool I use that is flat is a feeler gage, all the rest have three dimensions. The concept that the datum was not a line but a round hole was not something that was acceptable to smiths and reloaders.

Anyhow, to a machinist, datum is ‘measured from’. The box of junk I purchases was a box of holes drilled into metal plates, cylinders and die parts. A few of the pieces were case holders for Wilson case trimmers. To use the holders for datums all I had to do is butt grind the ends to remove the radius.

The datum/round hole for the 30/06 is .375”. It is not difficult to drill a .375” hole perpendicular to the surface of a plate. For me it has never been necessary to use a .375” hole,

http://www.saami.org/PubResources/CC...pringfield.pdf

I can use a round hole that is larger in diameter than .339” and smaller in diameter than .441”, I do not recommend getting close to the edge but when using a round hole the smith/reloader needs to understand they are using a comparator, they are measuring a fired case and comparing the length of the case from the datum/shoulder with a sized case, or they do as I do, I measure the case before firing and again after firing because I want to know the effect the chamber had on the case when fired. As a side benefit, when measuring the case before firing the reloader will. always be able to use a comparator to determine why a sized case will not chamber.

“diameter than .339” and smaller in diameter than .441” for years it has been claimed the datum was half way between the case body shoulder juncture and the shoulder neck juncture, for the same numbers I have ask: “How can that be when the the .375” datum is used for the 8m06, 30/06 280 R, 270W, 7.7 Japanese, etc., etc., 25/06, I can make datums/round holes that are half way between the shoulder junctures because I understand the information I want can be obtained with a comparator.

If I choose to tie all the loose ends together and get the chamber, case length from the datum to the case head and die and case gage and head space gage along with the shell holder to agree I have to start with SAAMI specifications. Problem! SAAMI does not require anyone reaming chambers to be exact, so I do the next best thing, I measure the length of the chamber from the shoulder/datum to the bolt face, this allows me to leave out head space gages that do not fit except for +/-.

I am the fan of transfers and standards and verifying is not far behind.

F. Guffey
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Old December 5, 2013, 04:56 PM   #35
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Datums

Thanky all.
Thing is I was under the impression OP was looking to ID a vintage fixture of
some sort not a geometric reference point.All those years,who knew.
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Old December 5, 2013, 07:28 PM   #36
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@MadMo Ha Ha! That's it thread over you called it!! @Poly....INFO OVERLOAD! Ha! Ill probably be snowed in here in central OK. tomorrow (Keep the 1/2" snow panic jokes to yourself) so I find that a great time to clean the piece up and look for any other clues. I did notice the knurling on the cone. again as for now the long cylinder does not turn. Could be locked mechanically or frozen with time. Ill find out soon. my guess is the long L shaped bolts with wing nuts compresses and holds the work securely to the face of this fixture. I say that because The width of the legs on the bolts exceeds that of the cone. but the cone could be some kind of additional locking mechanism of some sort. Ill take It as far apart as I can get it tomorrow and take a few more pictures. My guess is the cylinder does rotate to either turn the work or like hibc is saying maybe tighten something. although there are no threads on this large cylinder that I can see. but a lathe tool does secure into the end of it via set screw in the center of the end of the large cylinder. Maybe this is some kind of facing device. Every one of your guesses is better than mine. Hopefully more info tomorrow. Thank you all for your attention and interest. Again more info tomorrow.
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Old December 5, 2013, 09:28 PM   #37
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Correction. The L bolts do have the ability to clamp the cone. If that's what they are for im unsure. But the fit is quite precise so im thinking that is what they are for.
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Old December 5, 2013, 11:47 PM   #38
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It also reminds me of a purpose built live or dead center tail stock for a lathe.
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Seams like once we the people give what, at the time, seams like a reasonable inch and "they" take the unreasonable mile we can only get that mile back one inch at a time.

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Old December 9, 2013, 11:02 AM   #39
F. Guffey
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The ‘L’ hold down looking bolts could be hold back bolts if the equipment does not stand up, The cone has has the appearance of having been adjusted to the bolts, if that is the case the hold back? bolts could be used to limit travel. I believe there are pieces missing. I have old equipment that goes back to Champion Blower & Forge, some of it bolted to the leg of a table and or a tree. As has been pointed out the journals do not have lube cups/oilers, meaning the shaft does not rotate. I have owned honing equipment that was used to hone/lap two pieces together and equipment that was used to cut slots, I do not see an index so I will assume if the devise was used for cutting slots it only cut one.

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Last edited by F. Guffey; December 9, 2013 at 11:06 AM. Reason: turn around su
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Old December 9, 2013, 11:04 AM   #40
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Problem with using the hold back bolts as limiters, if the bolts are loose they will rotate.

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