Unknown object

[Paul BarterParticipant @paulbarter66156]

Hello all,

Please does anyone know what the purpose of this thing is?It seems carefully made witha gimbal arrangement that has provision for locking one axis with a thumb screw, the other axis has small adjustment screws to adjust end float,there is a collett chuck on the gimbal. The larger clamp screw has sharp point on the outer surface! and the connecting strap is spring steel.

Any suggestions gratefully received.

Paul

[Paul BarterParticipant @paulbarter66156]

[magpieParticipant @magpie]

It's a fingymajig.

[DC31kParticipant @dc31k]

I think it is a precursor to a dial test indicator, used for centring up work in a four jaw chuck.

There is a long, slender rod that goes through the collet. The end of this locates in a centre drilled in the work. The length of rod between holder and workpiece needs to be relatively short; the free end relatively long to amplify any out of trueness. When the free end stops wobbling about, the work is true.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by DC31k on 20/07/2019 06:59:26:

I think it is a precursor to a dial test indicator, used for centring up work in a four jaw chuck.

There is a long, slender rod that goes through the collet. The end of this locates in a centre drilled in the work. The length of rod between holder and workpiece needs to be relatively short; the free end relatively long to amplify any out of trueness. When the free end stops wobbling about, the work is true.

.

Brilliant deduction … I'm sure you are correct

It merits a cross-reference to this thread: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=143609&p=1

MichaelG.

Edited By Michael Gilligan on 20/07/2019 07:40:34

[JasonBModerator @jasonb]

Possible but all the ones I have seen the rod goes straight through so you can compare it's movement against a tailstock ctr. This item looks like the long rod would be at 90deg to the point and wave about in the air?

[Paul BarterParticipant @paulbarter66156]

Thanks to you all for such quick responses. Any ideas as to why it is supplied with an elaborate means to lock an axis on the gimbal? I thought a wiggler needs freedom in all directions and one end must be a datum ie on centre in either a tailstock chuck or mill Collett. The sharp point on the clamp screw is a puzzle, unless it was designed and used by a masochist!

Paul

[Paul BarterParticipant @paulbarter66156]

Jason you beat me to it, I agree it probably is not an ancient wiggler like Tina T

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 20/07/2019 07:52:20:

Possible but all the ones I have seen the rod goes straight through so you can compare it's movement against a tailstock ctr. This item looks like the long rod would be at 90deg to the point and wave about in the air?

.

If you set those pivots appropriately, I'm pretty sure it could do as the others

If you have time, Jason, break-out the 3D CAD please …

MichaelG.

[MichaelRParticipant @michaelr]

It could be something to do with tying fishing flies !!

Mike.

[Michael GilliganParticipant @michaelgilligan61133]

A Starrett tool, with 'a close family resemblance' I would say: **LINK**

https://www.practicalmachinist.com/vb/general/starrett-mystery-tool-141785/

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

**LINK**

https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=US&NR=617501A&KC=A&FT=D&ND=3&date=18990110&DB=EPODOC&locale=en_EP

[DC31kParticipant @dc31k]

Posted by Paul Barter on 20/07/2019 07:58:41:

Any ideas as to why it is supplied with an elaborate means to lock an axis on the gimbal?

Thanks to Michael for digging up the PM thread. To quote from post 14 of that one:

“The indicating needle is 12 ¾ inches long when jointed together, magnifying greatly the slightest movement at the indicating point, and being in two sections it may be carried in the mechanic's kit conveniently.
The needle also passes through the ball, having a split stem, forming a chuck for holding it, and it may be adjusted to any length. The ball is pivoted to form a universal joint but may be instantly converted into a single joint for vertical motion by merely tightening the knurled knob, adapting it for inside and outside surface contact. A steel ball about .175 inch in diameter slips over the point for inside work. . . .”

So you need to make it uniaxial if not using with a centre-punch mark.

Very clever, those old boys.

[Ian S CParticipant @iansc]

I'v never seen one like that, but many years ago I made one, the rod I used was a double ended steel sock knitting needle about 8" long.

Ian S C

[Paul BarterParticipant @paulbarter66156]

Thank you all for taking the time to educate me yet again. Thank you especially Michael Gilliian, you have nailed it, now to find a silver steel rod.

regards to all Paul

[duncan webster 1Participant @duncanwebster1]

Posted by Paul Barter on 20/07/2019 13:44:54:

Thank you all for taking the time to educate me yet again. Thank you especially Michael Gilliian, you have nailed it, now to find a silver steel rod.

regards to all Paul

Why silver steel, no strength required

[Author]

Posts