Thread: Which 8 inch Rotary Table to Buy?

Can't comment on the other one but I have a 6" Vertex RT and I think it is a quality bit of kit, bought it at the same place I bought my DM45 mill.

Am about to buy a 130mm front mounting chuck for it from H&F, I think that is on special as well.

Thanks Fred,

I am leaning towards the vertex. I have only heard good things about them. Plus I can always get extras for it later....

Simon

Simon,

I, like Fred, have a 6 inch Vertex. Not bad quality for the price. The table is made more useful with the acquisition of the dividing attachment and the tailstock though the latter is cumbersome, ugly looking thing.

Buy the Vertex.

Bob.

I too have a 6" vertex. The one thing you may need to keep in mind is how to bolt it to your table. The hole spacing on the 6" are too small for the 50 sized mills, I would think that the 8" might be too big for the smaller mills (I'm referring to tuning it on its side). This can be fixed by using one bolt and a clamp but you may run out of space on the smaller table and the clamp may foul on a chuck or the rt itself. The best thing about them is they have a mt bore so you can put a collet chuck in them, saves on a 3 jaw until you really need one.

That's certainly true Ewan, even on the DM45, this is how I mount mine



Also shows the MT2 collet chuck, but I frequently need to mount bigger diameter stuff than it can handle, hence my planned purchase of the 3 jaw chuck.

I too have the 6" Vertex RT. I feel it is pretty good quality for the price. I can recommend this maker - just as it was recommended to me. Vertex is still made in Taiwan. I personally believe it is worth a small premium over the China made RT's.

You are looking for an 8" RT. Check its weight, make sure this is what you are prepared to handle. Check what distance from workpiece to tool is left on your mill, whan the RT is mounted horixonally and with a chuck mountend onto it. Check the center height when mounted horizontally. I do not want to talk you out of an 8" if that is what you want and need. Just think about what you want to do with it, maybe it can be done on a 6" and that would not only cost less but also be easier to manage.

I sometimes leave the RT mounted to one end of the milling table, and the vise to the other end of the table. That gives me two instantly usable setups. It may not be that easy to do the same with an 8" RT, its weight at one table end may cause excessive table droop unless your mill is heavy and rigid.

You will also need to consider if you want to buy the dividing plates with it. Because a very interesting alternative could be to fit a step motor and a controller to electronically select any number of divisions. There is one ready made unit called the "division master", I think nowdays it is sold via Harald Hall's website - yes found it:
DivisionMaster - Model Engineers Digital Workshop

But if you were into electronic projects, there are plans to make it all yourself for very little money. Like the one by Steve Ward on the CNC zone forum, complete with open source software:
Rotary table indexer - CNCzone.com-The Largest Machinist Community on the net!
That thread is now 47 pages long! Yes, one day when I come around to it.... I may make this.

Finally, depending on what exatly you want/need to make, have you considered an indexer instead of an RT? Have you considered a dividing head instead of an RT? The one or the other may (or may not) suit you better.

Chris

Hi all,

Thankyou all so much for your views and input. Initially when I started looking at RT I was looking at 6 inch, it was then that Dave J (Yes I'm dobbing you in Dave!) suggested I look at an 8 inch on the basis that not knowing what projects I may be building in the future, that an 8 inch may be less restrictive in terms of size. It's one of these things that until you have used one, you don't know what you will eventually use it for, a bit like my mill. There is no way I could have imagined all the projects I am now considering now that I have one. I have considered the weight (30Kg!) and ATM I'm fit and healthy and it does not bother me, maybe in 10 years I may get slower at lifting it and perhaps in 15 years I'll sell it and buy a 6 inch, Dunno.

At 265mm high, it leaves a maximum of 265mm from the top of the table to the spindle nose (obviously less with a tool fitted) but is it sensible to assume that any workpiece would be not much more than 200mm in diameter or be contained within the table dimensions?

At 30Kg, it would be silly for me to mount the RT at one end of the table and expect no droop, my 45 size mill is not that rigid. Any RT action on my mill would have to be reasonably central to the table, or slightly off to allow machining of the length of the workpiece.

I did ask which 8 inch RT to buy but I am open to reasoning to the purchase of the 6 inch and I value all input before I decide, which will be by Thursday when the H&F sale starts.

A 6 inch RT will leave some spare cash to purchase "other" related items, perhaps a TS or some dividing plates or a chuck?

As for purchasing a DH instead of a RT, I think that (unless I have it wrong) a DH may be too specific in it's task for me and that a RT will be better suited to a number of varied tasks, even if it's not perfectly suited to some envisaged tasks. Am I making sense?

You probably asking "what do I want to use it for?" Most likely anything that requires circular bolt patterns, milling curved slots etc. I don't have a specific need yet but I would love to make some gears. I have a workshop series book on gear cutting and I'd love to have a crack! You will probably tell me that a DH would be better for that and you would be correct but gear cutting would be the minority of the work.

Also thanks for the link to the electronic indexer. I had seen this prior and thought it ws a great idea. Something I may consider in the future. Slowly swinging to the 6 inch based on others opinions. Is there anyone out there with a 6 inch RT that found they could not perform a task as it required an 8 inch RT?

Any other issues or opinions?

Cheers

Simon

Hi Simon,
I would get the 8 inch one, just to give you an idea of size cut out a piece of paper 6 inch round, one at 8 inch round and draw the T slots, then place something simple on the center and dummy sit you clamp hold downs on it and see how much room you have. You will soon see you run out of room real quick.

I plan on getting on of those small (110mm for $329 I think) tilting rotary tables from this sale. This way I can use it for simple jobs instead of getting the 10 inch one out. It has the advantage of machining things at any angle.

Dave

> At 265mm high, it leaves a maximum of 265mm from the top of the table to the spindle nose (obviously less with a tool fitted) but is it sensible to assume that any workpiece would be not much more than 200mm in diameter or be contained within the table dimensions?


Lets assume you have turned a flange workpiece in the 3-jaw chuck on your lathe. Now you want to accurately drill the flange holes on your rotary table. To retain accuracy, you directly mount the lathe chuck with the workpiece still in it onto the RT. For this purpose, you have made a self centering adapter plate that eats about 20mm between chuck and top of RT table. The lathe chuck itself is 100mm thick. The workpiece protrudes only 50mm from the chuck. Together 180mm. In the spindle you put a 13mm drill ckuck, costs you anoyher 110mm. Together 290mm. And... you are yet to put a drill into the drill chuck.

Of course, you could put a short stubby drill into a collet that mounts directly into the spindle bore, then it would work. I am just trying to visualize the space problems when using large rotary tables. Chris

Originally Posted by cba_melbourne

> At 265mm high, it leaves a maximum of 265mm from the top of the table to the spindle nose (obviously less with a tool fitted) but is it sensible to assume that any workpiece would be not much more than 200mm in diameter or be contained within the table dimensions?


Lets assume you have turned a flange workpiece in the 3-jaw chuck on your lathe. Now you want to accurately drill the flange holes on your rotary table. To retain accuracy, you directly mount the lathe chuck with the workpiece still in it onto the RT. For this purpose, you have made a self centering adapter plate that eats about 20mm between chuck and top of RT table. The lathe chuck itself is 100mm thick. The workpiece protrudes only 50mm from the chuck. Together 180mm. In the spindle you put a 13mm drill ckuck, costs you anoyher 110mm. Together 290mm. And... you are yet to put a drill into the drill chuck.

Of course, you could put a short stubby drill into a collet that mounts directly into the spindle bore, then it would work. I am just trying to visualize the space problems when using large rotary tables. Chris

Hi Chris,

I see your point. The 265mm headroom is if I were to place the RT in the horizontal axis, in the flat I would have 425mm clearance. To be honest, my main concern would be the weight, at 30Kg plus a chuck at maybe 8 - 10Kg and then the workpiece, I could easily be placing 45 - 50Kg on my 45 size mill table. Is this an issue if place in a sensible place on the table?

Simon

Your mill should handle that weight no problem, but if your worried about the lifting weight for yourself you might be better off with the 6 inch.
I usually set up the chuck on the rotary table once it's on the mill table, so I am not having to lift the while lot together.

Dave

I stated i had the Vertex 6" as another +1 on the vertex. I would still be worried about getting clamps in to hold it down, unlike Freds pic above the clamps will be inline with the X axis or toeing out a bit, i would just be worried about them fouling the table.
The way i would do it, and the way i am going to, one day, is buy a 6" for now, the indexing plates and T/S. That way you can index, cut gears etc straight away. Then one day down the track buy a much bigger one, 10" or more. Really the 8" doesn't give you that much more acreage than the 6", and for decent sized jobs i would think the bigger the better as to the dia of the RT.

What I know about the Vertex is they supply the exact same 'test" chart with every 8" rotary table.... Seem one from 20 years ago and it is identical to mine, even down the the QI inspector...

Originally Posted by simonl

Hi Chris,
To be honest, my main concern would be the weight, at 30Kg plus a chuck at maybe 8 - 10Kg and then the workpiece, I could easily be placing 45 - 50Kg on my 45 size mill table. Is this an issue if place in a sensible place on the table?
Simon

Simon, your 45 mill is itself around 300kg, and will have absolutely no problem with 50kg on its table. The problem is really yourself. If it turns out to be too hard to lift comfortably, chances are you are not going to use that rotary table as often as you would otherwise. Then again, if you really need a large RT it would be silly to get a smaller one. Choices....