Swivel base as a general purpose, set any angle, device is an oversold concept as setting up a precise angle isn’t a trivial task. But if you haven’t got a rotary table a swivel base can get the job done a darn sight cheaper. Unless it’s a very shallow angle or simple 90° rotation I generally figure it’s easier to dig out one of my rotary tables. rotating the job.
Setting a a vice to a precise angle is easy enough with a sine bar or if not available the use of trigonometry, a DTI and the machine dials/DRO.
Tony
Sorry Tony I really can’t agree that setting a vice to “any” precise angle is easy with a sine bar or trigonometry and dials/DRO.
Especially where less experienced folk are concerned.
You need to be happy and confident with trig to convert angle to offset distance at a specified radius and understand the various set up traps if doing it the DRO/dials way. The effects of offset between vice jaw and rotational axis can be particularly perplexing for the inexperienced when changing the angle doesn’t give you the expected shift at one end of the vice jaw.
If you use a sine bar you need a carrier so the bar can lie horizontal, a set of gauge blocks or a sufficiently good screw jack substitute along with an understanding of why setting large angles isn’t good practice and know the tricks needed to avoid that necessity.
Possibly using a set of angle blocks to gauge angle would be nearest to an easy way. But the achievable angles are limited. Understanding the permutations and combinations if your set doesn’t have full instructions is hard work for neophyte. My set pretty much doesn’t get used because I generally have other options with less thinking needed.
As a card carrying old fart I know this stuff, even if never used. For a neophyte it can be frankly terrifying.
Turning the handle and reading the dials on a rotary table is far easier. But it’s still important to keep track of the effects of jaw and axis offset relative to the rotational axis. Important when dealing with two angles on one job without changing set up.
Sine bar or DRO / dials methods pretty much force a teardown and reset-up if a second angle is needed.
Of course for less precise work where reading the scale is good enough the vice swivel does just fine. Just don’t expect to replicate the angle to better than ± 1/4° or so.
Clive