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International 16" rotary table on a Series I Bridgeport CNC?

lrgoodger

Plastic
Joined
Oct 8, 2015
I just picked up this International 16" rotary table today. Drove all day to get it. Didn't know if it would be too big or not until I set it on the mill. What do you think?

It is an awesome piece of machinery. It has absolutely rock solid positioning of the motor driven table. It will actually swing 150 degrees, so it will go within 30 degrees of laying over on it's face. The positioning scale is insanely accurate. It can be fine positioned by hand to exactly where you want it. The rotary movement is smooth and solid as a rock, but there is a bit of backlash in the hand wheel. I was debating using a couple of my spare mill stepper motors to turn this thing into a fourth axis. I don't think it would be hard to do.

The problem is, it takes up so much room on the mill table. I set it all the way on just to check it out, but I could probably move it back about five inches and let the rotary base hang off the mill table by that much and be OK. The thing is so heavy I could probably cut parts without even bolting it down, but I gotta get it squared up. I'll have to make some T bolts and cut some mounting slots to fit the Bridgeport table.

With the Bridgeport knee all the way down, I only have about five inches above the rotary table center to work. That means I could do up to a 10" diameter workpiece by keeping all the work on the top half. That's about as big as the Bridgeport can handle on the Y axis anyway. I never do anything that big, so I should be good.

I think the center hole is a Morse taper, but I don't have anything that big to check it with. I'll have to make an adapter to mount my lathe chuck on it.

Does anyone know where I can find documentation for this thing? Anybody want to trade for a smaller one of equal quality, like maybe a 10"? I'm a little worried about the effect all that weight hanging way out on the left end will have on the mill table ways.

There is another one just like it (except it doesn't have a motor driven tilt) for sale on Ebay here;
International Precision Rotary Table (Inv.873) | eBay


The first photo shows the table at 45 degrees.
20171202_201218.jpg

The next one shows the motor side.
20171202_201248.jpg

This is the tilt scale.
20171202_201408.jpg

This shows the table at 90 degrees.
20171202_204209.jpg

Another 90 degree shot.
20171202_204847.jpg
 
I'm pretty sure the table is rated to hold 750lbs max. I'm guessing that doesn't mean with the table hanging way out. I have a 12" tilting rotary that weighs 220lbs and it does just fine on mine. I would guess your rotary weighs in the 500lb range judging by that vise sitting next to it.

You may be able to use it on there, but I bet it will be a pain to clamp down, and kills the usable range of your machine. I would either look for a smaller rotary, or get a bigger mill.
 
That table is way too big for your mill and I would not even think about cutting extra T bolt slots in it. You might look into a riser To get more Z clearance, I would look for a smaller table.
 
I wouldn't recommend cranking the table in X+ very far!


Why is this in the "CNC" board?



I had an NC20" Troyke on a Ser II Bridgeport, which is prolly about the weight of this one, but on a machine that is 2wiced as heavy.



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Think Snow Eh!
Ox
 
I hate to say it but I think this was a not the best purchase. That table will bend like a wet noodle with the rotary hanging off like that. On top of that, it makes your mill nearly useless for any other operations not involving the rotary.

The rotary is a nice one but is just not even close to fitting your little Bridgeport.
 
I wouldn't recommend cranking the table in X+ very far!


Why is this in the "CNC" board?



I had an NC20" Troyke on a Ser II Bridgeport, which is prolly about the weight of this one, but on a machine that is 2wiced as heavy.



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Think Snow Eh!
Ox

It's on the CNC board because it's mounted on a CNC Bridgeport. My next step is to get my spare axis driver working, then I'll fabricate a coupling to drive the rotary table and turn it into a 4th axis for the Bridgeport. Yeah, it's big, but I don't do parts big enough so that it will be in the way. If I really need to, I can always take the rotary table off the mill.

I'm thinking to put a couple of locator pins on the bottom of the rotary table (like what's on the bottom of the Kurt vise) so it will quickly and easily align on the mill table.

Heck, when I get all that done I will be able to do spiral fluting on rifle bolts!
 
This may seem a bit red neck, but I wonder of you could hook onto that table with a cable and the other end to the ceiling joist, and put a heavy pull spring in there to help (zero G) the table weight? You might need a cpl of cables/springs to get near the weight of the unit, but should work better in application than in text.


Only catch being that you would need to re-adjust anytime that you move the knee up or down. But you could move the knee and then adjust the cables (come along?) before moving the table.

This sounds ridiculous, but will save a LOT of wear on your table and saddle!

Splurging for a nice used ARO or Gorbel unit on E-bay would work way easier tho.


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Think Snow Eh!
Ox
 
Like the cable idea from Ox but probably just as easy (hard?) to arrange a constant force gas spring under the left hand end of the table. UK suppliers list them up to 850 lb so I'm sure you can find similar in your area. Fit via pivot carrier blocks fixed under the end of the table and on the base. Plenty of room under the table for the pivot block given the amount by which the rotary axis reduces right wards travel. Obviously not going to be constant compensation as the angle at which the gas spring works changes as the table moves leftwards but should be possible to take most of the load off.

Need to arrange QD system for the gas spring for when you aren't using the rotary axis. Way I see it is set the table so spring is near enough vertical, hook a keeper on so it doesn't go sprong (recompressing a 300 - 400 lb gas spring is gonna be serious) crane off the rotary and pull the pivot pins. I'd use vertically oval holes for the pivots so you can lift the table a touch to unload the pins before pulling. Also make darn sure the keeper stays put whatever you do to it.

Were I intending to use it I'd arrange similar support for when using it as a horizontal rotary table. Perhaps two more smaller gas springs, one each side set to allow limited X travel.

Agreed its way, way too big so some degree of rectal pain is inevitable if you are gonna get any reliable use out of it. In general pivoting rotaries re-define ****-great-big-awkward-*****.

Clive
 
This may seem a bit red neck, but I wonder of you could hook onto that table with a cable and the other end to the ceiling joist, and put a heavy pull spring in there to help (zero G) the table weight? You might need a cpl of cables/springs to get near the weight of the unit, but should work better in application than in text.


Only catch being that you would need to re-adjust anytime that you move the knee up or down. But you could move the knee and then adjust the cables (come along?) before moving the table.

This sounds ridiculous, but will save a LOT of wear on your table and saddle!

Splurging for a nice used ARO or Gorbel unit on E-bay would work way easier tho.


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Think Snow Eh!
Ox

Sorry to dredge this out of the past but...
There is no need for springs and such or gas cylinders even. Just put a pulley on the rafter instead of the upper end of the cable.
Run the cable through the pulley and down to a weight that is about the same as the rotab and all the adjustment youwant is always balanced. Best to run the cable over to a wall so the hanging weight is not above you and the mill, easy with a second pulley. The weight can sit on a shelf or even the ground when the mill table is all the way up so it is easy to disconnect when rotab comes off. I have this set up on on of my flypresses and it is GREAT.
 
I thought about this afterwards too.
Much more better, cheaper, quicker, and prolly some other descriptive werds 'er yet too.


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Think Snow Eh!
Ox
 
Hi , I just bought exactly same without motors and i am wondering how to make it go beyond 90 deg. Mine has scale going to 150 deg but it only tilts to 90 deg.
Any help will be much appreciated.
Also there is a lever looking rod/handle on tilt around tilt scale what is the use of that?
 








 
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