Dividing Plates

[martin107Participant @martin107]

Hi I have bought a HV6 Rotary Table with Dividing Plates​, is there an Idiots guide on how to use the Dividing Plates, what I have seen up to now a degree in maths would be handy.

Cheers

Martin

[martin107Participant @martin107]

[Stuart BridgerParticipant @stuartbridger82290]

If you Google "dividing head manual" and find the Grizzly manual. That has a good worked example.

[Michael GilliganParticipant @michaelgilligan61133]

This is probably the best introduction I have seen, Martin **LINK**

http://www.arceurotrade.co.uk/projects/rotarytable/UsingARotaryTable.pdf

But do be aware that the example he is using is 1:72 ratio

… Yours is most probably 1:90

MichaelG.

[Alan Waddington 2Participant @alanwaddington2]

There are quite a few online calculators that take out the maths and any head scratching. Just punch in the numbers.

**LINK**

[RobboParticipant @robbo]

The Vertex HV6 rotary table is certainly a 1:90 ratio worm/wheel

Edited By Robbo on 26/11/2017 19:23:46

[martin107Participant @martin107]

You are quite correct it is a 1:90 one from Warco and thanks for all your advice you have managed to fry my brain nicely on a Sunday evening, I think I will have to fit it and have a play just to give me some Idea what's what because I'm afraid at present it all seem's double dutch but hopefully when I have had a play it will make some sort of sense Cheers

[Stuart BridgerParticipant @stuartbridger82290]

As an apprentice piece we had an exercise called a polygonal pyramid to get us used to working with a dividing head. A 3 inch turned blank of aluminium with steps of decreasing diameters. Onto this we had to mill polygons from 3 to about 10 sides. Mine went well apart from one was a few degrees out from backlash. That was over 35 years ago and I haven't used a dividing plate since… I would recommend this sort of exercise to practice before cutting anything important.

[Michael GilliganParticipant @michaelgilligan61133]

Martin,

If you can follow the explanation for the 1:72 model

AND then convert for 1:90

Then; as my lecturer daughter likes to say "learning will be seen to have taken place".

Sit down quietly with a glass of malt …

MichaelG.

[Yngvar FParticipant @yngvarf]

Grizzly has a pdf. Instruction that is quite good.

Included is the numbers for most divisions. No math requred.

When it says e.g. 3 12/30 that means 3 whole turns and 12 holes on a 30 hole plate.

Then the fingers need to be 13 holes apart.

[mark smith 20Participant @marksmith20]

I found this video quite informative and easy to follow , for simple indexing , when i started using mine .

You have to make sure you know your worm ratio as mentioned above.

**LINK**

[Tim StevensParticipant @timstevens64731]

With a 90:1 dividing head, each full turn of the handle moves the work round by 360 / 90 = 4 degrees. For one degree, turn the handle a quarter turn exactly.

For angles that are not neat multiples of 4 degrees, a dividing plate allows you to turn the handle by a set smaller amount, and so to turn the work by a set even smaller amount. A ring of 10 holes allows the handle to be turned 1/10 of a turn, so as one turn = 4 degrees, 1/10 of a turn moves it 4/10 degree = 0.4 degrees. So, a ring of 40 holes gives you 1/10 degree = 0.1 degree.

And so on. It can get complicated if you want an angle of seven degrees and thirteen minutes and nine seconds – but it is just a matter of choosing a plate with the 'nearest correct' number of teeth. Unless you have a large number of plate circles of different numbers, an approximation is the best you can do, usually.

Cheers, Tim

[martin107Participant @martin107]

I think I'm starting to get the grasp of it, but with me I find actually doing it gives me a lot better understanding of it.

As to the malt ahh the good old days, strictly soft drinks now, but thanks for the advice.

Thanks

Martin

[SillyOldDufferModerator @sillyoldduffer]

Posted by martin107 on 26/11/2017 20:24:52:

I think I'm starting to get the grasp of it, but with me I find actually doing it gives me a lot better understanding of it.

…

I think that's essential. You have to suss out the table in the manual, select the right plate, and the right ring of holes, set up the hands, and then keep count as the handle is turned relative to them. Takes a bit of getting used to!

I 'got it' by first experimenting with very simple angles. I was able to confirm I was doing it right by checking the HV6 was turning correctly against its degree scale.

Once the table in the manual is understood it's not too difficult to use in principle. In practice I make mistakes. You have to take care not to lose count whilst cranking the handle. That's why quite a few of us have added stepper motors to our rotary tables and use a small computer to do the sums. Ask again if you're interested in that; there's been much discussion on the forum about an MEW article describing how to make one.

Dave

[WearyParticipant @weary]

Cheap and simple way of keeping count of handle turns in short youtube video here.

Regards,

Phil.

[Brian WoodParticipant @brianwood45127]

You can also use bits of cocktail stick in spare holes to block unintended movement of the sector arms if you catch them with the peg in the turning handle whilst winding. That too will prevent a ruined job.

Regards Brian

[Brian HParticipant @brianh50089]

Just be aware that a couple of errors have been reported with the table in the Vertex handbook. I forget the details but someone posted on here several months ago (or it might have been years knowing my memory!)

Brian

[Dave HalfordParticipant @davehalford22513]

Use the dividing plates, it's very easy.

Just did my first gear – 16dp 90 tooth. Use the online calculator, set the depth of cut to just enough to mark the blank and pretend to cut the gear. When you end up back at the start on the same mark, do it again with the proper depth of cut. Just make sure the finger relationship doesn't move.

I was surprised how easy it was.

just takes a while

[John HaineParticipant @johnhaine32865]

…or of course you can add an electronic indexer and forget all these problems…

[RobboParticipant @robbo]

Posted by Brian Hutchings on 27/11/2017 15:08:03:

Just be aware that a couple of errors have been reported with the table in the Vertex handbook. I forget the details but someone posted on here several months ago (or it might have been years knowing my memory!)

Brian

Howard Lewis pointed out the errors on this thread **LINK**

Neil has posted the revised tables somewhere      click on "Workshop" to find it

Edited By Robbo on 27/11/2017 23:11:50

[larry PhelanParticipant @larryphelan54019]

There a many errors in the books supplied with these tables,no matter what the make. Dont believe all you read !

[Michael GilliganParticipant @michaelgilligan61133]

Posted by larry Phelan on 28/11/2017 10:02:01:

There a many errors in the books supplied with these tables,no matter what the make. Dont believe all you read !

.

Which is exactly why I suggested 'learning' …

MichaelG.

[Neil WyattModerator @neilwyatt]

Workshop –> Processes

Or use this link:

http://www.model-engineer.co.uk/news/article/corrected-dividing-tables-for-vertex-hv6-dividing-head/23123

[Andrew TinsleyParticipant @andrewtinsley63637]

Hello Neil,

I seem to remember that someone spotted an error in the table you refer to. I cannot work out if that error has been corrected or not. Can you confirm it is now as error free as possible?

Andrew

[Brian WoodParticipant @brianwood45127]

Andrew,

You can do some checking yourself to be sure what you read makes sense.

As an example with a 40:1 dividing head (Brown and Sharpe design) the maths is 40 divided by the number of divisions you are wanting to put into the component. You can then compare that with the table results to see if the maths is correct and if not, the table value will be wrong.

Regards Brian

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