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View Full Version : Dividing Head: Universal versus Semi-Universal



EddyCurr
02-17-2012, 09:56 AM
For less demanding tasks, is a full Universal Dividing Head (such as those
built under the Vertex brand) equally convenient to use as the Semi-Universal
Dividing Head? Or does the added complexity of the change gears and their
mechanisms contribute to greater set-up & operation?

If you only needed to knock some corners onto a piece of round to turn it
into a hex, would it matter whether you had a Universal or a Semi-Universal
at your disposal, say in a BS-1 size?

.

JCHannum
02-17-2012, 10:06 AM
If your only requirements are for simple indexing in the combinations provided by the standard set of index plates, there is no need for the universal dividing head.

In the event of needing some other combinations, John Stevenson offers index plates with other hole combinations to fill the voids.

In other words, save your money and purchase the plain vanilla variety.

Pherdie
02-17-2012, 10:19 AM
When my universal is set for for the semi-universal mode, it operates exactly the same as my smaller semi-universal head (I have both and have yet to use the full universal).

As for putting hex flats on round bar stock, for small lengths and diameters, I'd probably use a 5C hex collet holder in a vise, simple and fast.

Back to the universal head, I bought mine new and for me it was a waste of money. Given the choice again, I'd go for an electronically controlled indexing system, which I view as superior for most complex division tasks (lots of division rates, fewer errors). The only advantage I see in a universal is the ability to couple to something like a mill table for helical cuts, something I don't do.

EddyCurr
02-17-2012, 07:23 PM
Thank you JCHannum and Pherdie.

I presently own a hor/ver 8" rotary table that came equipped w/ two index
plates. I also have a 5C Spin Index.

However, an essentially new, BS-1 10-3/8" swing Universal Dividing Head
of the Vertex swiveling head design w/ all pieces, including tail stock,
is available to me for a modest sum (decidedly less $$ than an equivalent
Semi-Universal.) The collection weighs something in the order of 68 kg
(150 lbs).

The swivel feature and tail stock alone put the UDH ahead of my current
rotary table.

Pherdie has answered the OP to say a UDH in S-UDH mode operates akin to
the S-UDH. So: in for a penny, in for a pound. If I am prepared to take
on a Semi-Universal, then I will not be disadvantaged by taking on a full
Universal at a favourable price.

The suggestion about an electronically controlled indexer caught my
attention. I knew that there are 4th-axis units for CNC applications but didn't
consider that there might be stand-alone indexers with an easy-to-use
pendant controller like the little Sherline CNC 4" Rotary Indexer.

From what I can see so far, though, a unit with features and capacity
similar to a Vertex BS-1 would be several thousand dollars - beyond my
reach.

.

krutch
02-20-2012, 02:47 PM
Eddy,
I have a Haas 5C Indexer/servo controler and tailstock which I also fitted with a Buck Set-True 4" three jaw chuck. I also made a 'face plate' for the unit, which has really been useful.
It has been worth the money when I need it. I have used it on my manual mills and surface grinder but wish it could be 'timed' with table movement. The only way I have been able to do so is by timing, with a stopwatch, but repeating is still iffy. All movement must occur exactly the same to produce the work. I believe the universal D Head unit would have been a better deal for that type (helical) of work, at least on the mills.
If I had a lot of helix work and the money, I would get the universal for the timing ability.
Just my opinion.


After thought, the Haas unit did cost $5000.00+

EddyCurr
02-21-2012, 07:46 PM
I have a Haas 5C Indexer/servo controler and tailstock ... I have used
it on my manual mills and surface grinder, but wish it could be 'timed'
with table movement.I imagine with an encoder mounted to the table that a smart, motivated
person could create an interface that drove the Indexer in relation to table
travel. (Intuition tells me the results may not be to the standard of a 4-axis
machine, but it might be better than no integration between the Indexer
and table.)

Regrettably, such talents are not in my repertoire. In any event, the
buy-in for the Haas Indexer is a deal-breaker for me at this time.

.

keachier
02-23-2012, 06:21 PM
You can do a search on google like DIY cnc indexer,you will find interesting info on control and step motor that can be use on manual tool.