Author Topic: How do I select a rotary table?  (Read 4837 times)

Offline zeeprogrammer

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How do I select a rotary table?
« on: July 10, 2018, 10:32:14 PM »
I need to get a rotary table but I'm not very familiar with them nor do I have the experience to think about what features are, or would be, important to me.

I don't think I need anything fancy such as tilt capability but I do want to mount vertical and horizontal. Obviously a table lock is needed but not necessarily a release/lock for the 'hand wheel'. Certainly, graduations of the hand wheel is required.

I also think I want as low a profile as possible since Z range is always limited.

I still have a rotary table that I used for my mini-mill which may be sufficient...depending.

Some questions...

1) I remember using my small RT with the chuck transferred from the mini-lathe. The chuck I have now for the lathe is a 5" and it's not clear to me (or I don't remember) how to mount it. Seems a special backing plate was required. My question is...how often is the ability to transfer a chuck necessary? And I wonder whether the 5" can be transferred (or what it would take).

I see some kits come with a chuck but I expect that's for holding.

2) I also see some kits that come with dividing plates. But I've never done that, don't know how to do it, don't know when to do it, don't know anything about it. How important is it?

3) Some kits come with a tailstock. I've never used one with an RT. Not sure why it's needed. Support can be provided by a machinist jack etc. No?

4) Some kits have either 4 or 6 T slots. (And I believe you usually have to provide/make your own nuts/bolts.) Why wouldn't 4 be sufficient for me.

5) The size of RT is confusing to me. It sounds like it's the size of the 'box'. 5" 6" 8"...how to choose? If it's according to what chuck can be mounted...then given a 3" or 5"...what size RT is would suffice?

Prices can vary from a couple of hundred to thousands. My price range is a couple of hundred to a few hundred. And I have no problem buying a kit that may come with accessories that I may never use (since 'never' always bites my butt).

I welcome any thoughts on what I should look for, features etc., as well as suggestions for a specific RT (i.e. what do you use?).

Attached is a picture of my mill. (I need to move those aprons...at the moment they are actually 'swarf catchers'.)

Keep in mind I'm just a hobbyist and I probably live in that gray area where getting within a thou or two is happy (rather, ecstatic) land.

Thanks all.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Brian Rupnow

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Re: How do I select a rotary table?
« Reply #1 on: July 10, 2018, 11:24:38 PM »
Your mill seems to be very similar to mine. I have about $500 invested in rotary table, tailstock which goes with it, and divider plates. My rotary table is a 6" diameter x approximately 3 1/4" tall from mounting face to top of table when the main axis is vertical. You won't need tilt capability, but definitely want to be able to fix it to your mill table with the main axis either vertical or horizontal. I have a 4" diameter 3 jaw chuck attached to my rotary table with an adapter plate, and I never take the chuck off. I have built 27 engines now and never had to remove that chuck. You will definitely want a tailstock, because when you have the rotary table set up with its main axis horizontal and you want to mill a feature into something 5 or 6" long, you need to support the end which is farthest from the chuck with a center in the tailstock. (On my tailstock the center is part of the tailstock and there is an adjustment on the tailstock to raise, lower, or advance the pointed end). Divider plates are very important to have, because if you ever in future want to cut gears you will need a method to advance the rotary table not only in full degrees, but also in decimals of a degree. (That is what divider plates are for). Four mounting slots are enough, six slots would be okay too. I think I paid about 100 for the chuck by itself. You definitely want to be able to lock the rotary table at any point on its rotation. The top of my milling table measures 8" x 33" and the headroom is 18" from top of mill table to end of quill when there is no tooling in the quill. Hope this helps.---Brian
« Last Edit: July 10, 2018, 11:50:06 PM by Brian Rupnow »

Offline mklotz

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Re: How do I select a rotary table?
« Reply #2 on: July 10, 2018, 11:42:28 PM »
2)  Assuming you have some ability with math and are patient, you can do the dividing by computing the angular interval and dialing that in on the RT.  One of the programs on my page does all the work for you.  Given the built-in error reduction of the RT, you can make your own plates when needed.

3)  A TS can be handy but it's easy to fabricate your own.

I can't remember ever mounting a chuck to my RT.  Dividing jobs on parts with circular symmetry are handled via my homemade collet dividing chuck...

http://www.modelenginemaker.com/index.php/topic,386.msg2613.html#msg2613

Actual circular milling jobs are handled by clamping the part to the sacrificial plate I mounted on the RT the day I bought it.  Said plate is about 1.5 times the diameter of the RT table and provides outboard space for clamps.  It should be the first addition to any table, especially a smaller one.
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Regards, Marv


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Online crueby

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Re: How do I select a rotary table?
« Reply #3 on: July 10, 2018, 11:55:55 PM »
If the rotary table is the type with a worm gear driven dial, there is no need for divider plates, just advance the dial the number of degrees to the next hole to drill or tooth to cut. Thats the style my Sherline one is.  Handy for milling arcs too, turn the handle on the dial to rotate the part against the cutter. I use it with both a chuck centered on the rotab (has a threaded adapter to mount it), other times with a tooling plate full of threaded holes for holddowns.

Offline Mcgyver

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Re: How do I select a rotary table?
« Reply #4 on: July 11, 2018, 01:02:48 AM »
do you have a dividing head?  I mostly use a dividing head for dividing and an RT for cutting arcs, there's reason to prefer that, but if you didn't have a dividing head, I'd want dividing features on the RT; way to mount a chuck, can take index plates, take a centre and has a tailstock and can used horizontally or vertically.

If the plan is to use for rotation vs division, get as large a one as you can.  There is never enough real estate.  i've a 12" News (became or is the same Yuasa I believe), biggest I can lift, (I started using a crane, can still lift it but why pop something?) and I like that size.  Smaller of course works perfectly well, its just more convenient having the bigger surface.

Its a topic that will have endless answers as different things matter to different people so you may end up more confused that before asking :).

Offline zeeprogrammer

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Re: How do I select a rotary table?
« Reply #5 on: July 11, 2018, 01:06:45 AM »
Its a topic that will endless answers as different things matter to different people so you may end up more confused that before asking :).

And was entirely expected.  ;D Still, there's a lot of good information in the replies and I certainly appreciate all the replies I've gotten.

One area I'm really confused on...is the dividing plates. I've never understood the reason for that when you can rotate to whatever degree you want.
It just seems like I'm missing something.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Mcgyver

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Re: How do I select a rotary table?
« Reply #6 on: July 11, 2018, 01:12:43 AM »
One area I'm really confused on...is the dividing plates. I've never understood the reason for that when you can rotate to whatever degree you want.


I agree, mine doesn't have plates....but I divide with a dividing head which does.  Plates are needed for gear cutting among other things when you need accurate (and convenient) division into numbers that don't readily go into 360 degrees, i.e. a 28 tooth gear.

Offline b.lindsey

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Re: How do I select a rotary table?
« Reply #7 on: July 11, 2018, 01:29:58 AM »
Zee, I frequently use the church on my 4" RT but it had a screw in adapter which makes this handy. Great for laying out bolt circles, etc. Yes there are other ways to do it, but I find this the easiest for me.

Bill

Offline Gas_mantle

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Re: How do I select a rotary table?
« Reply #8 on: July 11, 2018, 01:31:19 AM »
Carl,

It looks like your mill is similar in size to mine, I bought this 6" dia table that seems well suited the size of my mill and I'm happy with its overall performance

http://www.chronos.ltd.uk/acatalog/info_110242.html

It can be bought as a set with a tailstock and dividing plates but for the work I do I see them more of a luxury than a necessity so I just bought the table and some clamping hardware. At some point I'll probably buy a chuck but so far I've managed without.

I guess a lot depends on the work you do and personal preference but I don't think I'd want to try using anything smaller, I find even now it can be a tight squeeze securing some work pieces with clamping hardware.

As for 3 or 4 slots ? I went for 4 as I thought if need be I could fix my milling vice to the top if I needed to (I guess it can also be done on a 3 slot table but a 4 slot would appear to be a better arrangement)


Online crueby

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Re: How do I select a rotary table?
« Reply #9 on: July 11, 2018, 01:41:30 AM »
One area I'm really confused on...is the dividing plates. I've never understood the reason for that when you can rotate to whatever degree you want.


I agree, mine doesn't have plates....but I divide with a dividing head which does.  Plates are needed for gear cutting among other things when you need accurate (and convenient) division into numbers that don't readily go into 360 degrees, i.e. a 28 tooth gear.
The marked ticks on my rotab go down to a tenth of a degree, very easy to visually get down to a quarter of that, plenty accurate for any gears I have done. If you are doing very high speed gears, maybe you need more precision, for most model and clock work, this is fine.

Offline AOG

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Re: How do I select a rotary table?
« Reply #10 on: July 11, 2018, 02:13:45 AM »
This may be out of your price range but I would highly recommend the Sherline CNC rotary table. Itís short you can mount a tooling plate or a chuck and it will do dividing as well as angle cuts. Best of all itís digital so you donít have to bend down to look at the markings. The dividing feature will help you a lot if you ever decide to cut your own gears.

https://sherline.com/product/8700-cnc-4-rotary-table-indexer/

Tony

Offline steamer

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Re: How do I select a rotary table?
« Reply #11 on: July 11, 2018, 02:48:02 AM »
My first was an 8 inch Vertex.  Still have it.   Great table...damn heavy.
Its too big really for the clausing, and it lives in a big draw.  For the clausing   5 inch or so is more like it, but i hate swapping over between vise and RT.   What im doing there right now is putting a baron the back of a 4" HV table, so that I can quicly clamp it in the vise horizontally and just use it.  I dont usually use the table in the verticle as ive got dividing heads for that job.   Ill post when I get closer.

Back to wallaby.....but perhaps later this week.

Dave
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Offline gary.a.ayres

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Re: How do I select a rotary table?
« Reply #12 on: July 11, 2018, 06:36:07 AM »
I mostly use a dividing head for dividing and an RT for cutting arcs, there's reason to prefer that, but if you didn't have a dividing head, I'd want dividing features on the RT; way to mount a chuck, can take index plates, take a centre and has a tailstock and can used horizontally or vertically.

Carl -

I have a small import rotary table which I keep almost permanently fitted with  dividing plate and a chuck. Effectively it functions as a dividing head, more or less. The dividing plate may not be essential for making measured divisions but I find it very convenient and use it both horizontally and vertically. A tailstock is great in horizontal mode for items which need to be supported at the other end. The picture below shows some candlesticks I made. Looking at the rather gothic one in the middle, the 'fluted column' was made horizontally using the tailstock with a ball-nosed endmill to cut the flutes (I guess this method can be used on the columns of some steam engines), and the 'crown' was done in vertical mode, again using a ball-nose endmill.



gary

Offline Jasonb

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Re: How do I select a rotary table?
« Reply #13 on: July 11, 2018, 07:31:43 AM »
1. I often use a 3-jaw on mine but it is a separate chuck just for the R/T, not found the need to transfer check complete with work between the two.

2. Simple dividing can easily be done using the scale on the R/T but for things like gears I use the dividing plates, don't have to buy them at the start as they can be added later though a package is often a bit cheaper.

3. Tailstock is used far more than division plates, in the same way as the lathe it is used to support the end of long work so it does not get pushed down or move sideways by the cutting action. Jack is not much use if you are rotating the work to cut a radial feature and will not stop sideways force.

4 6 slots would be on a large table, 3 or 4 is more common on our size tables

A 6" one would be right on your lathe, that refers to diameter of the table.

One feature I do like is a movable scale on the table ring, but these tables do cost about twice as much as the more common type that just has it engraved directly to the side of the table.

This is what I have used for about 10yrs and you should be able to get similar from one of the US suppliers.

https://www.chronos.ltd.uk/cgi-bin/sh000001.pl?WD=111015&PN=Soba_Rotary_Tables_and_accessories%2ehtml#a111015

And this is the one with the movable scale, not sure if it is done in the US but maybe a Sieg supplier will have one as they do similar. I've been using one of these (with all the bits)  quite a bit recently, the 72:1 ratio makes for less handle turning too!

https://www.arceurotrade.co.uk/Catalogue/Workholding/Rotary-Tables/6-Rotary-Table-and-Acessories

J

Online Jo

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Re: How do I select a rotary table?
« Reply #14 on: July 11, 2018, 08:04:42 AM »
Try to avoid a three slot table Zee, I have heard many owners complaining.

Try to avoid the ones made with Aluminium bases as they wear quickly :facepalm:

If possible try it before you buy it: You are looking to avoid sloppiness in the worm  :facepalm2: You want a comfortable handle to use and you don't want the handle going below the table base as that constrains how you bolt it down. You need to be able to clamp the table and preferably has end stops for arcs.


I have a 10" Jones and Shipman table  :Love:, the BCA has a built in 8" table  :Love: and I have two 6" tables - one Swiss and one Myford (Vertex with dividing plates etc). I don't waste my time with either of the 6" tables if I am going to get a table out it is the 10" one as it gives me more clamping space on the table. The only reason to keep the Myford one is it mounts vertically = another option but never used. The Swiss one just feels so nice, one has to have a twirl every now and then  :embarassed:

Jo
« Last Edit: July 11, 2018, 08:08:16 AM by Jo »
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