# Rotary table



## Coomba (Jul 8, 2016)

I have been looking at different rotary tables, and I'm thinking this one from Little machine Shop might be the one to get. Asking what you guys use and why? Am I going to small, or maybe buying to much? I would like to learn how to make gears. Appreciate your input before I put my money down. http://littlemachineshop.com/products/product_view.php?ProductID=3792&category=1963256910


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## Wizard69 (Jul 8, 2016)

I'm not really the skilled machinist like many on these forums but that does look like an interesting set or parts.   

The big problem that is see is the dividing head.    The plates look darn right funny in the picture.  Being no expert and considering the crummy photo, you might want to contact LMS for more information.   You would want to know how many dividing plates actually come with the unit and the number of holes in those plates.  

Beyond all of that more info on the size of you machine might be helpful.   I'm sure the experts will want to know




Coomba said:


> I have been looking at different rotary tables, and I'm thinking this one from Little machine Shop might be the one to get. Asking what you guys use and why? Am I going to small, or maybe buying to much? I would like to learn how to make gears. Appreciate your input before I put my money down. http://littlemachineshop.com/products/product_view.php?ProductID=3792&category=1963256910


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## petertha (Jul 8, 2016)

As far as a 4" RT goes for smallish jobs, I really like the Sherline I bought.
http://sherline.com/product-category/mill-accessories/rotary-tables-mill-accessories/

- seems quite accurate, low profile, use in normal or upright mode
- they have a neat thread-in center stub that then integrates their same lathe 3-jaw & 4-jaw chucks for quick grip/centering jobs (have a look at their capacity as they are also on the smallish side)
- its a conventional worm screw dial, not detant indexing if that what you were seeking. Easy/logical divisions.

Because it is low profile, I mounted a square baseplate for mine & grip the whole RT in my 5" mill vise. It sets up so quick I almost hate dragging out the larger RT now.


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## Coomba (Jul 8, 2016)

Wizard69 said:


> I'm not really the skilled machinist like many on these forums but that does look like an interesting set or parts.
> 
> The big problem that is see is the dividing head. The plates look darn right funny in the picture. Being no expert and considering the crummy photo, you might want to contact LMS for more information. You would want to know how many dividing plates actually come with the unit and the number of holes in those plates.
> 
> Beyond all of that more info on the size of you machine might be helpful. I'm sure the experts will want to know


 
My mill is a PM450G, it has a 8 1/4" x 28 3/4" table. X travel 17 3/8", Y travel 11", Z travel 17 1/2" Spindle to table 20 1/2"


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## chucketn (Jul 8, 2016)

I bought a 4" Vertex, but without the indexing setup. I lucked out and was given a the indexing setup including plates, handle and tail stock for the cost of shipping it to the US from England. I have since added an Arduino driven controller and stepper setup to it for gear cutting. Works great on my X2 mill

Chuck


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## gus (Jul 8, 2016)

Given the time,one could build a 4'' D.H. with drawings from Taig Machine Tool Projects. Made mine successfully. As for the indexing plates,made it too with help from friends doing computer dividing print outs. DH is a twin bro. of LMS. Also made another D.H. using drawings from Harold Hall using direct indexing. Howell V-2 Gear Train were DIY Cut. Best to cut gears between centers for concentricity. Chuck are not best. Off Centered gears are hard to mesh. 

The DH from LMS should be OK but to cut a wide range of gears,additional indexing plates required. Cutting Gears will be another skill to pick up. Be mentally prepared to collect some gears with 1/2 tooth. About 10 HMEM folks and Gus took up gear cutting and had plenty of fun. Metric Involute Gear Cutters can be sourced from China cheaply but quite good. However they do make Imperial Gear Cutters. Sourcing same from UK was very expensive.


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## petertha (Jul 8, 2016)

Coomba said:


> My mill is a PM450G, it has a 8 1/4" x 28 3/4" table. X travel 17 3/8", Y travel 11", Z travel 17 1/2" Spindle to table 20 1/2"


 
I started answering your RT specific question, but maybe some added info would be useful. You have sufficient mill table real estate so you could go down 2 different paths, mostly influenced by anticipated work. For gear cutting I suspect most folks utilize dividing plates for accurate positional indexing. Dividing heads come with plates. You mount stock on their centers or integrate a chuck on the threaded spindle nose. The nicer imports like Vertex tend to cost about as much as similar size/quality RT. You can also typically pivot DH's for cutting bevel gears which is normally kind of a setup pain, but model engineers are resourceful & will always find a way.

Rotary tables for the most part don't come with plates, but some models do. You typically release or disassemble the worm screw handle & install plates. You probably should make that decision up front though as plates tend to fit only those specific RT models. Here is an import RT that includes plates (not pictured but that's what it says). 
http://littlemachineshop.com/products/product_view.php?ProductID=3566&category= 
I guess a conventional RT without plates can also 'rotate index' to nominal angular increments for gear cutting. You are reliant on hitting exact angular positions using the graduation lines (as opposed to holes in a plate). I cant tell you if this is accurate enough, haven't done gears yet. Some RT's have vernier scales for increased accuracy but anyway if your gears required oddball partial decimal degrees, you might be pushing the typical import jobbies. With RT's you can mill continuously through an arc like semi-circle slots. Plates require you to: move to specific angular position, do a machining operation, move to another position, repeat. Nothing in between.

You know how this story is going to end, eh? In an ideal world where money was no object you would probably have both! The other thing to consider is the related tooling, do you require chucks or collets or plates to hold the work you want to make. Check into those sizes & cost.

Hope this helps, god luck


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## Cogsy (Jul 8, 2016)

petertha said:


> With RT's you can mill continuously through an arc like semi-circle slots. Plates require you to: move to specific angular position, do a machining operation, move to another position, repeat. Nothing in between.


 
I have a Vertex dividing head and I can machine through an arc with no problems at all. I need to keep some small pressure on the handle to ensure it doesn't engage a hole in the plate, but it's exactly the same as when changing positions, except the cutter is engaged. If I couldn't machine an arc I'd never recommend a dividing head as that is the majority of the work I perform with it.


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## petertha (Jul 8, 2016)

There you go, learn something every day.


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## Charles Lamont (Jul 9, 2016)

Cogsy said:


> I have a Vertex dividing head and I can machine through an arc with no problems at all. I need to keep some small pressure on the handle to ensure it doesn't engage a hole in the plate.



Does it not have a latching position by twisting the handle to hold it disengaged?


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## Blogwitch (Jul 9, 2016)

Charles,

Before I modded my Vertex RT to a Divisionmaster setup, you could reposition the dividing location handle so that the locking pin just about sat around the outside of the division plate, so you used it just like a normal RT.

One of the main problems with an RT or even the Vertex BS0 dividing head, you would never get all the holes you required with the dividing plates supplied, in fact, with the Vertex there were many that just couldn't be obtained, mainly odd prime numbers. I spent a lot of time and money buying third party plates and modifying them to fit so that I could cut gears or drill holes in the counts I required.

I would suggest to anyone, if you have the means, to buy a basic RT and convert it to electronic operation with stepper control. With mine, I can get from 2 to 9,999 positions, and I can even use it to cut exact degree slots or full rotations very easily indeed.

John


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## Wizard69 (Jul 9, 2016)

Coomba said:


> My mill is a PM450G, it has a 8 1/4" x 28 3/4" table. X travel 17 3/8", Y travel 11", Z travel 17 1/2" Spindle to table 20 1/2"




I probably should have asked what size do you work in.   In any event here is my theory, it is easy to have a rotary table that is too small but a rotary table is seldom too large if it sits neatly on the machine table.  Given this I'd look for a slightly larger table.  

Size your rotary table such that it can be easily set up with the T-Slot arrangement on your machine table.   I'm not familiar with that machine so I'm thinking something in the 5-6 inch range will sit nicely on the table.    Now you may ask why, go bigger, my first thought there is more flexibility in set up and what you can do with the rotary without putting on a sub plate.  You might be able to go even bigger depending on the rotary and your mill table but do consider one thing: the big rotaries are very heavy.   I wish I could put that in bold, we have some real old RT's at work that are a real pain just to move around. 

Now we have a few other things to consider, if part of your goal is to do gears you may run into clearance issues with any RT.    Imagine your involuted cutters running into the table or the mills quill.    You can of course mount the gear blank on a shaft but that is least than ideal from a rigidity standpoint.     However if small gears are your game you might want to make something like the Versatile Dividing Head outlined in the book Worksop Techniques by Geo. H. Thomas.    This would be a supplement to the RT.   In my mind a dividing head and a RT are two different accessories even though a rotary table arranged vertically can take on some of the stuff that a dividing head does.  

In the end it is a matter of getting a handle on what you want to use the unit for.    One thing you can do for yourself is to get some cardboard and cut out some circles of 4, 5 and 6 inches in diameter.   Lay the circles on you mill table.  I'm willing to bet that the 4" table will look puny to you on that table.  Set up area increases significantly with each inch in diameter.   As you may guess I'm thinking about the table mostly in the horizontal position.  You will need to put a lot of thought into what you want to do in the vertical orientation.  A RT may be just what you need vertical or it might be a total pain in the rear.  

If it looks like I dwelled a long time on setup it is because it can be a huge pain to work with really small stuff.   This can be the case on shop machinery of automation equipment.  At work my focus is on automation equipment, handing very small stuff, it is a real pain if you have big hands.    Everything becomes tedious to say the least.    Of course if you are working on models that fit into the palm of the hand you have different considerations.


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## Cogsy (Jul 10, 2016)

Wizard69 said:


> In my mind a dividing head and a RT are two different accessories even though a rotary table arranged vertically can take on some of the stuff that a dividing head does.


 
I've never had/used a rotary table and I'm not really familiar with them. What can you do with a RT that you can't with a dividing head? If there's enough reason to, I might consider trying to make one sometime, but not if there's no point.


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## Blogwitch (Jul 10, 2016)

Cogsy,

The main difference is the amount of throat you have with an RT over a dividing head, especially on some of the smaller machines. The main advantage of a dividing head is that you can very easily set up angled cuts without resorting to angle tables or vices.

As most of you know, I use adaptive tooling (collet holders, chucks etc) to swap jobs between lathe and mill, including the RT and dividing head.

One of the advantages with what I have is that with a cheap Myford faceplate (less than 40UK pounds), I can convert my RT from 6" diameter to 9" within seconds. 
There is nothing stopping anyone getting a bit of plate metal and making their RT larger, you just have to make sure the plate doesn't interfere with the handle or dividing gear. 

A normal 9" RT would be much too heavy and bulky for my machine.

John


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## goldstar31 (Jul 10, 2016)

Agreed about the versatility of the Vertex Dividing head. I stuck with my old  Myford stuff( probably advanced senility)  

I discovered that it would all go on my Clarkson 1 T&C as well.

Unquestionably, John has the right idea. 

Regards


Norman


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## Wizard69 (Jul 10, 2016)

Cogsy said:


> I've never had/used a rotary table and I'm not really familiar with them. What can you do with a RT that you can't with a dividing head? If there's enough reason to, I might consider trying to make one sometime, but not if there's no point.




Generally when I think rotary table I think machining stuff with it arraigned horizontally.  Imagine being able to rotate your current mill table.    

When thinking like this you should realize that there are plenty of things doable on a rotary table that would be hard to do without on a manual machine.   Anything that requires a radius to be milled are a candidate, especially arcs that can't be done on a lathe.  

Sometimes you can do just as good maybe even better with a DRO, for example doing bolt circles. You can't however do continuous arcs with DROs.  

In the tool room world rotary tables have been largely replaced by CNC machines.  Even in the hobby world CNC solutions can often be cheaper than buying a decent rotary table.   CNC can also be faster to setup in some situations, for example if you have to blend a bunch of arcs into other arcs or tangent to flat surfaces at odd angles.    Of course CNC implies a CAD drawing and the ability translate it with CAM tools.  CNC actually brings some other advantages to small machine tools over rotary tables, rotary tables cause you to loose Z height which is always a problem on small machines. 

I guess I got off track here with the CNC stuff but it is a good alternative if you expect to do things normally done with the RT horizontal.   Depending upon the complexity of the part and the documentation you got, though a manual setup can be faster.   It is this issue of sometimes being faster sometimes not, that causes CNC to be dismissed in the hobby world as a RT replacement.   I just threw this out because it is good to understand the alternatives.   

Someplace in between all of the above are modified RT with electronic drives.  One might describe such as a single axis CNC!   Such upgrades can be highly recommended even if you never see a full blown CNC in your future.  Electronic drive eliminates a lot of tedious indexing and can eliminate some of the mistakes that can be made indexing materials. 

Probably a lot to think about here.


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## Blogwitch (Jul 10, 2016)

With reference to Wizards last paragraph.
This has been shown before, but the vid explains things so easily.

[ame]https://www.youtube.com/watch?v=P1ifPuImERA[/ame]


John


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## Cogsy (Jul 10, 2016)

Thanks for the replies. My mill, although not the most precise thing in the world, has lots of throat so I can set up the dividing head vertically and still use a coax indicator to centre the workpiece, so I guess I don't need an RT. I thought I must be missing some RT capability but if it's really just the size issue I don't need to worry about it. Just as well too, I have a list a mile long of tools I need/want to build already...


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## Wizard69 (Jul 11, 2016)

Blogwitch said:


> With reference to Wizards last paragraph.
> This has been shown before, but the vid explains things so easily.
> 
> 
> John




Thanks John, excellent video that should help a person understand rotary tables and their uses.    Certainly better than my stumbling to find a verbal description.  

It looks like your Division Master is one of those devices that is quick to learn as you mention only having it for two days.  If so that is great because working with rotary tables manually, with or without dividing plates takes a while to learn and is error prone.   There are a few open sourced solutions to making an electronic RT for those who seek a build it you're self adventure.  

Probably the only thing missing is showing making tapered flat components.   I like to call them pie sections.


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## Blogwitch (Jul 11, 2016)

Wizard,

A few people on here have gone down the Arduino route for controlling their RT's, unfortunately, I can't get my head around them.
Supposedly they do much the same thing as my division master but at a much lower cost.

http://divisionmaster.co.uk/divisionmaster.html

John


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## AlbertdeWitte (Jul 11, 2016)

Hi Guys

I have the Vertex HV6 with indexing plates, 4"Chuck and tail stock which I find to be quite fine, I would love to add the Division master to it one day. I am sure it can be fitted with a few mods, what do you think?


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## rodw (Jul 11, 2016)

AlbertdeWitte said:


> Hi Guys
> 
> I have the Vertex HV6 with indexing plates, 4"Chuck and tail stock which I find to be quite fine, I would love to add the Division master to it one day. I am sure it can be fitted with a few mods, what do you think?



You dont need to spring for the divisionmaster when there are some excellent  solutions right here on this forum..

Here is the DIY stepper kit for a Vertex table.

http://www.homemodelenginemachinist.com/showpost.php?p=262292&postcount=103


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## Wizard69 (Jul 11, 2016)

Blogwitch said:


> Wizard,
> 
> A few people on here have gone down the Arduino route for controlling their RT's, unfortunately, I can't get my head around them.
> Supposedly they do much the same thing as my division master but at a much lower cost.
> ...




Division master seems to have well thought out software and is a complete product.   That in itself would justify the hardware to many people.  

As for the open source stuff you really need to be of the type of person that likes to tinker with software and electronic hardware.   I'm not sure which route I will go.   Right now it is very difficult to budget anything for the home shop.


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## Blogwitch (Jul 11, 2016)

I am not pushing anyone towards the division master, just giving people the info if they want to go down that route, I personally wouldn't know where to start with Arduino, and I think there are a lot of people like that.

It just might be like the DRO saga, buy cheapo scale units and end up spending more money and time trying to get it accurate and reliable than it would have cost to buy a glass read head unit in the first place.

Rod,

You have only shown half the job on that link, where are the thrust bearings that get rid of most of the backlash inside of the Vertex head? It is easy just whacking on a stepper, getting rid of the shaft backlash is a whole new ball game.

This is how I got around the thrust bearing problem on the Vertex 6" and smaller. Thrust bearings aren't available in the correct size, so I made a pair from sintered bronze that do a great job.







On the expensive ones from Arc Euro and LMS in the US, the proper sized thrust bearings are available, and it was much easier to mod that type of RT. But it wasn't just thrust bearings that were fitted, needle rollers were fitted inside the offset bored shaft carrier as well, to take the side loads from the worm.












Without doing that mod, you can only really send the RT in one direction so that it takes up the worm and wheel backlash, unlike mine, which works very accurately in BOTH directions because of no detectable backlash.

John


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## Coomba (Jul 11, 2016)

Lots of good information here. I have much to consider. Thanks


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## Coomba (Jul 11, 2016)

petertha said:


> I started answering your RT specific question, but maybe some added info would be useful. You have sufficient mill table real estate so you could go down 2 different paths, mostly influenced by anticipated work. For gear cutting I suspect most folks utilize dividing plates for accurate positional indexing. Dividing heads come with plates. You mount stock on their centers or integrate a chuck on the threaded spindle nose. The nicer imports like Vertex tend to cost about as much as similar size/quality RT. You can also typically pivot DH's for cutting bevel gears which is normally kind of a setup pain, but model engineers are resourceful & will always find a way.
> 
> Rotary tables for the most part don't come with plates, but some models do. You typically release or disassemble the worm screw handle & install plates. You probably should make that decision up front though as plates tend to fit only those specific RT models. Here is an import RT that includes plates (not pictured but that's what it says).
> http://littlemachineshop.com/products/product_view.php?ProductID=3566&category=
> ...



That was the first RT. that I considered, but didn't think I could handle the weight. The second was also from The Little Machine Shop, but is a four inch,and is much less in weight. There is a link to it in my original post.It also has a Chuck, dividing plates,and a tail stock.


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## Buchanan (Jul 12, 2016)

I have used many  RT's over the years.  From home built to repairing thrown out, to new. one thing I would not be with out is my Divisionmaster. It takes out at least half the stress in cutting gears. Vertex are a good economy RT  and very respectably accurate. Divisionmaster is also very easy to fit. I gives the ability to power feed as well as take up backlash. The ability to cut any number of teeth, or index any angle is a great advantage and it almost totally removes the potential for counting errors or slips.  There is very reasonable tooling available from CTC tools.  I would recommend a ER collet chuck to fit the taper in the table as well as a 3 jaw chuck as both greatly extend the usefulness of a RT. Next better is CNC, but that is another ball game.


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## AlbertdeWitte (Jul 12, 2016)

Great post John with clear guidelines!!


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## Wizard69 (Jul 12, 2016)

Coomba said:


> That was the first RT. that I considered, but didn't think I could handle the weight. The second was also from The Little Machine Shop, but is a four inch,and is much less in weight. There is a link to it in my original post.It also has a Chuck, dividing plates,and a tail stock.




That listed weight might be for shipping the entire set of components.    In any event you are right to be concerned about weight, these tables get heavy fast.   It is a good reason to consider installing a jib crane of some sort or another lifting aid.   Guys have come up with all sorts of aids to get vises and RTs off a mills table.    The last thing we want are lifting injuries while engaged in a hobby. 

You still need to think about how this table will be used.   For some uses a big RT gets in the way in vertical mode.


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## Blogwitch (Jul 12, 2016)

I have had my RT and vice (soon to be a larger more versatile vice) both fitted at the same time for the past few years, and haven't come across any problems where I need to remove both of them at the same time. In fact, it is a bit of a squeeze, but I can also mount my angled vice on there as well at the same time.
It took a bit of working out and fiddling with positioning, but things work just perfectly now. It saves hours on setup times

The only time I would ever have to move them off the table was if I needed to fit my dividing head, in which case only the RT needs to be moved, or the job was so large, I would have to use my 2 piece vice along the table. The last time was when I was machining out the back side of an electric guitar, not the sort of job that comes along very often.






John


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## rodw (Jul 12, 2016)

Blogwitch said:


> Rod,
> 
> You have only shown half the job on that link, where are the thrust bearings that get rid of most of the backlash inside of the Vertex head? It is easy just whacking on a stepper, getting rid of the shaft backlash is a whole new ball game.
> 
> John



I don't see backlash being mechanical factors within a rotary table has anything to do with stepper motor control. My RT had no appreciable backlash so I did not bother with backlash compensation within the software. For super precise stuff, the operator can choose to turn one direction only.


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## Blogwitch (Jul 12, 2016)

Everyone to their own Rod, and if you can work with it in one direction, then fine.

The problems arise Rod when you need to cut slots that maybe travel backwards and forwards half a dozen times. In your situation, you will have to lift the cutter, advance however many degrees to the start of the slot and start cutting again, repeat as required. For making things like flywheels, it is perfect as you get no over-run, a thing I used to suffer from when making them on a manual RT.

As I said, each to his own, I only raised the point because it really is a thing that needs to be done if you are searching for repeat accuracy with your RT or dividing head. I haven't as yet modded my dividing head, but it will be done, eventually.

If you don't eliminate that backlash you will forever be restricted to one accurate direction only.

The inner shaft on my Vertex with sintered bearings is at most 0.001"  end float, just enough to allow the shaft to rotate without binding, and  on the AE ones, no end float at all, as they use roller bearing thrust  washers and it can all be adjusted out.

On the second one I showed, the high priced Arc Euro one, that is almost exactly the same mod done by AE on their 4th axis CNC RT's, but I use mechanical fixings on the stepper coupling tube rather than a Loctite approach.

http://www.arceurotrade.co.uk/Catalogue/Workholding/Rotary-Tables/4-Rotary-Table-with-Stepper-Motor

For the extra couple of hours machining and the few bucks it takes to do the mods, it is well worth it in the knowledge that you have an RT that can be used accurately in both directions without having to turn back and move forwards again to eliminate your backlash and get to where you were in the first place.

John


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## Coomba (Jul 13, 2016)

Blogwitch said:


> Everyone to their own Rod, and if you can work with it in one direction, then fine.
> 
> The problems arise Rod when you need to cut slots that maybe travel backwards and forwards half a dozen times. In your situation, you will have to lift the cutter, advance however many degrees to the start of the slot and start cutting again, repeat as required. For making things like flywheels, it is perfect as you get no over-run, a thing I used to suffer from when making them on a manual RT.
> 
> ...



I can see where a stepper motor would be a big plus, but right now,I think I need to crawl a bit,before I step up.  Can we talk a little about division plates? How do I determine how many to buy,and which ones I will be needing? Also would a four jaw Chuck be better option than a three?


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## rodw (Jul 13, 2016)

Coomba said:


> I can see where a stepper motor would be a big plus, but right now,I think I need to crawl a bit,before I step up.  Can we talk a little about division plates? How do I determine how many to buy,and which ones I will be needing? Also would a four jaw Chuck be better option than a three?



Just buy a dividing plate kit for the rotary table you choose. Here is one to suit the Vertex 4" and 6" tables http://www.machineryhouse.com.au/R016

And there are complete kits with the chuck as well. http://www.machineryhouse.com.au/R016

You can see this has a mounting  plate to hold the chuck that sits on a tapered spindle so it is quick and easy fit the RT. The alternative is to bolt the chuck directly to the T slots on the table and you can buy a t slot bolt kit to do this as well. There is a setting up issue.

Some people set up so they can move the chuck from their table to their lathe. 

A quick and dirty method of  locating the table is to place a taper in your mill and engage it in your table. I found that this was still a fair way out when checked with a coaxial indicator so to me it is just a starting point.

I think the 3 jaw chuck is the way to go. Centreing something in a non rotating 4 jaw chuck might not be very easy!


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## Wizard69 (Jul 13, 2016)

Coomba said:


> I can see where a stepper motor would be a big plus, but right now,I think I need to crawl a bit,before I step up.


Probably not a bad idea .   Many people get frustrated with division plates, it takes a lot of focus and a bit of math to do a part from beginning to end without error.  I suspect most people have screwed something up with a rotary table.    


> Can we talk a little about division plates? How do I determine how many to buy,and which ones I will be needing?


There is no way to really answer that because what you need varies with what you are doing at the time.   Some times guys end up making their own plates.  Before going to far I'd suggest finding a book that dives into the use of these RT and other indexing systems.  Once you get a handle on it, the math is focused on ratios, you will find the knowledge useful for indexing things beyond rotary tables.   For example you can index a lathe spindle in the same manner as a RT.  


> Also would a four jaw Chuck be better option than a three?




If you only have one, the four jaw will be preferred.  If you are going to do gears, you will want to be able to dial in concentricity to with in a couple of tenths.  Of course you may be able to dial in the 3 jaw but it depends upon how you mount the chuck to the rotary table.  So to an extent the answer here depends upon the specifics of the chuck / RT combination. 

By the way not to confuse things but the chuck needs to be concentric (hold a part concentric) to the axis of rotation of the rotary table.  This is different than setting up the spindle to be on center with the RT rotation axis which can be required for some uses.


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## Blogwitch (Jul 14, 2016)

Sorry to have displaced your original post by giving information about powered RT's, but it might have helped someone to understand things better.

Anyway, back to your problem.

If you buy say a Vertex RT, then as already mentioned, you can buy division sets that bolt almost straight on, but a word of warning, if you do fit one, don't lose the little keyway key when you remove the main handle, tape it to the handle for safe keeping.

As with any dividing set, you just can't get enough hole sets on the three plates that are supplied, so there will be some holes or divisions that you just can't get. Most people go through life with just those supplied plates, but if you are into gears then it just might be you will hit on the plates that just don't have what you require. I spent many hours going through what numbers were on the plates to find out what numbers I needed to get.

If you go to page three of the downloads section, about half way down, you will find that I have put up 'Vertex Charts'. If you download it, it explains how to do your indirect indexing and on the charts, what holes you can or can't get. You won't be able to do Differential indexing to get the holes you want as that only comes with gears on the more expensive Dividing Head.

So now down to your problem.

Say you need X number of teeth on your gear, and you don't have the correct hole numbers on your plate to get it, there is only one easy way to do it. 
Find someone with a powered RT and get them to make a plate for you with the correct hole set on it. In fact, get them to put more hole sets on it for all the other numbers you can't achieve.

Years ago, I went the hard way as at the time you could buy punched plates with all different numbers on them, it was just a matter of cleaning them up and adapting them to fit the dividing set. I don't think they still do them, and I gave away all my modified plates to a friend when I converted to power otherwise you would have been quite welcome to them.

Sorry to have been so negative, but I do hope what I have said will help.

John


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## goldstar31 (Jul 14, 2016)

Arguably, the best book is actually two. The classic English model engineer George H. Thomas wrote and described his workshop tools in Model Engineer. Actually, it was the late Professor Dennis Chaddock, designer of the Quorn tool and cutter grinder encouraged GHT to do this. If you add 'Ned' Westbury, Tom Walshaw writing as Tubal Cain and Kenneth Cleeve Hart writing as Martin Cleeve, one has a pretty heady mixture of talent. When Thomas died, Neil Hemingway of Hemmingwaykits encouraged Dr Bill Bennett - a fellow student with my late wife to complete the intended books.

These became the Model Engineers Workshop Manual and Workshop Techniques. The latter embodies the earlier Universal Pillar Tool book and Dividing and Graduating. 

So George starts with a basic little rotary table which hadn't any of these complicated ball bearings and even degrees around its perimeter to perhaps the most sophisticated dividing head which contained not one worm wheel but two to do ANY configuration.
To mention the construction of division plates, Thomas describes how he drilled his with a pair of dividers but goes on to described what can be achieved with a division plate with ONE hole.

Somewhere, under a heap of rusting metal- my workshop roof came off- are my Quorn and assorted GHT 'goodies' Nearer and probably just as inaccessible is the knowledge of how I tried to copy the 'Words and music'

There you have it

Norman


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## ShopShoe (Jul 14, 2016)

Coomba,

I Just went back to your original post. On your original link, click Chriss Tips and read the instructions for using the dividing plates he has posted at LMS. Think through a part or gear you want to make and see if you think you could follow the instructions to use a division plate to make that part. You may have to read the instructions more than once: I did, but my first attempt at a gear turned out OK except the gear blank slipped while cutting and made the infamous half-tooth. Second one turned out well and is still working after three years and hundreds of hours of operation. The main skill in doing this being able to concentrate through the boredom that comes with lots of cranks and lots of re-indexing the sector arms.

I bought my division plates with my rotary table almost by accident: I originally did not think I would be doing that type of work. It was only a few weeks later that I found myself using them. You will not be sorry if you buy them, unless you buy the electronic option from day one.

Only my two cents worth,

ShopShoe


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## petertha (Jul 14, 2016)

Speaking of dividing head, I thought it might be a neat accessory to have an ER collet on the end for quick round stock setups. I cant recall the thread, maybe 1.5x8 tpi? Has anyone made such an adapter?


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## Blogwitch (Jul 14, 2016)

Peter,
They are fairly easy to make, just cut the internal thread for the ER adapter first, matching the nose thread on the DH, then make up a blank thread on your lathe to match the nose thread of the Dividing Head.
Without removing the threaded nose from your lathe chuck, screw on the ER adapter and cut away as I have shown here.

http://www.homemodelenginemachinist.com/showthread.php?t=24123

That way, you should end up with a fully concentric ER nose adapter.

 BTW, I cut the internal thread to match the Myford nose I had made for my RT in that post, plus I also made the adapter to turn my lathe from a D 1-4 into a Myford nose thread for doing this sort of interchangeable tooling.

John


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## petertha (Jul 14, 2016)

Nice John. I'm sure yours is the pictorial I must have saw, just forgot where. Thanks.


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## goldstar31 (Jul 15, 2016)

petertha said:


> Speaking of dividing head, I thought it might be a neat accessory to have an ER collet on the end for quick round stock setups. I cant recall the thread, maybe 1.5x8 tpi? Has anyone made such an adapter?


 
I suspect that you missed the import of my reply. So might I apologise and try again?

Mine is the standard Myford nose which takes Number 2 Morse taper tooling. Again, it not only takes the Myford chucks but also the Myford face plates and catch plate( 4 in all) and the ER25 collets but these are not particular accurate as John points out but the considerably better Imperial Myford ones.

So this goes on the mill drill as a Dividing head but also as a rotary table but can be moved to serve as a replacement to my cheap £100 and not too nasty Clarkson tool and cutter grinder but at a pinch goes on the bigger Myford lathe.

If the scene is allowed to develop, I have a 3 Jaw chuck which peppered with locating holes to use a detent on either lathe- thus using both the two vertical slides but I thought it nice to add a 4 jaw self centring Myford 'type' chuck to widen the scope of my little simple workshop.

However, with limited space and limited time and funds, I have three Potts mills to go on the various tools. One takes 8mm collets. The Potts, there are 3 varieties are ancient items which date back to Sparey and Westbury.

Confession is good for the soul and I am simply unable to get my head around things like Arduino, Raspberry Pie( except to eat) and these silly things like 'handies' and Eye Pads and whatever.

Are you a bit clearer now? It may be that bit 'Heath Robinson' but works.

Norman


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## petertha (Jul 15, 2016)

Thanks Norman. In my case, the DH is the only item in my shop with that 1.5x8 thread (or whatever it is). I don't have any other chucks or tooling that matches that. My lathe chucks are D1-4. Thus far I have only used the DH between centers, but I'd like the ability to (rapidly) grip round stock for indexing. I do have an ER40 collet set & that's where the inspiration came from to marry the two.

..kind of this idea but no back plate of course
http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks/ER40-Lathe-Collet-Chucks

Johns procedure of first turning a sacrificial male threaded arbor stub in the lathe (mimicking the DH nose thread) then screw on the ER accessory blank before cutting the collet taper & threads ensures better concentric accuracy than my much more convoluted plan of using adjusting set screws like how SetTrue chucks are dialed in.


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## goldstar31 (Jul 15, 2016)

Thanks Peter. No way am I trying to unduly influence you but GHT in Workshop Techniques did some thing similar with his excellent small dividing head. Being equally pedantic, I made mine to suit the Myford 'theme' to suit me. He's worth a read!

Unfortunately, I'm still trying to sort out family finances after the loss of my wife but I stumbled on a couple of oddities. The first was a 'Bevel-Box Angle sensor' which is fairly inexpensive and I thought would do tool angles but the second was incredibly cheap  and is called a 'Strait-Line Laser Level 120' and made out of plastic. 

For those who have reasons for not going to exotic stuff, they, they certainly are worth considering. Obviously, I must leave it there and get back  into the dreary realms of finance, tax and survival. 

Meantime, success in your endeavours

Norman


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## Wizard69 (Jul 15, 2016)

Norman; thanks for this bit of history.    I have my copy of Workshop Techniques at my desk and always wondered what role Bennett played in the book.  There is a lot of knowledge in that paper backed book.  




goldstar31 said:


> Arguably, the best book is actually two. The classic English model engineer George H. Thomas wrote and described his workshop tools in Model Engineer. Actually, it was the late Professor Dennis Chaddock, designer of the Quorn tool and cutter grinder encouraged GHT to do this. If you add 'Ned' Westbury, Tom Walshaw writing as Tubal Cain and Kenneth Cleeve Hart writing as Martin Cleeve, one has a pretty heady mixture of talent. When Thomas died, Neil Hemingway of Hemmingwaykits encouraged Dr Bill Bennett - a fellow student with my late wife to complete the intended books.
> 
> These became the Model Engineers Workshop Manual and Workshop Techniques. The latter embodies the earlier Universal Pillar Tool book and Dividing and Graduating.
> 
> ...


Reading GHT books is a good way to answer the questions "do I need one of these" or " what is it for".  


> Somewhere, under a heap of rusting metal- my workshop roof came off- are my Quorn and assorted GHT 'goodies' Nearer and probably just as inaccessible is the knowledge of how I tried to copy the 'Words and music'
> 
> There you have it
> 
> Norman




Sorry to hear about the workshop, that really has to suck, especially with all the other challenges you are dealing with.


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## goldstar31 (Jul 15, 2016)

Dr W.A Bennett BDS( Dunelm)? Actually Bill is a retired dentist and one of the last of the Durhams- Durham University in Newcastle upon Tyne. My late wife graduated at the same.  

We were with Bill when they got their 50 year Reunion in.

Quite a few got the model engineering bug- probably in part from senior consultants who made a lot of their own tools. 

I suspect that Bill was connected through his contact with Neil Hemingway who seems to have been either a beneficiary or even executor of George. N H certainly had all of GHT's stuff. I recall Bill being persuaded to complete Model Engineer's Workshop Manual . GHT was originally too ill. GHT, however, published the Universal Pillar Tool book along with Dividing and Graduating- all of which had been articles in Model Engineer earlier. I tried with Jim Early to do the same with 'Martin Cleeve's' articles lest they also became lost. Jim and I ran into copyright issues. Unfortunately, I digress. I hope that it gives a little more insight. 

As far as my own problems- workshop wise, it is really of little consequence in the overall situation but I must thank you for your kind words. 

Regards

Norman


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## Blogwitch (Jul 16, 2016)

This attached PDF file should help in setting up and using an RT. Unfortunately, it is for the high precision type as sold by LMS and Arc Euro, which has a different wormwheel ratio that the Vertex type. but it does give a lot of useful information.

Hope it helps

John 

View attachment UsingARotaryTable.pdf


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## Coomba (Jul 16, 2016)

Guys I have been reading through all of these post, and their accompany links. One big thing I have learned is, I have a lot to learn. This is all great information. At the moment I'm leaning towards the 6" Vertex, and it's accessories. But I'm going to continual to study up before I make a final decision.


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## gus (Jul 16, 2016)

Blogwitch said:


> This attached PDF file should help in setting up and using an RT. Unfortunately, it is for the high precision type as sold by LMS and Arc Euro, which has a different wormwheel ratio that the Vertex type. but it does give a lot of useful information.
> 
> Hope it helps
> 
> John



Hi John,

Thanks for sharing the info on RT Usage. I DIY a carbon copy of the 4'' LMS 
RT from Taig Tool Projects. Very useful tool when building steam/petrol engines. Now in Southern Thailand which is very much cheaper than Singapore food and hotel room wise.Hotel WiFi excellent.


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## Coomba (Jul 18, 2016)

Blogwitch said:


> This attached PDF file should help in setting up and using an RT. Unfortunately, it is for the high precision type as sold by LMS and Arc Euro, which has a different wormwheel ratio that the Vertex type. but it does give a lot of useful information.
> 
> Hope it helps
> 
> John


 
John, I have read through the link you posted. Did so when I was considering the RT from LMS. Your statement then raised more questions. Is the LMS, RT better quality then the Vertex, and what role does the ratio play? 72-1 LMS as to 90-1 with the Vertex. Also looking at the 6" Vertex I cannot find any mention of the center to center distance of the two hole that may be used for mounting in the Vertical position. Is there something I'm missing?


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## Blogwitch (Jul 18, 2016)

C,

There are many varied ratios in both RT's and DH's, in fact, if you can work out how to get the degrees, minutes and seconds ranges sorted onto a turning handle to give you accurate rotations, then you could use almost any ratio that you want, but you will find that the most popular (as far as I know) is the 90:1 that Vertex use, purely because it must be one of the easiest to arrange the handle settings around.

Now you come to the sticking point with most of the cast RT's like the Vertex.

Because we all have different pitches between our table slots, you will most probably, unless you are very lucky, find you can only get one T-nut and bolt fitted for mounting upright as the other bolt slot just won't line up with the other slots on your table. No big problem though, just use a normal clamp to hold that side down. I actually machined my second slot on my Vertex RT into a longer one so that I could use 2 T-nuts and bolts.
That is one of the advantages of the LMS & AE RT's, just machine up a couple of small hold down clamps and you are in business.

Like these.

http://www.arceurotrade.co.uk/Catalogue/Workholding/Clamping-Sets/Hold-down-Clamps

I still have a 4" LMS RT and a BSO DHead to convert to stepper, and a very large vice that I need to make up some T-nut clamps for, but once done, they don't need doing again.

Do bear in mind though, for the T-nuts, only use good quality materials or actually buy some as I have done for my new vice. I have seen table slots ripped out because someone thought they could get away with inferior items or even hex headed bolts that don't quite fit right.

John


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## rodw (Jul 19, 2016)

Coomba said:


> Also looking at the 6" Vertex I cannot find any mention of the center to center distance of the two hole that may be used for mounting in the Vertical position. Is there something I'm missing?



You will be OK with the 6" Vertex on your mill. I managed to fit it on my SX3 mill which has a narrower table than yours but I had to lengthen the slots so I can bolt it to the narrower pitched T slots on my mill when the RT is on its side (eg. to use the tail stock). To do this, I mounted the RT via an angle plate to the milling table and being Cast Iron, the base was very easy to machine. I think this mod to use the larger RT is worthwhile as the 4" table is very restrictive in my view due to the much smaller working area.

Mounting it with the table facing upwards under the spindle was not an issue.


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## Coomba (Jul 19, 2016)

rodw said:


> You will be OK with the 6" Vertex on your mill. I managed to fit it on my SX3 mill which has a narrower table than yours but I had to lengthen the slots so I can bolt it to the narrower pitched T slots on my mill when the RT is on its side (eg. to use the tail stock). To do this, I mounted the RT via an angle plate to the milling table and being Cast Iron, the base was very easy to machine. I think this mod to use the larger RT is worthwhile as the 4" table is very restrictive in my view due to the much smaller working area.
> 
> Mounting it with the table facing upwards under the spindle was not an issue.


 
Rod, Thanks for that info. Unless I get very lucky, I figured I'd have to do as you did. Any ideal what the center to center dimensions were before you machined them?


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## rodw (Jul 20, 2016)

Coomba said:


> Rod, Thanks for that info. Unless I get very lucky, I figured I'd have to do as you did. Any ideal what the center to center dimensions were before you machined them?



I have no idea, but I think I only needed about 5mm taken off each slot to get a fit. This does not need to be accurate so if you have trouble holding the table and getting it all true before you start, near enough will be good enough.

I may have documented the mod in my Shed thread but I can't remember.... Look here. http://www.homemodelenginemachinist.com/showthread.php?t=19885


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## Blogwitch (Aug 7, 2016)

I mentioned earlier on in this post about how I can very easily convert my 6" RT into a 9" one without having the size and weight limitations of the larger RT.

I have actually found the picture that I was looking for.






Because I use interchangeable tooling based around a Myford spindle nose, I just bought a cheap 9" faceplate and screwed it onto my 6" RT.
Ideal for those largish jobs that overhang the normal RT table. Plus it has 6 T-slots instead of the normal 4, as mine has, some only have 3.

John


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## goldstar31 (Aug 7, 2016)

Blogwitch said:


> C,
> 
> 
> Do bear in mind though, for the T-nuts, only use good quality materials or actually buy some as I have done for my new vice. I have seen table slots ripped out because someone thought they could get away with inferior items or even hex headed bolts that don't quite fit right.
> ...


 
Ah! The intentional  Myford 'compromise 'in using too small a tee slot and then, as John says, a further compromise. BANG!


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## Blogwitch (Aug 7, 2016)

Norman, 
I am very fastidious when it comes to clamping down into a T-slot, in fact I would class it as obsessive.

For every different size of T-slot in my shop, I have a full set of clamps for each of them, plus, if I need something clamping semi permanent or permanent I buy the correct nuts, bolts and studs to clamp it down to save robbing my full sets of clamps.

I have seen slots in table ripped out into big holes. How much damage would be done to the operator if those had been the chocolate nuts and studs that some people use. I would suspect that there would have been a few more missiles flying about.

In fact it was only two days ago a chap contacted me to see if I knew where he could get a bulge ground off the top of his mill table. In reality, it needs a new table, as his has been 'strained', most probably by the quill running into a large bit that was clamped to the table. Unfortunately, it is a rather rare beast and spares just aren't easy to come by, plus because it is now in the hands of a model engineer, not in a jobbing shop, where he got it from, he should be able to keep within acceptable limits and not overstrain it again.

John


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## goldstar31 (Aug 7, 2016)

Yes, indeed, John. 

My first Myford Super 7 B had a distorted boring table caused by incorrect use. I had the awful job of having to scrape it because Myford could not/would not supply a new saddle casting. 

As you are aware, Myford slots are not the standard way of doing things  and I'm glad you've highlighted the dangers. 

Meantime, my regards

Norman


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## Wizard69 (Aug 7, 2016)

goldstar31 said:


> Yes, indeed, John.
> 
> My first Myford Super 7 B had a distorted boring table caused by incorrect use. I had the awful job of having to scrape it because Myford could not/would not supply a new saddle casting.
> 
> ...




One big issue with T-slots, that a lot of amateur machinist don't understand, is that the threads in the T-Nuts are suppose to dead end.   This keeps bolts and rods from running down into the table.  When that happens you basically have a screw jack push up on the table casting.  This just doesn't happen to model engineers because I've seen broken tables on a number of larger machines in shops.   Of course other practices can lead to table breakout so we can't blame them all on bad T-nuts.  

In any event if you are making your own T-nuts make sure the threads end up short and do not allow bolts to protrude through the nut.  I don't see homemade nuts as bad, you just need to take care that the thread properly prevent jacking of the tables T-slot ledges.


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## goldstar31 (Aug 7, 2016)

Of course I agree. Regularly lock my tee nuts with a drop of silver solder. However, the distortion mentioned was because the bolts were not fastened down- on top of the table and subsequently not spreading the load. 

BIG topic!

Cheers

Norman


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## Blogwitch (Aug 8, 2016)

Wizard, spot on.

On commercial ones, they stake the bottom of the nut so the thread just can't pass through, unless you are a gorilla with a spanner, but who would admit to that?

John


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## Wizard69 (Aug 10, 2016)

Blogwitch said:


> Wizard, spot on.
> 
> On commercial ones, they stake the bottom of the nut so the thread just can't pass through, unless you are a gorilla with a spanner, but who would admit to that?
> 
> John




The only exceptions I know of are things like low profile clamps where the idea is to look the clamp in the slot.  Here though the goal is understood in the design of the clamp.  That is the user should understand the clamp and how it works.  

For the really small machines some modelers make use of the sudden tin a few entries ago to silver solder nuts to create T-Bolts is a good one.   This would be especially good if there isn't enough beef to hold threads partially into the nut.


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## RichD (Aug 17, 2016)

This dividing plate fits the Phase II 4" Rotary Table (PN 1727) and the 4" H/V rotary table (PN 1927). It consists of one plate with a set of 10 holes. This lets you divide a circle into 1/2 degree increments.
 Because this is 1/720 of a circle, you can also divide a circle into any  number of parts that can be evenly divided into 720. You can divide a  circle into the following number of divisions 2, 3, 4, 5, 6, 8, 9, 10,  12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144,  180, 240, 360, 720.


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## Blogwitch (Aug 17, 2016)

Here is a PDF chart that has the corrected setups for the Vertex 6" RT and it's generic copies using the plates provided. This, as far as I know, should also be able to be used with the 4" version. It will save you a lot of time calculating things out as everything is shown and is easily understandable.
This isn't mine BTW, just something that was shown on another site where the same sort of discussion is going on.
As you can see, there are quite a few gaps in the sequences that this RT can't achieve, and other RT's have the same problem, maybe more on other makes that use a different worm and wheel angle.

This is where a digital setup, like the Arduino and Divisionmaster score. My Divisionmaster can give me all numbers up to 9999, plus it is able to very accurately machine radii, curved slots of any angle plus full rotational machining under power.

John 

View attachment vertex division settings.pdf


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## Coomba (Aug 22, 2016)

Would anyone have any experience or knowledge of this rotary table ? They offer it in two sizes, a 6" and an 8". Could it be a generic of the Vortex ?

http://www.ebay.com/itm/311611757244?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT


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