Rotary table size for mill/drill

[FanMan]

I'm figuring I need a rotary table for various projects, but I can't spend a lot... this is for a Jet mill/drill. I see lots of cheap (<$100) 3" and 4" imports with horizontal/vertical mounting on ebay, or I can get an unknown brand used 6" one with only horizontal mounting for a comparable price. How useful/accurate are the tiny imported ones?

 

[Rbeckett]

Unfortunately they too suffer from "cheapitis". Indian made tools fall into two definate classes of good and not so good. The problem being that there is little or no consistency from model, size or brand. Bison and some of the other vendors like Grizzly do have a decent quality offering, but they are not sub 100 dollar items. You definately want the largest table that your mill will accomodate because you also need room to be able to clamp and secure the piece you are working on. I am not familiar with the dimensions of your lathe/mill but you want to try to keep the quill retracted as close to the head as possible to impprove stiffness and reduce chatter, but you do not want to crowd the head too much either. I would also opt for the horz/verticle mounting options to increase the tools use and versatility. The sub 100 dollar units seem to be rough, have a good bit of looseness and have been found to even still have casting dirt still in the cavities. This is especially prevalent in the cheapest offerings from places like CDCO and Shars. So I would suggest a bit more shopping with an eye toward making one slightly more expensive purchase rather than having to revuild/repair a smaller unit that you will ultimately replace or relegate to the "spare parts" dungeon. I have not bught one myself yet, but I have been following a number of threads outlining the woes of others who failed too remember the old adage of :Ya gets what ya pays for, and nothing more" Hope this helps and is not intended to discourage just inform and to help you become aware of the pitfalls with rotary tables in general.

Bob

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Unfortunately they too suffer from "cheapitis". Indian made tools fall into two definate classes of good and not so good. The problem being that there is little or no consistency from model, size or brand. Bison and some of the other vendors like Grizzly do have a decent quality offering, but they are not sub 100 dollar items. You definately want the largest table that your mill will accomodate because you also need room to be able to clamp and secure the piece you are working on. I am not familiar with the dimensions of your lathe/mill but you want to try to keep the quill retracted as close to the head as possible to impprove stiffness and reduce chatter, but you do not want to crowd the head too much either. I would also opt for the horz/verticle mounting options to increase the tools use and versatility. The sub 100 dollar units seem to be rough, have a good bit of looseness and have been found to even still have casting dirt still in the cavities. This is especially prevalent in the cheapest offerings from places like CDCO and Shars. So I would suggest a bit more shopping with an eye toward making one slightly more expensive purchase rather than having to revuild/repair a smaller unit that you will ultimately replace or relegate to the "spare parts" dungeon. I have not bught one myself yet, but I have been following a number of threads outlining the woes of others who failed too remember the old adage of "Ya gets what ya pays for, and nothing more" Hope this helps and is not intended to discourage just inform and to help you become aware of the pitfalls with rotary tables in general.

Bob

 

[8ntsane]

Bob has pointed out some very valid points about rotary tables. I too would suggest a horizontal/vertical model as well.

Myself, I learned the hard way with rotary tables. I have had 3 of them, and learned the down falls of the cheap stuff. Though Chinese and the like would need to be chosen carefully, I would avoid products from india. Here in Canada, the local Busy-Bee outlets sell many products from that country, including rotary tables. They would make a pretty good boat anchor, but a very loose item for a machine tool.

Best to research the brands, get a feel for what to look at, and what to run away from. The rotary table I currently have is a H/V that is made in Tiawon, by a company called Homege. Its a large 12 inch, but it is a decent piece, but it did cost me good money.

 

[FanMan]

Thanks... the small ones do seem too small to be really useful... but even at 6" it's getting a big large to use in a vertical orientation, my Jet 15 is not a large mill. The 6" I'm looking at is horizontal only, but I have a couple of large cast precision angles in my office that are currently being used only as expensive bookends so I could easily adapt it for vertical use.

Unknown brand, quality, age, or condition, but it doesn't look like one of those cheap newer imports:

 

[Rbeckett]

Another possible use would be to mount the rotary at various angles on an adjustale vice or sine table That would give you 180 degrees of use from verticle to hosizontal and any degree in between. You could theoretically do 3D milling if you had a reasonabley simple piece to make. I would not attempt an ultra precise complex piece, but it would worl very nicely for roughing out a basic outline of the part prior to finishing. Just a thought.... But the angle vise does use a bit of your room too.

Bob

 

[8ntsane]

That appears to be a very old table, but if its cheap enough it would still be usefull. As you say, your unused book ends would have a new purpose as well. With any luck, that was built back at a time when quality did matter. Its hard to tell from the pic, but the grads on the dial, do they atleast have full 360 grads. Depening on your projects, is there any chance you may require a table with dividing plates? If not, no worries. I quess at this point the ratio is unknown?

As long as the jobs are simple, it possibly could be good for your first R/T. Hope it fits your requirements.

 

[David Kirtley]

I have one ultra cheap 3" HF table from India and one fairly cheap but nice 4" from LMS (I think Chinese) They can be a mixed bag but honestly, until you get to dividing plates and such, they are a relatively low tech item and even a cheap one is good for many purposes. A bearing, a worm gear, and a worm with handle. Not much to go wrong. Above a certain level, you get better scales and verniers but for putting a radius or cutting a head for a bolt, it can quickly become overkill. Also, before you drop serious money on a large one, I would look at some of the smaller ones with stand alone CNC capability such as the little Sherline 4". If you don't have to get in and read scales and turn wheels, you have the freedom to get more creative with clamping.

The only thing I found wrong with my India made 3" was the hole through the axis wasn't threaded completely and the locking knob is not knurled very well. When I got it, I stripped it down and greased and adjusted. No real complaints. Clear degree markings, markings to 15 seconds on the crank.

 

[FanMan]

I don't see myself needing dividing plates... mainly what I want is the ability to machine circular shapes, trepanning o-ring grooves with an end mill, etc. Some things I could do with a boring head (which I also don't have, yet), but not all.

It does appear to have full 360° markings. I had the same thought; it looks to be old enough that I'm hoping it will be good quality.