Rotary tables - how often are they actually used?

[Swede]

I have a question for experienced hobbyists... how often do you actually use your R/T? Many years ago, when I was into acquiring tools and tooling, I picked up a truly sweet Yuasa 5" R/T. I cleaned and oiled it, and put it on the top shelf.

Decade(s) later, it has never been used.

I have used my dividing head extensively for gears and splines. I've used a 5C spacer for similar tasks. For bolt-circles, I use a simple computer program that outputs X, Y coordinates for any bolt circle imaginable. And for those occasions where I need to cut an arc of any size, I turn to the lathe.

If one's mill has no DRO, then I could see the R/T as being very important for bolt circles. And without a dividing head, you'd need one for gears, although I shudder at the work involved in progressively adding up degrees, minutes, and seconds, to cut an oddball gear tooth number.

Does anyone use their R/T for a specific operation that cannot be done on another piece of tooling?

 

[Sparticusrye]

I haven't used one often, but I did use one to help a friend to customize a flywheel for an air engine. He had a complex design that he wanted machined into the hub. So I had a large Rotary table with an indexing head on it so that I could achieve the compound angles that he required. That was a long time ago and there are much easier ways of achieving the same result now. But we didn't have a CNC machine in the shop at that time.

 

[JorgensenSteam]

You can use them to make the Stephenson's links for steam engines.

Pat J

 

[mklotz]

And without a dividing head, you'd need one for gears, although I shudder at the work involved in progressively adding up degrees, minutes, and seconds, to cut an oddball gear tooth number.

Do that and the accumulated round-off error will kill you. This is a trivial operation on the computer - see my ROTARY program.

Number of divisions = 13 

DIVISION   degdec   deg   min   sec
    0   0.0000    0    0    0
    1   27.6923   27   41   32
    2   55.3846   55   23    5
    3   83.0769   83    4   37
    4  110.7692   110   46    9
    5  138.4615   138   27   42
    6  166.1538   166    9   14
    7  193.8462   193   50   46
    8  221.5385   221   32   18
    9  249.2308   249   13   51
   10  276.9231   276   55   23
   11  304.6154   304   36   55
   12  332.3077   332   18   28
   13  360.0000    0    0    0

 

[kcmillin]

Any time I need to mill a radius on something I get out the rotary table.

Her are some pics of things I have done on the R/T that cant be done on an indexer without some way of turning the table while milling.

A hall sensor strap for the TI4 Distrubitor

Timing Cover

Here I am milling out the water jacket on the TI4 with a key cutter.

Flywheels

Here are some Radius's on MY Double Poppin Standard

I am sure there is more than one way to do this though, this is just what I do.

Kel

 

[kvom]

I used one the first time at school to mill the spokes on the flywheel of my first engine, and then I bought my own to machine the crankcase and a few other operations for the Liney Halo 5-cylinder engine. However, since I acquired my CNC mill my rotab has been sitting idle.

 

[mu38&Bg#]

KVOM has the answer. I've made plenty of parts that would, if not for CNC milling, require a rotary table. I do not own a rotary table other than the one I'm putting together to add a 4th axis to the CNC.

The guys that can do wonders on a manual machine use them a lot.

 

[Ken I]

I use mine a lot - more than I though I would - but then I don't have a dividing head or NC.

My 6" vertex does have an optional set of division plates and detent pin handwheel a'la dividing head.

Ken

 

[user 284]

Ken,
I've got the same R/T and dividing plates. For what the add on dividing plates cost their well worth it. Since I bought them I wouldn't buy another rotary table that didn't have these as an option. To be honest, A rotary table without the dividing accessory is only half a R/T to me.

Pete

 

[Maryak]

Because I know zip about CNC, my rotary table is an indispensable accessory for use with my mill and I use it for any milling operation requiring going round corners as well as gear cutting. Probably the only thing it can't do, that a dividing head can, is cut helical gears.

I would not part with mine 8)

Best Regards
Bob

 

[Troutsqueezer]

Does anyone use their R/T for a specific operation that cannot be done on another piece of tooling?

I use mine quite a bit. As you know, a lathe can make many of the same cuts that can be made on a mill but I wouldn't give up my mill for anything. Same for the RT.

 

[Blogwitch]

When I am in my shop, I use mine a lot, anywhere where radius milling and hole drilling around a PCD is required, even though the second job could easily be done using my DRO.

I do have the advantage of running mine from a Division Master which is a form of NC, and I will soon be modding my dividing head the same way.

In fact, I have both my vice and RT mounted onto the table at the same time, which I think makes it easier for me to use it, I don't have to fiddle about swapping it out with the vice, which I think is why a lot of people with RT's tend to do things by using other means first.


John

 

[Ken I]

I've fitted my RT and various vices with tennons - so that I can bolt them to the table and (generally) not bother to clock up.

Ken

 

[mzetati]

John,

I do not have room/travel enough on my mill table to keep both the RT and vice ever ready on the mill.
Found a way to clamp the RT without removing the vice.
;D

Marcello

 

[Swede]

There's definitely some good examples of work that use the R/T here. I have used one in the past, but I've always thought the setup was a pain, and in general, I've always figured out a way to work around it.

For arcs, 80% of the time, I'll use the lathe and then mill or cut out the arc section I need. I've also used boring heads for both inside and outside arc segments. And I can absolutely see their utility for flywheels and some other oddly shaped widgets.

Thanks, I was just curious as to how much other guys used theirs. And I'll agree, if given the choice, absolutely pick up an R/T that can double as a dividing head with the correct plates... I love my dividing head and use it often.

 

[petertha]

Im glad this post got initiated. A few years back I bought an 8" Taiwanese RT. I didnt buy the dividing plates at the time which probably was a mistake. I'm pretty sure its the same as this one offered by KBC & was thinking of picking up the accessories.

Re RT dividing plates, do you unscrew the graduated dial, bolt on the plates + detant pointer thingy & thats how it indexes? Looks like they size them by the nominal table diameter... I hope they fit.

Also, do you guys use the tailstock accessory much?

 

[petertha]

Another question. From some of the RT milling examples, it looks like having the ability to quickly locate a base plate fixture or the milling part itself on the RT center would be useful. I envisioned an MT3 plug that drops in the RT, below the surface of the table. It would have a precise hole sized for a removable dowel pin. Nothing like this seems to exist in tooling catalogs from what I can tell. Do you guys have a procedure for this type of operation, or am I making a big deal out of nothing? Ivethough of lopping off commercial MT arbours but I'm leary that they are hardened. I wish the RT tapered center hole was an ER taper or something, those collets would be perfect!

On trick I use for centering my 3-jaw chuck on the RT for is: drop an MT3 arbor into the RT. It has a straight section that extends a couple inches above the RT table. Lightly clamp the chuck jaws to the arbor, now its centered. Then secure the chuck to the RT in that position & remove the arbor. (I still have to make myself a better mounting plate vs my jerrry-rig, but this works good from the quick positioning perspective).

 

[user 284]

Petertha,
You can buy what are called by some companys, MT blank arbours. Their soft, and for at least the MT 2 come with a 1" plained turned section. You can modify them easily to what's needed. Not too expensive either. About $10 each for the MT 2.

Pete

 

[mhirst121]

An old or broken mt drill can be used for the mt. I cut off the end of an old drill and mounted in the lathe headstock centre and faced off and centre drilled, a point was then turned from another piece of bar. the point is put in my er chuck and the centre in the rt, thehead is then lowered to lace the point in the centre drill hole and voila the table is centred.
martinh

 

[petertha]

You can buy what are called by some companys, MT blank arbours. Their soft...

Thats good to know, I'll commence locating them. What would be a good way of holding a tapered MT arbor part like that in the lathe in order to do operations like facing, machining an end profile, center drilling etc?