# Holding irregular parts with an old gear



## Winegrower (Nov 29, 2020)

I saw this somewhere awhile ago, and finally tried it.  Hey, this really works, and might solve some weird problem for you someday.

Cut an old gear in half, mill the cut faces square, and put them in a vise ”tooth to tooth”.   As the vise compresses the gears against the work, they automatically rotate to the perfect angle to hold the work very tightly.


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## Ulma Doctor (Nov 29, 2020)

That’s thinking out of the box!!!!


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## ThinWoodsman (Nov 29, 2020)

Ulma Doctor said:


> That’s thinking out of the box!!!!


out of the ... gearbox 

okay, okay, I'm going


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## eugene13 (Nov 29, 2020)

Brilliant!


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## silverhawk (Nov 29, 2020)

ThinWoodsman said:


> out of the ... gearbox
> 
> okay, okay, I'm going


Only if going was missing the "keep" part, as in "keep going". I do think the quip and the original thought are awesome. 

joe


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## wrat (Nov 29, 2020)

ThinWoodsman said:


> out of the ... gearbox


This caused a real shift in my thinking.

The good ideas around here come at a higher ratio than one might expect - causing the need to sync one's thinking.  It almost requires a manual.
Because we all know it's not automatic.


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## NC Rick (Nov 29, 2020)

That's cool looking to but I'm not sure it quite meshes for me because I have seen a similar thing with a block shaped like a woodruff key with the radius against the other vise jaw.  Never tried either. If I happen upon a spare gear, I'll try it!


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## 7milesup (Nov 29, 2020)

wrat said:


> This caused a real shift in my thinking.
> 
> The good ideas around here come at a higher ratio than one might expect - causing the need to sync one's thinking.  It almost requires a manual.
> Because we all know it's not automatic.



Oh man.....


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## Braeden P (Nov 30, 2020)

watch out i heard they have sharp teeth and will bite!


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## Toolmaker51 (Jan 13, 2021)

NC Rick said:


> That's cool looking to but I'm not sure it quite meshes for me because I have seen a similar thing with a block shaped like a woodruff key with the radius against the other vise jaw.  Never tried either. If I happen upon a spare gear, I'll try it!


The Woodruff key shaped insert [chordal segment] is commonly used, but this gear concept is interesting. It would take some care that meshing occurs with centerline of part being clamped. The example of a ratchet is extreme in width, so little issue except the contact area is very small. Wouldn't take much torque of a cutter to spit it right out; chose whether to go conventional or climb wisely.


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## hman (Jan 13, 2021)

Wild hair ... inspired by the round shaft that @Winegrower has in his photo ... cut a "lengthwise" vee in one of the gear segments, so it will more securely clamp onto round parts.  If the part being held has a flattish surface, you can put the vee'd segment against the vise jaw.


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## Toolmaker51 (Jan 13, 2021)

Aaaahh K, twisted my arm: here's what I'll call Downtown Clamping, Home Shop Address.
We've directed attention to one remedy, a semicircular adjuster compensates misalignment of shaped parts between parallel jaws. 

This is not my creation, but one sample of others I've made.
Secure clamping relies on directing pressure quite figuratively 'through' the part to an opposing fixed surface; as in moving and fixed jaws of a vise. And whether vise, clamp, or hold down; they like parallel surfaces best. But that's just not always 100% feasible.

Just as a C-clamp needs a swivel pad to correct out-of-plane surfaces, this can take serious pressure, using a swivel action, for tapers, radii, curves and compound surfaces, as in cast or forged parts. Self adjusting, it uses less space, very advantageous when a vise is used.

This is a lathe or mill project, or combination of the two. A little planning will allow making two at a time. Test fits while work proceeds. Heat treating is not needed, or recommended; any steel will do. Only 'requirement' [grossly over-stated], a decent surface finish on swivel area mating to block.

Physical size isn't critical, use steel and adjust to suit material available. Procure two bearing balls, example uses .75/ 19mm. This block is about 2 1/2" long, 1 5/16" high, and 1" deep. The radius inside block [not through] and chord is 1". Allow .002-.004 clearance on one side.
The chord has two pockets bored to slip fit the bearing balls. Ball end milling can be used, but isn't required. If pocket is ball-milled, pilot drill around 1/4 ball diameter and somewhat beyond 1/2 the ball diameter. Seat depth is .020-.030 deeper than 1/2 the ball diameter; for staking. Before assembly, grind flats with any manner at your disposal, nice if close to same height. Lightly stake the balls in place to be retained, not locked. Top edge of chord is grooved for a roll pin pressed into the top plate. In the groove are 2 roll pins at 45° keeps chord from swiveling out of the block.
Top plate is countersunk for 2 #10 flat head screws, tapped in block.
This works in vises, hold-downs and a variety of fixturing.


If amplification is needed, feel free to post or email questions.


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## Shootymacshootface (Jan 13, 2021)

Has anyone seen my missing gear? It has about 50 teeth, kind of a thick hub, and is made of steel.
My tractor desperately misses it. Please pm me if you see it.

Shooty


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## 7milesup (Jan 13, 2021)

Toolmaker51 said:


> Lightly stake the balls in place to be retained, not locked.


What does that mean?


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## hman (Jan 13, 2021)

@Toolmaker51 - Wowsers!  That double swivel action should do a great job on just about anything.  I'm impressed!


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## Toolmaker51 (Jan 14, 2021)

_Lightly stake the balls in place to be retained, not locked._ 



7milesup said:


> What does that mean?



Hole diameter just larger than ball, and deeper than half diameter. Rim of hole is prick punched, so the deformed material retains the ball section. Staking could also be a ring around same rim, formed by a hard version of an arch punch.


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## Suzuki4evr (Jan 14, 2021)

Ulma Doctor said:


> That’s thinking out of the box!!!!


That's making the gears in your head work


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## Toolmaker51 (Jan 14, 2021)

re "Thinking Out Of The Box";
A friend of extraordinary skill and knowledge elevates that oft-used statement thus. 
Thinking out of the box is good, yet a box has finite coordinates, or points of reference. Instead, _"Think Out Of The Sphere" _as that employs Infinite coordinates.


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