Indexing Dividing Super Spacer what's the essential difference?

[RayG]

This weeks question in the ever growing category of misused confusing terms...

What's the difference between a "dividing head" an "indexing head" a "super spacer", let's throw in "spin indexer" as well, just to help muddy the waters?

Ray

[Ueee]

Hi Ray,
I would have thought dividing head and indexing head were the same. Super spacer is a new one for me. Anything I have looked at with the term spin in its name is generally free to turn and has no worm drive. It could have a detent plate though so simple indexing could be done.

Doesn't really help does it.

Ew

[Grahame Collins]

I think dividing head and indexing head are the same animal and can divide down into part of a degree, while a spin indexer is only does fixed degrees. Don't know a bout a super spacer, though.
Never mind, someone will come along who knows this and more.

Grahame

[.RC.]

Super Spacers are essentially one of those Horizontal/Vertical rotary tables with a very large spindle bore.... They also have index plates for simple indexing..

[Anorak Bob]

How about...a dividing head (non optical) utilises division plates driving the spindle by means of a worm and worm wheel to divide a circle. An indexing head divides a circle via the direct indexing of a spindle mounted plate. Most dividing heads have a provision for direct indexing but indexing heads being simpler devices, often don't readily facilitate the installation of a wormwheel, worm, sector arms, plates etc.

BT

[malb]

Not an area of expertise for me, but one of general interest. My understanding follows Anorak Bob's, not familiar with the other couple of names though.

[argeng]

I have one that is actually the best Gray's pickup I have acquired. The picture only showed the chuck and was advertised as such. Repco badged but not the Repco chain that is around now, made in Melbourne Bayswater, I now have 2 Melbourne bits of kit, this and Shaper that were made when engeneering gear was made to a high standard.
They basically have interchangeable discs with different notches to provide set indexing, very quick and sturdy. Shame I don't have the mill to use it on.

Might need to move it on.

Cheers
Bruce

[RayG]

How about...a dividing head (non optical) utilises division plates driving the spindle by means of a worm and worm wheel to divide a circle. An indexing head divides a circle via the direct indexing of a spindle mounted plate. Most dividing heads have a provision for direct indexing but indexing heads being simpler devices, often don't readily facilitate the installation of a wormwheel, worm, sector arms, plates etc.

BT

I think I get what you are saying, the dividing head has division plates attached to the worm input worm drive. Part of the confusion I think is that most dividing heads also have an indexing plate. (that's the one attached to the spindle? )

So, is this correct?

Dividing head
http://images.machineryhouse.com.au/M585D/2/700


Dividing Head with indexing plate?
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/IndexingHead-SimplePlate.jpg/220px-IndexingHead-SimplePlate.jpg



The super spacer, is I think a mostly American term, I think it's usually a notched indexing wheel attached to the spindle. Some times with pneumatic or lever operated indexing, pull the lever and it rotates a preset number of degrees, not as accurate as a dividing head.

Super Spacer https://www.huronindustrial.com/bison-8-horizontal-veritcal-super-spacer-with-e-zee-interchangeable-dividing-plates-5902
https://www.huronindustrial.com/image/cache/data/products/7-609-006-500x500.gif


Spin Indexer, no gear drive, just spins.
http://i239.photobucket.com/albums/ff206/arwatch/Shop/Butterknife/IMG_1711.jpg


Ray

[Ueee]

Just to add another level of complexity....

In the Brown and sharp d/h book they call indexing on the spindle direct indexing, on the worm indirect indexing and using indirect indexing but with a gear train to slip the indexing plate differential indexing. The last one is for doing things like prime numbers.

Ew

[Anorak Bob]

Here's a bit about the spin indexer that may be of interest - http://www.thegaragegazette.com/index.php?topic=109.0

Further reading has suggested that spin indexers are fairly lightweight bits of gear. Most of the readily available versions accommodate 5C collets which means there's another set of collets to purchase.

Some spin indexers are cheaper than chips - http://www.ebay.com/itm/5C-Precision-Collet-Spin-Index-Fixture-Milling-Collets-/360886119493?pt=BI_Tool_Work_Holding&hash=item54067d2c45 and some less so - http://www.ebay.com/itm/Suburban-Tool-Inc-GM-3-SPIN-INDEX-FIXURE-/251478286962?pt=BI_Tool_Work_Holding&hash=item3a8d462272

Having the indexing plate so close to the spindle nose would give me the sh.ts. For short workpieces, and without tailstock support you could only really work on short stuff, it would be bloody hard to get a chuck and cutter in close enough to do any good. A grinding wheel might be another story.

BT

[Michael G]

Further reading has suggested that spin indexers are fairly lightweight bits of gear. Most of the readily available versions accommodate 5C collets which means there's another set of collets to purchase.

I think they are cheap to copy, but Yuasa who do some very nice kit (my R/T and large D/H are both theirs) so there are some better ones out there. The problem is as you say the 5C collets. I quite liked Bruce's indexing chuck mount so I'd probably take something like that over a spin indexer. I have a small Ellis dividing head that I have to make up some index plates for that was going to be my simple indexing device.

Michael

[Stustoys]

Dividing Head with indexing plate?
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/IndexingHead-SimplePlate.jpg/220px-IndexingHead-SimplePlate.jpg



That's a Universal Dividing Head :wink:

You left out rotary table hehe

Stuart

[Michael G]

That's a Universal Dividing Head

No- that's a semi universal. What's the difference? about $1000 and some gears on the side to rotate the index plates.

Michael

[Stustoys]

Are we helping? :D

[RayG]

Are we helping? :D

Only if you want to... :) I thought universal dividing head was one that tilts as well as rotates?

Ray

[Michael G]

All the dividing heads I've seen can tilt in one axis. A semi-universal will (usually) allow direct indexing as well as indexing using dividing plates. A universal dividing head will allow you to do that but also enable gears to be attached for differential indexing and couple to the mill table so you can do helical milling operations.
If all you wanted to do was put hexes or flats on the ends of round shafts then a spin indexer*/ super spacer*/ indexing head would be fine. If you wanted to have more divisions or cut spur gears then you need a semi-universal dividing head**. If you want to cut spur gears with difficult numbers of teeth*** (like t=127) or helical gears then you are likely to need a universal dividing head.

Michael

*All the spin indexers I've seen are restricted to integer numbers of degrees. All the super spacer indexing plates I've seen are restricted to integer divisions. Which one you get depends on what you want to do.
**Rotary tables with indexing plates are available but like S/U dividing heads are not able to cover every single division over a certain number. From memory the certain number for a S/U D/H is 50 (ish)
***Of course, you could use special plates or compound indexing but that's a whole new can of worms

[Stustoys]

Ok maybe we forget the names and just call them by what they do
Direct Indexing
Indirect Indexing
Differential Indexing
????

Found something that I thought was interesting(even if I've never seen a table like it). A indexing head that wears in not out. (Of course there is a table that can use a sine bar to set angles between the steps.)

I can post a scan of one page of a book right? hope its readable

Stuart

[RayG]

Ok maybe we forget the names and just call them by what they do
Direct Indexing
Indirect Indexing
Differential Indexing
????

Found something that I thought was interesting(even if I've never seen a table like it). A indexing head that wears in not out. (Of course there is a table that can use a sine bar to set angles between the steps.)

I can post a scan of one page of a book right? hope its readable

Stuart

I like the self correcting error idea.. very clever. :2tsup:


So for nomenclature we have... in order of accuracy?

Spin indexer
Super Spacer
Direct Indexing
Rotary Table must fit in here somewhere?
Indirect Indexing
Differential indexing

and not sure where to put the latest addition to the family...

Indexing table with meshing radial serrations.. ( super accurate, but I think only integer degrees? )


Ray

[Stustoys]

Hi Ray

Yes that's what I though was so interesting.. the more you use it the better it gets as long as you arent repeatedly using the same angles.
I guess you could use a worn rotary table to make one then use that table to make another one and be pretty damn close.
Making dividing plates is about the only other thing I recall that can "self improv", though thats a little different.

Well not exactly what I meant.
Spin indexer, super spacer, some rotary table, some dividing heads= direct indexing
rotary table, dividing heads, things with worm wheels etc= indirect indexing
Dividing heads that are geared to another axis=Differential indexing

Lets not even start on dividing heads with 2 axis indirect indexing:D

So the one device might well come under to or even three headings... just depending on how its being used.

Its not really an order of accuracy.... that would me more about who built it. I remember Greg showing some pictures of a optical indexing head that the had a correction table supplied to correct errors in the worm wheel even though every wheel was lapped it a new lap etc etc.

" but I think only integer degrees? ) "
No, as I tried to say in my last post, there is a model that takes care of that.
I wonder if anyone has ever seem one in the flesh? lol... looks light ;)

Stuart

[Bryan]

Stu, remember the Hirth Coupling thread? I bet that is the principle at work here.
I still haven't got around to making one, but building a simple indexer sounds like a good excuse.
Oh wait, I have all this other stuff to do... :doh:

PS: It was actually in your shaper thread, regarding adjustable tool holders:
http://www.woodworkforums.com/showthread.php?t=124309&p=1213831&highlight=hirth#post1213831

[Ropetangler]

I think dividing head and indexing head are the same animal and can divide down into part of a degree, while a spin indexer is only does fixed degrees. Don't know a bout a super spacer, though.
Never mind, someone will come along who knows this and more.

Grahame

I'm not sure, but I was under the impression that Spin Indexers could theoretically divide down to a tenth of a degree, courtesy of a vernier action with the choice of detent hole.
Rob.

Ahh, I may just have seen some light. It would seem that the vernier action was to get individual degrees, not the tenths I was confusing myself with.:B

[cba_melbourne]

This weeks question in the ever growing category of misused confusing terms...

What's the difference between a "dividing head" an "indexing head" a "super spacer", let's throw in "spin indexer" as well, just to help muddy the waters?

Ray


Ray, to mud the waters even more you could add the rotary table to your list. It is indeed a confusing theme. Essentially they all do some sort of dividing, but each are optimised for different tasks.

The "Hartford Super Spacer", as well as an "Indexing Head" or a "Spin Indexer" all belong to the category of Indexers. Indexers do not use an "analog" drive like worm gears to set angles or divisions. Indexers use a "digital" type of mechanical indexing. Most usually this is an exchangeable indexing plate with square teeth, but sometimes a hole plate or a common gear is used as the indexing plate. Sometimes the indexer is as simple as a number of equally spaced holes drilled at the circumference of a chuck or it's backplate.

Anyway, an indexer always has an integer number of divisions, it cannot be set to any arbitrary angle in between. Sometimes it is easily possible to convert a fixture back and forth from "digital" to "analog" dividing modes, by disengaging the indexing feature and instead engaging a worm drive (with or without indexing discs). Or you could use a CNC approach, with a step motor driving a worm drive, which would let you choose either way how to use it (either as a divider or to set any random arc or angle).

The advantage of a (digital mechanical) indexer is speed, reliability and ease of use, as it can very quickly be set. Imagine an indexer based on a gear with 24 teeth. Move it 12 clicks to divide by 2. Move it 8 clicks to divide by 3. Move it 6 clicks to divide by 4., and so forth. Very quick and easy to drill holes in a flange or the like, and it is hard to do a mistake too. But there is no way with a 24T indexer to divide by 5 or 7 or 9 or 10 or 11.... So you may need a number of different index plates.

A "Spin Indexer" is usually a simpler design than a "Dividing Head", made to accept collets, not tiltable, and fitted with a hole plate and vernier. There are motorized versions too, but unlike CNC controlled dividing heads or rotary tables, these motorized rotary indexers can only index to the steps given by their hole plate. Not to any arbitrary angle.

[Stustoys]

I still haven't got around to making one, but building a simple indexer sounds like a good excuse.


Me either lol One day. I still have way to much stuff to do as well.

Stuart

[Anorak Bob]

Me either lol One day. I still have way to much stuff to do as well.

Stuart


One day how about something like this....

Hercus' simple indexing attachment for their vertical milling attachment - http://www.woodworkforums.com/showthread.php?t=143842&p=1403096#post1403096

or if you like knurling :) -

308348308349308350

BT