ROTARY TABLES

[Gkohl]

I have been ordered to purchase 2 rotary tables. This place is great for advice since I am just a PA and not an engineer. The only thing I could find on a quick google run was the Haas line.

The prices are well within the alloted budget, but before I start doing my own dd I was hoping someone had some insight and could drop some names. Like I said I have the budget to spend quite a bit more than what it would cost me to get the 2 Haas tables. Any high end alternatives? Thanks

[Geof]

High end, low end, middle of the road? I think this could be less important than making sure you get rotary tables that are compatible with the application they are for, and the machines they will be used on.

Are these tables going to be used in full fourth axis mode or are they just going to be positioning, like an indexer?

If they are going to be used in full axis mode what kind of cutting load are they likely to encounter and what type of feedrate is wanted.

If they are going to be used just for indexing the position of something is it necessary to have a very fast index time?

What is the weight of the parts to be machined; the table has to carry any cantilevered load.

How will the parts be mounted, with a chuck, custom fixture, collets? Are these items included in the budget?

Or will it be long parts so a tail bearing will be needed.

I cannot come up with any other questions but I am sure someone will.

[cam1]

Hi: Take the time to evaluate the requirements.

Another source....

http://www.hhrobertsmachinery.com/Ac...Meca/meca.html

http://www.divimek.com/ingles/index.htm

regards

[Gkohl]

Originally Posted by Geof High end, low end, middle of the road? I think this could be less important than making sure you get rotary tables that are compatible with the application they are for, and the machines they will be used on. Are these tables going to be used in full fourth axis mode or are they just going to be positioning, like an indexer? If they are going to be used in full axis mode what kind of cutting load are they likely to encounter and what type of feedrate is wanted. If they are going to be used just for indexing the position of something is it necessary to have a very fast index time? What is the weight of the parts to be machined; the table has to carry any cantilevered load. How will the parts be mounted, with a chuck, custom fixture, collets? Are these items included in the budget? Or will it be long parts so a tail bearing will be needed. I cannot come up with any other questions but I am sure someone will.

Thanks for the help guys. I will know more on Monday, but for now the specs I have been given are;

Programmable "M-code" table (not indexer)
Table size: 200-220 mm
minimum horizontal load: 200 lbs
minimum vertical load: 100 lbs
AC servomotor (used as 4th axis)
Positioning accuracy: =/- 10 seconds
Dual disc Hydraulic brakes
collet mounted (not in budget)

[Geof]

Originally Posted by Gkohl Thanks for the help guys. I will know more on Monday, but for now the specs I have been given are; Programmable "M-code" table (not indexer)....

All the others that I deleted make sense. Actually the Haas HST210 would fit the bill.

The bit I kept up there is contradictory; or at least to my knowledge and experience it is contradictory, but I admit I am not infallible.

I have several Haas HRT 210 rotary tables which are Gcode programmable as a full fourth axis; the Aaxis, which is programmed in G code like and other axis.

I also have a couple of Haas HIT 210 Indexers which are programmed using MMcodes; the M code simply commands the indexer to rotate by one increment, which on the HIT210 is 45 degrees.

So you see why I say; "Programmable "M-code" table (not indexer)...", is contradictory.

[RICHARD ZASTROW]

Gkohl, Did you mean +/- 10 seconds? Is the table axis vertical or horizontal? What is the tables diameter requirement?

Ex. @+/- 10 seconds, on a 6" dia. piece would be +/- 0.000145" on the circumference. That may or may not be more accurate than you need. Remember, like speed, precision (accuracy) costs money. How precise (accurate) do you want to be?

There are rotary tables out there that can obtain extreme accuracy but they are extremely pricey. I just had one priced @ $28,000 for a servo driven spindle capable of 4 arc seconds accuracy and 1,000 rpm. I don't think that's what your looking for, that's just an extreme example. Sounds overly extremely redundant. lol

Tighten up a bit on the requirements and you should get a lot of info.

Dick Z

[Gkohl]

Originally Posted by RICHARD ZASTROW Gkohl, Did you mean +/- 10 seconds? Is the table axis vertical or horizontal? What is the tables diameter requirement? Ex. @+/- 10 seconds, on a 6" dia. piece would be +/- 0.000145" on the circumference. That may or may not be more accurate than you need. Remember, like speed, precision (accuracy) costs money. How precise (accurate) do you want to be? There are rotary tables out there that can obtain extreme accuracy but they are extremely pricey. I just had one priced @ $28,000 for a servo driven spindle capable of 4 arc seconds accuracy and 1,000 rpm. I don't think that's what your looking for, that's just an extreme example. Sounds overly extremely redundant. lol Tighten up a bit on the requirements and you should get a lot of info. Dick Z

Again, thanks for the input. In any case that was the spec I was given. More info I got before I get all the details Monday.

Nothing said about the rpm, but the spindle torque = 190 lbs ft.
Setting position may be either, Vertical or Horizontal
(Resolution degree??) 0.0005"
Gear Ratio: 90:1
Repeatability: +/- 2 seconds
The only thing I found about about diameter is the the thru-hole which is 2.5"

[Gkohl]

Originally Posted by Geof All the others that I deleted make sense. Actually the Haas HST210 would fit the bill. The bit I kept up there is contradictory; or at least to my knowledge and experience it is contradictory, but I admit I am not infallible. I have several Haas HRT 210 rotary tables which are Gcode programmable as a full fourth axis; the Aaxis, which is programmed in G code like and other axis. I also have a couple of Haas HIT 210 Indexers which are programmed using MMcodes; the M code simply commands the indexer to rotate by one increment, which on the HIT210 is 45 degrees. So you see why I say; "Programmable "M-code" table (not indexer)...", is contradictory.

Sorry about that, this is to be a "stand alone programmable "M-Code" style rotary table" which is supposed to be compatible with a cnc machine from the spare M-code output of said machine. I'm starting to get a headache

[RICHARD ZASTROW]

Gkohl, From the info given to you, it seems like somebody is using the specs from an advertising brochure. If that's true, find out what the vendor is selling.

One spec. you use is .0005" (resolution /degree) with repeatability +/- 2 seconds. Thats 2 different types of measurement. .0005" @ what dia.? Resolution more or less indicates what the readout will display, not the accuracy of the device. Repeatability tells you that the device will return to the same location within that tolerance. Unfortunately that could mean it will return precisely to the same wrong place.

What you will need to find are the system accuracy requirements in arc second (angular) and repeatability in arc seconds (angular) OR dimensional accuracy at a given diameter (.0005" at a 6.0000" diameter with a repeatability of +/- .0002" at a 6.0000" diameter).

Does the device locate at any or all positions (ex. 243 deg 3 min. 27 sec.)? Or known incremental positions (4 divisions, 90 deg.; 6 divisions, 60 deg. etc.), typical of indexers using M code induced movements.

It's really not all that complicated if the terms are understood. Hang in there, it'll soon be clear as mud. lol

Dick Z

[Gkohl]

Originally Posted by RICHARD ZASTROW Gkohl, From the info given to you, it seems like somebody is using the specs from an advertising brochure. If that's true, find out what the vendor is selling. One spec. you use is .0005" (resolution /degree) with repeatability +/- 2 seconds. Thats 2 different types of measurement. .0005" @ what dia.? Resolution more or less indicates what the readout will display, not the accuracy of the device. Repeatability tells you that the device will return to the same location within that tolerance. Unfortunately that could mean it will return precisely to the same wrong place. What you will need to find are the system accuracy requirements in arc second (angular) and repeatability in arc seconds (angular) OR dimensional accuracy at a given diameter (.0005" at a 6.0000" diameter with a repeatability of +/- .0002" at a 6.0000" diameter). Does the device locate at any or all positions (ex. 243 deg 3 min. 27 sec.)? Or known incremental positions (4 divisions, 90 deg.; 6 divisions, 60 deg. etc.), typical of indexers using M code induced movements. It's really not all that complicated if the terms are understood. Hang in there, it'll soon be clear as mud. lol Dick Z

Yep, that's exactly what happened.
I found out the foreman was approached by a dealer peddling the following line. He went to my boss, and then they asked me if I could find an established high end brand that has the same or better stats.

http://www.yuasa-intl.com/products_indv.aspx?pid=1

They want the equivalent to the 220 and 400 versions of this table

[RICHARD ZASTROW]

Gkohl, What machine(s) are these tables to be mounted on? Do any have a 4th axis control? What are the workpiece requirements as far as features and accuracy requirements?

You can unnecessarily spend a lot of money on over-kill rotary tables. Other names are Walter, Hoffman, Detlev Hoffman, Eimeldingen, Haas, Kitigawa, Nikin, Peisler, Rotomors, Lehmann and?

If your boss really wants to go extreme, contact International Machine & Tool for the satellite tracking stuff and their special rotary tables. Back in the 1980's they could divide into sub second increments. God, I'm getting old. lol

You have the requirement information, so you'll have to sift thru all the info and pick out the best unit for the least money to accomplish the job. How's that for cliche's.

Dick Z

[Gkohl]

Thanks for all your help.
I am told the tables will be mounted on a DMG 60 Monoblock Mill and and a Mori NT 4000 series machining center.
BTW, correct me if I'm wrong, but these two machines would require a tilted table to mount right?