Dividing head and rotary table

[benmychree]

About small diameter rotary tables; yes, they are nearly useless when one needs to toe clamp work down, which in my experience is nearly all the time, mine is a 16" Gorton, my dividing head is a 10" B&S universal with all the plates, including an angular indexing plate and all the change gears for differential indexing and spiral cutting.

 

[Alberto-sp]

Thanks for all your answers and advice.

Don´t get me wrong. You are the experts but I need to understand everything. And my english is not very well so maybe it could be misunderstandings. If I have understood, both can make the same divisións accurately, the problem is clampig big parts to them, right?

Forgive me if I say a stupid thing, but both came whit the same chuck no?? At least this is what I see in the pictures. And that chuck can be removed and you get a backplate where you can attach parts also.

And by the way my mill is very small, and I use it for small parts. And I have checks the specs of the rotary table and can make up to 360 divisions.
I´m not going to use it to make complicate things, just small things, but onw thing I want is precision

Finally, I´m from Spain, things like dividing heads or rotary tables are very hard to find second hand in Spain .

And again, thanks for the time you spend helping me.

 

[talvare]

In the photo you posted of the rotary table, there is no chuck on it. That is just the table with slots for clamping. You can attach a chuck to the table if you want, but that is an extra accessory.
Ted

 

[Alberto-sp]

In the photo you posted of the rotary table, there is no chuck on it. That is just the table with slots for clamping. You can attach a chuck to the table if you want, but that is an extra accessory.
Ted

Yes yes. But i have 2 chucks.

So since both of them clamp the parts woth chucks I see no difference

 

[talvare]

One of the major differences is that the dividing head tilts whereas the rotary table is either horizontally or vertically mounted. Like others here have said, they both have their strong and weak points. Personally, I only have a rotary table, but I do have dividing plates for it and can do most of what the average dividing head will do, other than tilt. Of course, the rotary table can be set up at an angle if need be, but it's a lot more work. The rotary table may have the advantage of being able to set up odd shaped parts more easily. If you can only have one, you really need to figure out what type of work you will be doing most of the time to make a good decision.

Ted

 

[Manual Mac]

Just to further muddy the waters, I have a 5x7 tilting table, that I have mounted my 6” rotary table to.
I have the indexing plates and the tailstock that came with the 6” RT.
I guess i don’t need a dividing head? Not that I would use it anyway?
And I’m no longer working as a machinist/welder on huge construction, mining & logging equipment, I build small steam engines for fun & the odd part for mine or my neighbors small tractors. A 6” RT etc. etc. is plenty big.

 

[Alberto-sp]

Thanks for your answers.

Yes, for me it is the same, my next big project is to biuld a steam engine. And as all I do, is just for fun.

Last weekend I use a small oxyacetilene to repair my sisters in law barbacue. I was the hero of the weekend, but I think is the most usefull thing I have done with my tools in the las 2 years, since I start with the metal/machining thing.

So if I can cut gears and that kind of things with the rotary table, I guess I´ll go for it, since it costs 220$ while the dividing head costs 500$. Propably I´ll need to make some apparatur to work with 45 degrees gears, but I think I will be able to manage it.

 

[pontiac428]

Dividing heads are nice for gears, since they divide. It's easier to divide using a plate than to count minutes and seconds on a vernier. Rather than divide 360 by a prime number for example and try to math out the unending decimal into sixtieths and getting a mess, you can grab the right prime number plate and make even steps without even thinking about decimals. The only numbers that matter are the drive ratio and the number of holes. Of course, it depends on what you're doing. I must be the oddball, I use my lowly rotary table (horizontal only) more than the dividing head, but they are not interchangeable attachments. They are good at one thing usually, and can do other things sometimes.

 

[Alberto-sp]

Dividing heads are nice for gears, since they divide. It's easier to divide using a plate than to count minutes and seconds on a vernier. Rather than divide 360 by a prime number for example and try to math out the unending decimal into sixtieths and getting a mess, you can grab the right prime number plate and make even steps without even thinking about decimals. The only numbers that matter are the drive ratio and the number of holes. Of course, it depends on what you're doing. I must be the oddball, I use my lowly rotary table (horizontal only) more than the dividing head, but they are not interchangeable attachments. They are good at one thing usually, and can do other things sometimes.

Thanks for your answer. Yes but the rotary table I want it has the dividing plates. I mean, no calculations are needed. It came with tables and the table tell you the plate and the hole you have to use. This is why I don't see difference

 

[Bi11Hudson]

At the bottom line, an indexer is a rotary table with fixed (fraction) plates. Cutting gears on a rotary table is basicly an exercise in futility. Cutting bevel gears, or anything other than straight 90 degree spur gears takes much more work. A good understanding of gears and how they work would be a starting point there.

A rotary table usually has 72 rotations to a full circle. An indexer usually has 40 rotations to a full circle. 72 divisions will give better resolution when dividing a circle into degrees, minutes, and seconds. However, dividing a circle with an indexer can be done, albeit at lower resolution. All that is needed is a "fraction plate" with a circle of even numbered holes. Just decide how many sides are needed and mill away.

In my own case, I have both, plus a spin indexer and some specifically sided collet blocks. But mostly because I do model building where physical size of the fixture matters. For most work, I can use most any fixture to get 6, or 12, or even 30 sides. But for cutting gears, an indexer is a must. I cut worm wheels with 40 or 50 teeth and a diameter of less than an inch, 25mm. There is no room for an "almost" fit.

For general uses, a rotary table with an attachment of a fraction plate and associated parts would be the preference in my shop. The fraction plate can be broken down, removing the fraction plate and reinstalling the handwheel. The one thing it cannot do is tilt. In most cases, with spur gears, tilting is really not an issue. Only when one gets into bevel gears and the like does tilting become necessary. And that's where my sine vise comes into play. But my fixtures are small, doing full size work requires full size fixtures. That is a call only you can make. As you gain experience and more complicated work rears its' ugly head, purchasing another fixture comes into its' own. But it does spread the cost out. . .

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