Need help figuring out how to use a rotary table operation.

[Dabbler]

@D.sebens your work looks small enough to do on the mill without a rotary table. put them all together, insert a 1/2" pin through the centre, and put it in the milling chuck with the centre pin on top of the jaws. It helps to tack them together with a welder first, to make the milling easier.

Make successuve cuts across the work, rotating the work in the vise and reclamping. I can cut this 1.5" radius in soft steel 1" deep in about 10 minutes this way. No setup time.

 

[projectnut]

These are 1/4”. I don’t really want to do 1” thick of belt sanding. Thanks for the idea though!

That's how I cut the 1/4" plates and made the radiuses for the plates that mount the casters on my radial arm saw. It took about 10 minutes to make the radiuses (or is it radii) on the Rockwell/Delta belt sander.

 

[homebrewed]

Rotary tables aren't perfect, they will have backlash. So one procedural thing to keep in mind is that you don't want to rotate your work so you are climb milling. Conventional milling only, otherwise you will get chatter (and if the backlash is very large, perhaps a broken end mill or damaged workpiece).

For example, if the RT's center of rotation is to the left of your cutter, you want to rotate the table clockwise. If the RT's center of rotation is to the right of your cutter, you want to rotate the table counterclockwise. This swap of feed directions really isn't any different than what you'd do when milling stuff held in a vise. You feed the work against the cutter's direction of rotation, not with it. That way it tries to push the work away, not pull it in.

 

[Net30]

I messed around with a RT a bit and the hole location in center of table will always produce a proper round no matter where the cutter is. But here's the thing. The distance from hole to top of radius needs to be identical to sides for a perfect round else you get more of an arch. ( o

 

[D.sebens]

Well I did it! Definitely spent as long making these as I did with the whole carrier but I had never used my rotab before and wanted to use it. I think they turned out good. Either the hole or my centering of the pieces up the rotab was slightly off. I had to mill one size slightly due to the radius cutting in to that side more. As these are dumb pieces of metal it doesn’t matter that they are slightly smaller.
Thanks for advice everybody!

 

[D.sebens]

Also, here’s a picture of my rotary table. When I got it I got it for a good price and bigger is better right? This thing is so freaking heavy! I wish it was smaller or I also had a smaller one. It’s a 12”. I need to buy the dividing plates for it sometime but they are an extra $200 I believe.

 

[Net30]

Bigger definitely not better or you just never use it. I have the same exact one and since I took it off haven't put back on. I think 8 or 10 is the sweet spot.

 

[GeneT45]

Mine (10" Bison) is heavy as hell, but you have to figure out a convenient way to put it on the mill - then bigger is (mostly) better. I have a Horror-Fraught hydraulic table that I store my rotab on (in addition to some other heavy bits). I can roll it up to the mill, raise the hydraulic table, lower the mill table, and slide it right on. A crane would probably be nicer, but that's not in the cards at the moment.

GsT

 

[D.sebens]

Mine (10" Bison) is heavy as hell, but you have to figure out a convenient way to put it on the mill - then bigger is (mostly) better. I have a Horror-Fraught hydraulic table that I store my rotab on (in addition to some other heavy bits). I can roll it up to the mill, raise the hydraulic table, lower the mill table, and slide it right on. A crane would probably be nicer, but that's not in the cards at the moment.

GsT

I was lazy and just heaved it up there this time. Was really heavy! When I first got it I used a lifting strap through the center hole and my engine picker to move it. That should be the way I do it from now on.

 

[GeneT45]

I was lazy and just heaved it up there this time. Was really heavy! When I first got it I used a lifting strap through the center hole and my engine picker to move it. That should be the way I do it from now on.

When I first got my rotab (maybe 20 years ago) I'd stick a piece of pipe through the lifting eye and just heft it on to the table. Age, wisdom, laziness - some combination of the three conspired to make me find an easier way. If there are any young guys (or gals) here, *today* is the day to start thinking about how you're going to handle this stuff as you get older...

GsT